New peptides and the use of same for modulating accumulation of a protein

Abstract

The present invention relates to new peptides (cPEPs), a method for their preparation, and their use for modulating the accumulation of specific proteins.

Description

[0001] DESCRIPTION

[0002] TITLE: NOVEL PEPTIDES AND THEIR USE TO MODULATE PROTEIN ACCUMULATION

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to novel peptides (cPEPs), their preparation process and their use for modulating the accumulation of specific proteins.

[0005] PREVIOUS ART

[0006] Generally speaking, peptides are short sequences of 2 to about 100 amino acids. They are often highly active molecules, such as hormones or venom compounds.

[0007] In plants, peptides perform many biological functions, such as development or defense mechanisms. Since peptide detection is relatively difficult, only a limited number of peptides have been identified, probably underestimating the quantity and role of peptides in these organisms.

[0008] Most of the peptides characterized in plants likely result from the degradation of functional proteins. However, it has been shown that primary transcripts of microRNAs (miRs) in plants actually contain small open reading frames (miORFs) encoding regulatory peptides, called miPEPs (Lauressergues D et al. Primary transcripts of microRNAs encode regulatory peptides. Nature. 2015 Apr 2;520(7545):90-3.). MiPEPs are produced at the same location as the miRs from which they originate and enhance the transcription of the corresponding pri-miRs. The activity of a miPEP is highly specific to the corresponding miR, allowing the chosen miR to be upregulated without affecting the expression of other miRs. The use of miPEPs can modulate the expression of a gene, if it is regulated by a miR, itself regulated by a miPEP (WO 2015 / 063431). BRIEF OVERVIEW

[0009] In this context, the present invention provides a universal, and easily exploitable, means for specifically modulating the accumulation of a selected protein in a plant using a non-natural peptide, i.e. a peptide which is not naturally produced by the plant.

[0010] One aspect of the invention is to provide a method for preparing and determining a "cPEP" peptide capable of modulating the accumulation (expression) of a specific protein in a plant cell. A second aspect of the invention is to provide a method for modulating the accumulation of a protein in a plant using a cPEP. A third aspect of the invention is to provide the use of a cPEP for modulating the accumulation of a protein in a plant. A fourth aspect of the invention is to provide a method for promoting, slowing down or preventing the development of a plant. A fifth aspect of the invention is to provide cPEP peptides for modulating the accumulation of a protein in a plant. Other complementary aspects of the invention relate to a nucleic acid encoding a cPEP, compositions comprising a cPEP and modified or transgenic plants comprising a cPEP.

[0011] DETAILED DESCRIPTION

[0012] In a first aspect, the invention relates to a method for preparing and determining a cPEP, said cPEP: having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids; being capable of modulating the accumulation of a protein in a plant cell; and not being capable of modulating the accumulation of the mRNA encoding said protein, said method comprising: a. a step of determining the nucleic acid sequence of the pre-messenger RNA (pre-mRNA) encoding said protein; b. a step of determining within this pre-mRNA one of the nucleic acid sequences deemed non-coding; c. a step of determining within this nucleic acid sequence deemed non-coding a fragment thereof, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41; d. a step of producing the peptide encoded by said fragment; and e. a comparison step:

[0013] - between the accumulation of said protein in a plant cell in the presence of said peptide and the accumulation of said protein in a plant cell of the same type in the absence of said peptide; and / or

[0014] - between the phenotype of a plant in the presence of said peptide and the phenotype of a plant of the same type in the absence of said peptide, in which:

[0015] - a difference in the amount of said protein in the presence of said peptide compared to the amount of said protein in the absence of said peptide; and / or

[0016] - a difference in the phenotype in the presence of said peptide compared to the phenotype in the absence of said peptide, indicates that said peptide is a cPEP capable of modulating the accumulation of said protein in a plant cell.

[0017] The present invention is based on the unexpected observation made by the Inventors that it is possible to specifically modulate the accumulation of a protein using a particular peptide not produced naturally, the sequence of which corresponds to the (artificial) translation of a fragment of the pre-messenger RNA (pre-mRNA) coding for said protein, said fragment being chosen from one of the nucleic acid sequences known to be non-coding for said pre-mRNA.

[0018] In the invention, the term “cPEP” (complementary peptide) designates a peptide capable of specifically modulating the accumulation of a protein once introduced into a plant cell.

[0019] According to the invention, a cPEP is not naturally present in a plant cell. This means that the plant cell contains the information of the cPEP but does not contain the nucleic sequence capable of allowing its expression. Only the peptide sequence of the cPEP can be deduced from the sequence of the pre-messenger RNA (pre-mRNA) encoding the said protein whose accumulation is to be modulated.

[0020] A cPEP is only present in a plant cell once it has been introduced in the form of a peptide or in the form of a nucleic acid encoding said peptide. The specificity of the cPEP with respect to a target protein (of a target gene) is determined by its amino acid sequence. Indeed, the sequence of a cPEP corresponds to the in silico (artificial) translation into amino acids of a fragment of the pre-messenger RNA (pre-mRNA) encoding said protein, said fragment being chosen from one of the nucleic acid sequences known to be non-coding of said pre-mRNA. In particular, said fragment has a size smaller than that of the naturally translated nucleic acid sequence.

[0021] The peptide sequence of a cPEP can therefore be determined from a fragment of the pre-messenger RNA (pre-mRNA) coding for said protein by applying, from the first nucleotide of said fragment, the genetic code assigning to each triplet of nucleotides a specific amino acid (AUC = Isoleucine, ACA = Threonine, etc.).

[0022] In the invention, the fragment of the pre-mRNA used to determine the sequence of the cPEP can be selected from the three reading frames existing on the sequence of the pre-mRNA. In other words, a fragment can be selected from the reading frames +1, +2 or +3. In this respect, it is possible that all three of the reading frames contain the information of a cPEP as it is possible that only one of the three of the reading frames (the +1, the +2 or the +3) or two of the three of the reading frames (the +1 and the +2, the +1 and the +3, or the +2 and the +3) contain the information of a cPEP.

[0023] In the invention, the term "reading frame" designates the grouping of nucleotides constituting a nucleic acid sequence into consecutive triplets (or codons), which follow one another without interruption or overlap.

[0024] Generally, cPEPs have a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, in particular a size of 5 to 40 amino acids, 7 to 20 amino acids or more particularly a size of 8 to 15 amino acids. Consequently, the sequence of a cPEP corresponds to the translation of a fragment of 4 to 70 nucleotide triplets, in particular of 4 to 41 nucleotide triplets, in particular of a fragment of 5 to 40 nucleotide triplets, of 7 to 20 nucleotide triplets or more particularly of a fragment of 8 to 15 nucleotide triplets.

[0025] In other words, the sequence of a cPEP corresponds to the translation into amino acids of a fragment of "3n" nucleotides of the pre-mRNA of the target protein, n being comprised from 4 to 70, in particular n being comprised from 4 to 70, in particular comprised from 4 to 41, in particular comprised from 5 to 40, from 7 to 20 or more particularly comprised from 8 to 15. For example, if n is equal to 5, the cPEP has a size of 5 amino acids and corresponds to the translation of a fragment of 15 (= 3 x 5) nucleotides. For example, if n is equal to 40, the cPEP has a size of 40 amino acids and corresponds to the translation of a fragment of 120 (= 3 x 40) nucleotides. For example, if n is equal to 70, the cPEP has a size of 70 amino acids and corresponds to the translation of a fragment of 210 (= 3 x 70) nucleotides. Etc.

[0026] The cPEPs are 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70 amino acids, and correspond respectively to the translation of fragments of 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99, 102, 105, 108, 111, 114, 117, 120, 123, 126, 129, 132, 135, 138, 141, 144, 147, 150, 153, 156, 159, 162, 165, 168, 171, 174, 177, 180, 183, 186, 189, 192, 195, 198, 201, 204, 207 or 210 nucleotides.

[0027] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said fragment has a size of 3n nucleotides, n being comprised: from 4 to 41; from 5 to 40; from 7 to 20; or from 8 to 15.

[0028] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said peptide has a size selected from: 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 and 70 amino acids.

[0029] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said cPEP has a size smaller than that of said protein (i.e. that of which the cPEP modulates the accumulation).

[0030] As mentioned above, cPEPs have the ability to specifically modulate the accumulation of a protein without impacting the accumulation of its corresponding mRNA. In other words, adding a cPEP to a plant cell does not change the amount of mRNA that can express the protein it regulates, but only the amount of the protein itself.

[0031] According to the invention, the term "protein" designates an amino acid sequence whose information is encoded by a gene present in the genome of a plant cell. By "gene" is therefore meant, in particular, the nucleic acid sequence necessary for the synthesis of said protein. Also, a gene comprises more than the nucleotides encoding the amino acid sequence of the protein. For example, a gene includes the DNA sequences necessary for the synthesis of a pre-messenger (pre-mRNA), which is then matured by the cellular machinery into a messenger RNA (mRNA). The latter can then be translated, via the ribosomes, into a protein.

[0032] From the above, it is understood that pre-messenger RNA (pre-mRNA) has not undergone splicing and is likely to contain introns, while mature messenger RNA (mRNA) may have undergone splicing and contains only exons.

[0033] To prepare a cPEP capable of modulating the accumulation of a protein, it is necessary to translate a fragment of the pre-messenger RNA (pre-mRNA) coding for said protein in order to obtain the sequence of said cPEP, which fragment is chosen from a nucleic acid sequence of the pre-mRNA known to be non-coding (e.g. introns, 5'-UTR part or 3'-UTR part).

[0034] In the invention, the "modulation" of the accumulation of a protein means either an increase in the accumulation of said protein ( / .e. an increase in the amount of protein in the plant cell), or a decrease in the accumulation of said protein ( / .e. a decrease in the amount of protein in the plant cell). In other words, an embodiment of the invention relates to the method for preparing and determining a cPEP as described above, in which said modulation of the accumulation of said protein induced by said cPEP is: a decrease in the accumulation of said protein; or an increase in the accumulation of said protein.

[0035] The increase and decrease in the accumulation of said protein can be measured and monitored using methods well known to those skilled in the art, such as coupling the protein to a marker via the use of particular expression cassettes, or a Western blot.

[0036] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein in step e., the amount of protein in the presence of said peptide is greater than the amount of protein in the absence of said peptide. In other words, in the presence of a cPEP promoting increased accumulation of the protein, the translation of the corresponding mRNA is increased, which leads to greater production of the protein without the amount of said mRNA being modified.

[0037] In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein in step e., the amount of protein in the presence of said peptide is less than the amount of protein in the absence of said peptide. In other words, in the presence of a cPEP promoting the reduction of the accumulation of the protein, the translation of the corresponding mRNA is reduced (inhibited), which leads to a lower production of the protein without the amount of said mRNA being modified.

[0038] In the invention, since the fragment of the pre-mRNA coding said cPEP is located within one of the nucleic acid sequences of the pre-mRNA deemed to be non-coding, this means on the one hand that these nucleic acid sequences deemed to be non-coding are not naturally translated in said plant cell. On the other hand, this also means that the fragment of the pre-mRNA coding said cPEP is not naturally translated in said plant cell. The existence of a cPEP within said plant cell is therefore artificial and originates from a human action. For this, it is possible either to artificially introduce said cPEP as such, or to introduce an expression cassette comprising the nucleic acid sequence coding said cPEP and the means for expressing it in said plant cell.

[0039] In the invention, a region of the pre-mRNA that is not naturally translated, also referred to as "non-coding", corresponds to a region of the pre-mRNA that does not encode any part of the functional protein of the gene, i.e. the protein encoded by the main open reading frame whose accumulation is desired to be modulated.

[0040] In the invention, the terms "open reading frame" and "ORF" (open reading frame) are equivalent and can be used interchangeably. They correspond to a sequence of nucleotides (nucleic acids) in a DNA or RNA molecule that can potentially encode a peptide or a protein: said open reading frame begins with a START codon (the START codon generally encoding a methionine), followed by a series of codons (each codon encoding an amino acid), and ends with a STOP codon (the STOP codon not being translated). In a non-limiting manner, a non-coding region of a pre-mRNA, i.e. one of the nucleic acid sequences known to be non-coding, corresponds to: the 5'IITR region, i.e. the untranslated region located upstream of the main ORF; the 3'IITR region, i.e. the untranslated region located downstream of the main ORF; or an intron, i.e. a region of the pre-mRNA deleted by splicing and absent from the mature mRNA.

