Corn plant height and ear height regulation gene and application thereof

Abstract

The invention discloses a corn plant height and spike height regulation gene and application thereof, belongs to the technical field of plant biology, and particularly relates to application of a ZmTCP gene in regulation of corn plant height and spike height. According to the gene for regulating and controlling the plant height and the ear position height of the corn provided by the invention, after endogenous ZmTCP4, ZmTCP14, ZmTCP16 and ZmTCP25 genes of the corn plant are mutated, the plant has a phenotype that the plant height and / or the ear position height is reduced. The gene resource provided by the invention and the application thereof have huge application value in the field of corn density-tolerant lodging-resistant breeding.

Description

Technical Field

[0001] The present invention belongs to the field of plant biotechnology, and particularly relates to ZmTCP the application of a gene in regulating the plant height and ear height of maize. Background Art

[0002] Reasonably increasing the maize planting density is one of the effective ways to improve the maize yield per unit area. However, dense planting triggers the shade avoidance response of plants (such as increased plant height and ear height, poor lodging resistance, decreased seed setting rate, etc.), ultimately leading to a reduction in yield. Therefore, cultivating ideal plant type varieties with tolerance to dense planting, high photosynthetic efficiency, and suitability for mechanized operation is the most important technical measure to increase the maize yield per unit area.

[0003] The "Green Revolution" is of great significance to agricultural production. It is generally believed that maize dwarfing breeding is also one of the development directions of future maize breeding. However, most dwarf mutants in maize have adverse phenotypes such as reduced yield or even no yield, making it difficult to apply them in agricultural production. During the research process, the inventors of the present application used CRISPR / Cas9 technology to knockout the endogenous ZmTCP4, 14、16、25 gene, and observed phenotypes such as plant height and ear height in the maize mutant plants. It was unexpectedly found that ZmTCP4, 14, 16、25 the gene mutation has the function of reducing the plant height and ear height of maize, and has no adverse effects on other agronomic traits. The research results provide a theoretical basis for the genetic improvement of maize tolerance to dense planting and lodging resistance, and are of great significance to high-yield and dense-planting maize breeding. Summary of the Invention

[0004] All references mentioned herein are incorporated herein by reference. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. Unless otherwise specified, the techniques used or mentioned herein are standard techniques well known to those of ordinary skill in the art. The materials, methods, and examples are for illustrative purposes only and not for limitation.

[0005] The embodiments of the present application provide a gene for regulating the plant height and ear height of maize. After the endogenous ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 gene of the maize plant mutates, the plant can have a phenotype of reduced plant height and / or ear height. The gene resources and their applications provided by the present application have great application value in the field of maize breeding for tolerance to dense planting and lodging resistance.

[0006] The embodiments of the present application provide a method for regulating the agronomic traits of maize. The method obtains a loss-of-function mutant by mutating the endogenous gene ZmTCP4, ZmTCP14 of maize, so that the plant line containing the mutant gene has a phenotype of reduced plant height and / or ear height. The polynucleotide sequence of the endogenous gene is selected from one of the sequences of the following groups: (a)A polynucleotide sequence as shown in SEQ ID No: 1, 9, 16 and / or 22; (b)A polynucleotide sequence encoding an amino acid sequence as shown in SEQ ID No: 2, 10, 17 and / or 23; (c)A polynucleotide sequence that hybridizes with the polynucleotide sequence described in (a) or (b) under stringent conditions and encodes a functional protein with reduced plant height and / or ear height after mutation; (d)A polynucleotide sequence having at least 90%, 95%, 98% or more similarity to the polynucleotide sequence shown in any one of (a)-(c), and the polynucleotide sequence has the function of reducing plant height and / or ear height after mutation; or (e)A polynucleotide sequence complementary to the sequence described in any one of (a)-(d).

