Gene segment and molecular marker for regulating and controlling ear length and drought resistance of corn and application of gene segment and molecular marker

Abstract

The invention relates to a gene segment for regulating and controlling ear length and drought resistance of corn, a molecular marker and application of the gene segment and the molecular marker. The gene segment for regulating and controlling the ear length and the drought resistance of the corn is a ZmLBD38 gene, and the DNA (Deoxyribose Nucleic Acid) sequence of the gene segment is shown as SEQ ID No: 1. According to the gene segment and the molecular marker for regulating and controlling the ear length and the drought resistance of the corn and the application of the gene segment and the molecular marker, the ZmLBD38 gene, the molecular marker SV292bp, SNP8126851389C / T and the like provided by the invention can be applied to cultivation of new varieties of high-yield or close-planting-resistant corn, and particularly applied to the aspects of improving the ear length of the corn, increasing the yield of the corn and the like.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to gene segments and molecular markers for regulating corn ear length and drought resistance, and applications thereof. Background Art

[0002] Corn (Zea mays L.), one of the world's three major food crops, is not only a vital source of nutrition for humans but also a core raw material for the livestock and bioenergy industries. According to the National Bureau of Statistics, my country's corn planting area consistently exceeds 600 million mu (approximately 1.6 million hectares), and its annual output accounts for over 35% of the country's total grain output. Its stable and high yields are directly linked to my country's food security strategy. Improving corn yields per unit area through corn breeding is a key technical measure to ensure corn supply.

[0003] Maize ear length is a key factor in corn yield. Increased ear length can significantly increase corn yield. Research has shown a positive correlation between ear length and yield. Increased ear length provides more space for kernel development, thereby increasing the number of kernels per row and per ear, and ultimately increasing yield. Ear length is a complex quantitative trait controlled by multiple genes, and research on its genetic basis is of great significance for maize breeding. Through QTL mapping and gene cloning, scientists have identified several genes associated with ear length, such as YIGE1, YIGE2, EAD1, KRN2, and KRN4, providing a theoretical basis for breeding high-yield maize varieties. Mutations in these genes that cause frameshifts, premature termination, or other changes in protein function can alter ear development and lead to adverse effects such as abnormal plant height, poor tassel development, and / or abnormal leaf organ development, making them difficult to directly apply to maize breeding practices.

[0004] ZmLBD38 is a transcription factor of the LATERAL ORGAN BOUNDARIESDOMAIN (LBD) family. As a plant-specific regulatory factor, it plays a key role in many aspects of plant organ development, hormone response, adverse stress response, and growth regulation. However, to date, there are no reports of ZmLBD38 regulating the length phenotype of corn ears. In addition, studies have shown that natural variations in some non-gene coding regions often only change the expression level of genes and rarely bring adverse effects; in particular, some natural variations that have been retained after a long period of breeding selection have broad application prospects in breeding. Based on this, the present invention further explores corn genes through experimental research, and improves corn genes through genetic engineering technology to fully explore the uses of corn genes. Summary of the Invention

[0005] The first invention object of the present invention is to provide a gene fragment for regulating corn ear length and drought resistance. The gene fragment is involved in regulating corn ear length and drought resistance and is valuable for corn stress resistance breeding, etc.

[0006] In order to achieve the above objectives, the technical solutions adopted are:

[0007] The gene segment for regulating corn ear length and drought resistance is the ZmLBD38 gene, and its DNA sequence is shown in SEQ ID No: 1.

[0008] The second object of the present invention is to provide an amino acid for regulating corn ear length and drought resistance.

[0009] In order to achieve the above objectives, the technical solutions adopted are:

[0010] The amino acids that regulate corn ear length and drought resistance are encoded by the above-mentioned gene fragments.

[0011] Furthermore, the amino acid sequence is shown in SEQ ID No: 2.

[0012] The third invention object of the present invention is to provide a molecular marker for regulating corn cob length and drought resistance. The expression of the ZmLBD38 gene in the female ear of corn can be regulated by regulating the molecular marker of corn cob length, which is of great significance for improving corn cob length and corn yield, and can also be further applied to the breeding of new corn varieties.

