Salt stress regulation gene osdnr1 of rice and application thereof

Abstract

This invention discloses rice salt stress regulatory genes. OsDNR1 Its applications. This invention belongs to the field of biotechnology, specifically relating to rice salt stress regulatory genes. OsDNR1 And its applications. The present invention provides a method for cultivating plants with altered salt tolerance, comprising the following steps: 1) inhibiting, reducing, or silencing the expression level of protein-coding genes in the recipient plant, and / or inhibiting, reducing, or silencing the activity and / or content of protein-coding genes, to obtain plants with increased salt tolerance; 2) increasing, enhancing, and / or upregulating the expression level of protein-coding genes in the recipient plant, and / or increasing, enhancing, and / or upregulating the activity and / or content of protein-coding genes, to obtain plants with decreased salt tolerance. OsDNR1 After CRISPR gene editing and knockout, followed by salt stress treatment osdnaj The knockout mutant exhibits a salt-tolerant phenotype, indicating that... OsDNR1 Genes play an important role in regulating salt tolerance in rice.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to rice salt stress regulatory genes. OsDNR1 And its applications. Background Technology

[0002] As one of the world's most important food crops, the stability of rice yields is crucial to food security. However, with the continued intensification of global warming, soil salinization is becoming increasingly serious, posing a severe threat to monocotyledonous crops, including rice.

[0003] High salinity environments induce osmotic stress by lowering soil water potential, preventing rice roots from absorbing sufficient water from the soil. This leads to plant cell dehydration and decreased turgor pressure, thus inhibiting growth. Simultaneously, the excessive accumulation of sodium and chloride ions caused by salt stress not only directly interferes with cellular physiological functions but also results in the loss of key mineral ions such as potassium and calcium ions, disrupting intracellular ion balance and signal transduction. Furthermore, salt stress-induced reactive oxygen species (ROS) accumulation triggers oxidative stress, damaging cell membrane systems, proteins, and genetic material, further weakening the physiological activity and stress resistance of rice. To counter these adverse effects, rice adapts to salt stress through a series of complex mechanisms. Its osmotic regulation mechanism helps plant cells maintain water balance by accumulating solute molecules such as proline, betaine, and soluble sugars; its ion homeostasis regulation mechanism enhances the activity of ion pumps and transport proteins (such as the SOS1, NHX, and HKT families) to expel toxic ions from the cell or isolate them in vacuoles, preventing ion poisoning. Furthermore, rice activates its antioxidant defense system (such as increasing the activity of glutathione and antioxidant enzymes) to scavenge excess reactive oxygen species and mitigate oxidative damage. At the stress signaling level, rice enhances its salt tolerance by expressing stress-resistance genes and activating signaling pathways (such as ABA, MAPK, and ROS signaling) to regulate downstream functional genes and metabolic networks. These regulatory mechanisms work together to enable rice to maintain relatively normal growth and development under salt stress conditions.

[0004] In rice, 迟钝氮响应1 ( DNR1 The gene encodes one type of aminotransferase. Phylogenetic analysis indicates... DNR1 with Arabidopsis VAS1 Homologous, the latter encodes an aminotransferase that catalyzes the conversion of indole-3-pyruvate to L-tryptophan, thereby antagonizing auxin biosynthesis. DNR1 It is mainly expressed in the roots, leaves, and nodes of rice, and the application of nitrogen fertilizer can increase its efficiency. DNR1 The expression of . Studies have shown that external nitrogen sources regulate . DNR1 The expression level of genes can be altered to change the auxin content in rice, thereby affecting the response genes of the auxin signaling pathway. OsARFsThe ability to activate downstream nitrogen metabolism-related genes ultimately enables the regulation of nitrogen fertilizer utilization efficiency in rice. DNR1 The promoter sequence differs by 520 bp between the indica and japonica subspecies. DNR1 indica Low expression of alleles leads to increased auxin content in indica rice, resulting in a higher nitrogen fertilizer absorption rate and utilization capacity. This was observed in japonica rice varieties and... DNR1 The knockout lines were planted in fields with different nitrogen fertilizer levels. DNR1 Knockout lines can increase production by 8%-25%, which indicates that DNR1 It has great application potential and value in improving the nitrogen fertilizer utilization rate of japonica rice. However, OsDNR1 Whether it participates in the rice's salt stress response is unclear. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to regulate the salt tolerance of plants to obtain rice varieties with strong salt tolerance.