[0007] In this application, the hybridization refers to DNA molecule hybridization, also known as DNA probe technology. Those skilled in the art know that when the single strands of DNA molecules of two organisms are put together, if these two single strands have complementary base sequences, a hybrid double-stranded region will be formed. The more complementary base sequences there are, the more hybrid double-stranded regions will be formed, indicating that the genetic relationship between the two organisms is closer and the similarity of genes is also higher. Under the stringent hybridization conditions of this application, sequences highly similar to the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 gene sequence of the present invention can be screened out, including the same gene sequence with SNP differences from different maize varieties and the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 sequence disclosed in this application. The SNP is also known as Single Nucleotide Polymorphism (SNP), which refers to the existence of single nucleotide diversity in the same gene among different varieties of the same plant, that is, there are often differences in individual bases in the nucleotide sequence of the same gene. However, there are a large number of varieties of the same crop, and it is impossible for the inventor to list them one by one. Therefore, the embodiments of this application only provide the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 gene sequences of representative varieties in maize crops. Therefore, those skilled in the art should know that the nucleotide sequences of the same ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 gene with SNP differences from the genes and their nucleotide sequences disclosed in the present invention ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 are also within the protection scope of the present invention.

[0008] Optionally, the stringent conditions may be: incubation in 50% formamide, 5×SSC and 1% SDS at 42°C; or incubation in 5×SSC, 1% SDS at 65°C, washing in 0.2×SSC and washing in 0.1% SDS at 65°C. The washing can be carried out for 5, 15, 30, 60, 120 minutes or longer. Under these stringent conditions, the polynucleotide sequences in item (c) above that hybridize with the polynucleotide sequences described in (a) or (b) and encode functional proteins with reduced plant height and / or ear height after mutation can be screened out. More specifically, detailed guidance on nucleic acid hybridization can be referred to relevant literature (Tijssen, Techniques in Biochemistry and Molecular Biology - Hybridization with Nucleic Probes, "Overview of principles of hybridization and the strategy of nucleic acid assays. 1993). Optionally, the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 genes provided in the embodiments of the present application also include homologous genes with at least 80%, 85%, 90%, 95%, 98% or 99% sequence similarity to the polynucleotide sequences disclosed in the embodiments of the present application, or homologous genes with at least 90%, 95% or 98% sequence similarity to the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 amino acid sequences disclosed in the embodiments of the present invention, and after homozygous mutation of the endogenous of the homologous genes, they have the function of reducing plant height and / or ear height of the plant, and the homologous genes can be isolated from any plant or any maize variety.

[0009] The percentage of sequence similarity described in the present application can be obtained by well-known bioinformatics algorithms, including the algorithms of Myers and Miller, the Needleman-Wunsch global alignment method, the Smith-Waterman local alignment method, the Pearson and Lipman similarity search method, and the algorithm of Karlin and Altschul, which are well-known to those skilled in the art.

[0010] Optionally, the mutations described in the present application include substitution, deletion and / or addition of one or more nucleotides in the nucleotide sequence of the gene.

[0011] Optionally, the mutation is obtained by techniques such as physical mutagenesis, chemical mutagenesis, ZFN, TALEN, and / or CRISPR / Cas gene editing. The mutation site of the mutant strain can also be obtained by crossing the wild type with the mutant strain. The physical mutagenesis refers to the method of inducing random DNA mutations in plants by various rays, such as ultraviolet rays, X-rays, γ-rays, etc., and finally obtaining the target mutant through phenotypic screening and PCR detection of the experimental population. The chemical mutagenesis refers to the method of screening the target mutant by treating plants with chemical reagents to cause random DNA mutations and then combining phenotypic observation, PCR detection, etc.

[0012] Optionally, when CRISPR / Cas is the CRISPR / Cas9 gene editing method, the target sequence used is selected from one of the sequences in the following group: (a) A fragment conforming to the 5'-Nx-NGG-3' sequence arrangement rule in the nucleotide sequences shown in SEQ ID No: 1, 9, 16, or 22, where N represents any one of A, G, C, and T, 14 < X < 30, and X is an integer, and Nx represents X consecutive nucleotides; or (b) A nucleotide sequence complementary to the polynucleotide sequence described in (a).