[0013] In order to achieve the above objectives, the technical solutions adopted are:

[0014] A molecular marker for regulating the expression of the gene fragment according to claim 1 in corn, characterized in that the molecular marker is SNP_8_126851389_C / T and / or SV_292bp, which is a molecular marker that can regulate corn ear length and drought resistance;

[0015] The sequence of SNP_8_126851389_C / T is shown in SEQ ID No: 3;

[0016] The sequence of SV_292bp is shown in SEQ ID No: 4 and SEQ ID No: 5.

[0017] The fourth invention object of the present invention is to provide applications of the above-mentioned gene fragments, amino acids and molecular markers.

[0018] In order to achieve the above objectives, the technical solutions adopted are:

[0019] The application of the above gene fragment in regulating corn ear length and improving drought resistance.

[0020] The above amino acids are used to regulate corn ear length and improve drought resistance.

[0021] The application of the above-mentioned molecular markers in regulating corn ear length and improving drought resistance.

[0022] The application of the above gene fragments in breeding new corn varieties.

[0023] The application of the above amino acids in breeding new corn varieties.

[0024] Application of the above molecular markers in breeding new corn varieties.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The technical solution of the present invention first discloses the application of the ZmLBD38 gene in regulating corn ear length and drought resistance, and its polynucleotide sequence is shown in SEQ ID No.1.

[0027] 2. The technical solution of the present invention provides a key molecular marker for regulating corn ear length. The provided molecular marker for regulating corn ear length can regulate the expression of the ZmLBD38 gene in corn female ears, can be used to improve corn ear length, and can also be further used to cultivate new corn varieties. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The ZmLBD38 gene sequence was constructed into the pYES2-NTB vector and transformed into the yeast strain INVSC1 for drought treatment. The results showed that the ZmLBD38 gene could continue to grow in 135mM PEG solution, indicating that the ZmLBD38 gene is drought-resistant.

[0029] Figure 2 Two variant sites in the ZmLBD38 promoter region were found to be significantly associated with the maize ear length phenotype through GWAS. The two variant sites are SNP_8_126851389_C / T and SV_292bp. The upper part of the figure shows the genetic structure of ZmLBD38 and the location information of the two variant sites, SNP_8_126851389_C / T and SV_292bp.

[0030] Figure 3 The figure shows the variation of 10 different types of inbred lines at the insertion / deletion molecular marker SV_292bp; overall, two haplotypes were formed: Hap1_0 / 0 and Hap2_SV292.

[0031] Figure 4 A is the statistical analysis of the ear length phenotype of two types of inbred lines, Hap1_0 / 0 and Hap2_SV292. Figure 3 Two haplotypes in the middle; Figure 4B is the frequency comparison of the two haplotypes Hap1_0 / 0 and Hap2_SV292 in breeding materials in different breeding eras; overall, the ear length of the haplotype Hap2_SV292 increased during the corn breeding process and the frequency of this haplotype increased during the breeding process. DETAILED DESCRIPTION

[0032] In order to further illustrate the gene fragments, molecular markers and their applications for regulating corn ear length and drought resistance of the present invention and to achieve the intended purpose of the invention, the following, in conjunction with the preferred embodiments, describes in detail the gene fragments, molecular markers and their applications for regulating corn ear length and drought resistance proposed in the present invention, as well as their specific implementation methods, structures, features and their efficacy. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics of one or more embodiments may be combined in any suitable form.

[0033] Before elaborating in detail the gene fragments, molecular markers and applications thereof for regulating corn ear length and drought resistance of the present invention, it is necessary to further explain the relevant terminology mentioned in the present invention to achieve better results.

[0034] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. In the practice or testing of the present invention, any methods, devices and materials similar or equivalent to those described herein may be used.