[0041] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, one of said nucleic acid sequences deemed non-coding being: the 5'IITR region; the 3'IITR region; or an intron.

[0042] In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, one of said nucleic acid sequences deemed non-coding being the 5'IITR region or the 3'IITR region. In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, one of said nucleic acid sequences deemed non-coding being the 5'IITR region. In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, one of said nucleic acid sequences deemed non-coding being the 3'IITR region. In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, one of said nucleic acid sequences deemed non-coding being an intron.

[0043] In the invention, the sequence of a cPEP is determined by performing an (artificial) translation of a fragment of the pre-mRNA of the protein whose accumulation is to be modulated, said fragment being chosen from the non-coding nucleic acid sequence. Also, the same non-coding nucleic acid sequence in said plant cell can give different cPEPs depending on the fragment of the pre-mRNA chosen. Furthermore, this same fragment of the pre-mRNA can also give different cPEPs depending on the reading frame used to translate it (artificially), i.e. depending on the grouping of the nucleotides of the sequence into consecutive triplets. Indeed, and as previously mentioned, a translation can be carried out in the three different reading frames, thus potentially leading to three different cPEPs. According to the invention, the reading frame “+1” corresponds to the reading frame determined by the initiation codon of the protein, i.e.the START codon of the open reading frame used naturally for the translation of mRNA, which serves as a reference to identify the +1 reading frame of the pre-mRNA. In other words, in the case of a fragment of the pre-mRNA corresponding to a non-coding region and artificially translated according to the +1 reading frame, the latter corresponds to that allowing the translation of the mRNA.

[0044] The “+2” and “+3” reading frames correspond to shifted reading frames. According to the invention, the “+2” reading frame corresponds to the reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the +1 open reading frame. According to the invention, the “+3” reading frame corresponds to the reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the +1 open reading frame.

[0045] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0046] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0047] It is therefore understood that a cPEP, according to the embodiments above, comprises either an AUG codon (and no STOP codon), or a STOP codon (and no AUG codon), or neither of these two elements. In this case, it is the person skilled in the art who adds, if necessary, the missing element or these missing elements to allow, in a non-limiting manner, either to produce a cPEP in vitro by means of, for example, a microorganism and then to use it (in a composition for example), or to introduce the sequence and the means of expressing it via a vector in a plant cell or a plant.

[0048] In view of the above, it is understood that in another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, said cPEP: having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids; being capable of modulating the accumulation of a protein in a plant cell; and not being capable of modulating the accumulation of the mRNA encoding said protein, said method comprising: a. a step of determining the nucleic acid sequence of the pre-messenger RNA (pre-mRNA) encoding said protein; b. a step of determining within this pre-mRNA one of the nucleic acid sequences deemed non-coding; c.a step of determining within this nucleic acid sequence deemed non-coding a non-naturally translated fragment thereof, said non-naturally translated fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41; d. a step of producing the peptide encoded by said fragment; and e. a comparison step:.

[0049] - between the accumulation of said protein in a plant cell in the presence of said peptide and the accumulation of said protein in a plant cell of the same type in the absence of said peptide; and / or

[0050] - between the phenotype of a plant in the presence of said peptide and the phenotype of a plant of the same type in the absence of said peptide, in which:

[0051] - a difference in the amount of said protein in the presence of said peptide compared to the amount of said protein in the absence of said peptide; and / or

[0052] - a difference in the phenotype in the presence of said peptide compared to the phenotype in the absence of said peptide, indicates that said peptide is a cPEP capable of modulating the accumulation of said protein in a plant cell.

[0053] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0054] In one embodiment, the invention therefore relates to the method for preparing and determining a cPEP as described above, in which said fragment comprises an initiator codon AUG coding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the method for preparing and determining a cPEP as described above, in which said fragment is devoid of an initiator codon AUG coding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0055] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0056] Although a cPEP, according to the above embodiments, comprises an AUG codon and / or a STOP codon, it should be remembered that the peptide resulting from the in silico translation of the fragment of the pre-mRNA of the protein whose accumulation is to be modulated does not exist naturally in a plant cell or a plant. In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which the translation of the fragment of the pre-mRNA is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the method for preparing and determining a cPEP as described above, in which the translation of the fragment of the pre-mRNA is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0057] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the method for preparing and determining a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the method for preparing and determining a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the method for preparing and determining a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0058] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said cPEP is a hydrophobic peptide or a hydrophilic peptide. In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said cPEP is a hydrophobic peptide. By "hydrophobic peptide" is meant a peptide whose amino acid sequence comprises more than 50% hydrophobic amino acids. By "more than 50%" is meant that the amino acid sequence comprises more than 55%, more than 60%, more than 65%, more than 70%, more than 75% or more than 80% hydrophobic amino acids. By "more than 50%" is also meant that the amino acid sequence comprises at least 51%, at least 56%, at least 61%, at least 66%, at least 71%, at least 76% or at least 81% of hydrophobic amino acids.By "hydrophobic amino acids" is meant amino acids selected from: alanine (Ala / A), isoleucine (Ile / I), leucine (Leu / L), methionine (Met / M), phenylalanine (Phe / F), tryptophan (Trp / W), tyrosine (Tyr / Y) and valine (Val / V).

[0059] In particular, the invention also relates to the method for preparing and determining a cPEP as described above, wherein said cPEP is a hydrophilic peptide. By "hydrophilic peptide" is meant a peptide whose amino acid sequence comprises more than 50% hydrophilic amino acids. By "more than 50%" is meant that the amino acid sequence comprises more than 55%, more than 60%, more than 65%, more than 70%, more than 75% or more than 80% hydrophilic amino acids. By "more than 50%" is also meant that the amino acid sequence comprises at least 51%, at least 56%, at least 61%, at least 66%, at least 71%, at least 76% or at least 81% hydrophilic amino acids. By "hydrophilic amino acids" we mean amino acids chosen from: aspartic acid (Asp / D), glutamic acid (Glu / E), arginine (Arg /

[0060] R), asparagine (Asn / N), glutamine (Gin / Q), histidine (His IH), lysine (Lys / K), serine (Ser /

[0061] S) and threonine (Thr / T).

[0062] A cPEP whose sequence corresponds to the translation of a fragment located in a non-coding region of the pre-mRNA has a different sequence from that of a fragment of the protein naturally encoded by said pre-mRNA.

[0063] According to the invention, the sequence of a cPEP is determined by carrying out a translation of a fragment of the pre-mRNA. The same fragment of this pre-mRNA can therefore give different cPEPs depending on the reading frame used for the translation (+1, +2 or +3), / .e. depending on the grouping of the nucleotides of the sequence into consecutive triplets.

[0064] In a particular embodiment, the subject of the invention is a method for preparing and determining a cPEP, said cPEP: having a size of from 4 to 70 amino acids, in particular from 4 to 71 amino acids; being capable of modulating the accumulation of a protein in a plant cell; and not being capable of modulating the accumulation of the mRNA encoding said protein, said method comprising: a. a step of determining the nucleic acid sequence of the pre-messenger RNA (pre-mRNA) encoding said protein; b. a step of determining within this pre-mRNA one of the nucleic acid sequences comprising two contiguous parts:

[0065] - a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, e.g. intron), and

[0066] - a part located within a nucleic acid sequence deemed to be coding ( / .e. naturally translated, e.g. exon); c. a step of determining within this nucleic acid sequence comprising two contiguous parts a fragment thereof, said fragment having a size of 3n nucleotides capable of being translated via the genetic code into a peptide, n being from 4 to 70, in particular n being from 4 to 41; d. a step of producing said peptide; and e. a step of comparing:

[0067] - between the accumulation of said protein in a plant cell in the presence of said peptide and the accumulation of said protein in a plant cell of the same type in the absence of said peptide; and / or

[0068] - between the phenotype of a plant in the presence of said peptide and the phenotype of a plant of the same type in the absence of said peptide, in which:

[0069] - a difference in the amount of said protein in the presence of said peptide compared to the amount of said protein in the absence of said peptide; and / or

[0070] - a difference in the phenotype in the presence of said peptide compared to the phenotype in the absence of said peptide, indicates that said peptide is a cPEP capable of modulating the accumulation of said protein in a plant cell.

[0071] According to the invention, a cPEP can be produced by any type of means accessible to those skilled in the art.

[0072] In a non-limiting manner, a cPEP can be produced both synthetically and by recombinant expression in homologous or heterologous systems. The cPEP thus produced can then be introduced into a cell to modulate the accumulation of a target protein. In a non-limiting manner, it is also possible to produce a cPEP directly in the plant cell containing the target protein, by artificially introducing into it a nucleic acid (such as an expression vector) encoding said cPEP.

[0073] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein, in step d., the production of said peptide is carried out by peptide synthesis or by recombinant expression.

[0074] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein, in step d., the production of said peptide is carried out using a nucleic acid encoding said peptide introduced into a cell.

[0075] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein, in step e., the production of said peptide is carried out using a nucleic acid encoding said peptide introduced into said plant cell or into said plant.

[0076] In one embodiment, the invention relates to a method for preparing and determining a cPEP as described above, wherein, in step e., said peptide is brought into contact with said plant cell or in said plant.

[0077] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein, in step e., said peptide is present in said plant cell or in said plant following the expression of a nucleic acid encoding said peptide in said plant cell or in said plant.

[0078] In view of the above, it is understood that another embodiment of the invention relates to the method for preparing and determining a cPEP as described above, in which, in step e., the presence of said peptide in said plant cell or in said plant results:

[0079] - the introduction of a nucleic acid sequence encoding said peptide and comprising the means for expressing it; or

[0080] - the introduction of an amino acid sequence corresponding to said peptide.

[0081] A cPEP can be used to modulate the accumulation of a protein that is naturally occurring (i.e. endogenous) or not (i.e. exogenous) in said plant cell or plant. A "protein naturally occurring in a plant cell or plant" means an endogenous protein encoded by a gene present in the genome of the plant cell or plant without the need for direct or indirect human intervention.

[0082] A “protein that is not naturally present in a plant cell or in a plant” corresponds to an exogenous protein encoded by a nucleic acid sequence present in the genome of the plant cell or of the plant which required the intervention of a human being and the use of means known to those skilled in the art. Such a nucleic acid sequence may come from the same species of plant or from another species of plant.

[0083] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is of endogenous origin in said plant cells or said plants used in step e.

[0084] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said protein is of exogenous origin in said plant cells or said plants used in step e., said plant cells or said plants used in step e. then comprising a nucleic acid sequence allowing the expression of said protein.

[0085] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which the accumulation of said protein is determined via the implementation of a technique chosen from: Western blot, measurement of enzymatic activity, mass spectrometry and translational fusion. In particular, the invention relates to the method for preparing and determining a cPEP as described above, in which the accumulation of said protein is determined via the implementation of a Western blot.

[0086] The inventors have surprisingly found that the use of cPEPs makes it possible to modify the phenotypes of a plant visible at the macroscopic scale. It is therefore entirely possible to use the latter to affirm (or refute) that the peptide determined in steps a., b. and c., and possibly produced in step d. is a cPEP (or not). This is also what the so-called phenotypic comparison alternative implemented in step e allows. For example, if the peptide determined on the pre-mRNA of a protein involved in the size of the stem of a plant causes an increase, or a decrease, in the size of the stem of a plant treated with the latter compared to an untreated plant, this means that said peptide is a cPEP capable of modulating the accumulation of said protein in the size of the stem.

[0087] In the invention, the term "plant" refers generally to: a set of plant cells organized in all or part of a plant whatever its stage of development (including the plant in the form of a seed or young shoot); to one or more organs of the plant (such as for example the leaves, the roots, the stem, the flowers); to one or more cells of the plant; or to a mass of cells of the plant (eg a callus).

[0088] In the invention, the term "phenotype" designates, in a non-limiting manner, the characteristics visible on a macroscopic scale such as the number of lateral roots, the number of leaves, the size of the stem, the duration of flowering and the resistance to stress.In one embodiment, the invention therefore relates to the method for preparing and determining a cPEP as described above, wherein said protein is involved in at least one plant phenotype selected from: size, shape, surface area, volume, mass and number of leaves; size, shape, surface area, volume, mass and number of flowers; size of the stem (or floral stalk); root biomass; number, length and branching level of the roots; earliness of germination; earliness of budding; earliness of floral induction (or floral transition); germination vigor and duration of juvenile phase; duration of flowering; resistance to biotic stress; resistance to abiotic stress; and number of cells.