[0013] Optionally, the mutant nucleotide sequence possessed by the mutant strain is as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25, or 26.

[0014] Optionally, the present application also includes an application of a gene in regulating the plant height and / or ear height of maize, and the polynucleotide sequence of the gene is selected from one of the sequences in the following group: (a) The polynucleotide sequence as shown in SEQ ID No: 1, 9, 16, and / or 22; (b) The polynucleotide sequence encoding the amino acid sequence as shown in SEQ ID No: 2, 10, 17, and / or 23; (c) A polynucleotide sequence that hybridizes with the polynucleotide sequence described in (a) or (b) under stringent conditions and encodes a protein with the function of reducing plant height and / or ear height after mutation; (d) A polynucleotide sequence having at least 90%, 95%, 98% or more similarity to the polynucleotide sequence shown in any one of (a)-(c), and the polynucleotide sequence has the function of reducing plant height and / or ear height after mutation; or (e) A polynucleotide sequence complementary to the sequence shown in any one of (a)-(d).

[0015] The present application also provides a gene mutant sequence, which is obtained by ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 gene mutation. The maize plants containing this gene mutant sequence have the phenotype of reduced plant height and / or ear height. The ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 nucleotide sequence of the gene is selected from one of the sequences in the following groups: (a) a polynucleotide sequence as shown in SEQ ID No: 1, 9, 16 and / or 22; (b) a polynucleotide sequence encoding an amino acid sequence as shown in SEQ ID No: 2, 10, 17 and / or 23; (c) a polynucleotide sequence that hybridizes with the polynucleotide sequence described in (a) or (b) under stringent conditions and encodes a protein with the function of reduced plant height and / or ear height after mutation; (d) a polynucleotide sequence having at least 90%, 95%, 98% or more similarity to the polynucleotide sequence shown in any one of (a)-(c), and the polynucleotide sequence has the function of reduced plant height and / or ear height after mutation; or (e) a polynucleotide sequence complementary to the sequence described in any one of (a)-(d).

[0016] Optionally, the nucleotide sequence of the gene mutant is as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

[0017] The present application also provides a plant cell, tissue, organ or product that is not used as a propagation material, and the plant cell, tissue, organ or product contains ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 the mutant sequence of the gene.

[0018] Optionally, the embodiments of the present application provide a maize protein, feed, meal or oil product obtained by any of the above methods. The characteristics are that the maize protein, feed, meal or oil product is made from maize seeds containing ZmTCP4, ZmTCP14, ZmTCP16 or ZmTCP25 any gene mutant sequence of the gene.

[0019] Optionally, for the maize protein, feed, meal or oil product, the gene mutant sequence is as shown in SEQID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

[0020] Optionally, the present application provides a plant cell, tissue, organ or product that is not used as a propagation material, and the plant cell, tissue, organ or product contains ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25Mutant sequences of genes, the nucleotide sequences of which are shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

[0021] Compared with the prior art, the present application has the following beneficial effects: (1) The present application provides genes for regulating the plant height and ear height of maize ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25, and their regulation methods and applications. By mutating the endogenous ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 genes of the plant, the plant obtains the phenotype of reduced plant height and / or ear height, providing a new gene resource for lodging-resistant and density-tolerant breeding, and having great application prospects in maize lodging-resistant and high-yield breeding with high density.

[0022] (2) The new gene resources, breeding methods and their applications provided by the present application make it possible to cultivate new maize varieties adapted to different conditions, and are of great significance to global food security and agricultural sustainable development. Term definitions

[0023] Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, the preferred methods, devices and materials are now described.

[0024] In the context of the present application, the term "polynucleotide" or "nucleotide" means deoxyribonucleotides, deoxyribonucleosides, ribonucleosides or ribonucleotides in single-stranded or double-stranded form and their polymers. Unless specifically restricted, the term covers nucleic acids containing known analogs of natural nucleotides, which have binding properties similar to the reference nucleic acid and are metabolized in a manner similar to naturally occurring nucleotides.

