Application of BnaA06.MYBL gene in regulating the height of brassica napus

Abstract

The application discloses application of BnaA06.MYBL gene in regulating plant height of Brassica napus. The application identifies a gene BnaA06.MYBL significantly associated with plant height traits from Brassica napus through whole genome association analysis, the nucleotide sequence of the gene is shown as SEQ ID NO. 1, the amino acid sequence of the encoded protein is shown as SEQ ID NO. 2, and the gene has a higher expression level in stem tip meristem. The application also constructs a 35S promoter driven BnaA06.MYBL gene overexpression vector, and transforms Brassica napus, and the obtained transgenic plant has a plant height which is 35.54% lower than that of a wild type control. The application provides an effective molecular tool for improving plant type of Brassica napus, and can be used for breeding semi-dwarf rapeseed varieties with excellent comprehensive traits and suitable for mechanized harvesting demand.

Description

Technical Field

[0001] This application relates to the field of plant molecular biology technology, specifically to the application of the BnaA06.MYBL gene in regulating the growth and development of Brassica napus plants. Background Technology

[0002] Rapeseed is my country's largest source of edible oil and second largest source of feed protein. Rapeseed production mainly utilizes fallow winter fields, avoiding competition for land with other major grain crops. Therefore, it has enormous potential in terms of planting area, yield, economic benefits, and demand, but also faces significant challenges. Traditional rapeseed production and management suffer from low mechanization, high costs, labor intensity, and low efficiency. Labor shortages in rural areas, coupled with a lack of arable land suitable for commercial rapeseed cultivation, further compel farmers to adopt modern mechanized farming tools. Therefore, a "green revolution" in rapeseed is a current necessity for the rapeseed industry, and improving the rapeseed plant structure is a bottleneck to overcome in this "green revolution" and a major challenge for rapeseed breeding.

[0003] In recent years, significant progress has been made in identifying dwarfing genes in rapeseed. Currently, most cloned dwarfing mutants of Brassica napus are gibberellin and auxin-insensitive mutants. For example, two EMS mutants of rapeseed with a plant height of approximately 70 cm have height-controlling genes located on chromosomes A06 and C07. Studies have confirmed that their dwarfing mechanism is caused by missense mutations in the VHYNP domain of the DELLA protein, a negative regulator of the gibberellin signal transduction pathway. Another example is the mutation in the sca mutant of Brassica napus, which encodes the auxin-inducible protein gene (BnaA3.IAA7). This mutation disrupts the conserved degradation motif GWPPV and reduces the affinity of BnaA3.IAA7 for transport inhibitors in a dose-dependent manner. This change inhibits the degradation of BnaA3.IAA7, thereby suppressing auxin signal transduction and ultimately leading to plant dwarfing.

[0004] Although significant progress has been made in the study of rapeseed plant type traits, existing technologies still have significant shortcomings. First, currently cloned dwarfing genes often result in excessively short rapeseed plants with poor overall traits, such as reduced seed setting rate, decreased biomass, and weakened stress resistance, making them difficult to apply directly in production or having limited application value. Second, existing dwarfing resources mostly rely on mutant materials with a single genetic background, limiting their breeding applications. Furthermore, the field of rapeseed breeding still lacks gene resources that can moderately reduce plant height while maintaining good agronomic traits, and effective molecular tools for fine-tuning plant height are lacking.

[0005] Therefore, there is an urgent need to provide a molecular tool that can effectively regulate the plant height of Brassica napus and apply it to plant type improvement breeding to obtain semi-dwarf varieties. Summary of the Invention

[0006] In view of this, the purpose of this application is to provide an application of the BnaA06.MYBL gene in regulating plant height in Brassica napus. This application identified and obtained a gene, BnaA06.MYBL, significantly associated with plant height in Brassica napus through genome-wide association analysis. This gene exhibits high expression levels in the shoot apical meristem. This application applies this gene to regulate plant height in Brassica napus, and in particular, by promoting the expression of the BnaA06.MYBL gene, it can significantly reduce the plant height of Brassica napus. This application provides an effective molecular tool and a new technical approach for improving the plant architecture of Brassica napus, which will help in breeding semi-dwarf rapeseed varieties with excellent comprehensive traits to meet the needs of mechanized harvesting.