[0006] To address the problems existing in the prior art, the present invention provides a method for cultivating plants with altered salt tolerance, comprising the following 1) or 2): 1) Inhibit or reduce or silence the expression level of protein-coding genes in recipient plants, and / or inhibit or reduce or silence the activity and / or content of protein-coding genes to obtain plants with improved salt tolerance. 2) Increase, enhance and / or upregulate the expression level of protein-coding genes in recipient plants, or / and increase, enhance and / or upregulate the activity and / or content of protein-coding genes to obtain plants with reduced salt tolerance. The protein may be any of the following: A1) A protein with the amino acid sequence shown in SEQ ID No:3; A2) A protein obtained by substituting and / or deleting and / or adding amino acid residues of the protein in A1) that has more than 75% identity with the protein shown in A1) and has the ability to regulate plant salt tolerance; for example, those skilled in the art can, based on the amino acid sequence shown in SEQ ID No:3 and conventional techniques such as the conserved substitution of amino acids, obtain a protein mutant with the same function as the amino acid sequence shown in SEQ ID No:3 by substituting, deleting and / or adding one or more amino acids without affecting its activity. A3) A fusion protein obtained by attaching a protein tag to the N-terminus and / or C-terminus of A1) or A2).

[0007] The protein described in A1 above is named OsDNR1. The OsDNR1 protein consists of 394 amino acids.

[0008] To facilitate the purification or detection of the protein in A1), a tag protein can be attached to the amino or carboxyl terminus of the protein, which consists of the amino acid sequence shown in SEQ ID No:3 in the sequence listing.

[0009] The proteins mentioned above can be synthesized artificially, or their encoding genes can be synthesized first and then expressed biologically.

[0010] The tag proteins include, but are not limited to: GST (glutathione thiotransferase) tag protein, His6 tag protein (His-tag), MBP (maltose-binding protein) tag protein, Flag tag protein, SUMO tag protein, HA tag protein, Myc tag protein, eGFP (enhanced green fluorescent protein), eCFP (enhanced cyan fluorescent protein), eYFP (enhanced yellow-green fluorescent protein), mCherry (monomer red fluorescent protein), or AviTag tag protein.

[0011] Those skilled in the art can readily mutate the nucleotide sequence encoding the protein OsDNR1 of this invention using known methods, such as directed evolution or point mutation. Any artificially modified nucleotides that possess 75% or more of the nucleotide sequence identity with the protein OsDNR1 isolated in this invention, provided they encode and function as protein OsDNR1, are derived from and equivalent to the nucleotide sequence of this invention.

[0012] The aforementioned 75% or higher degree of identity can be 80%, 85%, 90%, or 95% or higher degree of identity.

[0013] In this article, identity refers to the similarity of amino acid or nucleotide sequences. The identity of amino acid or nucleotide sequences can be determined using homology search sites on the Internet, such as the BLAST page on the NCBI homepage. For example, in Advanced BLAST 2.1, using blastp as the procedure, setting the Expect value to 10, setting all filters to OFF, using BLOSUM62 as the matrix, setting the Gap existence cost, Per residue gap cost, and Lambda ratio to 11, 1, and 0.85 (default values) respectively, and performing a search to calculate the identity of a pair of amino acid sequences or nucleotide sequences, then the identity value (%) can be obtained.

[0014] In this document, the 80% or more of identity can be at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity.

[0015] In this document, the above 90% identity can be at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity.

[0016] The protein mentioned above is derived from rice ( 水稻 L.).

[0017] In one specific embodiment, a method for cultivating plants with enhanced salt tolerance includes the following steps: inhibiting the expression of nucleic acid molecules encoding the OsDNR1 protein in the target plant to obtain transgenic plants with enhanced salt tolerance.