[0089] According to the invention, a protein is "involved in a phenotype" if a modification of the accumulation thereof is associated with a modification of said phenotype. In other words, a protein is involved in a phenotype if it is involved in the characteristic(s) corresponding to said phenotype. In view of the above, it is understood that an object of the invention is the method for preparing and determining a cPEP as described above, in which the phenotype observed in step e.is selected from: the size, shape, surface area, volume, mass and number of leaves; the size, shape, surface area, volume, mass and number of flowers; the size of the stem (or floral stalk); the root biomass; the number, length and level of branching of the roots; the earliness of germination; the earliness of budding; the earliness of floral induction (or floral transition); the germination vigor and duration of the juvenile phase; the duration of flowering; the resistance to biotic stress; the resistance to abiotic stress; and the number of cells.

[0090] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, said cPEP: having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids; being capable of modulating the accumulation of a protein in a plant cell; and not being capable of modulating the accumulation of the mRNA encoding said protein, and in which said plant cell ( / e. that in which it is desired to modulate the accumulation of a protein) belongs to: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis lyrata, Arabidopsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rapeseed), Brassica oleracea, Brassica rapa (rapeseed), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soybean), Gossypium raimondii, Gossypium spp.(cotton), Hordeum vulgare (barley), Lollium spp., Lotus japonicus (lotus), Medicago sativa (alfalfa), Medicago truncatula (alfalfa), Nicotiana benthamiana (tobacco), Oryza sativa (rice), Pisum sativum (pea), Raphanus sativus, Solanum lycopersicum (tomato), Solanum melongena (eggplant), Solanum tuberosum (potato), Thellungiella halophila, Theobroma cacao, Triticum spp. (wheat), Vitis vignifera (grape) and Zea mays (corn).

[0091] In one embodiment, the invention relates to the process of preparing and determining a cPEP as previously described, wherein said plant cells or plants are used in step e. belong to: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis lyrata, Arabidopsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassicaca, Brassicacea, older Brassicacea turnip (rape), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soybean), Gossypium raimondii, Gossypium spp. (cotton), Hordeum vulgare (barley), Lollium spp., Lotus japonicus (trefoil), Medicago sativa (alfalfa), Medicago truncatula (alfalfa), Nicotiana benthamiana (tobacco), Oryza sativa (rice), Pisum sativum (pea), Raphanus sativus, Solanum lycopersicum (tomato), Solanum melongena (eggplant), Solanum tuberosum (potato), Thellungiella halophila, Theobroma cacao, Triticum spp. (wheat), Vitis vignifera (vine) and Zea mays (corn).

[0092] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said plant cell (i.e. the one in which it is desired to modulate the accumulation of a protein) is a cell of an algae.

[0093] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said plant cells or said plants used in step e belong to an algae.

[0094] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which said protein is encoded by a gene selected from: Aae15 (Acyl-activating enzyme 15), Aae16 (AMP-dependent synthetase and ligase family protein), Abcg11 (White-brown complex-like protein), Abdcg34 (ABC transporter G family member 34), Acc1 (Acetyl-CoA Carboxylase), Agb1 (GTP binding protein beta 1), Als (Acetolactate synthase (chloroplastic)), Anac076 (NAC domaincontaining protein 76), Apg9 (Autophagy 9), Arlbl (GTP-binding protein 1), Arr1 (Two-component response regulator ARR1), Arr5 (Two-component response regulator ARR5), Arr6 (Two-component response regulator ARR6), At59 (Pedate lyase family protein), Bak1 (Brassinosteroid insensitive 1 -associated receptor kinase 1), Bccpl (Acetyl-CoA Carboxylase (chloroplastic) subunit 1), Bccp2 (Acetyl-CoA Carboxylase (chloroplastic) subunit 2), Bril (Brassinosteroid insensitive 1),Bzo2h3 (bZIP transcription factor family protein), Cesa6 (Cellulose synthase A catalytic subunit 6), Cipk3 (CBL-interacting protein kinase 3), Cks1 (Cyclin-dependent kinases regulatory subunit 1), Cobl8 (COBRA-like protein 8 precursor), Coil (Coronatine-insensitive protein 1), Cpk3 (Calcium-dependent protein kinase 3), Crk34 (Cysteine-rich receptor-like protein kinase 34), Cyp705a18 (Cytochrome P450, family 705, subfamily A, polypeptide 18), Cyp71b26 (Cytochrome P450, family 71, subfamily B, polypeptide 26), Cyp78a8 (Cytochrome P450, family 78, subfamily A, polypeptide 8), Cyp97b3 (Cytochrome P450, family 97, subfamily B, polypeptide 3), Dell (Endoribonuclease Dicer homolog 1), Dur3 (Urea-proton symporter DUR3), Ein2 (Ethylene-insensitive protein 2), Emb 175 (Pentatricopeptide repeat-containing protein), Emb2726 (Elongation factor Ts family protein), Emb9 (Dihydrofolate synthetase), Epsps (5-enolpyruvylshikimate-3-phosphate (chloroplastic)), Fnr1 (Ferredoxin-NADP[+]-oxidoreductase 1),Fve (Transducin family protein / WD-40 repeat family protein), Ga2ox7 (Gibberellin 2-beta-dioxygenase 7), Gape (Glyceraldehyde-3-phosphate dehydrogenase), Gcn2 (ABC transporter family protein), Gdi2 (Guanosine nucleotide diphosphate dissociation inhibitor 2), Gln2 (Glutamine synthetase (chloroplastic)), Gsl3 (Callose synthase 2), Hag5 (Histone acetyltransferase of the MYST family 2), Hda18 (Histone deacetylase 18), Hexol (Beta-hexosaminidase 1), Hppd (4- hydroxyphenyl-pyruvate-dioxygenase), Hsl1 (B3 domain-containing transcription repressor VAL2), Iaa31 (lndole-3-acetic acid inducible 31), Iqd28 (IQ-domain 28), Jac1 (J-domain protein required for chloroplast accumulation response 1), Jar1 (Jasmonoyl-L-amino acid synthetase), Kp1 (Kinesin-like protein 1), Lrx2 (Leucine-rich repeat / extensin 2), Mapkkk3 (Mitogen-activated protein kinase kinase kinase 3), Mapkkk5 (Mitogen-activated protein kinase kinase kinase 5), Mfp2 (Multifunctional protein 2), Mrb1 (Transmembrane protein,putative (DUF3537)), Nsp1 (Nodulation signaling pathway 1), Pds (Phytoene desaturase (chloroplastic)), Pen3 (Phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and protein- tyrosine-phosphatase), Phyb (Phytochrome B), Pif3 (Phytochrome interacting factor 3), Pizza (Brassinosteroid-related acyltransferase 1), Ppoxl (Protoporphyrinogen oxidase (chloroplastic) 1), Ppox2 (Protoporphyrinogen oxidase (chloroplastic) 2), Prp39 (Tetra tricopeptide repeat (TPR)-like superfamily protein), PsbA (Photosystem II D1 protein), Pskrl (Phytosulfokin receptor 1), Rd21 (Granulin repeat cysteine protease family protein), Ringl (RING / U-box superfamily protein), Rosi (DNA glycosylase / AP lyase ROS1), Rpt4a (26S proteasome regulatory subunit 10B homolog A), Sfr6 (Mediator of RNA polymerase II transcription subunit 16), Shr (Protein SHORT-ROOT), Shy2 (Auxin-responsive protein IAA3), Ski (EIN2-like protein, nramp transporter), Sps1 (Sucrose phosphate synthase 2F), Spt (Transcription factor SPATULA),Stn8 (Serine / threonine-protein kinase), Tap46 (PP2A regulatory subunit TAP46), Topp6 (Serine / threonine-protein phosphatase PP1 isozyme 7), TubB6 (Tubulin), TubB8 (Tubulin), Ubala (RNA-binding (RRM / RBD / RNP motifs) family protein), Vim3 (E3 ubiquitin-protein ligase), Sgr1 (Magnesium dechelatase), Abi5 (Abscisic acid (ABA)-insensitive 5), Hsp101 (Heat shock protein 101), Rh10 (ATP-dependent RNA helicase) et Wus (WUSCHEL).,

[0095] In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene selected from: Cpk3, Dell and Nsp1. In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by the Cpk3 gene. In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by the Dell gene. In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by the Nsp1 gene.

[0096] The genes Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1, Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Fve, Ga2ox7, Gapc, Gcn2, Gdi2, Gln2, Gsl3, Hag5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkk5, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif 3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Rosi, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Topp6, TubB6, TubB8, Ubala, Vim3, Sgr1, Abi5, Hsp101, Rh10 and l / l / us refer to the proteins indicated in parentheses. Of course, the invention also relates to homologous and / or similar genes which may have different names. For example, in A. thaliana the Gsl3 gene encoding callose synthase 2 is also called Cals2.