[0025] The term "homologous gene" in the present application refers to two or more gene sequences with a sequence similarity of 80%, which includes orthologous genes (also known as vertical homologous genes, orthologous genes or orthologous genes by directed evolution), paralogous genes (also known as paralogous genes, co-orthologous genes or paralogous genes by parallel evolution) and / or xenologous genes.

[0026] The term "sequence similarity" refers to the degree of similarity between two sequences, which is a quantitative concept used to compare the similarity between different sequences, so as to discover and analyze the association between two sequences. Sequence similarity can be used to compare gene sequences, protein sequences, DNA sequences, etc.

[0027] As used herein, "stringent hybridization conditions" refers to conditions of low ionic strength and high temperature known in the art. Typically, under stringent hybridization conditions, a probe hybridizes to its target sequence with a detectable degree that is higher than that of hybridization to other sequences (e.g., at least 2-fold over background). Stringent hybridization conditions are sequence-dependent and will vary in different environmental conditions. Longer sequences hybridize specifically at higher temperatures. Target sequences that are 100% complementary to the probe can be identified by controlling the stringency of hybridization or the wash conditions. Exhaustive guidance on nucleic acid hybridization can be found in the relevant literature (Tijssen, Techniques in Biochemistry and Molecular Biology - Hybridization with Nucleic Probes, "Overview of principles of hybridization and the strategy of nucleic acid assays. 1993). More specifically, the stringent conditions are typically selected to be about 5 - 10 °C below the thermal melting point (T m m) of the specific sequence at a specified ionic strength and pH. T m m is the temperature at which 50% of the probe complementary to the target hybridizes to the target sequence at equilibrium (at a specified ionic strength, pH, and nucleic acid concentration) (since the target sequence is present in excess, 50% of the probe is occupied at equilibrium at T m m). Stringent conditions can be those in which the salt concentration is less than about 1.0 M sodium ion concentration at pH 7.0 to 8.3, typically about 0.01 to 1.0 M sodium ion concentration (or other salts), and the temperature is at least about 30 °C for short probes (including (but not limited to) 10 to 50 nucleotides), and at least about 60 °C for long probes (including (but not limited to) greater than 50 nucleotides). Stringent conditions can also be achieved by adding destabilizing agents such as formamide. For selective or specific hybridization, a positive signal can be at least twice the background hybridization, or 10-fold background hybridization as the case may be. Exemplary stringent hybridization conditions can be as follows: 50% formamide, 5×SSC, and 1% SDS, incubated at 42 °C; or 5×SSC, 1% SDS, incubated at 65 °C, washed in 0.2×SSC and washed in 0.1% SDS at 65 °C. The wash can be carried out for 5, 15, 30, 60, 120 minutes or longer.

[0028] The term "recombinant expression vector": one or more DNA vectors for achieving plant transformation; these vectors are often referred to as binary vectors in the art. Binary vectors, together with vectors having helper plasmids, are most commonly used for Agrobacterium-mediated transformation. Binary vectors typically include: cis-acting sequences required for T-DNA transfer, selectable markers engineered to be able to express in plant cells, heterologous DNA sequences to be transcribed, etc.

[0029] The term "hybridization" refers to hybridization in a broad sense, which means the process of gamete combination between individuals of different populations or genotypes to produce hybrids. Depending on the genetic relationship of the parents, it includes related hybridization and distant hybridization.

[0030] In the present application, the "mutation" refers to a "loss-of-function mutation", which is a mutation in the coding sequence of a gene that causes a decrease or complete loss of the function of the gene product (usually a protein). A loss-of-function mutation can be caused, for example, by truncation of the gene product (resulting from frameshift or nonsense mutations). The phenotype associated with an allele having a loss-of-function mutation can be recessive or dominant. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is ZmTCP4, 14, 16, 25 Schematic diagram of Cas9 target sites of four genes, where Target refers to the target site, exon refers to the exon, and UTR refers to the non-coding region.