[0018] The inhibition of the expression of nucleic acid molecules encoding the OsDNR1 protein in the target plant can be achieved by introducing a knockout vector or interference vector that targets the nucleic acid molecules encoding the OsDNR1 protein into the target plant.

[0019] In this paper, the knockout is implemented using the CRISPR / Cas9 system.

[0020] In this article, the gene encoding the protein of the target plant to be knocked out can be made by mutating the gene encoding the protein in the plant genome (nucleotide sequence of SEQ ID No:1) as follows: replacing 5'-GGAGACGGAAGCGCCGG(A)TCATGG-3' in the gene encoding the protein in the plant genomic DNA with 5'-GGAGACGGAAGCGCCGGTCATGG-3' (corresponding to positions 479 to 501 of SEQ ID No:1 and positions 36 to 58 of SEQ ID No:2), thereby knocking out the gene encoding the OsDNR1 protein.

[0021] The purpose of plant breeding described in this article includes cultivating plants with increased / decreased salt tolerance.

[0022] The present invention also provides a method for regulating the salt tolerance of plants, including regulating the activity and / or content of the proteins described above in the target plant, and / or the expression level of the genes encoding the proteins, to regulate the salt tolerance of plants.

[0023] In the above method, regulating the activity and / or content of the protein OsDNR1 in the target plant, and / or the expression level of the gene encoding the protein, includes introducing a gene encoding the protein that inhibits its expression into the recipient plant. OsDNR1 The expressed substance was used to obtain a target plant with altered salt tolerance; OsDNR1 The gene encodes the protein OsDNR1.

[0024] The aforementioned proteins also fall within the scope of protection claimed in this invention.

[0025] The present invention also provides biomaterials related to the above-mentioned proteins, said biomaterials may be any of the following: B1) Nucleic acid molecules that encode the proteins described above; B2) An expression cassette containing the nucleic acid molecule described in B1); B3) A recombinant vector containing the nucleic acid molecule described in B1), or a recombinant vector containing the expression cassette described in B2); B4) Recombinant microorganisms containing the nucleic acid molecules described in B1), or recombinant microorganisms containing the expression cassette described in B2), or recombinant microorganisms containing the recombinant vector described in B3); B5) A transgenic plant cell line containing the nucleic acid molecule described in B1), or a transgenic plant cell line containing the expression cassette described in B2); B6) Transgenic plant tissue containing the nucleic acid molecules described in B1), or transgenic plant tissue containing the expression cassette described in B2); B7) Transgenic plant organs containing the nucleic acid molecules described in B1), or transgenic plant organs containing the expression cassette described in B2); C1) Nucleic acid molecules that inhibit, reduce, or silence the expression of the genes encoding the proteins described above; C2) expresses the gene encoding the nucleic acid molecule described in C1); C3) contains an expression cassette encoding the gene described in C2); C4) A recombinant vector containing the encoding gene described in C2), or a recombinant vector containing the expression cassette described in C3); C5) A recombinant microorganism containing the encoding gene described in C2), or a recombinant microorganism containing the expression cassette described in C3), or a recombinant microorganism containing the recombinant vector described in C4); C6) A transgenic plant cell line containing the encoding gene described in C2), or a transgenic plant cell line containing the expression cassette described in C3), or a transgenic plant cell line containing the recombinant vector described in C4); C7) Transgenic plant tissue containing the encoding gene described in C2), or transgenic plant tissue containing the expression cassette described in C3), or transgenic plant tissue containing the recombinant vector described in C4); C8) A transgenic plant organ containing the encoding gene described in C2), or a transgenic plant organ containing the expression cassette described in C3), or a transgenic plant organ containing the recombinant vector described in C4).

[0026] In the above-mentioned biological materials, the nucleic acid molecule described in B1) may be a gene as shown in E1) or E2) below: E1) The coding sequence is a cDNA molecule or DNA molecule of SEQ ID No:2; E2) The nucleotide sequence is the cDNA molecule or DNA molecule of SEQ ID No:1.

[0027] The DNA molecule shown in SEQ ID No:2 (which regulates plant salt tolerance) OsDNR1 The gene encodes the protein OsDNR1, whose amino acid sequence is SEQ ID No:3.