[0035] The term "polynucleotide" or "nucleotide" means deoxyribonucleotides, deoxyribonucleosides, ribonucleosides or ribonucleotides and polymers thereof in single or double stranded form. Unless specifically limited, the term encompasses nucleic acids containing known analogs of natural nucleotides that have binding properties similar to the reference nucleic acid and are metabolized in a manner similar to naturally occurring nucleotides. Unless otherwise specifically limited, the term also means oligonucleotide analogs, including PNA (peptide nucleic acid), DNA analogs used in antisense technology (phosphorothioate, phosphoramidate, etc.). Unless otherwise specified, a specific nucleic acid sequence also implicitly encompasses conservatively modified variants thereof (including but not limited to degenerate codon substitutions) and complementary sequences as well as explicitly specified sequences. In particular, degenerate codon substitutions can be achieved by generating sequences in which position 3 of one or more selected (or all) codons is substituted with mixed-base and / or deoxyinosine residues (Batzer et al., Nucleic Acid Res. 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. 260:2605-2608 (1985); and Cassol et al., (1992); Rossolini et al., Mol Cell. Probes 8:91-98 (1994)).

[0036] The term "homology" refers to the level of similarity or percent identity between polynucleotide sequences in terms of percentage nucleotide position identity (i.e., sequence similarity or identity). The term homology as used herein also refers to the concept of similar functional properties between different polynucleotide molecules, for example, promoters with similar functions may have homologous cis elements. When polynucleotide molecules specifically hybridize to form duplex molecules under specific conditions, they are homologous. Under these conditions (referred to as stringent hybridization conditions), a polynucleotide molecule can be used as a probe or primer to identify another polynucleotide molecule that has a common homology.

[0037] The "stringent hybridization conditions" described in the present invention refer to conditions of low ionic strength and high temperature as known in the art. Generally, under stringent conditions, the detectable degree of hybridization of the probe to its target sequence is higher than the detectable degree of hybridization to other sequences (for example, at least 2 times higher than the background). Stringent hybridization conditions are sequence-dependent and will be different under different environmental conditions, with longer sequences specifically hybridizing at higher temperatures. By controlling the stringency of hybridization or washing conditions, target sequences that are 100% complementary to the probe can be identified. For detailed guidance on nucleic acid hybridization, reference can be made to 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 generally selected to be lower than the thermal melting point (T ) of the specific sequence at a specified ionic strength pH. m ) about 5-10℃. m The temperature at which 50% of the probes complementary to the target hybridize to the target sequence in equilibrium (under specified ionic strength, pH, and nucleic acid concentration) (because the target sequence is present in excess, the target sequence is present at T m Stringent conditions may be those in which the salt concentration is less than about 1.0 M sodium ion concentration, typically about 0.01 to 1.0 M sodium ion concentration (or other salts), at pH 7.0 to 8.3, 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 may also be achieved by the addition of destabilizing agents such as formamide. For selective or specific hybridization, a positive signal may be at least twice the background hybridization, optionally 10 times the background hybridization. Exemplary stringent hybridization conditions may be as follows: 50% formamide, 5× SSC, and 1% SDS, incubation at 42°C; or 5× SSC, 1% SDS, incubation at 65°C, wash in 0.2× SSC, and wash in 0.1% SDS at 65°C. The washing may be performed for 5, 15, 30, 60, 120 minutes or longer.

[0038] The "multiple" mentioned in the present invention generally means 2-8, preferably 2-4; the "replacement" refers to the replacement of one or more amino acid residues with different amino acid residues; the "deletion" refers to a reduction in the number of amino acid residues, that is, the lack of one or more amino acid residues; the "insertion" refers to a change in the amino acid residue sequence, and the change results in the addition of one or more amino acid residues relative to the natural molecule.

[0039] The term "promoter" refers to a polynucleotide molecule that is located upstream or 5' of the translation start codon of an open reading frame (or protein coding region) in its natural state and is involved in the recognition and binding of RNA polymerase II and other proteins (trans-acting transcription factors) to initiate transcription.

[0040] The term "expression" refers to the transcription and / or translation of an endogenous gene or a transgene in a plant cell.