[0007] To achieve the above objectives, this application provides the following technical solution:

[0008] Firstly, this application provides the application of the BnaA06.MYBL gene in regulating the growth rate of Brassica napus plants.

[0009] In some embodiments, the nucleotide sequence of the BnaA06.MYBL gene is shown in SEQ ID NO.1, and the amino acid sequence of the protein encoded by the BnaA06.MYBL gene is shown in SEQ ID NO.2.

[0010] In some implementations, the regulation is negative regulation, that is, promoting the expression of the BnaA06.MYBL gene and reducing the plant height of Brassica napus.

[0011] In some embodiments, the negative regulation is achieved by constructing a recombinant vector to promote the expression of the BnaA06.MYBL gene and transforming the recombinant vector into Brassica napus plants to achieve negative regulation of Brassica napus plant height.

[0012] In some embodiments, the recombinant vector is a 35S promoter-driven BnaA06.MYBL gene overexpression vector, the construction of which includes the following steps:

[0013] (1) Synthesize the BnaA06.MYBL gene, the nucleotide sequence of which is shown in SEQ ID NO.1;

[0014] (2) The BnaA06.MYBL gene was ligated into the pCAMBIA1300 vector via homologous recombination to obtain the recombinant vector.

[0015] In some embodiments, the transformed Brassica napus plants are produced using an Agrobacterium-mediated transformation method.

[0016] In some preferred embodiments, the rapeseed plant is the variety "Zhongshuang 11".

[0017] Secondly, this application provides a method for cultivating Brassica napus with reduced plant height, comprising the following steps: promoting the expression of the BnaA06.MYBL gene in Brassica napus to obtain transgenic plants with increased BnaA06.MYBL gene expression, wherein the plant height of the transgenic plants is reduced compared to wild-type Brassica napus.

[0018] In some embodiments, the promotion of BnaA06.MYBL gene expression is achieved by transforming a recombinant vector into Brassica napus plants; the recombinant vector is a 35S promoter-driven BnaA06.MYBL gene overexpression vector, the construction of which includes the following steps:

[0019] (1) Synthesize the BnaA06.MYBL gene, the nucleotide sequence of which is shown in SEQ ID NO.1;

[0020] (2) The BnaA06.MYBL gene was ligated into the pCAMBIA1300 vector via homologous recombination to obtain the recombinant vector.

[0021] In some embodiments, the transformation is performed using Agrobacterium-mediated transformation, wherein the Agrobacterium is a GV3101 strain containing a BnaA06.MYBL gene overexpression vector driven by the aforementioned 35S promoter.

[0022] Thirdly, this application provides the application of promoter variation of the BnaA06.MYBL gene in regulating the height of Brassica napus plants. The promoter variation is manifested as different haplotypes in the promoter region. By detecting different haplotypes in the promoter region, tall or short Brassica napus germplasm resources can be screened, or it can be used as a molecular marker-assisted selection for breeding of Brassica napus plant height traits.

[0023] Compared with the prior art, the present application provides at least the following beneficial effects:

[0024] 1. This application cloned and identified a gene, BnaA06.MYBL, significantly associated with plant height trait from a Brassica napus germplasm resource population through genome-wide association analysis. This gene exhibits high expression levels in shoot apical meristems, and different haplotypes in its promoter region are significantly correlated with plant height phenotype. Applying this gene to the regulation of Brassica napus plant height compensates for the scarcity of existing dwarfing gene resources in rapeseed and the poor overall traits of existing dwarf mutants, making them difficult to directly apply to production. This provides a new and effective molecular tool and technical approach for improving the plant architecture of Brassica napus.

[0025] 2. This application demonstrates that overexpression of the BnaA06.MYBL gene significantly reduces the plant height of Brassica napus, providing a new approach for breeding semi-dwarf rapeseed varieties. This application constructed a 35S promoter-driven BnaA06.MYBL gene overexpression vector, which was transformed into Brassica napus using Agrobacterium-mediated transformation. The resulting transgenic plants were 35.54% shorter than the wild-type control. Furthermore, because the BnaA06.MYBL gene specifically regulates plant height, it does not lead to excessively stunted plants, which is beneficial for breeding semi-dwarf, compact varieties with excellent overall traits to meet the demands of mechanized rapeseed harvesting.