[0097] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NO: 1 (ORF of the Aae15 protein, A. thaliana), SEQ ID NO: 2 (ORF of the Aae16 protein, A. thaliana), SEQ ID NO: 3 (ORF of the abcg11 protein, A. thaliana), SEQ ID NO: 4 (ORF of the Abdcg34 protein, A. thaliana), SEQ ID NO: 5 (ORF of the Acc1 protein, A. thaliana), SEQ ID NO: 6 (ORF of the Agb1 protein, A. thaliana), SEQ ID NO: 7 (ORF of the Als protein, A. thaliana), SEQ ID NO: 8 (ORF of the Anac076 protein, A. thaliana), SEQ ID NO: 9 (ORF of the Apg9 protein, A. thaliana), SEQ ID NO: 10 (ORF of the Arlbl protein, A. thaliana), SEQ ID NO: 11 (ORF of the Arr1 protein, A.thaliana), SEQ ID NO : 12 (ORF of the Arr5 protein, A. thaliana), SEQ ID NO : 13 (ORF of the Arr6 protein, A. thaliana), SEQ ID NO : 14 (ORF of the At59 protein, A. thaliana), SEQ ID NO : 15 (ORF of the Bak1 protein, A. thaliana), SEQ ID NO : 16 (ORF of the Bccpl protein, A. thaliana), SEQ ID NO : 17 (ORF of the Bccp2 protein, A. thaliana), SEQ ID NO : 18 (ORF of the Bril protein, A. thaliana), SEQ ID NO : 19 (ORF of the Bzo2h3 protein, A. thaliana), SEQ ID NO : 20 (ORF of the Bccp2 protein, A. thaliana), Cesa6, A. thaliana), SEQ ID NO : 21 (ORF of the Cipk3 protein, A. thaliana), SEQ ID NO : 22 (ORF of the Cks1 protein, A. thaliana), SEQ ID NO : 23 (ORF of the Cobl8 protein, A. thaliana), SEQ ID NO : 24 (ORF of the Coil protein, A. thaliana), SEQ ID NO : 25 (ORF of the Coil protein, A. thaliana), SEQ ID NO : 26 (ORF of the Cpk3 protein, A. thaliana), SEQ ID NO : 27 (ORF of the Cpk3 protein, A. hypochondriacus), SEQ ID NO : 28 (ORF of the Cpk3 protein, B.distachyon), SEQ ID NO: 29 (ORF of Cpk3 protein, B. distachyon), SEQ ID NO: 30 (ORF of Cpk3 protein, G. max), SEQ ID NO: 31 (ORF of Cpk3 protein, G. max), SEQ ID NO: 32 (ORF of Cpk3 protein, G. max), SEQ ID NO: 33 (ORF of the Cpk3 protein, G. max), SEQ ID NO: 34 (ORF of the Cpk3 protein, O. sativa), SEQ ID NO: 35 (ORF of the Cpk3 protein, O. sativa), SEQ ID NO: 36 (ORF of the Cpk3 protein, S. lyco), ID NO: 37 (ORF of the Cpk3 protein, S. sativa), SEQ ID: Cpk3 protein, Z. mays), SEQ ID NO: 38 (ORF of Cpk3 protein, Z. mays), SEQ ID NO: 39 (ORF of Cpk3 protein, Z. mays), SEQ ID NO: 40 (ORF of Cpk3 protein, B. rapa), SEQ ID NO: 41 (ORF of Cpk3 protein, B. rapa), SEQ ID NO: 41 (ORF of Cpk3 protein, rapa). SEQ ID NO : 42 (ORF of Cpk3 protein, H. vulgare), SEQ ID NO : 43 (ORF of Cpk3 protein, H. vulgare), SEQ ID NO : 44 (ORF of Cpk3 protein, S. tuberosum), SEQ ID NO : 45 (ORF of Cpk3 protein, S. tuberosum), SEQ ID NO : 46 (ORF of Cpk3 protein, A. palm). (ORF of Cpk3 protein, Mtruncatula), SEQ ID NO : 47 (ORF of Cpk3 protein, M. truncatula), SEQ ID NO : 48 (ORF of Cpk3 protein, T. aestivum), SEQ ID NO : 49 (ORF of Cpk3 protein, T. aestivum), SEQ ID NO : 50 (ORF of Cpk3 protein, T. aestivum), SEQ ID NO : 50 (ORF of Cpk3 protein, T. aestivum). ID NO: 51 (ORF of the Cpk3 protein, T. aestivum), SEQ ID NO: 52 (ORF of the Cpk3 protein, L. perenne), SEQ ID NO: 53 (ORF of the Cpk3 protein, L. perenne), SEQ ID NO: 54 (ORF of the Cpk3 protein, L. perenne), SEQ ID NO: 5 (ORF of the Cpk3 protein, 5). of the Cpk3 protein, L. perenne), SEQ ID NO: 56 (ORF of the Crk34 protein, A. thaliana), SEQ ID NO: 57 (ORF of the Cyp705a18 protein, A. thaliana), SEQ ID NO: 58 (ORF of the protein Cyp71b26, A. thaliana), AQ ID NO: 56 (ORF of the thaliana protein). the Cyp78a8 protein, A. thaliana), SEQ ID NO: 60 (ORF of the Cyp97b3 protein, A. thaliana), SEQ ID NO: 61 (ORF of the Dell protein, A. thaliana), SEQ ID NO: 62 (ORF of the Dell protein, A. thaliana), SEQ ID NO: 63 (ORF of the Dell protein, A. thaliana). TO.hypochondriacus), SEQ ID NO: 64 (ORF of the Dell protein, B. distachyon), SEQ ID NO: 65 (ORF of the Dell protein, G. max), SEQ ID NO: 66 (ORF of the Dell protein, G. max), SEQ ID NO: 67 (ORF of the Dell protein, O. sativa), SEQ ID NO: 68 (ORF of the Dell protein, S. lycopersicum), SEQ ID NO: 69 (ORF of the Dell protein, Z. mays), SEQ ID NO: 70 (ORF of the Dell protein, B. rapa), SEQ ID NO: 71 (ORF of the Dell protein, H. vulgare), SEQ ID NO: 72 (ORF of the Dell protein, S. tuberosum), SEQ ID NO: 73 (ORF of the protein Dell, M. truncatula), SEQ ID NO: 74 (ORF of the protein Dell, T. aestivum), SEQ ID NO: 75 (ORF of the protein Dell, T. aestivum), SEQ ID NO: 76 (ORF of the protein Dell, T. aestivum), SEQ ID NO: 77 (ORF of the protein Dell, T. aestivum), SEQ ID NO: 78 (ORF of the protein Dell, L. perenne), SEQ ID NO: 79 (ORF of the protein Dell, L. perenne), SEQ ID NO: 80 (ORF of the protein Dur3, A. thaliana), SEQ ID NO: 81 (ORF of the protein Ein2, A.thaliana), SEQ ID NO : 82 (ORF of the protein Emb175, A. thaliana), SEQ ID NO : 83 (ORF of the protein Emb2726, A. thaliana), SEQ ID NO : 84 (ORF of the protein Emb9, A. thaliana), SEQ ID NO : 85 (ORF of the protein Emb9, A. thaliana), IDAs. : 86 (ORF of the Fnr1 protein, A. thaliana), SEQ ID NO: 87 (ORF of the Fve protein, A. thaliana), SEQ ID NO: 88 (ORF of the Ga2ox7 protein, A. thaliana), SEQ ID NO: 89 (ORF of the Gape protein, N.thaliana), SEQ ID NO: 90 (ORF of the Bentha protein: NO Gcn2, A. thaliana), SEQ ID NO: 91 (ORF of protein Gdi2, A. thaliana), SEQ ID NO: 92 (ORF of protein Gln2, A. thaliana), SEQ ID NO: 93 (ORF of protein Gsl3, A. thaliana), SEQ ID NO: 9 (ORF of protein Gsl3, A. thaliana), SEQ ID NO: 9 (ORF of Haga protein, A. thaliana). ID NO : 95 (ORF of Hda18 protein, A. thaliana), SEQ ID NO : 96 (ORF of Hexol protein, A. thaliana), SEQ ID NO : 97 (ORF of Hppd protein, A. thaliana), SEQ ID NO : 98 (ORF of Hsl1 protein, A. thaliana).thaliana), SEQ ID NO: 99 (ORF of the Iaa31 protein, A. thaliana), SEQ ID NO: 100 (ORF of the Iqd28 protein, A. thaliana), SEQ ID NO: 101 (ORF of the Jac1 protein, A. thaliana), SEQ ID NO: 102 (ORF of the Jac1 protein, A. thaliana). SEQ ID NO: 103 (ORF of Kp1 protein, A. thaliana), SEQ ID NO: 104 (ORF of Lrx2 protein, A. thaliana), SEQ ID NO: 105 (ORF of Mapkkk3 protein, A. thaliana), SEQ ID NO: 106 (ORF of Mapkk protein A. thaliana), SEQ ID NO: 107 (ORF of the protein Mfp2, A. thaliana), SEQ ID NO: 108 (ORF of the protein Mrb1, A. thaliana), SEQ ID NO: 109 (ORF of the protein Nsp1, M. truncatula), SEQ ID NO: 110 (ORF of the protein Nsp1, A. thaliana), SEQ ID NO: 11 (ORF of the thaliana protein: 11). Nsp1 protein, B. distachyon), SEQ ID NO: 112 (ORF of Nsp1 protein, G. max), SEQ ID NO: 113 (ORF of Nsp1 protein, G. max), SEQ ID NO: 114 (ORF of Nsp1 protein, O. sativa), SEQ ID NO: 115 (ORF of Nsp1 protein, G. max).lycopersicum), SEQ ID NO : 116 (ORF of the Nsp1 protein, S. lycopersicum), SEQ ID NO : 117 (ORF of the Nsp1 protein, Z. mays), SEQ ID NO : 118 (ORF of the Nsp1 protein, Z. mays), SEQ ID NO : 119 (ORF of the Nsp1 protein, Z. mays), SEQ ID NO : 120 (ORF of the Nsp1 protein, Z. mays), SEQ ID NO : 121 (ORF of the Nsp1 protein, B. rapa), SEQ ID NO : 122 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 123 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 124 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 125 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 126 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 127 (ORF of the Nsp1 protein, H. vulgare), SEQ ID NO : 128 (ORF of the Nsp1 protein, H. vulgare), Nsp1, H. vulgare), SEQ ID NO : 129 (ORF of the Nsp1 protein, S. tuberosum), SEQ ID NO : 130 (ORF of the Nsp1 protein, S. tuberosum), SEQ ID NO : 131 (ORF of the Nsp1 protein, T. aestivum), SEQ ID NO : 132 (ORF of the Nsp1 protein, T. aestivum), SEQ ID NO: 133 (ORF of the Nsp1 protein, L.perenne), SEQ ID NO: 134 (ORF of protein Nsp1, L. perenne), SEQ ID NO: 135 (ORF of protein Pds, A. thaliana), SEQ ID NO: 136 (ORF of protein Pen3, A. thaliana), SEQ ID NO: 137 (ORF of protein Phy, A. thaliana), SEQ ID NO: 138 (ORF of the protein Pif3, A. thaliana), SEQ ID NO: 139 (ORF of the protein Pizza, A. thaliana), SEQ ID NO: 140 (ORF of the protein Ppoxl, A. thaliana), SEQ ID NO: 141 (ORF of the protein Ppox2, A. thaliana), SEQ ID NO: the Prp39 protein, A. thaliana), SEQ ID NO: 143 (ORF of the PsbA protein, A. thaliana), SEQ ID NO: 144 (ORF of the Pskrl protein, A. thaliana), SEQ ID NO: 145 (ORF of the Rd21 protein, A. thaliana), SEQ ID NO: 146 (ORF of the A. thaliana protein: NORF). Ringl, A. thaliana), SEQ ID NO: 147 (ORF of the Rosi protein, A. thaliana), SEQ ID NO: 148 (ORF of the Rpt4a protein, A. thaliana), SEQ ID NO: 149 (ORF of the Sfr6 protein, A. thaliana), SEQ ID NO: 150 (ORF of the Shr protein, A. thaliana).thaliana), SEQ ID NO: 151 (ORF of Shy2 protein, A. thaliana), SEQ ID NO: 152 (ORF of Ski protein, M. truncatula), SEQ ID NO: 153 (ORF of Sps1 protein, A. thaliana), SEQ ID NO: 154 (ORF of Sps1 protein, A. thaliana), SEQ ID NO: 155 (ORF of the Stn8 protein, A. thaliana), SEQ ID NO: 156 (ORF of the Tap46 protein, A. thaliana), SEQ ID NO: 157 (ORF of the Topp6 protein, A. thaliana), SEQ ID NO: 158 (ORF of the TubB6 protein, A. thaliana), SEQ ID NO: the TubB8 protein, A. thaliana), SEQ ID NO: 160 (ORF of the llbala protein, A. thaliana), SEQ ID NO: 161 (ORF of the Vim3 protein, A. thaliana), SEQ ID NO: 171 (ORF of the Sgr1 protein, A. thaliana), SEQ ID NO: 15 (ORF of the Abi protein, A. thaliana). A. thaliana), SEQ ID NO : 173 (ORF of Hsp101 protein, A. thaliana), SEQ ID NO : 174 (ORF of Rh10 protein, M. truncatula) and SEQ ID NO : 175 (ORF of Wus protein, A. thaliana).

[0098] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0099] In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 61 to 79 (Dell).In particular, the invention relates to the method for preparing and determining a cPEP as described above, in which said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0100] By "percentage identity" between two nucleic acid (or amino acid) sequences, we mean a percentage of nucleotides (or amino acid residues) that are identical between the two sequences to be compared, obtained after the best alignment. This percentage is purely statistical and the differences between the two sequences are randomly distributed over the entire length of the sequences. The best alignment (or optimal alignment) is the alignment for which the percentage identity between the two sequences to be compared, as calculated below, is the highest. Sequence comparisons between two nucleic acid (or amino acid) sequences are traditionally performed by comparing these sequences after having aligned them optimally, said comparison being performed by segment or comparison window to identify and compare local regions of sequence similarity.Optimal alignment of sequences for comparison can be performed manually or by means of algorithms and software available to those skilled in the art, for example, the BLAST platform or the MatGat program (Campanella, Bitincka and Smalley, 2003).

[0101] The percentage identity between two sequences is determined by comparing these two optimally aligned sequences by comparison window in which the region of the sequence to be compared may include additions or deletions relative to the reference sequence for optimal alignment between these two sequences. The percentage identity is calculated by determining the number of identical positions for which the nucleotide (or amino acid) is identical between the two sequences, dividing this number of identical positions by the total number of positions in the comparison window and multiplying the result obtained by 100.

[0102] For the purposes of the invention, it is understood in the invention that sequences having “at least 80% identity” with a reference sequence may in particular have at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% with said reference sequence.

[0103] In one embodiment, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175. In one embodiment, the invention also relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0104] In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention relates to the method for preparing and determining a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0105] In another embodiment, the invention relates to the method for preparing and determining a cPEP as described above, in which the sequence of said peptide is chosen from the sequences: SEQ ID NO: 162 (NSP1-5'UTR-11), SEQ ID NO: 163 (NSP1-5'UTR-5) and SEQ ID NO: 164 (NSP1-3'UTR).