[0028] The nucleotide sequence shown in SEQ ID No:2 is the nucleotide sequence of the gene encoding protein OsDNR1 (CDS).

[0029] The present invention OsDNR1 Genes can be any nucleotide sequence that encodes the protein OsDNR1. Considering codon degeneracy and the codon preferences of different species, those skilled in the art can use codons suitable for expression in a specific species as needed.

[0030] B1) The nucleic acid molecule may also include a nucleic acid molecule obtained by codon preference modification based on the nucleotide sequence shown in SEQ ID No:2.

[0031] B1) The nucleic acid molecule may also include nucleic acid molecules that have a nucleotide sequence identity of more than 95% with the nucleotide sequence shown in SEQ ID No:2 and originate from the same species.

[0032] The nucleic acid molecules mentioned in this article can be DNA, such as cDNA, genomic DNA, or recombinant DNA; the nucleic acid molecules can also be RNA, such as gRNA, mRNA, siRNA, shRNA, sgRNA, miRNA, or antisense RNA.

[0033] The vectors described herein are known to those skilled in the art and include, but are not limited to: plasmids, bacteriophages (such as λ phage or M13 filamentous phage), granules (i.e., Cos plasmids), Ti plasmids, or viral vectors.

[0034] To facilitate the identification and screening of transgenic plant cells or plants, the plant expression vectors used can be processed, such as by adding genes that can be expressed in plants, encoding enzymes or luminescent compounds that produce color changes (GUS genes, luciferase genes, etc.), antibiotic resistance markers (gentamicin markers, kanamycin markers, etc.), or chemical reagent resistance marker genes (such as herbicide resistance genes). From a safety perspective, transgenic plants can be screened directly under stress without adding any selective marker genes.

[0035] The microorganisms mentioned in this article may be yeast, bacteria, algae, or fungi. Among them, bacteria may originate from the genus *Escherichia* (…). 埃希氏菌属 Erwinia ( 欧文氏菌属 Agrobacterium tumefaciens ( ), Agrobacterium tumefaciens 根癌土壤杆菌 Flavobacterium ( 黄杆菌属 Alcaligenes ( ) 产碱菌属 ), Pseudomonas ( 假单胞菌属 ), Bacillus spp. ( 芽孢杆菌属 (e.g., Agrobacterium tumefaciens EHA105).

[0036] The present invention also provides the use of the protein OsDNR1 described above, or a substance regulating the expression of the gene, or a substance regulating the activity or content of said protein, in any of the following: Application of U1 in regulating plant salt tolerance; Application of U2 in the preparation of products that regulate plant salt tolerance; U3) Applications in cultivating plants with salt tolerance; U4) Applications in the preparation of products that cultivate salt-tolerant plants; U5) Applications in plant breeding.

[0037] In this article, the substance that regulates the activity and / or content of the protein may be a substance that regulates gene expression, wherein the gene encodes the protein OsDNR1.

[0038] In the above applications, the substance that regulates gene expression or the substance that regulates the activity or content of the protein can be a biological material related to the protein, and the biological material can be the biological material described above.

[0039] In the above applications and methods, the regulation can be to increase, enhance, or upregulate. The regulation can also be to inhibit, reduce, or silence.

[0040] In the above applications or methods, the plant is any one of the following: N1) Monocotyledonous or dicotyledonous plants; N2) Plants of the order Poales; N3) Gramineae plants; N4) Rice plants; N5) rice.

[0041] The present invention relates to OsDNR1, a rice salt stress regulator that belongs to the aminotransferase family and regulates nitrogen use efficiency in rice. OsDNR1 After CRISPR gene editing and knockout, compared with the recipient rice Zhonghua 11 (ZH11), the salt stress treatment resulted in... osdnr1 The knockout mutant exhibits a salt-tolerant phenotype, indicating that... OsDNR1 Genes play an important role in regulating rice salt tolerance and are of great significance for improving rice salt tolerance and rice breeding. Attached Figure Description

[0042] Figure 1 Wild-type ZH11 and mutant after treatment with 180 mM NaCl salt stress osdnr1 Phenotypic images were obtained. First, photos were taken before treatment. During treatment, 180 mM NaCl was added to the nutrient solution. Photos were taken 21 days after treatment. Then, during recovery, normal nutrient solution without salt was added, and photos were taken 14 days after recovery.