[0026] 3. This application provides a convenient approach for early screening and marker-assisted breeding of plant height traits in Brassica napus. This application identified a significant association between different haplotypes in the promoter region of the BnaA06.MYBL gene and plant height traits in Brassica napus. By detecting the haplotypes in this promoter region, tall or short plants in Brassica napus germplasm resources or breeding populations can be effectively screened and identified at the seedling stage without relying on naturally matured phenotypes. This significantly improves the early selection efficiency of plant type breeding and accelerates the breeding process of varieties with ideal plant types. Attached Figure Description

[0027] Figure 1 This is a diagram showing the phenotypic results of the plant height trait of the rapeseed germplasm resource population in Example 1 of this application.

[0028] Figure 2 This is a diagram showing the results of genome-wide association analysis in Example 1 of this application for identifying genes related to plant height in Brassica napus; where A is the Manhattan diagram, B is the LD Block diagram, C is the expression analysis diagram of each gene in different tissues of Brassica napus within the candidate region, and D is the association analysis diagram of different haplotypes in the promoter region of the BnaA06.MYBL gene with plant height phenotype.

[0029] Figure 3 This is the functional verification result of the regulation of plant height trait in Brassica napus by overexpression of the BnaA06.MYBL gene in Example 3 of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] The materials used in the following examples are merely illustrative and not limited to these. Those skilled in the art can use other similar materials as substitutes. Unless otherwise specified, the instruments used are operated under conventional conditions or conditions recommended by the manufacturer. Unless otherwise stated, the technical means used in the examples are all conventional means well known to those skilled in the art, such as those described in "Molecular Cloning: A Laboratory Manual (Fourth Edition)" published by Cold Spring Harbor Laboratory.

[0032] It should be noted that those skilled in the art will understand that the method of obtaining the target gene is not limited to the PCR amplification method described in the examples; when the nucleotide sequence of the target gene is disclosed, the target gene can be directly synthesized by chemical synthesis based on the sequence information, which is also a conventional and clearly feasible technical means in the art, and commercial gene synthesis services are now widely available, without relying on natural templates or original biological materials.

[0033] In this application, unless the context clearly indicates otherwise, the terms “including,” “comprising,” “containing,” “having,” etc., shall be understood as open-ended and mean “including but not limited to.”

[0034] To better understand this teaching and without limiting its scope, all figures and other numerical values ​​used in the specification and claims to express quantities, percentages, or proportions should, in all cases, be understood to be modified by the term "about." Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​that may be adjusted according to the desired performance. At a minimum, each numerical parameter should be interpreted based on the reported significant figures and by applying common rounding techniques.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter of this application pertains. Before a detailed description of this application, the following explanations of terminology are provided to better understand this application.

[0036] 1. Plant height (PH): refers to the vertical distance from the base of the plant (cotyledonary node) to the highest point of the plant (growing point or apical meristem). In this application, for Brassica napus, the specific measurement standard is: the height from the cotyledonary node to the top of the plant (or the highest part of the plant).

[0037] 2. Genome-wide association analysis (GWAS): This refers to an analytical method that uses natural populations as materials and leverages the linkage disequilibrium (LD) principle to detect genetic markers or candidate genes associated with a target trait across the entire genome.

[0038] 3. Linkage disequilibrium (LD): refers to the phenomenon of non-random combination of alleles at different loci, and is the genetic basis of association analysis.

[0039] 4. Haplotype: refers to a group of related polymorphic sites (such as SNPs) located in a specific region of the same chromosome that tend to be inherited as a whole by offspring.

[0040] 5. Overexpression: refers to the use of genetic engineering techniques to make the transcription or translation level of a specific gene in the host cell significantly higher than its endogenous expression level.

[0041] 6. Promoter variation: refers to natural variations in the promoter region of a gene, including but not limited to single nucleotide polymorphisms (SNPs), insertions / deletions (InDel), etc. Different forms of variation can lead to differences in gene expression levels.

