Gene sw18.1, use of the encoded protein in modulating soybean seed traits
Patent Information
- Application Number
- CN202611386019.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-08
- Publication Date
- 2026-11-03
AI Technical Summary
Existing technologies are insufficient to effectively and precisely locate and clone key genes that regulate the 100-seed weight of soybeans, resulting in low efficiency of direct phenotypic selection. Furthermore, the differential regulatory mechanisms of homologous genes between cultivated and wild soybeans are unclear, affecting high-yield molecular breeding of soybeans.
The SW18.1 gene on soybean chromosome 18 was precisely located and cloned, and it was confirmed to be the major E3 ubiquitin ligase that regulates the 100-seed weight of soybean. By regulating the seed traits of plants through gene editing and overexpression, a method for improving soybean seed size was provided.
This study enabled precise control of the 100-seed weight of soybeans, significantly increasing seed size, including 1000-seed weight, seed length, and seed width, and provided core gene targets and theoretical support for high-yield molecular breeding of soybeans.
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Figure CN123027248A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the fields of molecular biology and soybean breeding technology, specifically relating to the application of soybean gene SW18.1 and its encoded protein in regulating soybean grain traits. Background Technology
[0002] Soybean [Glycine max (L.) Merr.] is an important global economic crop used for both food and oil production. It is a major source of vegetable oil and high-quality plant protein, as well as a core raw material for feed protein. Currently, my country's dependence on imported soybeans remains high, and insufficient domestic soybean production capacity has become a key bottleneck restricting my country's food and oil security and the stable development of the feed industry. Therefore, developing high-yield soybean varieties is the core research goal of domestic soybean breeding.
[0003] Soybean yield is comprised of three core traits: number of plants per unit area, number of seeds per plant, and 100-seed weight, with 100-seed weight being one of the key traits determining soybean yield. However, 100-seed weight is a complex quantitative trait, controlled by multiple genes and easily influenced by the environment, making direct phenotypic selection inefficient. To date, although more than 400 QTLs regulating soybean 100-seed weight have been reported, only a portion of the key genes regulating it have been identified. Currently, a large number of 100-seed weight QTLs have not yet been finely mapped and their functional genes have not been cloned. Due to their large mapping regions, these 100-seed weight QTLs cannot yet be directly applied to marker-assisted breeding and gene-editing-directed breeding.
[0004] Existing research indicates that cloned genes controlling 100-grain weight primarily involve the ubiquitin-proteasome pathway, hormone pathway, and photoperiod pathway. E3 ubiquitin ligases play a crucial regulatory role in plant seed development and cell proliferation; however, the major E3 ubiquitin ligase gene controlling 100-grain weight on soybean chromosome 18 has not yet been cloned and its function verified. Natural allelic variations exist between cultivated and wild soybean homologous genes, and these superior natural variations are core genetic resources for soybean domestication and variety improvement. However, the differential regulatory mechanisms of these two types of homologous genes on grain development remain unclear. Therefore, there is an urgent need for applied research on genes and proteins regulating soybean 100-grain weight to provide core gene targets and theoretical support for high-yield molecular breeding of soybean. Summary of the Invention
[0005] The technical problem this invention aims to solve is how to improve the 100-seed weight and seed size of soybeans. Given the gaps in existing research, this invention provides the application of gene SW18.1 and its encoded protein in regulating soybean seed traits. This invention precisely locates the major QTL for soybean 100-seed weight, performs map-based cloning of the key functional gene SW18.1, and systematically verifies its biological function, providing core gene targets and theoretical support for high-yield molecular breeding of soybeans.
[0006] The technical solution provided by this invention is as follows:
[0007] The application of the SW18.1 gene, its encoded protein, or biological materials containing the gene in regulating soybean seed traits, wherein the amino acid sequence of the protein encoded by the SW18.1 gene is shown in SEQ ID NO: 1; the CDS sequence of the SW18.1 gene is shown in SEQ ID NO: 2; and its full-length nucleotide sequence is shown in SEQ ID NO: 3.
[0008] Furthermore, the biological material is a recombinant vector expressing sgRNA that targets and knocks out the SW18.1 gene; the sgRNA is a guide RNA that targets and knocks out the SW18.1 gene; the sgRNA sequence of the SW18.1 gene is shown in SEQ ID NO: 4 and SEQ ID NO: 5.