[0032] Figure 2 is Zmtcp4, 14, 16, 25 Genotype analysis of each mutant. The numbers corresponding to the two slashes in the sequence refer to the number of base pairs between the two target sites.

[0033] Figure 3 is Zmtcp4, 14, 16, 25 Morphological changes of each double or multiple mutant plant type, where (a) is the plant type diagram of each mutant; (b) is the statistical chart of plant height of each mutant; (c) is the statistical chart of ear height of each mutant; Bar = 30 cm; where Plant height refers to plant height and Ear height refers to ear height.

[0034] Figure 4 is Zmtcp4, 14, 16, 25 Phenotype analysis of ears of each mutant, where (a) is the ear morphology of each mutant; (b) is the statistical chart of ear length of each mutant; (c) is the statistical chart of ear width of each mutant; (d) is the statistical chart of the number of kernel rows of each mutant; (e) is the statistical chart of the number of kernels per row of each mutant; (f) is the statistical chart of 100-grain weight of each mutant; (g) is the statistical chart of grain weight per single ear of each mutant; Bar = 2.5 cm; where Ear length refers to ear length, Ear diameter refers to ear width, Kernel row number refers to the number of kernel rows, Kernel number per row refers to the number of kernels per row, Hundred-grain weight refers to 100-grain weight, and Grain yield per plant refers to grain weight per single ear. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, these embodiments are merely exemplary and do not constitute any limitation to the scope of the present invention. Those skilled in the art should understand that the details and forms of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but such modifications and replacements all fall within the protection scope of the present invention.

[0036] Example 1: Gene knockout using CRISPR / Cas9 technology ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Gene knockout In this application, ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 the genomic DNA and coding region (CDS) sequences of these 4 genes from the start codon to the stop codon are the same. Specifically, the ZmTCP4 genomic DNA sequence is shown in SEQ ID NO:1, and the amino acid sequence is shown in SEQ ID NO:2; ZmTCP14 the genomic DNA sequence is shown in SEQ ID NO:9, and the amino acid sequence is shown in SEQ ID NO:10; ZmTCP16 the genomic DNA sequence is shown in SEQ ID NO:16, and the amino acid sequence is shown in SEQ ID NO:17; ZmTCP25 the genomic DNA sequence is shown in SEQ ID NO:22, and the amino acid sequence is shown in SEQ ID NO:23.

[0037] In order to verify the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 function, the inventor used CRISPR / Cas9 technology to genetically edit the above four genes endogenous to maize plants to obtain ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 single, double, or multiple knockout mutants of the four genes. The target positions of the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 four genes are as shown in Figure 1 , and the target sequences are as shown in Figure 2 . The Figure 2 underlined part in ZmTCP4 is the specific target sequence. Among them, 3 target sequences were designed for ZmTCP14, ZmTCP16, ZmTCP25 , and 2 target sequences were designed for each of the

[0038] Different types of mutants obtained by CRISPR / Cas9 technology are as shown in Figure 2 . The different mutation situations of the ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 four genes are shown in Table 1 below. In Table 1, Gene type (genotype) refers to different mutants, corresponding to the different numbered sequences on the left Figure 2 . For example, the second row in Table 1 Zmtcp4#1The number 1 in the second column at the back corresponds to the mutant sequence number 1, and the specific mutant sequence is shown in SEQ ID NO:3, and so on.