[0042] In the following embodiments, the rapeseed variety is the representative variety "Zhongshuang 11" (ZS11), which originated from the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences; the "two-year multi-point" is a standard field trial design model, which means regional trials or production trials conducted in two different years and multiple different locations.

[0043] Example 1: Screening and identification of genes related to plant height in Brassica napus

[0044] 1. Phenotypic determination of plant height trait in Brassica napus germplasm resources

[0045] This embodiment used 226 Brassica napus germplasm resources collected from major rapeseed-producing countries worldwide as the association analysis population. Direct seeding was employed with a row spacing of 33 cm and a plant spacing of 15 cm, with four rows planted per plot. A randomized block design was used, with three biological replicates. Protective rows were planted around the perimeter of the experimental plots to avoid marginal effects. After the plants matured, 10 Brassica napus plants were randomly selected from each plot, and their plant height was measured and phenotypic data recorded.

[0046] Phenotypic determination results are as follows Figure 1 As shown in the figure, the frequency distribution histogram of best linear unbiased prediction (BLUP) is presented, with the vertical axis representing the frequency of different plant heights. The results show that the plant height trait of this germplasm resource population exhibits a continuous normal distribution, indicating that plant height is a typical quantitative trait suitable for genome-wide association analysis.

[0047] 2. Obtaining high-quality SNP datasets for related populations

[0048] Genomic DNA (gDNA) was extracted from young leaves of 226 germplasm resources using the CTAB method. The specific steps are as follows:

[0049] (1) Rinse the tender leaves in a 10% ethanol solution;

[0050] (2) Cut 0.1 g of leaf tissue, place it in a mortar, add liquid nitrogen and grind it quickly into powder;

[0051] (3) Transfer the powder to a centrifuge tube, add 700 μL of CTAB extraction solution (Beijing Zhongke Ruitai Biotechnology Co., Ltd., product number: RTG2405), mix thoroughly, and then place in a 65 ℃ water bath for 1 h, mixing once every 10-15 min during the process.

[0052] (4) Add 700 μL of the first mixture (phenol, chloroform and isoamyl alcohol in a volume ratio of 25:24:1) and mix by inverting for 10 min;

[0053] (5) Centrifuge at 25 ℃ and 10000 g for 15 min;

[0054] (6) Take the supernatant, add an equal volume of the second mixture (chloroform and isoamyl alcohol in a volume ratio of 24:1), mix by inversion, let stand for 5 min, and centrifuge at 10000 g for 15 min.

[0055] (7) Take the supernatant, add 2 times the volume of anhydrous ethanol, mix well, let stand at -20 ℃ for 1 h, centrifuge at 10000 g for 10 min, and discard the supernatant.

[0056] (8) Add 500 μL of 75% ethanol solution to wash the precipitate, remove the supernatant, repeat the washing twice, and then air dry the precipitate.

[0057] (9) Add 100 μL of RNase A solution with a mass concentration of 2%, let stand at 37 °C for 1 h, and then transfer to 4 °C overnight;

[0058] (10) Add an equal volume of the second mixture to extract DNA again, invert and mix well, let stand for 10 min, and centrifuge at 10000 g for 15 min to remove RNase A components.

[0059] (11) Take the supernatant, centrifuge again for 1 min, and collect the genomic DNA (gDNA).

[0060] The concentration, quality, and integrity of the extracted DNA were assessed using agarose gel electrophoresis and UV spectrophotometry to ensure that the OD260 / 280 ratio of all DNA samples was between 1.8 and 2.0. DNA samples that passed quality control were then sent to BGI Genomics Co., Ltd. in Shenzhen for 7× coverage depth whole-genome resequencing.

[0061] The sequencing data were assessed using FastQC software (https: / / www.bioinformatics.babraham.ac.uk / projects / fastqc / ). Adapter sequences and low-quality reads were filtered to obtain clean data for each sample. Reference genome alignment and variant detection were performed on the clean data using BWA (https: / / github.com / lh3 / bwa) and GATK (https: / / github.com / broadinstitute / gatk) software to obtain the total SNP dataset for the associated population. The total SNP dataset was further filtered using the criteria of "minimum allele frequency (MAF) ≥ 0.05, deletion rate ≤ 0.1%, and heterozygosity ≤ 0.15" to obtain a high-quality SNP dataset for subsequent genome-wide association studies.