[0009] The present invention also provides a method for identifying the type of gene editing in soybean SW18.1, comprising the following steps: performing PCR on soybean genomic DNA using primer sequences shown in SEQ ID NO: 6-9, sequencing the PCR product, comparing the sequencing results with the original sequence of wild-type unedited soybean SW18.1 gene, and determining the type of gene editing mutation.
[0010] The present invention also provides a method for regulating the seed traits of plants, which obtains transgenic plants by regulating the expression of the SW18.1 gene in plants, thereby achieving targeted regulation of the seed traits of plants; the CDS sequence of the SW18.1 gene is shown in SEQ ID NO: 2.
[0011] Furthermore, the grain characteristics include at least one of the following: 100-grain weight, grain length, grain width, and grain thickness.
[0012] Furthermore, the regulation of the SW18.1 gene involves overexpression of the SW18.1 gene.
[0013] Furthermore, the primer sequences for gene amplification and vector construction of the transgenic plant are shown in SEQ ID NO: 44~47.
[0014] Furthermore, the plant is soybean or Arabidopsis thaliana.
[0015] This invention also provides a method for identifying soybean seed traits, which involves performing PCR on soybean genomic DNA using primer sequences shown in SEQ ID NO: 6-9, sequencing the PCR product, comparing the sequencing results with the original sequence of the wild-type unedited soybean SW18.1 gene, and determining the gene editing mutation type; if the identification result is wild-type, the seed traits are superior; if the identification result is mutant, the seed traits are inferior.
[0016] The present invention also provides an allele that regulates soybean seed traits. The allele is located on soybean chromosome 18, 5828967~5831963 bp, with a total genome length of 2996 bp and a coding region of 732 bp. The sequence of the allele is shown in SEQ ID NO: 3. A base mutation on the 4th exon of the allele results in a mutation of the encoded amino acid from serine to threonine.
[0017] This invention provides the application of the SW18.1 gene and its encoded protein in regulating the 100-seed weight of soybean. The gene encodes an E3 ubiquitin ligase, and the amino acid sequence of the encoded protein is shown in SEQ ID NO: 1, the CDS sequence is shown in SEQ ID NO: 2, and the full-length nucleotide sequence is shown in SEQ ID NO: 3.
[0018] This invention completed the fine mapping and gene cloning of the major site qSW18.1 for soybean 100-seed weight, discovering a gene SW18.1 that regulates soybean 100-seed weight. This gene is located on soybean chromosome 18, 5828967~5831963 bp, with a total genome length of 2996 bp and a coding region of 732 bp. Cultivated soybean NN1138-2 and wild soybean N24852 have a single-base non-synonymous mutation in this gene, where the G in cultivated soybean NN1138-2 is mutated to the C in wild soybean N24852 at base 1715, resulting in a change from serine to threonine in exon 4. The cultivated allele GmSW18.1 has a synergistic effect on 100-seed weight, while the wild-type allele GsSW18.1 has a detrimental effect.
[0019] This invention provides a breeding method for targeted improvement of soybean 100-seed weight: Upregulating the soybean cultivar allele GmSW18.1 can significantly increase Arabidopsis seed size, including 1000-seed weight, seed length, seed width, and seed thickness; knocking out the cultivar allele GmSW18.1 will lead to a significant decrease in various soybean seed traits, including 100-seed weight, seed length, seed width, and seed thickness.
[0020] Beneficial effects
[0021] This invention marks the first time that the major-effect E3 ubiquitin ligase gene SW18.1, which regulates soybean 100-seed weight, has been precisely located and cloned on soybean chromosome 18. It clarifies that this gene has a positive biological function in regulating soybean seed size, including increasing 100-seed weight, seed length, width, and thickness. This invention provides a novel method for improving soybean 100-seed weight. It can create new large-seed soybean materials through overexpression of the cultivar allele GmSW18.1, and can also reverse-engineer seed traits through SW18.1 gene editing, providing a key target for soybean germplasm resource domestication and the discovery of superior alleles. Attached Figure Description
[0022] Figure 1 The population 100-seed weight representation used for fine mapping of the qSW18.1 site for soybean 100-seed weight; among which, Figure 1 In figure A, the seed morphology comparison is shown between the parents NN1138-2 and NIL-w used to construct the secondary mapping population NZR-F2. NIL-w is a near-isogenic line carrying wild-type allelic variation. Figure 1 Differences in grain morphology in BG between NN1138-2 and NIL-w; Figure 1 H represents the distribution of the number of times the 100 grains are weighed in the secondary mapping population NZR-F2.
