Maize plant height, ear height control genes and their applications

Abstract

The application discloses a maize plant height and ear position height regulation gene and application thereof, belongs to the field of plant biotechnology, and particularly relates to ZmTCP Application of the gene in regulation of maize plant height and ear position height. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The gene mutation can make the plant have the phenotype of reduced plant height and / or ear position height. The gene resource and the application thereof provided in the application have great application value in the field of maize density tolerance and lodging resistance breeding.

Description

Technical Field

[0001] This invention belongs to the field of plant biotechnology, specifically involving ZmTCP Application of genes in regulating maize plant height and ear height. Background Technology

[0002] Increasing corn planting density appropriately is one of the effective ways to improve corn yield per unit area. However, dense planting can trigger shading responses in plants (such as increased plant height and ear height, poor lodging resistance, and decreased seed setting rate), ultimately leading to reduced yield. Therefore, cultivating varieties that are tolerant of dense planting, have high light efficiency, and are suitable for mechanized operations is the most important technical measure to improve corn yield per unit area.

[0003] The "Green Revolution" is of great significance to agricultural production, and dwarfing breeding of maize is generally considered one of the future directions of maize breeding. However, most dwarfing mutants in maize exhibit undesirable phenotypes such as reduced yield or even complete crop failure, making them difficult to apply in agricultural production. In this application, the inventors utilized CRISPR / Cas9 technology to knock out endogenous... ZmTCP4, 14、16、25 After gene sequencing, phenotypes such as plant height and ear height were observed in maize mutant plants, and unexpected discoveries were made. ZmTCP4, 14, 16、25 The gene mutation reduces maize plant height and ear height without adversely affecting other agronomic traits. These findings provide a theoretical basis for the genetic improvement of maize tolerating dense planting and resisting lodging, and are of great significance for high-yield, dense-planting-tolerant maize breeding. Summary of the Invention

[0004] All references cited herein are incorporated herein by reference. Unless otherwise stated, 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 pertains. Unless otherwise stated, the techniques used or mentioned herein are standard techniques known to one of ordinary skill in the art. Materials, methods, and examples are for illustrative purposes only and are not intended to be limiting.

[0005] This application provides a gene that regulates maize plant height and ear height, the endogenous gene of the maize plant. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Gene mutations can result in a phenotype of reduced plant height and / or ear height. The gene resources provided in this application and their applications have significant value in the field of maize breeding for high-density planting and lodging resistance.

[0006] This application provides a method for regulating agronomic traits of maize, which involves mutating endogenous maize genes. ZmTCP4, ZmTCP14 To obtain a loss-of-function mutant, resulting in lines containing the mutant gene exhibiting a phenotype of reduced plant height and / or ear height, wherein the polynucleotide sequence of the endogenous gene is selected from one of the following groups:

[0007] (a) Polynucleotide sequences as shown in SEQ ID No: 1, 9, 16 and / or 22;

[0008] (b) The polynucleotide sequence encoding the amino acid sequence shown in SEQ ID No: 2, 10, 17 and / or 23;

[0009] (c) A polynucleotide sequence that hybridizes under stringent conditions with the polynucleotide sequence described in (a) or (b) and encodes a protein that, when mutated, reduces plant height and / or ear height;

[0010] (d) A polynucleotide sequence that has at least 90%, 95%, or 98% similarity to any of the polynucleotide sequences shown in (a)-(c), wherein the mutation of said polynucleotide sequence has the function of reducing plant height and / or ear height; or

[0011] (e) A polynucleotide sequence complementary to any of the sequences described in (a)-(d).

[0012] In this application, the hybridization refers to DNA molecular hybridization, also known as DNA probe technology. Those skilled in the art know that when single strands of DNA molecules from two organisms are placed together, if these two single strands have complementary base sequences, a heterozygous double-stranded region will be formed. The more complementary base sequences, the more heterozygous double-stranded regions are formed, indicating a closer kinship between the two organisms and a higher degree of gene similarity. Under the stringent hybridization conditions of this application, it is possible to screen for organisms similar to those of the present invention. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Sequences with highly similar gene sequences, including those from different maize varieties and those disclosed in this application. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The sequences of the same gene exhibiting SNP differences. SNPs, also known as Single Nucleotide Polymorphism (SNP), refer to the diversity of single nucleotides in the same gene among different varieties of the same plant species. This means that the nucleotide sequences of the same gene often differ by a few bases. However, there are many varieties of the same crop, and it is impossible for the inventors to list them all. Therefore, the embodiments in this application only provide representative varieties of maize. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Gene sequences. Therefore, those skilled in the art should understand that different varieties originate from sources different from those disclosed in this invention. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The same gene and its nucleotide sequence have SNP differences ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The nucleotide sequence of a gene is also within the scope of protection of this invention.