[0062] 3. Genome-wide association analysis and screening of superior haplotypes for plant height trait.

[0063] Genome-wide association analysis (GWAS) was performed on the above plant height phenotypic data and high-quality SNP genotypic data using the software EMMAX (https: / / csg.sph.umich.edu / kang / emmax / download / ). The Q+K model in the mixed linear model (MLM) (with the population structure Q matrix and the kinship K matrix as covariates) was used to control for false positive associations caused by population stratification.

[0064] GWAS analysis results are as follows Figure 2 As shown. Among them, Figure 2 Figure A in the figure is a Manhattan plot from a GWAS analysis. Figure 2 Figure B in the diagram is the LD Block diagram (linkage disequilibrium block diagram) from the GWAS analysis. The results showed that under different models, SNP peaks significantly associated with plant height (p<10) were detected on chromosome A06 of Brassica napus. -7 This indicates that a key gene locus regulating plant height exists in this chromosome segment.

[0065] The expression patterns of each gene within the candidate region in different tissues of Brassica napus were analyzed, and the results are as follows: Figure 2 As shown in Figure C. The results showed that among the multiple genes within the candidate region, only the BnaA06.MYBL gene exhibited the highest expression level in the shoot apical meristem, suggesting that this gene may be involved in regulating the plant height development of Brassica napus.

[0066] Further analysis revealed a significant association between different haplotypes in the promoter region of this gene and the plant height phenotype of Brassica napus. Stratified comparison of different haplotypes in the promoter region of the BnaA06.MYBL gene yielded the following results: Figure 2 As shown in Figure D, the results showed that individuals of Brassica napus carrying different promoter haplotypes exhibited significant differences in plant height phenotype, indicating that the natural variation in the promoter region of the BnaA06.MYBL gene is closely related to plant height trait, and the haplotype of this promoter region can serve as a molecular marker for screening plant height trait.

[0067] This application names the highly correlated gene located on chromosome A06 as the BnaA06.MYBL gene, whose nucleotide sequence is shown in SEQ ID NO.1 (sequence length 888 bp), and whose amino acid sequence encoding the protein is shown in SEQ ID NO.2 (amino acid sequence length 295 aa). The specific sequence is as follows:

[0068] BnaA06.MYBL gene (SEQ ID NO.1):

[0069] ATGGAGAGTGTGGCAGTTACATGGAGCAGAGAAGAAGAGAAATCATTCGAGAACGCAATTGCTATACATTGTGTAGGAGAAGAGATAACAGAGGAAAAATGGAGCAAAATGGCGTCAACGGTTCCAACAAAAACGTTAGAACAAGTAAAGAAACATTACCAAATCCTTTTAGAAGACGTGAAGGCAATAGAGAACGGACAAGTCCCATTGCCTCGTTATCACAGAACCGGAGACGAAGCTTCTCCTGCGAACAGAGACTGTCATTCCTCCGGTGGAAGCGGATCACCGGAGAAGAAACCAAACCACGGAGTCTCCGGGACAAATGGCGGCGGAAGAAGTAGTTCAAGACATGAGCAGGAGAGAAGAAAAGGGATTCCATGGACAGAAGAAGAGCATAGGTTGTTTCTGTTGGGTTTGGAGAAATTTGGGAAGGGAGATTGGAGAAGCATCTCAAGGAACTTTGTGATCACAAGAACACCAACTCAAGTAGCAAGTCATGCTCAAAAATACTTCATCAGGCTTAACTCGATGAACCGAGATCGAAGACGGTCTAGCATTCACGACATCACTTCTGTGAACAATCAAGCTCCTGCGGTTACAGGACAACAACAGCAACAAGTAGCTAAACCTAGACCAGCACAGCCGCAACCGCATCATCCGACAATGGCTGGAGTAGGGATGTATGGTGGTGCGCCTGTGGGACAACCGATTATTGCACCACCTGATCATATGGGTTCAGCTGTTGGAACACCAGTGATGCTTCCACCTCCAATGGGAGCTCATCATCATCATCATCCCCATCATCTTGGAGTTGCTCCTTATGCTGTACCGGCTTATCCGGTTCCACCGATACCGCAACAACATCCAACTCCGTCGACTATGCATTGA