[0043] Figure 2 homozygous mutant osdnr1 A statistical chart showing the survival rate of wild-type ZH11 three-week-old seedlings after salt stress recovery.

[0044] Figure 3 To obtain ZH11 background using CRISPR / Cas9 technology osdnr1 Mutation type of mutant (abbreviation) osdnr1 This mutant is a loss-of-function mutant. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0046] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0047] Unless otherwise specified, the quantitative experiments in the following examples are all repeated three times, and the results are averaged.

[0048] CRISPR / Cas9 mutants in the following examples -osdnr1 The mutant was purchased from Biogle Gene Technology (Jiangsu) Co., Ltd., product number BG110170A11, purchase website: http: / / biogle.cn / geo / index / geo / val / BG110170A11.

[0049] The japonica rice variety Zhonghua 11 (ZH11, abbreviated as ZH11) in the following examples was purchased from Baige Gene Technology (Jiangsu) Co., Ltd. Zhonghua 11 is a CRISPR / Cas9 mutant. osdnr1 Receptor control material for mutants.

[0050] The nutrient solution B formula in the following examples is as follows: It is prepared by mixing A mother liquor, B mother liquor, EDTA-Fe mother liquor and trace element mother liquor in a ratio of 5:5:1:1 per liter of nutrient solution.

[0051] Among them, 1 L (200×) of mother liquor A contains 9.64 g of (NH4)2SO4, 3.7 g of KNO3, 4.96 g of KH2PO4, 3.18 g of K2SO4 and 29.965 g of MgSO4·7H2O; 1 L (200×) of mother liquor B contains 17.235 g of Ca(NO3)2·4H2O; In 1 L (1000×) of EDTA-Fe mother liquor: first, dissolve 5.57 g FeSO4·7H2O in 200 mL of distilled water, then heat and dissolve 7.45 g Na2EDTA in 200 mL of distilled water. Stir the FeSO4·7H2O solution and Na2EDTA solution continuously, cool, and then bring the volume to 1 L. 1 L (1000×) of trace element mother liquor contains: 2.86 g H3BO4, 0.08 g CuSO4·H2O, 0.22 g ZnSO4·7H2O, 1.81 g MnCl2·4H2O and 0.09 g NaMO4·H2O.

[0052] Add 300 ng sodium silicate per liter of nutrient solution, then adjust the pH to between 5.8 and 6.0 with concentrated hydrochloric acid.

[0053] The following examples used SPSS statistical software to process the data. The experimental results are expressed as mean ± standard deviation. One-way ANOVA was used. P < 0.05 (*) indicates a significant difference, and P < 0.01 (**) indicates a highly significant difference.

[0054] Example 1, CRISPR / Cas9- osdnaj Identification of homozygous mutants In the rice variety Nipponbare, the amino acid sequence of the OsDNR1 protein is shown in SEQ ID No:3. OsDNR1 The genome sequence of the gene is shown in SEQ ID No:1. OsDNR1 The coding sequence (CDS) of the gene is shown in SEQ ID No:2.

[0055] Rice purchased from Baige Gene Technology (Jiangsu) Co., Ltd. osdnaj mutants only OsDNR1 The gene has mutated. Since the purchased mutant is not homozygous, it is necessary to identify a homozygous mutant.

[0056] Pick osdnaj DNA was extracted from the leaves of the mutant. Leaf DNA extraction was performed according to the CTAB method: Rice leaves were placed in 2.0 mL centrifuge tubes, and steel balls were added to grind them into powder using a grinder. 400 µL of CTAB extraction buffer was added to the centrifuge tube and vortexed to mix. An equal volume of a 1:1 mixture of chloroform and phenol was added, vortexed to mix, and centrifuged at 12000 rpm for 10 min. 200 µL of the supernatant was collected, and an equal volume of chloroform was added. The mixture was vigorously vortexed to mix, and centrifuged at 12000 rpm for 10 min. 100 µL of the supernatant was collected, and twice the volume of anhydrous ethanol was added to precipitate at 0℃ for 10 min. The mixture was then centrifuged at 12000 rpm for 10 min at 4℃. The supernatant was discarded, and the mixture was washed twice with 500 µL of 75% ethanol, dried, and dissolved in 30 µL of ddH2O.