[0013] Optionally, the stringent conditions may be: 50% formamide, 5×SSC and 1% SDS, cultured at 42°C; or 5×SSC, 1% SDS, cultured at 65°C, washed in 0.2×SSC and washed in 0.1% SDS at 65°C. The washing may be performed for 5, 15, 30, 60, 120 minutes or longer. Under these stringent conditions, polynucleotide sequences in item (c) above that hybridize with the polynucleotide sequences described in (a) or (b) and encode proteins that, after mutation, reduce plant height and / or ear height can be screened. More specifically, detailed instructions for the nucleic acid hybridization can be found in 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 embodiments provided in this application... ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Genes, including homologous genes that have at least 80%, 85%, 90%, 95%, 98%, or 99% sequence similarity to the polynucleotide sequences disclosed in the embodiments of this application, or genes that are similar to those disclosed in the embodiments of this invention. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The homologous gene has an amino acid sequence similarity of at least 90%, 95%, or 98%, and the homologous gene, after endogenous homozygous mutation, has the function of reducing plant height and / or ear height. The homologous gene can be isolated from any plant or any maize variety.

[0014] The percentage of sequence similarity described in this application can be obtained using well-known bioinformatics algorithms, including the Myers and Miller algorithm, the Needleman-Wunsch global alignment method, the Smith-Waterman local alignment method, the Pearson and Lipman similarity search method, and the Karlin and Altschul algorithm, which are well known to those skilled in the art.

[0015] Optionally, the mutations described in this application include substitutions, deletions, and / or additions of one or more nucleotides in the nucleotide sequence of the gene.

[0016] 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 a 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 a method of screening the target mutant by treating the plant with chemical reagents to cause random DNA mutations in the plant and then combining phenotypic observation, PCR detection, and other means.

[0017] 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:

[0018] (a) a fragment 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

[0019] (b) a nucleotide sequence complementary to the polynucleotide sequence described in (a).

[0020] 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.

[0021] 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:

[0022] (a) a polynucleotide sequence as shown in SEQ ID No: 1, 9, 16 and / or 22;

[0023] (b) a polynucleotide sequence encoding an amino acid sequence as shown in SEQ ID No: 2, 10, 17 and / or 23;

[0024] (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;

[0025] (d) a polynucleotide sequence having at least 90%, 95%, 98% or more similarity with 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

[0026] (e) A polynucleotide sequence complementary to any of the sequences described in (a)-(d).

[0027] This application also provides a gene mutant sequence, which is derived from... ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Obtained through gene mutation, maize plants containing this mutant gene sequence exhibit a phenotype of reduced plant height and / or ear height. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The nucleotide sequence of the gene is selected from one of the following groups:

[0028] (a) Polynucleotide sequences as shown in SEQ ID No: 1, 9, 16 and / or 22;

[0029] (b) The polynucleotide sequence encoding the amino acid sequence shown in SEQ ID No: 2, 10, 17 and / or 23;

[0030] (c) A polynucleotide sequence that hybridizes under stringent conditions with the polynucleotide sequence described in (a) or (b) and encodes a protein that, when mutated, reduces plant height and / or ear height;

[0031] (d) A polynucleotide sequence that has at least 90%, 95%, or 98% similarity to any of the polynucleotide sequences shown in (a)-(c), wherein the mutation of said polynucleotide sequence has the function of reducing plant height and / or ear height; or

[0032] (e) A polynucleotide sequence complementary to any of the sequences described in (a)-(d).

[0033] 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.

[0034] This application also provides a plant cell, tissue, organ, or product that is not used as propagation material, wherein the plant cell, tissue, organ, or product contains ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Mutant sequences of genes.

[0035] Optionally, embodiments of this application provide corn protein, feed, coarse flour, or oil products obtained by any of the methods described above, characterized in that the corn protein, feed, coarse flour, or oil products are composed of... ZmTCP4, ZmTCP14, ZmTCP16 or ZmTCP25 Made from corn seeds containing any mutant sequence of a gene.

[0036] Optionally, the corn protein, feed, crude flour, or oil product may contain a mutant sequence as shown in SEQ ID NO: 3, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 18, 19, 20, 24, 25, or 26.