[0041] After understanding the relevant terms mentioned in the present invention, the gene fragments, molecular markers and their applications for regulating corn ear length and drought resistance of the present invention will be further introduced in detail below in conjunction with specific examples:

[0042] Example 1.

[0043] (1) The ZmLBD38 gene that regulates corn ear length and drought resistance has a polynucleotide sequence, i.e., a DNA sequence, as shown in SEQ ID No: 1. The gene fragment is selected from variety B73.

[0044] SEQ ID No: 1 is ZmLBD38_CDS_B73, specifically:

[0045] atgcggatgagctgcaatggctgccgcgtcctgcgcaagggctgcggcgacgcctgcaccatccgcccctgcctgcagtggatcgaggcccccgaggcgcaggccaacgccaccgtcttcctcgcaaagttctacggccgggcgggcctgctcaacctgctcgccgccgcgcccgacgacggcgtccgccccgcggtcttccgctccctgctctacgaggcgtgcggccgcatcgtcaacccggtctacggctccgtcggcctgctctggtcgcgccagtggcacaggtgcgccgacgccgtcgaggccgtgctcaggggggaccccgtcgtgcaggtcgacgccgggtccgacgccgccgctgccccgccgctgctcgccggcgccaggccgccgccgccggccgccttcgacatccgccacgtccccagggatcccgacgccaccgccgccgacctcctccgcgccggccgcaagaggttcaagcgcgcgggttcgtcttccaacgcctccaaggcgaagcccctgcccctcgagctcgagggcaaggccggcaacaacgaacgcgcgtcgcccagccctcccccgacgcaacaacgagaggcggaggagctgcagccggtgccgatggtcgtcgagccagaacacggcgaggagtccgccggcagccacgaccaccacctgcagctgcaggggtggtcggaggaggacaccgacgtggaggcggcctcacacgtgagccaagccgaggctgagccgccagccagcagccagagccaggtgctggtagcggatcaggaggaagaggaggttgggctcgagctcacgcttgggttcgagcctgtcgtcaggcagcagccgaggtcgtcgcgctgcgacaagagcggcttgagcgcggcatcgagcctcatcggcctgcggctgcagctgccggccgcctaa

[0046] (2) Amino acid

[0047] The amino acid sequence encoded by the polynucleotide sequence shown in SEQ ID No: 1 is shown in SEQ ID No: 2.

[0048] SEQ ID No: 2 is ZmLBD38_Protein_B73, specifically:

[0049] MRMSCNGCRVLRKGCGDACTIRPCLQWIEAPEAQANATVFLAKFYGRAGLLNLLAAAPDDGVRPAVFRSLLYEACGRIVNPVYGSVGLLWSRQWHRCADAVEAVLRGDPVVQVDAGSDAAAAPPLLAGARPPPPAAFDIRHVPRDPDATAADLLRA GRKRFKRAGSSSNASKAKPLPLELEGKAGNNERASPSPPPTQQREAEELQPVPMVVEPEHGEESAGSHDHHLQLQGWSEEDTDVEAASHVSQAEAEPPASSQSQVLVADQEEEEVGLELTLGFEPVVRQQPRSSRCDKSGLSAASSLIGLRLQLPAA

[0050] (3) Molecular markers

[0051] The requirements for other related sequence molecular markers are:

[0052] ① A polynucleotide sequence that can hybridize with the polynucleotide sequence in SEQ ID No: 1 or SEQ ID No: 2 under stringent hybridization conditions, wherein a mutation in the polynucleotide sequence has the function of changing corn ear length and drought resistance.

[0053] ② A polynucleotide sequence having at least 95% or more similarity to any of the polynucleotide sequences shown above, wherein the mutation of the polynucleotide sequence has the function of changing the length and drought resistance of corn ears.

[0054] ③ A polynucleotide sequence complementary to any of the above sequences.

[0055] According to the requirements, the specific molecular markers are:

[0056] Molecular markers regulating corn ear length and drought resistance are SNP_8_126851389_C / T and / or SV_292bp, which are used to regulate the expression of the gene fragment described in SEQ ID No: 1 in corn ears. Specifically, the molecular markers regulating corn ear length in the ZmLBD38 gene are SNP_8_126851389_C / T and SV_292bp. The presence of these molecular markers in corn samples can be used to predict corn ear length variation.