[0023] Figure 2 This is a map-based clone of the soybean 100-seed weight gene SW18.1; among which, Figure 2 In Figure A, the results of single-marker analysis of the 100-grain heavy locus qSW18.1 based on the secondary mapping population NZR-F2 are shown. Figure 2 B is a high-density genetic map constructed for the preliminary mapping region of qSW18.1; Figure 2 C represents the linkage mapping results of qSW18.1 based on high-density genetic maps; Figure 2 D represents the fine localization of qSW18.1 of 6 recombinant individuals within the secondary mapping population NZR-F2; Figure 2 E represents the fine mapping of qSW18.1 of four recombinant individuals derived from the remaining heterozygous line; Figure 2 The diagram in F represents the analysis of key candidate genes within the finely mapped region and the structural diagram of genes with non-synonymous mutations.
[0024] Figure 3 Construction of the SW18.1 gene-editing mutant; among which, Figure 3 In the middle, A represents the CRISPR / Cas9 target sequence; Figure 3 Figure B shows the nucleotide sequence variations of the SW18.1 gene-editing mutants, where SP1 and SP2 edit two target sites of SW18.1; Figure 3 C represents the amino acid sequence variation of the gene-editing material.
[0025] Figure 4 A comparison of seed and plant traits between the SW18.1 gene-edited mutant and the recipient; among them, Figure 4 In section A, the mature edited mutant and the recipient's grain and plant phenotypes are compared. Figure 4 The values for BE represent the differences between the edited mutant and the recipient in terms of grain weight per 100 grains, grain length, grain width, and grain thickness, respectively. KO#1-2, KO#6-5, KO#4-1, and KO#3-6 are SW18.1 gene edited mutants with Wm82 as the recipient, respectively.
[0026] Figure 5To compare the phenotypes of Arabidopsis seeds and plants overexpressing GmSW18.1 / GsSW18.1; among them, Figure 5 In Figure A, the difference in thousand-seed weight between Arabidopsis thaliana overexpressing the cultivated soybean allele GmSW18.1 / wild soybean allele GsSW18.1 and wild type is analyzed. Figure 5 In section B and section C, the differences in grain length and width between Arabidopsis thaliana overexpressing the cultivated soybean allele GmSW18.1 / wild soybean allele GsSW18.1 and wild type were analyzed. Figure 5 D is a visual comparison of the morphology of transgenic Arabidopsis thaliana and wild-type seeds; Figure 5 The image shows a comparison of the mature morphology of transgenic Arabidopsis thaliana and wild-type Arabidopsis thaliana. Gs-OE#3, Gs-OE#1, and Gs-OE#6 represent transgenic Arabidopsis thaliana overexpressing the wild soybean gene GsSW18.1, while Gm-OE#2, Gm-OE#3, and Gm-OE#5 represent transgenic Arabidopsis thaliana overexpressing the cultivated soybean gene GmSW18.1. Detailed Implementation
[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0028] The soybean variety Nannong 1138-2 used in this invention is a bred variety, systematically selected by Nanjing Agricultural University from Suidaohuang in Fengxian County, and is suitable for soybean planting in the Yangtze River Basin of my country.
[0029] The soybean variety used in this invention is a wild soybean variety from South Korea, which can be obtained from the germplasm bank of the National Soybean Improvement Center of the Ministry of Agriculture and Rural Affairs, with the number N24852.