[0037] Optionally, this application provides a plant cell, tissue, organ, or product that is not used as propagation material, wherein the plant cell, tissue, organ, or product contains ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The mutant sequence of the gene, wherein the nucleotide sequence of the mutant gene 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.

[0038] Compared with the prior art, this application has the following beneficial effects:

[0039] (1) This application provides genes that regulate maize plant height and ear height. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25, Its regulation methods and applications. This application utilizes endogenous [resources / mechanisms] in mutant plants. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Genes that enable plants to acquire phenotypes with reduced plant height and / or higher ear position provide new genetic resources for lodging-resistant and high-density breeding, and have significant application prospects in lodging-resistant, high-density, and high-yield maize breeding.

[0040] (2) The new genetic resources, breeding methods and their applications provided in this application make it possible to breed new maize varieties that are adapted to different conditions, which is of great significance to global food security and sustainable agricultural development.

[0041] Terminology Definition

[0042] 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 pertains. While any methods, apparatus, and materials similar to or equivalent to those described herein may be used in the practice or testing of this invention, preferred methods, apparatus, and materials are now described.

[0043] In the context of this application, the terms "polynucleotide" or "nucleotide" mean deoxyribonucleotides, deoxyribonucleosides, ribonucleosides, or ribonucleotides and their polymers in single-stranded or double-stranded form. Unless specifically limited, the term covers nucleic acids containing known analogs of natural nucleotides, which have similar binding properties to a reference nucleic acid and are metabolized in a manner similar to naturally occurring nucleotides.

[0044] In this application, the term "homologous gene" refers to two or more gene sequences with a sequence similarity of 80%, including orthologous genes (also known as vertical homologous genes, positive homologous genes, or directed evolutionary homologous genes), transverse homologous genes (also known as paralogous genes, paralogous homologous genes, or parallel evolutionary homologous genes), and / or heterologous genes.

[0045] The term "sequence similarity" refers to the degree of similarity between two sequences. It is a quantitative concept used to compare the similarity between different sequences, thereby discovering and analyzing the association between the two sequences. Sequence similarity can be used to compare gene sequences, protein sequences, DNA sequences, etc.

[0046] The term "strict hybridization conditions" as used in this application refers to conditions of low ionic strength and high temperature known in the art. Typically, under strict hybridization conditions, the detectability of a probe hybridizing with its target sequence is significantly higher than that with other sequences (e.g., at least twice the background level). Strict hybridization conditions are sequence-dependent and will vary under 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 strictness of hybridization or washing conditions. Detailed guidance on nucleic acid hybridization can be found in 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 chosen to be below the melting point (T0) of the specific sequence at a specified ionic strength pH. m Approximately 5-10℃. m The temperature at which 50% of the probe complementary to the target sequence hybridizes to the target sequence under equilibrium conditions (at specified ionic strength, pH, and nucleic acid concentration) (because the target sequence is present in excess, therefore at T...). m(Under equilibrium conditions, 50% of the probe is occupied). Strict conditions may include: a salt concentration of less than about 1.0 M sodium ions at pH 7.0 to 8.3, typically about 0.01 to 1.0 M sodium ions (or other salts), and a temperature of 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). Strict conditions can also be achieved by adding a destabilizing agent such as formamide. For selective or specific hybridization, the positive signal may be at least twice the background hybridization, and, where appropriate, 10 times the background hybridization. Exemplary strict hybridization conditions may be: 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 washing can be performed for 5, 15, 30, 60, 120 minutes or longer.

[0047] The term "recombinant expression vector" refers to one or more DNA vectors used to achieve plant transformation; these vectors are often referred to as binary vectors in the art. Binary vectors, along with vectors containing helper plasmids, are commonly used for Agrobacterium-mediated transformation. Binary vectors typically include: the cis-acting sequence required for T-DNA transfer, a selection marker engineered for expression in plant cells, and the heterologous DNA sequence to be transcribed.

[0048] The term "hybridization" is used in a broad sense to refer to the process by which gametes from different populations or genotypes combine to produce hybrids. Depending on the parental relationship, it includes close hybridization and distant hybridization.

[0049] In this application, "mutation" refers to a "loss-of-function mutation," which is a mutation in the coding sequence of a gene that causes a reduction or complete loss of function in the gene product (usually a protein). Loss-of-function mutations can be caused, for example, by truncation of the gene product (due to frameshift or nonsense mutations). The phenotype associated with an allele having a loss-of-function mutation can be recessive or dominant. Attached Figure Description

[0050] Figure 1 yes ZmTCP4, 14, 16, 25 A schematic diagram of Cas9 target sites for four genes, where Target refers to the target site, exon refers to the exon, and UTR refers to the non-coding region.