[0057] Using the extracted DNA as a template, OsDNR1 Gene-specific primers were used for PCR amplification. The primer sequences were F: 5'-TGTTCTTGGAGGGGTGAGGA-3'; R: 5'-TCCTTGTTCCCTCGAAGCAA-3'. The PCR reaction program was: 94℃ pre-denaturation for 2 min; 94℃ denaturation for 30 s, 56℃ annealing for 30 s, 72℃ extension for 30 s, 35 cycles; 72℃ extension for 5 min. The PCR products were then subjected to Sanger sequencing to check for mutations at the target site.

[0058] The final identification will be obtained OsDNR1 Transgenic plants with gene mutations are named osdnaj Comparison OsDNR1 The DNA sequence of the gene (nucleotide sequence is SEQ ID No:1), and its mutation sites are as follows: Figure 3 As shown.

[0059] Sequencing analysis revealed that, compared to the genomic DNA of rice Nipponbare, osdnajIn both homologous chromosomes of the plant, the gene encoding the OsDNR1 protein underwent the following mutation: "5'-GGAGACGGAAGCGCCGGTCATGG-3' (corresponding to positions 479-501 of SEQ ID No:1 and positions 36-58 of SEQ ID No:2)" was mutated to "5'-GGAGACGGAAGCGCCGG(A)TCATGG-3'", that is, an "A" base was inserted; this caused a frameshift mutation in OsDNR1, prematurely terminating the protein OsDNR1 at amino acid position 46 of SEQ ID No:3, resulting in its loss of function, thereby knocking out the gene encoding the OsDNR1 protein.

[0060] Example 2 osdnaj Salt tolerance analysis of mutants Samples to be tested: wild-type ZH11 and osdnaj mutant materials Rice seedlings were cultured as follows: Well-developed and plump seeds were selected and soaked in distilled water in a 37°C incubator for 48 hours, with the water changed every 12 hours. Germination was then continued for 24 hours under a humid environment. Seeds with uniform germination were selected and placed in bottomless 96-well plates, then placed in culture boxes containing Kimura B rice nutrient solution. Greenhouse growing conditions were 12 hours light / 12 hours darkness at 28°C. The rice nutrient solution was replaced with fresh solution every 3 days during the cultivation process.

[0061] wild-type ZH11 and osdnaj After three weeks of growth, the mutant material was subjected to 180 mM NaCl stress treatment. After 21 days of treatment, photos were taken of the treated and untreated materials. Then, a recovery treatment was initiated, and photos were taken 14 days later. Figure 1 As shown, where Figure 1 In osdnaj express OsDNR1 The mutant strain, ZH11, represents the wild-type ZH11. After 14 days of recovery treatment, the genetic mutations of ZH11 and... osdnaj Survival rate, such as Figure 2 As shown.

[0062] The results showed that the survival rate of ZH11 was approximately 21.1%, while osdnr1 The survival rate was approximately 86.3%, indicating that... OsDNR1 The loss of this function enhances the plant's tolerance to salt stress. Therefore, it can be seen that... OsDNR1 It plays a negative regulatory role in the plant's response to salt stress.

[0063] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. Methods for cultivating plants with altered salt tolerance, including the following 1) or 2): 1) Inhibit or reduce or silence the expression level of protein-coding genes in recipient plants, and / or inhibit or reduce or silence the activity and / or content of protein-coding genes to obtain plants with improved salt tolerance. 2) Increase, enhance and / or upregulate the expression level of protein-coding genes in recipient plants, or / and increase, enhance and / or upregulate the activity and / or content of protein-coding genes to obtain plants with reduced salt tolerance. The protein is any of the following: A1) A protein with the amino acid sequence shown in SEQ ID No:3; A2) A protein that has more than 80% identity with and has the same function as the protein shown in A1) obtained by substituting and / or deleting and / or adding amino acid residues of the protein in A1). A3) A fusion protein obtained by attaching a protein tag to the N-terminus and / or C-terminus of A1) or A2).