[0030] Example 1
[0031] Map-based cloning of the major locus qSW18.1 in soybean 100-seed weight
[0032] 1.1 Construction of Secondary Plotting Groups
[0033] Using a chromosome segment substitution line population covering the entire genome of wild soybean, a 100-seed redifferentiation locus, qSW18.1, was detected on chromosome 18. In this invention, the near-isogenic line NIL-w, carrying the target wild soybean fragment at the qSW18.1 locus, was selected as the maternal parent, and the recurrent parent NN1138-2 was selected as the paternal parent. A cross was constructed to create the F2 secondary mapping population NZR-F2, which contains 105 individual plants.
[0034] 1.2 Identification of grain traits in the secondary mapping population NZR-F2 and its parents
[0035] The grain traits of the parental lines used to construct the NZR-F2 secondary mapping population were evaluated under three environments: the Dangtu Experimental Field (2021D), the Suzhou Experimental Field (2021S), and the Dangtu Experimental Field (2022D) in 2021. Secondly, the grain traits of the NZR-F2 secondary mapping population were evaluated in the Dangtu Experimental Field (2022D) in 2022. The results showed that the 100-grain weight, grain length, grain width, and grain thickness of NN1138-2 were 18.61 g, 0.86 mm, 0.75 mm, and 0.61 mm, respectively, all significantly higher than those of NIL-w (…). Figure 1 BE); there was no significant difference between the two in protein and fat content (BE). Figure 1 The presence of F and G indicates that this site plays a role in regulating 100-grain weight and grain size.
[0036] The secondary mapping population NZR-F2 contained 105 F2 individuals. In 2022, the population's 100-seed weight ranged from 11.07 to 18.43 g, with an average of 14.82 g and a coefficient of variation of 9.48% (Table 1). The frequency distribution of the 100-seed weight of the secondary population NZR-F2 showed an approximately normal distribution. Figure 1 (H)
[0037]
[0038] 1.3 Extraction of population genomic DNA and identification of genotypes
[0039] Genomic DNA was extracted from leaves using the standard CTAB method. Based on the common SSR markers on soybean chromosome 18 and combined with the differences in the genomic sequences of the two parents, specific InDel molecular markers were developed. Seventeen pairs of molecular markers with stable polymorphism between the two parents were screened and obtained (Table 2), which were used for population genotyping and fine mapping.
[0040]
[0041] The PCR reaction system consisted of 10 μL of DNA template, 1.5 μL each of forward and reverse primers, and 4 μL of Taq enzyme. The PCR program was as follows: denaturation at 95°C for 5 min; 30 cycles of denaturation at 94°C for 30 s, annealing at 55°C for 30 s, and extension at 72°C for 30 s; followed by a final extension at 72°C for 5 min, and storage at 4°C. The PCR products were identified by genotyping using 8% polyacrylamide gel electrophoresis and silver staining.
[0042] 1.4 Analysis of QTL Initial Localization Results
[0043] Using SAS 9.4 software, linkage analysis was conducted by combining phenotypic and genotypic data of the secondary mapping population NZR-F2. The major locus of soybean 100-seed weight, qsw18.1, was located on chromosome 18 between markers InDel18-004 and InDel18-022. Figure 2 (A); combined with high-density maps ( Figure 2 (B) Using QTLIciMapping software, qSW18.1 was located between markers InDel18-038 and InDel18-018, with a physical location within 5638690-5985316 bp, a length of approximately 346.6 kb, and an LOD value of 31.01, which can explain 15.76% of the phenotypic variation. Figure 2 (C). At this locus, the wild-type allele has an additive effect of decreasing 100-grain weight by -1.74 g, while the cultivated soybean allele has an additive effect of increasing 100-grain weight.
[0044] 1.5 Map-based cloning of the soybean 100-seed weight gene SW18.1
[0045] Between markers InDel18-038 and InDel18-018, there were 6 recombinant families in the secondary mapping population NZR-F2. Based on their 100-grain weight phenotype and genotypic analysis of the target fragment, qSW18.1 was finally narrowed down to the molecular markers InDel18-062 and Satt_324, with a physical distance of 194 kb. Figure 2 (D).