[0106] In a second aspect, the subject of the invention is a cPEP as obtained by implementing the method as described above. According to this same aspect, the subject of the invention is also a cPEP, of 4 to 70 amino acids, in particular of 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in a plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein. In one embodiment, the invention relates to the cPEP as previously described, said fragment having a size of 3n nucleotides, n being comprised: from 4 to 41; from 5 to 40; from 7 to 20; or from 8 to 15.

[0107] In other words, the invention relates to the cPEP as described above, said cPEP comprising s, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,

[0108] 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70 amino acids.

[0109] In particular, the invention relates to cPEP as described above, said cPEP comprising from 5 to 40 amino acids. In particular, the invention relates to cPEP as described above, said cPEP comprising from 7 to 20 amino acids. In particular, the invention also relates to cPEP as described above, said cPEP comprising from 8 to 15 amino acids.

[0110] In one embodiment, the invention relates to cPEP as described above, wherein the size of said cPEP is smaller than that of said protein.

[0111] In the invention, the nucleic acid sequence carrying the peptide information of the cPEP is chosen from a region which is not naturally translated in said plant cell. In a non-limiting manner, it corresponds to: the 5'IITR region, i.e. the untranslated region located upstream of the main ORF; the 3'IITR region, i.e. the untranslated region located downstream of the main ORF; or an intron, i.e. a region of the pre-mRNA deleted by splicing and absent from the mature mRNA.

[0112] In one embodiment, the invention relates to cPEP as described above, said nucleic acid sequence deemed non-coding being: the 5'IITR region; the 3'IITR region; or an intron.

[0113] In another embodiment, the invention relates to cPEP as described above, wherein one of said nucleic acid sequences deemed non-coding is the 5'UTR region or the 3'UTR region. In another embodiment, the invention relates to cPEP as described above, wherein one of said nucleic acid sequences deemed non-coding is the 5'UTR region. In another embodiment, the invention relates to cPEP as described above, wherein one of said nucleic acid sequences deemed non-coding is the 3'UTR region. In another embodiment, the invention relates to cPEP as described above, wherein one of said nucleic acid sequences deemed non-coding is an intron.

[0114] In one embodiment, the invention relates to the cPEP as described above, said fragment being devoid of: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0115] In one embodiment, the invention relates to the cPEP as described above, said fragment being devoid of: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0116] In one embodiment, the invention relates to the cPEP as described above, said fragment comprising: an initiator codon AUG encoding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein. In one embodiment, the invention therefore relates to the cPEP as described above, said fragment comprising an initiator codon AUG encoding an initiator methionine and being devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to cPEP as described above, said fragment being devoid of an initiator codon AUG coding an initiator methionine and comprising a STOP codon chosen from the codons: UAG, UGA and UAA.

[0117] In one embodiment, the invention relates to cPEP as described above, said fragment comprising: an initiator codon AUG encoding an initiator methionine; and a STOP codon selected from the codons: UAG, UGA and UAA, and wherein said fragment is selected: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0118] In one embodiment, the invention relates to cPEP as described above, wherein the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to cPEP as described above, wherein the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0119] In one embodiment, the invention relates to cPEP as described above, wherein the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to cPEP as described above, wherein the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention also relates to cPEP as described above, wherein the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In other words, the invention relates to the cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0120] In one embodiment, the subject of the invention is a cPEP, of 4 to 70 amino acids, in particular of 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, eg intron); and a part located within a nucleic acid sequence deemed to be coding ( / .e. naturally translated, eg exon), said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said cPEP being capable of modulating the accumulation of said protein in a plant cell and not being capable of modulating the accumulation of the mRNA coding said protein.

[0121] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is capable of increasing the accumulation of said protein in said plant cell.

[0122] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is capable of decreasing the accumulation of said protein in said plant cell.

[0123] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is a synthetic peptide.

[0124] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is an isolated peptide.

[0125] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is a recombinant peptide.

[0126] In one embodiment, the invention relates to cPEP as described above, wherein said cPEP is a hydrophobic peptide or a hydrophilic peptide. In one embodiment, the invention relates to cPEP as described above, wherein said protein is naturally present in said plant cell.

[0127] In one embodiment, the invention relates to cPEP as described above, wherein said protein is not naturally present in said plant cell. In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a transgene artificially introduced into said plant cell. In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a vector artificially introduced into said plant cell.

[0128] In a way of realization, the invention concerns the cPEP as described previously, in which plant cells belong to: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis lyrata, Arabidopsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rape), Brassica oleracea, Brassica rapa (rape), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soya), Gossypium raimondii, Gossypium spp. (coton), Hordeum vulgare (orge), Lollium spp., Lotus japonicus (lotier), Medicago sativa (luzerne), Medicago truncatula (luzerne), Nicotiana benthamiana (tabac), Oryza sativa (riz), Pisum sativum (pois), Raphanus sativus, Solanum lycopersicum (tomate), Solanum melongena (aubergine), Solanum tuberosum (pomme de terre), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0129] In one embodiment, the invention relates to cPEP as described above, wherein said plant cell is a cell of an algae.

[0130] In one embodiment, the invention relates to cPEP as described above, wherein said protein is encoded by a gene selected from the genes: Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1, Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Fve, Ga2ox7, Gapc, Gcn2, Gdi2, Gln2, Gsl3, Hag5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkkô, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif 3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Rosi, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Toppô, TubB6, TubB8, Ubala, Vim3, Sgr1, Abi5, Hsp101, RhIO and l / l / us. In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a gene selected from the genes: Cpk3, Dell and Nsp1.In particular, the invention relates to cPEP as described above, wherein said protein is encoded by the Cpk3 gene. In particular, the invention relates to cPEP as described above, wherein said protein is encoded by the Dell gene. In particular, the invention relates to cPEP as described above, wherein said protein is encoded by the Nsp1 gene.

[0131] In one embodiment, the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175.

[0132] In particular, the invention relates to the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1). In particular, the invention also relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3).In particular, the invention also relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence selected from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention also relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence selected from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0133] In one embodiment, the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence chosen from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175. The invention relates in particular to cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0134] In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention relates to cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0135] In another embodiment, the invention relates to cPEP as described above, in which the sequence of said peptide is chosen from the sequences: SEQ ID NOs: 162 to 164.

[0136] In one embodiment, the invention relates to cPEP as described above, wherein said protein is involved in at least one plant phenotype selected from: leaf size, shape, area, volume, mass and number; flower size, shape, area, volume, mass and number; stem (or floral stalk) size; root biomass; root number, length and branching level; germination precocity; budding precocity; floral induction (or floral transition) precocity; germination vigor and juvenile phase duration; flowering duration; biotic stress resistance; abiotic stress resistance; and cell number.

[0137] In the invention, a cPEP may be fused or linked to one or more molecules that facilitate the entry of the cPEP into the cell. These molecules include, in particular, penetrating peptides (Numata, K., et al. Library screening of cell-penetrating peptide for BY-2 cells, leaves of Arabidopsis, tobacco, tomato, poplar, and rice callus. Sci Rep 8, 10966 (2018).) and palmitic acid. By "penetrating peptide" (hereinafter CPP), we mean small peptides that penetrate cellular lipid bilayers or destabilize cellular membranes. CPPs can be classified into three groups: cationic, amphipathic, and hydrophobic.In particular: cationic CPPs contain many positively charged amino acids, such as lysine (Lys) and arginine (Arg); amphipathic CPPs are generally composed of an alternating sequence of polar and nonpolar amino acids; and hydrophobic CPPs consist of nonpolar amino acids with relatively low net charges.

[0138] In one embodiment, the invention relates to cPEP as described above, said cPEP being fused to a peptide facilitating its entry into the plant cell. In particular, the invention relates to cPEP as described above, said cPEP being fused to a penetrating peptide.

[0139] In one embodiment, the invention relates to cPEP as described above, said cPEP being fused at the N-terminus or at the C-terminus with said peptide facilitating its entry into the plant cell. In particular, the invention relates to cPEP as described above, said cPEP being fused at the N-terminus or at the C-terminus with said penetrating peptide.

[0140] In one embodiment, the invention relates to cPEP as described above, said cPEP being fused with: the TAT peptide (SEQ ID NO: 170); penetratin; a polyhistidine peptide (in particular a peptide of at least 4 histidine residues); or a polyarginine peptide (in particular a peptide of 4 arginine residues).

[0141] In one embodiment, the invention relates to cPEP as described above, said cPEP being linked to one or more palmitic acid molecules.

[0142] In one embodiment, the invention relates to cPEP as described above, said cPEP being linked at the N-terminus or at the C-terminus to one or more palmitic acid molecules.

[0143] On this point, it should be noted that the amount of cPEP required to modulate the accumulation of a protein may vary depending on whether or not the cPEP is modified with one of the molecules facilitating its cellular penetration. In a third aspect, the subject of the invention is a nucleic acid encoding a cPEP as described above. According to this same aspect, the subject of the invention is also a nucleic acid of 3n nucleotides, which nucleic acid corresponds to a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein.

[0144] In one embodiment, the invention relates to the cPEP nucleic acid as described above, said fragment being devoid of: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0145] In one embodiment, the invention relates to the cPEP nucleic acid as described above, said fragment being devoid of: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0146] In one embodiment, the invention relates to the cPEP nucleic acid as described above, said fragment comprising: an initiator codon AUG encoding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0147] In one embodiment, the invention therefore relates to the nucleic acid as described above, said fragment comprising an initiator codon AUG coding an initiator methionine and being devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the nucleic acid as described above, said fragment being devoid of an initiator codon AUG coding an initiator methionine and comprising a STOP codon chosen from the codons: UAG, UGA and UAA.

[0148] In one embodiment, the invention relates to the cPEP nucleic acid as described above, said fragment comprising: an initiator codon AUG encoding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0149] In one embodiment, the invention relates to the cPEP nucleic acid as described above, wherein the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the cPEP nucleic acid as described above, wherein the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0150] In one embodiment, the invention relates to the cPEP nucleic acid as described above, wherein the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the cPEP nucleic acid as described above, wherein the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the cPEP nucleic acid as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the cPEP nucleic acid as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0151] In one embodiment, the invention relates to a nucleic acid of 3n nucleotides, which nucleic acid corresponds to a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, e.g. intron); and a part located within a nucleic acid sequence known to be coding ( / .e. naturally translated, e.g. exon).

[0152] In particular, the invention relates to the nucleic acid as described above, where n is comprised: from 4 to 70; from 4 to 41; from 5 to 40; from 7 to 20; or from 8 to 15.

[0153] In another aspect, the invention relates to a composition comprising a cPEP as described above as an active ingredient.

[0154] In another embodiment, the invention relates to a composition comprising a cPEP as an active substance, said cPEP:

[0155] - having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41; and

[0156] - being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0157] In one embodiment, the invention relates to the composition as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0158] In one embodiment, the invention relates to the composition as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0159] In one embodiment, the invention relates to the composition as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0160] In one embodiment, the invention therefore relates to the composition as described above, in which said fragment comprises an initiator codon AUG encoding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the composition as described above, in which said fragment is devoid of an initiator codon AUG encoding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0161] In one embodiment, the invention relates to the composition as described above, in which said fragment comprises: an initiator codon AUG encoding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0162] In one embodiment, the invention relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0163] In one embodiment, the invention relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the composition as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0164] In one embodiment, the invention relates to a composition comprising a cPEP as an active substance, said cPEP:

[0165] - having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said nucleic acid sequence comprising two contiguous parts:

[0166] ■ a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, eg intron); and

[0167] ■ a part located within a nucleic acid sequence known to be coding ( / .e. naturally translated, eg exon); and

[0168] - being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0169] In one embodiment, the invention relates to the composition as described above, wherein said cPEP is at a concentration of 10' 9 M to 10' 3 Mr. On this point, it should be noted on the one hand that the composition of the invention does not exist in its natural state and this is all the more true since such a concentration of cPEP cannot exist within a plant cell. In addition, and by "concentration of 10' 9 M to 10' 3 M”, we mean that the cPEP concentration can be understood from 10' 9 at 10' 4 M, 10' 8 at 10' 4 M, 10' 9 at 10' 5 M, 10' 8 at 10' 5 M, as it can be understood from 5 pM to 500 pM, from 30 pM to 70 pM, or even be 50 pM.