[0051] Figure 2 yes Zmtcp4, 14, 16, 25 Genotypic analysis of each mutant shows that the numbers corresponding to the two slashes in the sequence refer to the number of bp between the two target sites.

[0052] Figure 3 yes Zmtcp4, 14, 16, 25 Plant morphology changes of each double or multiple mutant, where (a) is the plant morphology diagram of each mutant; (b) is the plant height statistics of each mutant; (c) is the ear height statistics of each mutant; Bar=30cm; where Plant height refers to plant height and Ear height refers to ear height.

[0053] Figure 4 yes Zmtcp4, 14, 16, 25 Phenotypic analysis of each mutant ear, including (a) ear morphology of each mutant; (b) ear length statistics of each mutant; (c) ear width statistics of each mutant; (d) ear row number statistics of each mutant; (e) number of kernels per row statistics of each mutant; (f) weight per 100 kernels statistics of each mutant; (g) kernel weight per ear statistics 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 ear row number, Kernel number per row refers to kernel number per row, Hundred-grain weight refers to weight per 100 kernels, and Grain yield per plant refers to kernel weight per ear. Detailed Implementation

[0054] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions to the details and form of the present invention can be made without departing from the spirit and scope of the invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0055] Example 1: CRISPR / Cas9 technology ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Gene knockout

[0056] In this application, ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 These four genes have identical genomic DNA and coding sequence (CDS) from start codon to stop codon. Specifically, the... ZmTCP4 The 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.

[0057] In order to verify ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The function of this method involves using CRISPR / Cas9 technology to edit the four genes endogenously present in maize plants, thereby obtaining... ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 Single, double, or multiple knockout mutants of the four genes. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The target locations of the four genes are as follows: Figure 1 As shown, the target sequence is as follows Figure 2 As shown, Figure 2 The underlined part is the specific target sequence, in which ZmTCP4 Three target sequences were designed. ZmTCP14, ZmTCP16, ZmTCP25 Two target sequences for each.

[0058] Different types of mutants obtained through CRISPR / Cas9 technology, such as Figure 2 As shown. ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 The different mutations of the four genes are shown in Table 1 below. In Table 1, "Gene type" refers to different mutants, corresponding to... Figure 2 The left side shows different numbering sequences. For example, row 2 in Table 1. Zmtcp4#1 The number 1 in the second column corresponds to the mutant sequence number 1. The specific mutant sequence is shown in SEQ ID NO:3, and so on.

[0059] Table 1. Zmtcp4, 14, 16, 25 Genotypes of mutant plants

[0060] 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

[0061] Specifically, this application obtained CRISPR / Cas9 technology, respectively. Zmtcp4, 14, 16, 25 Single mutant, Zmtcp4 / 14, Zmtcp4 / 25, Zmtcp16 / 25, Zmtcp14 / 25 The double mutant, Zmtcp4 / 14 / 25, Zmtcp4 / 16 / 25, Zmtcp14 / 16 / 25 The three mutants, and Zmtcp4 / 14 / 16 / 25 The four mutants.

[0062] in, Zmtcp4 The mutant numbers are respectively Zmtcp4#1 to Zmtcp4#6 Their nucleotide sequences are shown in SEQ ID NO:3-8, respectively; Zmtcp14 The mutant numbers are respectively Zmtcp14#7 to Zmtcp4#11, Their nucleotide sequences are shown in SEQ ID NO:11-15, respectively; Zmtcp16 The mutants are numbered as follows: Zmtcp16#12 to Zmtcp16#15 Their nucleotide sequences are shown in SEQ ID NO:18-21, respectively; Zmtcp25The mutants are numbered as follows: Zmtcp25#16 to Zmtcp25# 18， The nucleotide sequences of each mutant are shown in SEQ ID NO:24-26.

[0063] Phenotypic analysis of mutant plant height and ear height

[0064] like Figure 3 As shown, for Zmtcp4, 14, 16, 25 Statistical analysis of the phenotypes of single-mutant and multi-mutant mutants showed that... 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 160.5cm, 153.4cm, 141.9cm, 134.5cm, 138.1cm, and 140.8cm, respectively, which were 14.1%, 17.9%, 24.0%, 28.0%, 26.1%, and 24.6% lower than those of the wild type (186.8cm).