[0057] SNP_8_126851389_C / T is used as a molecular marker for regulating the ZmLBD38 gene to regulate corn ear length. The gene fragment is selected from the variety B73, and the sequence is shown in SEQ ID No: 3, including:

[0058] (a) The nucleotide at position 114 of SEQ ID No: 3 was mutated from C to T.

[0059] (b) The 114th nucleotide from the end of the polynucleotide sequence complementary to SEQ ID No: 3 is mutated from G to A.

[0060] SEQ ID No: 3 is SNP_8_126851389_C / T_B73, specifically:

[0061] tgcctgccgtgccggcacggcacggctaaggatccttagtgccgtgtctgagcctgggttcaggcactagtgccgggccagcacgacaaggttactaatcgtgctaa acgggtcgtgccctaaccgtgccatacctggtcgtgccagtgccgggccgcccatttggccatctataaatctataaatgtagaggccgcgcgcggcggcgccttgc

[0062] SV_292bp was used as a molecular marker for regulating the expression of the ZmLBD38 gene in maize female ears. The gene fragment was selected from varieties B73 and Jing724, and its sequence is shown in SEQ ID No: 4 and SEQ ID No: 5, including:

[0063] (a) SEQ ID No: 4, 292 nucleotides are deleted between nucleotides 84 and 376;

[0064] (b) a polynucleotide sequence complementary to SEQ ID No: 4, wherein 292 nucleotides are missing from the 84th to the 376th nucleotides from the last nucleotide;

[0065] (c) 292 nucleotides are inserted between nucleotides 122 and 123 of SEQ ID No: 5;

[0066] (d) 292 nucleotides are inserted between the 122nd and 123rd nucleotides from the last nucleotide of the polynucleotide sequence complementary to SEQ ID No: 5.

[0067] SEQ ID No: 4 is 292bp_SV_Jing724, specifically:

[0068] acagaaattgaagactaacacttaaatgcttggtcattttttttctctgttggcgtgtgcctgcaggtgatggatgtaacttgtaagagcatctccaagagctctccataaaacgactcctcaaaatcagttttaagggatatctaaataataagtgggggtaaattttaatcctttctccaacaggtcccttaaagcagcagtttgtttctggggagcctaaaaaacccctcatttgtagctacaaatgagggagttttaagggctatgaaaaagttgggggcgctttaggggaactgttggagacatgtttttgtgtttttcccaaaaaaaatagatttaggggagacttctggggagcttttggagatgctctaaggagctacaaaagaccacttttgctctaagatgtatagaaatgcttttcaggaataggaggttggtccctggtccggccctg acagaaattgaagactaacacttaaatgcttggtcattttttttctctgttggcgtgtgcctgcaggtgatggatgtaacttgtaagagcatctccaagagctctccataaaacgactcctcaaaatcagttttaagggatatctaaataataagtgggggtaaattttaatcctttctccaacaggtcccttaaagcagcagtttgtttctggggagcctaaaaaacccctcatttgtagctacaaatgagggagttttaagggctatgaaaaagttgggggcgctttaggggaactgttggagacatgtttttgtgtttttcccaaaaaaaatagatttaggggagacttctggggagcttttggagatgctctaaggagctacaaaagaccacttttgctctaagatgtatagaaatgcttttcaggaataggaggttggtccctggtccggccctg

[0069] SEQ ID No: 5 is 292bp_SV_B73. Specifically:

[0070] gcccaacccctcatattcatcatctgtagacctataccaacagaaattgaagactaacacttaaatgcttggtcattttttttctctgttggcgtgtgcctgcaggtgatggatgtaacttgtaaggagctacaaaagaccacttttgctctaagatgtatagaaatgcttttcaggaataggaggttggtccctggtccggccctgtcacattgccatccctaataatagtactacattgtacgtttaactgttatgtttaactgttatgtagtttgtgaaaagctcaggtatc gcccaacccctcatattcatcatctgtagacctataccaacagaaattgaagactaacacttaaatgcttggtcattttttttctctgttggcgtgtgcctgcaggtgatggatgtaacttgtaaggagctacaaaagaccacttttgctctaagatgtatagaaatgcttttcaggaataggaggttggtccctggtccggccctgtcacattgccatccctaataatagtactacattgtacgtttaactgttatgtttaactgttatgtagtttgtgaaaagctcaggtatc

[0071] Therefore, SV_292bp and SNP_8_126851389_C / T can be used as molecular markers to regulate the expression of ZmLBD38 gene in maize female ears. By detecting the variation of SV_292bp or SNP_8_126851389_C / T, the expression of ZmLBD38 gene in maize can be regulated, thereby achieving the regulation of maize ear length.

[0072] (4) Primers

[0073] Other primers designed based on SEQ ID No: 3, SEQ ID No: 4, and SEQ ID No: 5, or primers designed by other methods, can be used to detect SV_292bp or SNP_8_126851389_C / T variations. These specific detection primers can be used to detect SV_292bp or SNP_8_126851389_C / T variations in corn varieties, thereby being used for molecular-assisted breeding of corn.

[0074] (5) Application

[0075] The above SEQ ID Nos: 1-5 are used in regulating ear length and cultivating new corn varieties with high yield or high density tolerance. The application process is as follows:

[0076] Specific implementation methods include:

[0077] (a) Constructing a ZmLBD38 gene overexpression recombinant plant expression vector; and transforming the constructed overexpression recombinant plant expression vector into corn.

[0078] (b) Molecular markers closely linked to ZmLBD38 were used to backcross the gene into maize with low expression of ZmLBD38.

[0079] (c) Other applications of increasing ear length and improving drought resistance by increasing the expression level of ZmLBD38.

[0080] The ZmLBD38 gene, molecular marker SV_292bp, SNP_8_126851389_C / T, etc. provided by the present invention can be applied to cultivating new varieties of corn that are high-yield or resistant to dense planting, and are particularly applied to aspects such as improving corn ear length and increasing corn yield. By increasing the expression of the ZmLBD38 gene in the corn ear, the corn ear length is increased, and corn yield per unit area is increased. Therefore, other methods for increasing corn ear length and improving corn yield per unit area by changing the expression of the ZmLBD38 gene in the corn ear should all fall within the scope of protection of the present invention; including using other constitutive or tissue-specific promoters and an expression cassette constructed with ZmLBD38 to drive the ZmLBD38 gene to be highly expressed in the corn ear, or by changing the expression of ZmLBD38 in the corn ear by gene editing the promoter of ZmLBD38, or by using other natural variations to change the method for highly expressing the ZmLBD38 gene in the corn ear.

[0081] The present invention can be used to transform any plant species, including but not limited to monocots or dicots, preferably maize.

[0082] Example 2: ZmLBD38 gene regulates drought resistance in maize

[0083] Methods: The ZmLBD38 gene (i.e., sequence SEQ ID No: 1) in Example 1 was constructed into the pYES2-NTB vector. The successfully constructed vector was transformed into the yeast strain INVSC1. The constructed pYES2-NTB-ZmLBD38 and the negative control pyes2-NTB were incubated in SG-U + 0mM, SG-U + 30mM, SG-U + 60mM, SG-U + 90mM, SG-U + 120mM, and SG-U + 135mM PEG liquid culture media for 1 day and their growth status was observed. The dilutions (1, 0.1, and 0.01) were spotted on SG-U plates and cultured in a 30°C incubator. The plates were observed and photographed after 3-4 days.

[0084] Results: As Figure 1 As shown, the experimental results showed that the pYES2-NTB-ZmLBD38 yeast solution could grow normally under the condition of 0.1 times dilution concentration of SG-U+135mM PEG solution, while the control group did not grow, indicating that the ZmLBD38 gene was drought-resistant.