[0170] In particular, the invention relates to the composition as described above, in which said cPEP is at a concentration of 10' 9at 10' 4 M, 10' 8 at 10' 4 M, 10' 9 at 10' 5 M or 10' 8 at 10' 5 M. In particular, the invention relates to the composition as described above, wherein said cPEP is at a concentration of from 5 pM to 500 pM or from 30 pM to 70 pM. In particular, the invention relates to the composition as described above, wherein said cPEP is at a concentration of 50 pM. In a non-limiting manner, this concentration may also be 10' 9 M, 10' 8 M, 10' 7 M, 10' 6 M, 10' 5 M or 10' 4 Mr.

[0171] In view of the above, it is understood that the invention also relates to the composition as described above comprising a cPEP as active substance, said cPEP:

[0172] - having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein; - being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA coding said protein; and

[0173] - being in particular at a concentration of from 5 pM to 500 pM or from 30 pM to 70 pM, or being in particular at a concentration of 50 pM.

[0174] It should be noted that by "composition comprising a cPEP" is meant that the composition of the invention comprises at least one cPEP. That is to say that a mixture of cPEPs is conceivable, said cPEPs being able to target the same protein or several proteins depending on the nucleic acid fragment from which they are derived. In this regard, the aforementioned concentrations relate either to the mixture of cPEPs as such, or to each of the cPEPs of said mixture, said cPEPs being able to be at the same concentration or being able to be at different concentrations among those mentioned above.

[0175] In one embodiment, the invention relates to the composition as described above, said composition being a phytopharmaceutical composition, a herbicidal composition or a coating composition, in particular said coating composition further comprising at least one fixing agent.

[0176] In particular, the invention relates to the composition as described above, said composition being a phytopharmaceutical composition. In particular, the invention relates to the composition as described above, said composition being a herbicidal composition. In particular, the invention relates to the composition as described above, said composition being a coating composition. Preferably, the invention relates to the composition as described above, said composition being a coating composition further comprising at least one fixing agent.

[0177] In one embodiment, the invention relates to the composition as described above, said composition further comprising at least one solvent. Preferably, said solvent is chosen from: acetone, acetonitrile, acetic acid, formic acid, dimethyl adipate, benzyl acetate, bi-butyl carbonate, dimethyl sulfoxide (DMSO), water, dimethyl glutarate, ammonium hydroxide, isobutanol, iso-propanol, diethyl hexyl lactate, light aromatic naphtha solvent, heavy aromatic naphtha solvent, diethyl succinate and mixtures thereof (e.g. mixture [water; acetic acid]; [acetonitrile; acetic acid], [water, acetonitrile; acetic acid], [water; DMSO], [water; acetonitrile] or [water; ammonium hydroxide]). The solubility properties of cPEPs are determined in particular by their amino acid composition. Hydrophilic cPEPs can be solubilized and packaged in aqueous solutions, such as water.Hydrophobic cPEPs can be solubilized and packaged in solvents, such as organic solvents.

[0178] For treatment of plants with cPEPs, organic solvents are non-toxic solvents for plants in small quantities, that is to say they have no deleterious effect on the development of the plant. In a non-limiting manner, the organic solvents may be those mentioned above and in particular chosen from acetonitrile and acetic acid.

[0179] As indicated above, cPEPs can also be solubilized and packaged in solvent mixtures, such as, for example, an organic solvent mixture [acetonitrile; acetic acid], a mixture [water; DMSO] in a volume:volume ratio of 99:1 to 1:99, a mixture [water; acetonitrile] in a volume:volume ratio of 99:1 to 1:99, or a mixture [water; ammonium hydroxide] in a volume:volume ratio of 99:1 to 99.9:0.1. cPEPs can also be solubilized in a solution comprising 50% acetonitrile, 10% acetic acid, and 40% water (volume / volume / volume).

[0180] In one embodiment, the invention relates to the composition as described above, said composition further comprising at least one diluent.

[0181] In one embodiment, the invention relates to the composition as described above, said composition further comprising at least one adjuvant.

[0182] In one embodiment, the invention relates to the composition as described above, said composition further comprising at least one fixing agent.

[0183] By "fixing agent" is meant a chemical or natural agent which allows the composition of the invention to be bonded to a plant seed so as to coat said plant seed. It also means a substance making it possible to apply and hold the active substance(s) on the grain. Among the available fixing agents are carboxymethyl cellulose (CMC) and gum arabic. In addition, and in a non-limiting manner, a fixing agent may comprise organic solvents, water, dispersants, emulsifiers, surfactants, wetting agents and colorants.

[0184] In one embodiment, the invention relates to the composition as described above, said composition further comprising at least one plant nutrient. In particular, the invention relates to the composition as described above, said composition further comprising at least one fixing agent and at least one plant nutrient.

[0185] By "plant nutrient" we mean an element assimilated by the plant to enable its development. A plant nutrient may be chosen, without limitation, from: nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, manganese, iron, copper, boron, zinc, molybdenum and mixtures thereof.

[0186] In view of the above, it is understood that another aspect of the invention relates to a coated seed comprising a plant seed, said plant seed being coated with a coating composition as described above.

[0187] The coating can be carried out using processes conventionally used in the food industry and can be obtained using a material capable of disintegrating in a solvent or in the earth, such as a binder or clay.

[0188] According to the invention, the coating can be used to confer particular properties to a seed in combination with a cPEP, such as improved growth or resistance to certain biotic or abiotic stresses.

[0189] In one embodiment, the invention relates to the enrobed seed as previously described, wherein said plant seed belongs to: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis, Arabidopsis, Arabidopsis, Arabidopsis, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rapeseed), Brassica oleracea, Brassica rapa (rapeseed), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soybean), Gopisimo spicium, Gopisy spis. (cotton), Hordeum vulgare (barley), Lollium spp., Lotus japonicus (lotier), Medicago sativa (alfalfa), Medicago truncatula (alfalfa), Nicotiana benthamiana (tobacco), Oryza sativa (rice), Pisum sativum (peas), Raphanus sativus, Solanum lycopersi (melon), Solanum (melon), Solanum tuberosum (potato), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0190] In one embodiment, the invention relates to the coated seed as described above, said seed being treated by soaking in a composition containing a cPEP. During soaking, the seed is then immersed totally or partially in a composition containing a cPEP. In another aspect, the invention relates to a use of a cPEP as a phytosanitary agent for modulating the accumulation of a protein in a plant cell, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0191] In one embodiment, the invention relates to the use of a cPEP as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0192] In one embodiment, the invention relates to the use of a cPEP as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0193] In one embodiment, the invention relates to the use of a cPEP as described above, in which said fragment comprises: an initiator codon AUG encoding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0194] In one embodiment, the invention therefore relates to the use of a cPEP as described above, in which said fragment comprises an initiator codon AUG encoding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the use of a cPEP as described above, in which said fragment is devoid of an initiator codon AUG encoding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0195] In one embodiment, the invention relates to the use of a cPEP as described above, in which said fragment comprises: an initiator codon AUG encoding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0196] In one embodiment, the invention relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0197] In one embodiment, the invention relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the use of a cPEP as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0198] In one embodiment, the invention relates to a use of a cPEP as a phytosanitary agent for modulating the accumulation of a protein in a plant cell, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, eg intron); and a part located within a nucleic acid sequence known to be coding ( / .e. naturally translated, egexon); said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0199] In one embodiment, the invention relates to the use of a cPEP as described above to increase the accumulation of said protein in the plant cell. The presence of the cPEP causes the amount of said protein in the treated plant cell to be greater than that in an untreated plant cell.

[0200] In one embodiment, the invention relates to the use of a cPEP as described above for decreasing (inhibiting) the accumulation of said protein in the plant cell. The presence of the cPEP causes the amount of said protein in the treated plant cell to be lower than that in an untreated plant cell.

[0201] In one embodiment, the invention relates to the use of a cPEP as described above, said nucleic acid sequence deemed non-coding (i.e. not naturally translated) being: the 5'UTR region; the 3'UTR region; or an intron.

[0202] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is produced outside of said plant cell before being introduced into said plant cell.

[0203] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is a synthetic peptide.

[0204] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is an isolated peptide.

[0205] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is a recombinant peptide.

[0206] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is a hydrophobic peptide or a hydrophilic peptide.

[0207] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is introduced into said plant cell in the form of a nucleic acid encoding said cPEP. In particular, the invention relates to the use of a cPEP as described above, wherein said cPEP is introduced into said plant cell in the form of a nucleic acid encoding said cPEP and comprising the means for expressing it.

[0208] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is naturally present in said plant cell.

[0209] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is not naturally present in said plant cell. In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a transgene artificially introduced into said plant cell. In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a vector artificially introduced into said plant cell. In one embodiment, the invention relates to the use of a cPEP as described above, wherein the accumulation of said protein is determined via the implementation of a technique chosen from: Western blot, measurement of enzymatic activity, mass spectrometry and translational fusion.In particular, the invention relates to the use of a cPEP as described above, in which the accumulation of said protein is determined via the implementation of a Western blot.

[0210] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP has a size of 4 to 41 amino acids, 5 to 40 amino acids, 7 to 20 amino acids or more particularly a size of 8 to 15 amino acids. In particular, said cPEP has a size of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,

[0211] 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,

[0212] 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,

[0213] 62, 63, 64, 65, 66, 67, 68, 69 or 70 amino acids.

[0214] In one embodiment, the invention involves the use of a cPEP as previously described, wherein said plant cell comprises: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis, Arabidopsis, Arabid opsis, Arabid opsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rapeseed), Brassica oleracea, Brassica rapa (rapeseed), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glyxy, Gondis, Raimosium, Raimox Gossypium spp. (cotton), Hordeum vulgare (barley), Lollium spp., Lotus japonicus (lotier), Medicago sativa (alfalfa), Medicago truncatula (alfalfa), Nicotiana benthamiana (tobacco), Oryza sativa (rice), Pisum sativum (peas), Raphanus sativus, Solanum lycopersi (melon), Solanum (melon), Solanum tuberosum (potato), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0215] In particular, the invention relates to the use of a cPEP as described above, wherein said plant cell is a cell of an algae.

[0216] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene selected from: Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1, Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Fve, Ga2ox7, Gapc, Gcn2, Gdi2, Gln2, Gsl3, Hag5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkkô, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif 3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Ros1, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Topp6, TubB6, TubB8, Uba 1a, Vim3, Sgr1, Abi5, Hsp101, Rh10 and Wus.

[0217] In view of the above, it is understood that in another embodiment, the invention relates to the use of a cPEP as described above, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a non-naturally translated fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein, said protein being encoded by a gene chosen from: Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1, Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Eve, Ga2ox7, Gapc, Gcn2,Gdi2, Gln2, Gsl3, Hag5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkkô, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif 3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Rosi, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Toppô, TubB6, TubB8, Ubala, Vim3, Sgr1, Abi5, Hsp101, RhIO and Wus.,

[0218] In one embodiment, the invention relates to the use of a cPEP as described above, in which said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175.

[0219] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0220] In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 61 to 79 (Dell).In particular, the invention relates to the use of a cPEP as described above, in which said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0221] In one embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175. In one embodiment, the invention also relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0222] In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention relates to the use of a cPEP as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0223] In another embodiment, the invention relates to the use of a cPEP as described above, wherein said cPEP is chosen from the sequences: SEQ ID NOs: 162 to 164.

[0224] In another embodiment, the invention relates to the use of a cPEP as described above, wherein said protein is involved in at least one plant phenotype selected from: size, shape, surface area, volume, mass and number of leaves; size, shape, surface area, volume, mass and number of flowers; size of the stem (or floral stalk); root biomass; number, length and branching level of the roots; earliness of germination; earliness of budding; earliness of floral induction (or floral transition); germination vigor and duration of juvenile phase; duration of flowering; resistance to biotic stress; resistance to abiotic stress; and number of cells.

[0225] In another embodiment, the invention relates to the use of a cPEP as described above, to modulate the accumulation of a recombinant protein whose nucleic acid sequence which encodes it corresponds to the fusion of the nucleic acid sequences of two distinct genes.

[0226] In particular, the coding sequence of at least one of the two genes is that of a reporter gene, for example a gene coding for a fluorescent protein (such as GFP) or a protein enabling the plant's resistance to a compound.

[0227] In one embodiment, the invention relates to the use of a cPEP as described above, for modulating the accumulation of a recombinant protein whose nucleic acid sequence which codes it corresponds to the fusion: of a nucleic acid sequence known to be non-coding of a first gene; and of a nucleic acid sequence coding for a second gene, the sequence of said cPEP corresponding to the translation via the genetic code of a fragment of the nucleic acid sequence known to be non-coding of the first gene.