2. The method according to claim 1, characterized in that: The protein is derived from rice ( Oryza sativa L.).

3. A method for regulating the salt tolerance of plants, characterized in that: This includes regulating the activity and / or content of the protein described in claim 1 in the recipient plant, and / or the expression level of the gene encoding the protein described in claim 1, to regulate the plant's salt tolerance.

4. The method according to claim 3, characterized in that: The regulation includes introducing a substance into the recipient plant that inhibits the expression of the gene encoding the protein, thereby obtaining a target plant with a higher salt tolerance than the recipient plant; the gene encoding the protein as described in claim 1.

5. The protein in any of the methods described in claims 1-4.

6. The use of the protein of claim 5, or a substance that regulates the activity or content of said protein, or regulates the expression of the gene encoding said protein, in any of the following: 1) Application in regulating plant salt tolerance; 2) Application in the preparation of products that regulate plant salt tolerance; 3) Applications in cultivating plants with altered salt tolerance; 4) Applications in the preparation of products containing plants with altered salt tolerance; 5) Applications in plant breeding.

7. The application according to claim 6, characterized in that: The substance that regulates the activity or content of the protein or regulates the expression of the gene encoding the protein is a biological material related to the protein of claim 5, wherein the biological material is any one of the following: B1) A nucleic acid molecule encoding the protein of claim 5; B2) An expression cassette containing the nucleic acid molecule described in B1); B3) A recombinant vector containing the nucleic acid molecule described in B1), or a recombinant vector containing the expression cassette described in B2); B4) Recombinant microorganisms containing the nucleic acid molecules described in B1), or recombinant microorganisms containing the expression cassette described in B2), or recombinant microorganisms containing the recombinant vector described in B3); B5) A transgenic plant cell line containing the nucleic acid molecule described in B1), or a transgenic plant cell line containing the expression cassette described in B2); B6) Transgenic plant tissue containing the nucleic acid molecules described in B1), or transgenic plant tissue containing the expression cassette described in B2); B7) Transgenic plant organs containing the nucleic acid molecules described in B1), or transgenic plant organs containing the expression cassette described in B2); C1) A nucleic acid molecule that inhibits, reduces, or silences the expression of the gene encoding the protein of claim 5; C2) expresses the gene encoding the nucleic acid molecule described in C1); C3) contains an expression cassette containing the gene encoding described in C2); C4) A recombinant vector containing the encoding gene described in C2), or a recombinant vector containing the expression cassette described in C3); C5) A recombinant microorganism containing the encoding gene described in C2), or a recombinant microorganism containing the expression cassette described in C3), or a recombinant microorganism containing the recombinant vector described in C4); C6) A transgenic plant cell line containing the encoding gene described in C2), or a transgenic plant cell line containing the expression cassette described in C3), or a transgenic plant cell line containing the recombinant vector described in C4); C7) Transgenic plant tissue containing the encoding gene described in C2), or transgenic plant tissue containing the expression cassette described in C3), or transgenic plant tissue containing the recombinant vector described in C4); C8) A transgenic plant organ containing the encoding gene described in C2), or a transgenic plant organ containing the expression cassette described in C3), or a transgenic plant organ containing the recombinant vector described in C4).

8. The application according to claim 7, characterized in that: B1) The nucleic acid molecule described is a gene as shown in E1) or E2) below: E1) The coding sequence is a cDNA molecule or DNA molecule of SEQ ID No:2; E2) The nucleotide is a cDNA molecule or DNA molecule of SEQ ID No:

1.

9. The biomaterial as described in claim 7 or 8.

10. The method according to any one of claims 1-4, or the application according to any one of claims 6-8, characterized in that: The plant is any one of the following: N1) Monocotyledonous or dicotyledonous plants; N2) Plants of the order Poales; N3) Gramineae plants; N4) Rice plants; N5) rice.

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