[0039] Table 1. Zmtcp4, 14, 16, 25 Genotypes of each mutant plant Material name Genotype Material name Genotype Material Name Genotype 1 1, 7 5, 8, 17 2 5, 8 4, 10, 16 7 1, 18 3, 13, 16 8 5, 17 4, 14, 16 12 12, 16 7, 12, 16 16 7, 16 4, 10, 14, 16 17 10, 16 6, 11,15,16 Specifically, in this application, through the CRISPR / Cas9 technology, single mutants of Zmtcp4, 14, 16, 25 were obtained respectively, Zmtcp4 / 14, Zmtcp4 / 25, Zmtcp16 / 25, Zmtcp14 / 25 double mutants of Zmtcp4 / 14 / 25, Zmtcp4 / 16 / 25, Zmtcp14 / 16 / 25 triple mutants, and Zmtcp4 / 14 / 16 / 25 quadruple mutants of

[0040] Among them, Zmtcp4 the mutant numbers are respectively Zmtcp4#1 to Zmtcp4#6 , and their nucleotide sequences are shown in SEQ ID NO:3-8 respectively; Zmtcp14 the mutant numbers are respectively Zmtcp14#7 to Zmtcp4#11, and their nucleotide sequences are shown in SEQ ID NO:11-15 respectively; Zmtcp16 the mutant numbers are respectively Zmtcp16#12 to Zmtcp16#15 , and their nucleotide sequences are shown in SEQ ID NO:18-21 respectively; Zmtcp25 the mutant numbers are respectively Zmtcp25#16 to Zmtcp25# 18， the nucleotide sequences of each mutant are shown in SEQ ID NO:24-26 respectively. Phenotypic analysis of mutant plant height and ear height

[0041] As Figure 3 shown, the phenotypes of each single mutant and multi-mutant were statistically analyzed, and the results showed that Zmtcp4, 14, 16, 25 , Zmtcp4 / 14 , Zmtcp4 / 14 / 25 , Zmtcp4 / 14 / 16 / 25 plant height and ear height were significantly reduced, Zmtcp4 / 14#1 , Zmtcp4 / 14#2 , Zmtcp4 / 14 / 25#1 , Zmtcp4 / 14 / 25#2 , Zmtcp4 / 14 / 16 / 25#1 , Zmtcp4 / 14 / 16 / 25#2 The average plant heights were 160.5 cm, 153.4 cm, 141.9 cm, 134.5 cm, 138.1 cm, and 140.8 cm respectively, and the plant heights were reduced by 14.1%, 17.9%, 24.0%, 28.0%, 26.1%, and 24.6% respectively compared with the wild type (186.8 cm).

[0042] Zmtcp4 / 14#1 , Zmtcp4 / 14#2 , Zmtcp4 / 14 / 25#1 , Zmtcp4 / 14 / 25#2 , Zmtcp4 / 14 / 16 / 25#1 , Zmtcp4 / 14 / 16 / 25#2 The average ear heights were 73.8, 72.4, 62.2, 57.1, 60.5, and 61.1 cm respectively. Compared with the wild type (93.47 cm), the plant heights were reduced by 21.0%, 22.5%, 33.5%, 38.9%, 35.3%, and 34.7% respectively.

[0043] Zmtcp16 , Zmtcp25 , Zmtcp16 / 25 , Zmtcp4 / 25 , Zmtcp14 / 25 , Zmtcp4 / 16 / 25 , Zmtcp14 / 16 / 25 There were no significant changes in the plant height and ear height of mutant materials such as... compared with the wild type.

[0044] The above results indicate that the four genes ZmTCP4, 14, 16, and 25 positively regulate maize plant height and ear height, and there may be functional redundancy. Zmtcp4 / 14 , Zmtcp4 / 14 / 25 , Zmtcp4 / 14 / 16 / 25 The plant height and ear height of the mutant plants were significantly reduced.

[0045] More specifically, ZmTCP4 and ZmTCP14 double mutation of the genes can significantly reduce the plant height and ear height of the plants. On this basis, ZmTCP25 gene mutation can further enhance this phenotype, indicating that this gene has a synergistic effect on regulating plant height and ear height. The aforementioned 4 genes have good application prospects in regulating maize lodging resistance breeding. Phenotypic analysis of mutant ears

[0046] As Figure 4 shown, the phenotypes of ear length, ear width, number of rows per ear, number of kernels per row, 100-kernel weight, and single-ear kernel weight of single and multiple mutants of the four genes were observed, and the results showed that there were no significant changes compared with the wild type. Zmtcp4, 14, 16, 25 According to existing research reports, most maize dwarf mutants have a significant reduction in yield or even a complete crop failure after the plant height decreases, making it difficult to apply them in production. However, the