[0228] In another aspect, the invention relates to a method for modulating the accumulation of a protein in a plant cell comprising a step of introducing: a cPEP; or a nucleic acid encoding said cPEP and the means for expressing it, into said plant cell, the introduction of said cPEP resulting in a modulation of the quantity of said protein in said plant cell, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0229] In one embodiment, the invention relates to the method as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0230] In one embodiment, the invention relates to the method as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0231] In one embodiment, the invention relates to the method as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0232] In one embodiment, the invention therefore relates to the method as described above, in which said fragment comprises an initiator codon AUG encoding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the method as described above, in which said fragment is devoid of an initiator codon AUG encoding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0233] In one embodiment, the invention relates to the method as described above, in which said fragment comprises: an initiator codon AUG encoding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame encoding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame encoding said protein.

[0234] In one embodiment, the invention relates to the method as described above, wherein the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the method as described above, wherein the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0235] In one embodiment, the invention relates to the method as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the method as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the method as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the method as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In one embodiment, the invention relates to a method of modulating the accumulation of a protein in a plant cell comprising a step of introducing: a cPEP; or a nucleic acid encoding said cPEP and the means for expressing it, in said plant cell, the introduction of said cPEP resulting in a modulation of the quantity of said protein in said plant cell, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence deemed non-coding ( / .e. not naturally translated, egintron); and a part located within a nucleic acid sequence deemed to be coding ( / .e. naturally translated, eg exon); said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA coding said protein.

[0236] In one embodiment, the invention relates to the method as described above, said method making it possible to: promote the development of a plant; or slow down or prevent the development of a plant.

[0237] In particular, the invention relates to the method as described above, said method making it possible to promote the development of a plant. In particular, the invention relates to the method as described above, said method making it possible to slow down or prevent the development of a plant.

[0238] In one embodiment, the invention relates to the method as described above for increasing the accumulation of said protein in the plant cell. The presence of cPEP causes the amount of said protein in the treated plant cell to be greater than that in an untreated plant cell.

[0239] In one embodiment, the invention relates to the method as described above for decreasing (inhibiting) the accumulation of said protein in the plant cell. The presence of cPEP causes the amount of said protein in the treated plant cell to be lower than that in an untreated plant cell.

[0240] In one embodiment, the invention relates to the method as described above, said nucleic acid sequence deemed non-coding (i.e. not naturally translated) being: the 5'IITR region; the 3'IITR region; or an intron.

[0241] In one embodiment, the invention relates to the method as described above, wherein said cPEP is produced outside said plant cell before being introduced into said plant cell.

[0242] In one embodiment, the invention relates to the method as described above, wherein said cPEP is a synthetic peptide.

[0243] In one embodiment, the invention relates to the method as described above, wherein said cPEP is an isolated peptide.

[0244] In one embodiment, the invention relates to the method as described above, wherein said cPEP is a recombinant peptide.

[0245] In one embodiment, the invention relates to the method as described above, wherein said cPEP is a hydrophobic peptide or a hydrophilic peptide.

[0246] In one embodiment, the invention relates to the method as described above, wherein said cPEP is introduced into said plant cell in the form of a nucleic acid encoding said cPEP. In particular, the invention relates to the method as described above, wherein said cPEP is introduced into said plant cell in the form of a nucleic acid encoding said cPEP and comprising the means for expressing it.

[0247] In one embodiment, the invention relates to the method as described above, wherein said protein is naturally present in said plant cell.

[0248] In one embodiment, the invention relates to the method as described above, wherein said protein is not naturally present in said plant cell. In particular, the invention relates to the method as described above, wherein said protein is encoded by a transgene artificially introduced into said plant cell. In particular, the invention relates to the method as described above, wherein said protein is encoded by a vector artificially introduced into said plant cell.

[0249] In one embodiment, the invention relates to the method as described above, in which the accumulation of said protein is determined via the implementation of a technique chosen from: Western blot, measurement of enzymatic activity, mass spectrometry and translational fusion. In particular, the invention relates to the method as described above, in which the accumulation of said protein is determined via the implementation of a Western blot.

[0250] In one embodiment, the invention relates to the method as described above, wherein said cPEP has a size of 4 to 41 amino acids, 5 to 40 amino acids, 7 to 20 amino acids or more particularly a size of 8 to 15 amino acids. In particular, said cPEP has a size of 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70 amino acids.

[0251] In one embodiment, the invention relates to the procedure as previously described, wherein said plant cell or said plant belongs to: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis, Arabidopsis, Arabidopsis, Arablyopsis halleri, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rapeseed), Brassica oleracea, Brassica rapa (rapeseed), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine maxine (Glycine maximus), Gopisyium, Gopisyiumpi spp. (cotton), Hordeum vulgare (barley), Lollium spp., Lotus japonicus (lotier), Medicago sativa (alfalfa), Medicago truncatula (alfalfa), Nicotiana benthamiana (tobacco), Oryza sativa (rice), Pisum sativum (peas), Raphanus sativus, Solanum lycopersi (melon), Solanum (melon), Solanum tuberosum (potato), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0252] In particular, the invention relates to the method as described above, wherein said plant cell is a cell of an algae.

[0253] In one embodiment, the invention relates to the method as described above, wherein said protein is encoded by a gene selected from: Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1, Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Fve, Ga2ox7, Gape, Gcn2, Gdi2, Gln2, Gsl3, Hag 5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkkô, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Ros1, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Topp6, TubB6, TubB8, Ubala, Vim3, Sgr1, Abi5, Hsp101, Rh10 and l / l / us.

[0254] In view of the above, it is understood that in another embodiment, the invention relates to the method as described previously comprising a step of introducing: a cPEP; or a nucleic acid encoding said cPEP and the means for expressing it, in said plant cell, the introduction of said cPEP resulting in a modulation of the quantity of said protein in said plant cell, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a non-naturally translated fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein, said protein being encoded by a gene chosen from: Aae15, Aae16, abcg11, Abdcg34, Acc1, Agb1,Als, Anac076, Apg9, Arlbl, Arr1, Arr5, Arr6, At59, Bak1, Bccpl, Bccp2, Bri1, Bzo2h3, Cesaô, Cipk3, Cks1, Cobl8, Coi1, Cpk3, Crk34, Cyp705a18, Cyp71b26, Cyp78a8, Cyp97b3, Dell, Dur3, Ein2, Emb175, Emb2726, Emb9, Epsps, Fnr1, Fve, Ga2ox7, Gape, Gcn2, Gdi2, Gln2, Gsl3, Hag5, Hda18, Hexol, Hppd, Hsl1, Iaa31, Iqd28, Jac1, Jar1, Kp1, Lrx2, Mapkkk3, Mapkkkô, Mfp2, Mrb1, Nsp1, Pds, Pen3, Phyb, Pif 3, Pizza, Ppoxl, Ppox2, Prp39, PsbA, Pskrl, Rd21, Ringl, Rosi, Rpt4a, Sfr6, Shr, Shy2, Ski, Sps1, Spt, Stn8, Tap46, Toppô, TubB6, TubB8, Ubala, Vim3, Sgr1, Abi5, Hsp101, RhIO and Wus.,

[0255] In one embodiment, the invention relates to the method as described above, in which said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175.

[0256] In one embodiment, the invention relates to the method as described above, wherein said protein is encoded by an ORF comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0257] In particular, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention relates to the method as described above, in which said protein is encoded by a gene comprising a nucleic acid sequence having at least 80% identity, preferably at least 90% identity, with a sequence chosen from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0258] In one embodiment, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 1 to 161 and 171 to 175. In one embodiment, the invention also relates to the method as described above, wherein said protein is encoded by a gene comprising a nucleic acid sequence selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3), SEQ ID NOs: 61 to 79 (Dell) and SEQ ID NOs: 109 to 134 (Nsp1).

[0259] In particular, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 26 to 55 (Cpk3). In particular, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 61 to 79 (Dell). In particular, the invention relates to the method as described above, wherein said protein is encoded by a gene comprising one selected from the sequences: SEQ ID NOs: 109 to 134 (Nsp1).

[0260] In another embodiment, the invention relates to the method as described above, wherein said cPEP is selected from the sequences: SEQ ID NOs: 162 to 164. In another embodiment, the invention relates to the method as described above, wherein said protein is involved in at least one plant phenotype selected from: size, shape, surface area, volume, mass and number of leaves; size, shape, surface area, volume, mass and number of flowers; size of the stem (or floral stalk); root biomass; number, length and branching level of roots; earliness of germination; earliness of budding; earliness of floral induction (or floral transition); germination vigor and duration of juvenile phase; duration of flowering; resistance to biotic stress; resistance to abiotic stress; and number of cells.

[0261] In one embodiment, the invention relates to the method as described above, wherein the introduction of said cPEP results in early bolting in said plant.

[0262] In one embodiment, the invention relates to the method as described above, wherein the introduction of said cPEP results in early flowering in said plant.

[0263] In one embodiment, the invention relates to the method as described above, wherein the introduction of said cPEP results in an increase in stem size in said plant.

[0264] In one embodiment, the invention relates to the method as described above, wherein the introduction of said cPEP results in earliness of stem growth in said plant.

[0265] The inventors have indeed unexpectedly found that it is possible to directly apply a cPEP to the plant, e.g. via the use of the composition of the invention (see above) comprising a cPEP, to modulate the accumulation of a target protein in the plant, which indicates that the cPEP is taken up by the plant. Consequently, in one embodiment, the invention relates to the method as described above, in which said cPEP is introduced into said plant: by watering, by spraying or by adding a fertilizer, a potting soil, a growing substrate or a support in contact with the plant, said cPEP being in particular administered to the plant in the form of a composition comprising 10' 9 M to 10' 4M of said cPEP; by watering, by soaking, by spraying or by adding a fertilizer, a potting soil, a growing substrate or a support in contact with the plant, said cPEP being in particular administered to a seed or a seed in the form of a composition comprising 10' 9 M to 10' 4 M of said cPEP; or by means of a nucleic acid encoding said cPEP and comprising the means for expressing said cPEP, said nucleic acid being artificially introduced into the plant.

[0266] In one embodiment, the invention relates to the method as defined above, in which said cPEP is artificially introduced externally into the plant, preferably by watering, by spraying or by adding a fertilizer, a potting soil, a growing substrate or an inert support.

[0267] In one embodiment, the invention relates to the method as defined above, in which said cPEP is introduced by watering.

[0268] In one embodiment, the invention relates to the method as defined above, in which said cPEP is introduced by spraying.

[0269] In one embodiment, the invention relates to the method as defined above, in which said cPEP is introduced by the addition of a fertilizer.

[0270] In one embodiment, the invention relates to the method as defined above, in which the plant is treated with a composition comprising 10' 9 M to 10' 4 M of said cPEP, or including in particular 10' 9 M, 10' 8 M, 10' 7 M, 10' 6 M, 10' 5 M or 10' 4 M of said cPEP. Preferably, the compositions have a concentration of 10' 8 M to 10' 5M for application by watering or spraying on the plant.

[0271] In a complementary manner, more or less concentrated compositions can be considered to treat the plant with cPEP. For example, and in a non-limiting manner, more concentrated compositions comprising 10' 1 M to 10' 3 M, or including in particular 10' 2 M of cPEP, can be used in the case where the artificially introduced cPEP externally is administered to the plant by spreading.

[0272] In another aspect, the invention relates to a modified plant containing a cPEP, which "modified plant" corresponds to a plant into which a cPEP has been artificially introduced, in particular by watering, by spraying or via a fertilizer.

[0273] In one embodiment, the invention relates to the modified plant comprising a cPEP artificially introduced by exogenous means as described above, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA coding for said protein.