[0065] 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, which were 21.0%, 22.5%, 33.5%, 38.9%, 35.3%, and 34.7% lower than those of the wild type (93.47 cm).

[0066] Zmtcp16 , Zmtcp25 , Zmtcp16 / 25 , Zmtcp4 / 25 , Zmtcp14 / 25 , Zmtcp4 / 16 / 25 , Zmtcp14 / 16 / 25 The plant height and ear height of the mutant materials were not significantly different from those of the wild type.

[0067] The above results indicate that the four genes ZmTCP4, 14, 16, and 25 positively regulate maize plant height and ear height, and may have functional redundancy. Zmtcp4 / 14 , Zmtcp4 / 14 / 25 , Zmtcp4 / 14 / 16 / 25 The mutant plants showed significantly reduced plant height and ear height.

[0068] More specifically,ZmTCP4 and ZmTCP14 Double gene mutations can significantly reduce plant height and ear height. Based on this, ZmTCP25 Gene mutation can further enhance this phenotype, indicating that the gene has a synergistic effect in regulating plant height and ear height. The aforementioned four genes have good application prospects in regulating maize lodging resistance breeding.

[0069] Phenotypic analysis of mutant ears

[0070] like Figure 4 As shown, for Zmtcp4, 14, 16, 25 Phenotypic changes in spike length, spike width, number of rows, number of grains per row, weight per 100 grains, and weight of grains per spike were observed in mutant materials of the four genes, including single and multiple mutants. The results showed no significant changes compared with the wild type.

[0071] Existing research reports that most maize dwarf mutants, after experiencing a decrease in plant height, also show a significant reduction in yield or even complete crop failure, making them unsuitable for production. However, the mutants provided in this application... Zmtcp4 / 14, Zmtcp4 / 14 / 25, Zmtcp4 / 14 / 16 / 25 The mutant has significantly reduced plant height and ear height compared to the wild type, but has no significant impact on yield. Therefore, it can effectively improve the lodging resistance and density tolerance of maize, as well as the lodging resistance of maize under high-density conditions.

[0072] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1.A method for modulating agronomic traits of maize by mutating endogenous genes ZmTCP4 and ZmTCP14, or ZmTCP4 and ZmTCP14 and ZmTCP25, or ZmTCP4 and ZmTCP14 and ZmTCP16 and ZmTCP25, to obtain a loss-of-function mutant with a phenotype of reduced plant height and / or ear height, wherein the polynucleotide sequence of the endogenous genes is selected from one of the following sequences: (a) the polynucleotide sequence of ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 is shown in SEQ ID No: 1, 9, 16, 22, respectively; (b) the polynucleotide sequence of ZmTCP4, ZmTCP14, ZmTCP16, ZmTCP25 encoding the amino acid sequence shown in SEQ ID No: 2, 10, 17 and / or 23, respectively; or (c) the polynucleotide sequence complementary to any of the sequences of (a) to (b). 2.The method of claim 1, wherein the mutation comprises substitution, deletion and / or addition of one or more nucleotides in the nucleotide sequence of the gene. 3.The method of claim 2, wherein the mutation is obtained by ZFN, TALEN and / or CRISPR / Cas gene editing technology. 4.The method of claim 3, wherein the CRISPR / Cas is CRISPR / Cas9 gene editing method, and the target sequence used is selected from one of the following sequences: (a) a fragment of the nucleotide sequence shown in SEQ ID No: 1, 9, 16 or 22, which conforms to the sequence arrangement rule of 5’-Nx-NGG-3’, wherein N represents any one of A, G, C and T, 14 < X < 30, and X is an integer, Nx represents X consecutive nucleotides; or (b) a nucleotide sequence complementary to the polynucleotide sequence of (a). 5.The method of any one of claims 1 to 4, wherein the polynucleotide sequence of the ZmTCP4 gene after mutation is shown in SEQ ID NO: 3, 4, 5, 6, 7 or 8; the polynucleotide sequence of the ZmTCP14 gene after mutation is shown in SEQ ID NO: 11, 12, 13, 14 or 15; the polynucleotide sequence of the ZmTCP16 gene after mutation is shown in SEQ ID NO: 18, 19, 20 or 21; and the polynucleotide sequence of the ZmTCP25 gene after mutation is shown in SEQ ID NO: 24, 25 or 26. 6.The method of any one of claims 1 to 5 for use in modulating plant height and / or ear height of maize. ​ ​ ​ ​ ​ ​

Images