[0047] mutants provided in this application have significantly reduced plant height and ear height compared with the wild type, but have no significant effect on yield. Therefore, they can effectively improve the lodging resistance and density tolerance of maize, as well as the lodging resistance of maize under high-density conditions. Zmtcp4 / 14, Zmtcp4 / 14 / 25, Zmtcp4 / 14 / 16 / 25 mutants

[0048] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A method for regulating maize agronomic traits, which obtains a loss-of-function mutant with a phenotype of reduced plant height and / or ear height by mutating an endogenous maize gene, and the polynucleotide sequence of the endogenous gene is selected from one of the sequences in the following groups: (a) The polynucleotide sequences shown in SEQ ID No: 1, 9, 16 and / or 22; (b) The polynucleotide sequences encoding amino acid sequences shown in SEQ ID No: 2, 10, 17 and / or 23; (c) Polynucleotide sequences that hybridize with the polynucleotide sequences described in (a) or (b) under stringent conditions and encode proteins with the function of reduced plant height and / or ear height after mutation; (d) Polynucleotide sequences having at least 90%, 95%, 98% or more similarity to the polynucleotide sequences shown in any of (a)-(c), and the polynucleotide sequences have the function of reduced plant height and / or ear height after mutation; or (e) Polynucleotide sequences complementary to any of the sequences described in (a)-(d).

2. The method according to claim 1, wherein the mutation includes substitution, deletion and / or addition of one or more nucleotides in the nucleotide sequence of the gene.

3. The method according to claim 2, wherein the mutation is obtained by physical mutagenesis, chemical mutagenesis, ZFN, TALEN and / or CRISPR / Cas gene editing technology.

4. The method according to claim 3, wherein the CRISPR / Cas is the CRISPR / Cas9 gene editing method, and the target sequences used are selected from one of the sequences in the following groups: (a) Fragments conforming to the sequence arrangement rule of 5'-Nx-NGG-3' in the nucleotide sequences shown in SEQ ID No: 1, 9, 16 or 22, where N represents any one of A, G, C and T, 14 < X < 30, and X is an integer, and Nx represents X consecutive nucleotides; or (b) Nucleotide sequences complementary to the polynucleotide sequences described in (a).

5. The method according to any one of claims 1-4, wherein the mutant nucleotide sequences of the mutant lines are as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

6. Application of the method according to any one of claims 1-5 in regulating maize plant height and / or ear height.

7. A loss-of-function gene mutant sequence, a maize plant containing the gene mutant sequence has a phenotype of reduced plant height and / or ear height, and the polynucleotide sequence of the gene is selected from one of the sequences in the following groups: (a) The polynucleotide sequences shown in SEQ ID No: 1, 9, 16 and / or 22; (b) The polynucleotide sequences encoding amino acid sequences shown in SEQ ID No: 2, 10, 17 and / or 232, 10, 17 and / or 23; (c) Polynucleotide sequences that hybridize with the polynucleotide sequences described in (a) or (b) under stringent conditions and encode proteins with the function of reduced plant height and / or ear height after mutation; (d) A polynucleotide sequence having at least 90%, 95%, 98% or more similarity to any of the polynucleotide sequences shown in (a)-(c), wherein the polynucleotide sequence has the function of reducing plant height and / or ear height after mutation; or (e) A polynucleotide sequence complementary to any of the sequences described in (a)-(d).

8. The gene mutant sequence according to claim 7, wherein the nucleotide sequence of the mutant is as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

9. A corn protein, feed, meal or oil product obtained by the method according to any one of claims 1-5, characterized in that, The corn protein, feed, meal or oil product is made from corn seeds containing any of the gene mutant sequences described in claim 7.

10. The corn protein, feed, meal or oil product according to claim 9, wherein the gene mutant sequence is as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25 or 26.

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