[0274] In one embodiment, the invention relates to the modified plant as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0275] In one embodiment, the invention relates to the modified plant as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.In one embodiment, the invention relates to the modified plant as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0276] In one embodiment, the invention therefore relates to the modified plant as described above, in which said fragment comprises an initiator codon AUG coding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the modified plant as described above, in which said fragment is devoid of an initiator codon AUG coding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0277] In one embodiment, the invention relates to the modified plant as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0278] In one embodiment, the invention relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0279] In one embodiment, the invention relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the modified plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0280] In one embodiment, the invention relates to a modified plant comprising an artificially introduced cPEP by exogenous means, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, eg intron); and a part located within a nucleic acid sequence known to be coding ( / .e. naturally translated, egexon); said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0281] In a way of realization, the invention concerns the modified plant described previously, with the following plants: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis lyrata, Arabidopsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rape), Brassica oleracea, Brassica rapa (rape), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soya), Gossypium raimondii, Gossypium spp. (coton), Hordeum vulgare (orge), Lollium spp., Lotus japonicus (lotier), Medicago sativa (luzerne), Medicago truncatula (luzerne), Nicotiana benthamiana (tabac), Oryza sativa (riz), Pisum sativum (pois), Raphanus sativus, Solanum lycopersicum (tomate), Solanum melongena (aubergine), Solanum tuberosum (pomme de terre), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0282] In another aspect, the invention relates to a transgenic plant comprising a nucleic acid encoding a cPEP and the means for expressing it, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0283] In one embodiment, the invention relates to the transgenic plant as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0284] In one embodiment, the invention relates to the transgenic plant as described above, in which said fragment lacks: the initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0285] In one embodiment, the invention relates to the transgenic plant as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; or a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0286] In one embodiment, the invention therefore relates to the transgenic plant as described above, in which said fragment comprises an initiator codon AUG coding an initiator methionine and is devoid of a STOP codon chosen from the codons: UAG, UGA and UAA. The invention also relates to the transgenic plant as described above, in which said fragment is devoid of an initiator codon AUG coding an initiator methionine and comprises a STOP codon chosen from the codons: UAG, UGA and UAA.

[0287] In one embodiment, the invention relates to the transgenic plant as described above, in which said fragment comprises: an initiator codon AUG coding an initiator methionine; and a STOP codon chosen from the codons: UAG, UGA and UAA, and in which said fragment is chosen: either in the same reading frame as the open reading frame coding said protein; or in a reading frame shifted by one or two nucleotides relative to the open reading frame coding said protein.

[0288] In one embodiment, the invention relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in the same reading frame as the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in the reading frame determined by the initiation codon of the open reading frame of said protein.

[0289] In one embodiment, the invention relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame different from the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In particular, the invention relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one nucleotide in 3' (or two nucleotides in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell.In particular, the invention also relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by two nucleotides in 3' (or one nucleotide in 5') relative to the open reading frame of the nucleic acid sequence naturally translated in said plant cell. In other words, the invention relates to the transgenic plant as described above, in which the translation of the pre-mRNA fragment is carried out in a reading frame shifted by one (or two nucleotides in 5') or two nucleotides in 3' (or one nucleotide in 5') relative to the initiation codon of the open reading frame of the nucleic acid sequence naturally translated in said plant cell.

[0290] In one embodiment, the invention relates to a transgenic plant comprising a nucleic acid encoding a cPEP and the means for expressing it, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence of a pre-mRNA of a protein, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41, and said nucleic acid sequence comprising two contiguous parts: a part located within a nucleic acid sequence known to be non-coding ( / .e. not naturally translated, eg intron); and a part located within a nucleic acid sequence known to be coding ( / .e. naturally translated, egexon); said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

[0291] In one embodiment, the invention relates to the transgenic plant as defined above, in which the sequence coding for said cPEP is shorter than the sequence of the pre-mRNA coding for said protein.

[0292] In a way of realization, the invention concerns the transgenic plant as described previously, with the following plants: Alopecurus myosuroides, Amaranthus hypochondriacus, Amaranthus palmeri, Amaranthus tuberculatus, Arabidopsis halleri, Arabidopsis lyrata, Arabidopsis lyrata, Arabidopsis thaliana, Barbarea vulgaris, Boechera stricta, Brachypodium distachyon, Brassica napus (rape), Brassica oleracea, Brassica rapa (rape), Camelina sativa, Capsella grandiflora, Capsella rubella, Carica papaya, Eutrema salsugineum, Glycine max (soya), Gossypium raimondii, Gossypium spp. (coton), Hordeum vulgare (orge), Lollium spp., Lotus japonicus (lotier), Medicago sativa (luzerne), Medicago truncatula (luzerne), Nicotiana benthamiana (tabac), Oryza sativa (riz), Pisum sativum (pois), Raphanus sativus, Solanum lycopersicum (tomate), Solanum melongena (aubergine), Solanum tuberosum (pomme de terre), Thellungiella halophila, Theobroma cacao, Triticum spp.(wheat), Vitis vignifera (vine) and Zea mays (corn).

[0293] In one embodiment, the invention relates to the transgenic plant as described above, wherein the expression of said cPEP is placed under the control of a strong promoter, preferably a constitutive strong promoter such as the 35S promoter.

[0294] In any respect, it should be noted that the various aspects of the invention, as well as the various embodiments thereof, are interdependent. The latter may therefore be combined with each other to obtain preferred aspects and / or embodiments of the invention not explicitly described. This is also valid for all the definitions provided in the present description, which applies to all aspects of the invention and its embodiments.

[0295] Further, the present invention is illustrated, but not limited to, the following Figures and Examples.

[0296] LIST OF FIGURES

[0297] Figure 1

[0298] Figure 1 is a schematic representation illustrating the first steps of the process for preparing and determining a cPEP. In particular, the steps are illustrated to determine within a pre-mRNA of a protein one of the nucleic acid sequences known to be non-coding from which the peptide to be tested (i.e. the potential cPEP) is identified.

[0299] The sequences SEQ ID NOs: 165 to 168 are provided for example purposes only.

[0300] Figure 2

[0301] Figure 2 is a schematic representation of the A / SP7-GUS construct expressed in transformed Medicago truncatula root.

[0302] The NSP1 promoter region, the NSP1 CDS, the β-glucuronidase (GUS) gene, and the NSP1 3'UTR region are indicated on the construct sequence. The cPEP peptides are positioned above the regions that were used to construct each of the cPEPs.

[0303] Figure 3

[0304] Figure 3 represents the effect of cPEP NSP1-5'UTR-10 on the accumulation of NSP1-GUS fusion protein in Medicago truncatula.

[0305] The y-axis represents the quantification of GUS activity in roots of an NSP1-GUS fusion in response to treatment for 5 days with 0.1 μM of a cPEP targeting the 5'UTR region of the NSP1 gene. Error bars represent SEM, asterisks indicate a significant difference between the test condition and the control according to Student's t-test (n = 30, p < 0.05).

[0306] Figure 4

[0307] Figure 4 represents the effect of cPEP NSP1-3'UTR-10 on the accumulation of NSP1-GUS fusion protein in Medicago truncatula.

[0308] The y-axis represents the quantification of GUS activity in roots of an NSP1-GUS fusion in response to treatment for 5 days with 0.1 μM of a cPEP targeting the 5'UTR region of the NSP1 gene. Error bars represent SEM, asterisks indicate a significant difference between the test condition and the control according to Student's t-test (n = 30, p < 0.05).

[0309] EXAMPLES

[0310] Materials & Methods

[0311] 1. Preparation of cPEPs

[0312] The sequence SEQ ID NO: 163 of cPEP NSP1-5'UTR-5 (5 amino acids) was obtained by translating a 15-nucleotide fragment located in the 5'UTR portion of the NSP1 pre-mRNA (SEQ ID NO: 169) in the +3 reading frame relative to the initiation codon of the nsp1 protein.

[0313] The sequence SEQ ID NO: 162 of cPEP NSP1-5'UTR-11 (11 amino acids) was obtained by translating a 30-nucleotide fragment located in the 5'UTR portion of the NSP1 pre-mRNA (SEQ ID NO: 169) in the +3 reading frame relative to the initiation codon of the nsp1 protein. The sequence SEQ ID NO: 164 of cPEP NSP1-3'UTR (10 amino acids) was obtained by translating a 30-nucleotide fragment located in the 3'IITR portion of the NSP1 pre-mRNA (SEQ ID NO: 169) in the +2 reading frame relative to the initiation codon of the nsp1 protein.

[0314] Each peptide was synthesized (Smartox Biotech) and diluted to 10 mM in water.

[0315] 2. Construction of the plasmid

[0316] The NSP1::GUS fusion was performed, using a modified pCambia vector (Lauressergues et al., Nature, 520:90-3, 2015), by cloning 3 kb of NSP1 promoter, the coding sequence of the NSP1 gene, the coding sequence of the GUS protein and 3 kb of the sequence downstream of the NSP1 gene (Figure 2).

[0317] 3. Plant transformation

[0318] Root transformation of M. truncatula was carried out according to the method described in Boisson-Dernier et al., Mol Plant Microbe Interact, 14(6): 695-700, 2001.

[0319] 4. Measurement of gene expression

[0320] Plants were treated by watering with a solution containing a low concentration of cPEPs (from 0.1 pM to 10 pM) or with water.

[0321] The accumulation of the cPEP-targeted protein was then measured in each plant by quantifying GUS activity or by quantifying protein activity by Western blotting (Blàzquez M., Quantitative GUS activity assay in intact plant tissue, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, USA, 2002).

[0322] Results

[0323] cPEPs targeting the 5'UTR (SEQ ID NO: 162) and 3'UTR (SEQ ID NO: 164) non-coding regions of the NSP1 gene induce increased NSP1 protein accumulation in Medicago truncatula, regardless of the reading frame used to elaborate the cPEP and regardless of the position of the fragment used to elaborate the cPEP (Figures 3 and 4).

Claims

CLAIMS Method for preparing and determining a cPEP, said cPEP: having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids; being capable of modulating the accumulation of a protein in a plant cell; and not being capable of modulating the accumulation of the mRNA encoding said protein, said method comprising: a. a step of determining the nucleic acid sequence of the pre-messenger RNA (pre-mRNA) encoding said protein; b. a step of determining within this pre-mRNA one of the nucleic acid sequences deemed non-coding; c. a step of determining within this nucleic acid sequence deemed non-coding a fragment thereof, said fragment having a size of 3n nucleotides, n being from 4 to 70, in particular n being from 4 to 41; d. a step of producing the peptide encoded by said fragment; and e. a comparison step: - between the accumulation of said protein in a plant cell in the presence of said peptide and the accumulation of said protein in a plant cell of the same type in the absence of said peptide; and / or - between the phenotype of a plant in the presence of said peptide and the phenotype of a plant of the same type in the absence of said peptide, in which: - a difference in the amount of said protein in the presence of said peptide compared to the amount of said protein in the absence of said peptide; and / or - a difference in the phenotype in the presence of said peptide compared to the phenotype in the absence of said peptide, indicates that said peptide is a cPEP capable of modulating the accumulation of said protein in a plant cell. cPEP, of 4 to 70 amino acids, in particular of 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in a plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein. Nucleic acid encoding a cPEP according to claim 2. Composition comprising a cPEP as an active substance, said cPEP: - having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein; - being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein; and - being in particular at a concentration of from 5 pM to 500 pM or from 30 pM to 70 pM, or being in particular at a concentration of 50 pM. Composition according to claim 4, said composition being a phytopharmaceutical composition, a herbicidal composition or a coating composition, in particular said coating composition further comprising at least one fixing agent. Coated seed comprising a plant seed, said plant seed being coated with a coating composition according to claim 5. Use of a cPEP as a phytosanitary agent for modulating the accumulation of a protein in a plant cell, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA coding said protein.A method for modulating the accumulation of a protein in a plant cell comprising a step of introducing: a cPEP; or a nucleic acid encoding said cPEP and the means for expressing it, into said plant cell, the introduction of said cPEP resulting in a modulation of the quantity of said protein in said plant cell, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein. Method according to claim 8, said method making it possible to: promote the development of a plant; or slow down or prevent the development of a plant.Modified plant comprising a cPEP artificially introduced by exogenous means as described above, said cPEP having a size of 4 to 70 amino acids, in particular 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein. said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein. Transgenic plant comprising a nucleic acid encoding a cPEP and the means for expressing it, said cPEP having a size of from 4 to 70 amino acids, in particular from 4 to 41 amino acids, the amino acid sequence of which corresponds to the translation via the genetic code of a fragment of a nucleic acid sequence known to be non-coding present on a pre-mRNA of a protein, said cPEP being capable of modulating the accumulation of said protein in the plant cell and not being capable of modulating the accumulation of the mRNA encoding said protein.

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