[0070] BnaA06.MYBL protein (SEQ ID NO. 2):

[0071] MESVAVTWSREEEKSFENAIAIHCVGEEITEEKWSKMASTVPTKTLEQVKKHYQILLEDVKAIENGQVPLPRYHRTGDEASPANRDCHSSGGSGSPEKKPNHGVSGTNGGGRSSSRHEQERRKGIPWTEEEHRLFLLGLEKFGKGDW RSISRNFVITRTPTQVASHAQKYFIRLNSMNRDRRRSSIHDITSVNNQAPAVTGQQQQQVAKPRPAQPQPHHPTMAGVGMYGGAPVGQPIIAPPDHMGSAVGTPVMLPPPMGAHHHHHPHHLGVAPYAVPAYPVPPIPQQHPTPSTMH

[0072] Example 2: Construction of BnaA06.MYBL gene overexpression vector and genetic transformation of Brassica napus

[0073] To verify the biological function of the BnaA06.MYBL gene in regulating the plant height phenotype of Brassica napus, this embodiment constructed a BnaA06.MYBL gene overexpression vector driven by the cauliflower mosaic virus 35S promoter and transformed it into Brassica napus plants for functional verification.

[0074] 1. Amplification of the CDS sequence of the BnaA06.MYBL gene

[0075] Using the CDS sequence (SEQ ID NO.1, sequence length 888 bp) of the haplotype BnaA06.MYBL cloned in Example 1 and the cDNA of Brassica napus ZS11 as templates, the BnaA06.MYBL sequence was obtained by PCR amplification using the upstream primer BnaA06.MYBL-F (ATGGAGAGTGTGGCAGTTAC, SEQ ID NO.3) and the downstream primer BnaA06.MYBL-R (TCAATGCATAGTCGACGGAG, SEQ ID NO.4).

[0076] 2. Construction of recombinant vectors

[0077] The BnaA06.MYBL gene sequence obtained in the above steps was ligated into the pCAMBIA1300 vector (Biovector NTCC Inc., catalog number: pCambia1300) via homologous recombination. Specifically, using SacI and XbaI as upstream and downstream restriction enzyme sites, the BnaA06.MYBL gene CDS was inserted downstream of the 35S promoter to obtain a 35S promoter-driven BnaA06.MYBL gene overexpression recombinant vector (denoted as 35S:BnaA06.MYBL recombinant vector). The specific conditions for the homologous recombination reaction, the transformation of the recombinant product, and the screening and identification of positive clones can all be performed according to standard procedures in this field or the instructions of relevant molecular biology kits, and will not be elaborated here.

[0078] 3. Agrobacterium-mediated genetic transformation

[0079] The constructed 35S:BnaA06.MYBL recombinant vector was transformed into Agrobacterium strain GV3101 (Beijing Cooler Master Technology Co., Ltd., catalog number: CC405) by freeze-thaw method or electroporation method, and positive transformants were obtained by antibiotic screening.

[0080] Using the Brassica napus cultivar "Zhongshuang 11" as the recipient plant, genetic transformation was performed via Agrobacterium-mediated hypocotyl infection. Transformed progeny plants were screened for antibiotic resistance. The integration and expression of the BnaA06.MYBL gene in the resistant plants were verified by PCR amplification and sequencing. Positive transgenic plants containing the 35S:BnaA06.MYBL recombinant vector were then selected. These positive transgenic plants were self-pollinated to obtain homozygous T1 generation seeds.

[0081] Example 3: Functional verification of the effect of overexpression of the BnaA06.MYBL gene on plant height in Brassica napus.