[0085] Example 3: Mutation sites in the ZmLBD38 promoter region regulate corn ear length

[0086] 1. Discovery of variant sites in the ZmLBD38 promoter region

[0087] Using deep (>10×) resequencing data from 350 published maize inbred lines combined with the published maize B73V3 genome, 11,839,476 single nucleotide polymorphism (SNPs) markers were mined from 137 Chinese maize inbred lines. These mined markers were used to estimate the population structure and kinship of the 137 maize inbred lines. GWAS analysis was then performed in conjunction with the ear length phenotypes collected from four environments. Among them, a SNP on chromosome 8, SNP_8_126851389_C / T, was found to be significantly associated with the ear length trait of maize (e.g., Figure 2 Further studies revealed that the mutation site was located in the promoter region of ZmLBD38 (SEQ ID No: 3).

[0088] 2. Obtaining the nucleotide sequence of the genomic region where the structural variation of the ZmLBD38 promoter region is located

[0089] In order to find the structural variation sequence linked to SNP_8_126851389_C / T, the genomic information of 10 maize inbred lines was used to compare the variation of ZmLBD38 gene in 10 genomes. The insertion / deletion fragment SV_292bp significantly linked to the variation site SNP_8_126851389_C / T was found, and the nucleotide sequence of this region and the accurate information of the variation were obtained (such as Figure 3 shown).

[0090] 3. Structural variation in the ZmLBD38 promoter regulates maize ear length

[0091] According to the haplotype of the insertion / deletion fragment SV_292bp, the 137 inbred lines sequenced were divided into two categories: Hap1_0 / 0 and Hap2_SV292 using the variant sequence (SEQ ID No: 4 and SEQ ID No: 5). Figure 3 Comparative analysis of the ear length phenotypes of these two types of representative inbred lines revealed that Hap2_SV292 had a significant effect on increasing corn ear length (e.g. Figure 4 (as shown in A).

[0092] Example 4: The variant sites in the ZmLBD38 promoter region are strongly selected in modern maize breeding.

[0093] In the early stage of this invention, 137 maize inbred line materials from different breeding periods in China were collected, including early China (CN1960s and 1970s), mid-China (CN1980s and 1990s), and current China (CN2000s and 1910s). The frequency distribution of the two haplotypes Hap1_0 / 0 and Hap2_SV292 of ZmLBD38 in these materials was analyzed. It was found that as the breeding period progressed, the frequency of Hap2_SV292 increased significantly in the Chinese maize breeding process, indicating that the haplotype Hap2_SV292 was strongly artificially selected in the modern maize breeding process ( Figure 4 B). This further confirms that the variant sequence in the ZmLBD38 promoter region has important breeding value in modern corn breeding.

[0094] The above is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the embodiments of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the embodiments of the present invention are still within the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gene fragment regulating corn ear length and drought resistance, characterized in that: The gene fragment is the ZmLBD38 gene, and its DNA sequence is shown in SEQ ID No:

1.

2. An amino acid for regulating corn ear length and drought resistance, characterized in that: The amino acids are encoded by the gene fragment according to claim 1.

3. The amino acid sequence according to claim 2, characterized in that The amino acid sequence is shown in SEQ ID No:

2.

4. A molecular marker for regulating the expression of the gene fragment according to claim 1 in corn, characterized in that: The molecular markers are SNP_8_126851389_C / T and / or SV_292bp; The sequence of SNP_8_126851389_C / T is shown in SEQ ID No: 3; The sequence of SV_292bp is shown in SEQ ID No: 4 and SEQ ID No:

5.

5. Use of the gene fragment according to claim 1 in regulating corn ear length and improving drought resistance.

6. Use of the amino acid according to any one of claims 2 to 3 in regulating corn ear length and improving drought resistance.

7. Use of the molecular marker according to any one of claims 4 to 5 in regulating corn ear length and improving drought resistance.

8. Use of the gene fragment according to claim 1 in breeding new corn varieties.

9. Use of the amino acid according to any one of claims 2 to 3 in breeding new corn varieties.

10. Use of the molecular marker according to any one of claims 4 to 5 in breeding new corn varieties.

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