[0082] Transgenic homozygous T1 generation seeds containing the 35S:BnaA06.MYBL recombinant vector obtained in Example 2 and wild-type Brassica napus ZS11 seeds (as a control group) were sown simultaneously under the same field planting and management conditions as in Example 1. Plant height was measured at maturity using the same method described in Example 1. Positive identification of plants (PCR amplification and sequencing) was repeated throughout the experiment to ensure that the statistical population consisted entirely of positive transgenic plants.

[0083] Data analysis: At least 10 plants were measured in each group, and the mean and standard deviation were calculated. Student's t test was used to analyze the significance of the difference between transgenic plants and control plants (p<0.05 was considered significant).

[0084] Plant height statistics results are as follows Figure 3As shown in the figure. The results showed that the plant height of the 35S:BnaA06.MYBL transgenic rapeseed was significantly lower than that of the wild-type control plant, with a decrease of 35.54%, and the difference was statistically significant by t-test.

[0085] The above results indicate that the BnaA06.MYBL gene has a negative regulatory effect on the plant height of Brassica napus. Specifically, promoting the overexpression of the BnaA06.MYBL gene significantly reduces the plant height of Brassica napus, without observing excessive dwarfing or significantly poor overall traits. Therefore, the BnaA06.MYBL gene and its overexpression can be applied to the breeding of semi-dwarf and compact plant types in Brassica napus, providing an effective molecular tool for improving plant type and breeding mechanized harvesting varieties.

[0086] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. The application of the BnaA06.MYBL gene in regulating the height of Brassica napus plants, characterized by, The nucleotide sequence of the BnaA06.MYBL gene is shown in SEQ ID NO.1, and the amino acid sequence of the protein encoded by the BnaA06.MYBL gene is shown in SEQ ID NO.2; the regulation is negative regulation, that is, promoting the expression of the BnaA06.MYBL gene and reducing the plant height of Brassica napus.

2. The application according to claim 1, characterized in that, The method to achieve the negative regulation is as follows: a recombinant vector for promoting the expression of the BnaA06.MYBL gene is constructed, and the recombinant vector is transformed into Brassica napus plants to achieve negative regulation of the plant height of Brassica napus.

3. The application according to claim 2, characterized in that, The recombinant vector is a 35S promoter-driven overexpression vector of the BnaA06.MYBL gene, and its construction includes the following steps: (1) Synthesize the BnaA06.MYBL gene, the nucleotide sequence of which is shown in SEQ ID NO.1; (2) The BnaA06.MYBL gene was ligated into the pCAMBIA1300 vector via homologous recombination to obtain the recombinant vector.

4. The application according to claim 3, characterized in that, The transformed Brassica napus plants were obtained using the Agrobacterium-mediated transformation method.

5. The application according to any one of claims 1-4, characterized in that, The rapeseed plant in question is of variety "Zhongshuang 11".

6. A method for cultivating Brassica napus with reduced plant height, characterized in that, Includes the following steps: To promote the expression of the BnaA06.MYBL gene in Brassica napus, transgenic plants with increased BnaA06.MYBL gene expression were obtained, and the plant height of the transgenic plants was reduced compared to wild-type Brassica napus. The promotion of BnaA06.MYBL gene expression was achieved by transforming a recombinant vector into Brassica napus plants. The recombinant vector was a 35S promoter-driven BnaA06.MYBL gene overexpression vector, and its construction included the following steps: (1) Synthesize the BnaA06.MYBL gene, the nucleotide sequence of which is shown in SEQ ID NO.1; (2) The BnaA06.MYBL gene was ligated into the pCAMBIA1300 vector via homologous recombination to obtain the recombinant vector; The transformation was performed using Agrobacterium-mediated transformation, wherein the Agrobacterium was strain GV3101 containing the BnaA06.MYBL gene overexpression vector driven by the aforementioned 35S promoter.

7. Application of promoter variation of the BnaA06.MYBL gene in regulating the height of Brassica napus plants, characterized by, The nucleotide sequence of the BnaA06.MYBL gene is shown in SEQ ID NO.1; the promoter variation is manifested as different haplotypes in the promoter region. By detecting different haplotypes in the promoter region, tall or short Brassica napus germplasm resources can be screened, or it can be used as a molecular marker-assisted selection for breeding of Brassica napus plant height traits.

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