[0046] Based on the genotype of the secondary mapping population NZR-F2, heterozygous families on the target interval InDel18-062-Satt_324 were selected and planted in the field in Fuyang, Anhui Province in the summer of 2023. This resulted in a population of 935 remaining heterozygous lines for further fine mapping. Genotyping of the 935 lines was performed using the two markers mentioned above, yielding four recombinant individuals for fine mapping. Using the newly developed marker Indel18-771 within the interval, combined with the phenotypes and genotypes of the parents and recombinant individuals, qSW18.1 was finally finely mapped to the interval between the InDel18-062-InDel18-771 markers, with a physical distance of 97 kb. Figure 2 The interval contains 7 candidate genes, only Glyma.18G063500 has a non-synonymous mutation between the parents, which is a single base substitution. Figure 2 (F). Gene annotation revealed that this gene is an E3 ubiquitin ligase, named SW18.1.
[0047] Example 2
[0048] Construction of the SW18.1 gene-editing mutant sw18.1
[0049] 2.1 Gene Editing Target Design
[0050] Using the soybean cultivar Williams 82 (Wm82) as the recipient material, two specific editing targets were designed targeting the exon region of the SW18.1 gene. The target sequences are shown in Table 3.
[0051]
[0052] 2.2 Primers and amplification system for molecular identification of gene-edited mutants
[0053] Four specific detection primers (SEQ ID NO: 6~9) were designed for PCR amplification and first-generation sequencing of mutant genomic DNA. The standard 50 μL PCR reaction system and amplification procedure are as follows:
[0054]
[0055]
[0056]
[0057] The amplified products were subjected to 1% agarose gel electrophoresis and then sent to Beijing Qingke Biotechnology Co., Ltd. for sequencing. Sequence alignment was performed using the bioinformatics software SnapGene to determine the type of editing. Figure 3 It can be seen that the sw18.1 mutant produced a total of 4 mutation types, indicating that the knockout material was successfully constructed.
[0058] Example 3
[0059] Phenotypic identification of sw18.1 gene-editing mutants
[0060] The sw18.1 mutant and wild-type Wm82 were planted in greenhouses using a randomized block design with three biological replicates, one row per plot, 1 meter row length, 0.5 meter row spacing, and 10 seedlings per row. Normal water and fertilizer management was implemented. The grains were harvested at maturity, dried to constant weight, and then the grain traits were measured.
[0061] Phenotypic identification results showed that the wild-type Wm82 had a 100-grain weight of 16.04 g, while the 100-grain weights of the four knockout mutants were 13.63 g, 14.30 g, 13.24 g, and 13.80 g, respectively, indicating a significant decrease in 100-grain weight after knockout. Simultaneously, the grain length, width, and thickness of the knockout mutants were significantly lower than those of the wild-type. Figure 4 The above results indicate that knocking out the SW18.1 gene inhibits soybean seed development, leading to a decrease in 100-seed weight. This gene is a positive regulator affecting the 100-seed weight of soybean.
[0062] Example 4
[0063] Construction of Arabidopsis thaliana strain overexpressing cultivated allele GmSW18.1 / wild allele GsSW18.1
[0064] The Arabidopsis thaliana wild-type cultivated in this invention is the Columbia wild-type Col-0, with an overexpression vector of Kanamycin resistance and a Bar selection marker; Escherichia coli competent cells are DH5α and Agrobacterium tumefaciens competent cells are GV3101. Using pYFP as the overexpression vector, overexpression vectors for the cultivated soybean allele GmSW18.1 and the wild soybean allele GsSW18.1 were constructed, respectively. The recombinant vectors were transformed into Agrobacterium tumefaciens GV3101 competent cells, and the inflorescence infection method was used to transform the Columbia wild-type Arabidopsis thaliana Col-0.
[0065] T1 generation positive transgenic lines were obtained through glufosinate resistance screening and PCR molecular identification. Single-copy lines were selected and continuously self-crossed to obtain T3 generation homozygous transgenic lines. Three GmSW18.1 overexpression homozygous lines (Gm-OE#2, Gm-OE#3 and Gm-OE#5) and three GsSW18.1 overexpression homozygous lines (Gs-OE#3, Gs-OE#1 and Gs-OE#6) were obtained for grain phenotypic identification.
[0066]
[0067] Example 5
[0068] Phenotypic identification of Arabidopsis thaliana overexpressing GmSW18.1 / GsSW18.1 gene
[0069] Seed traits were identified in wild-type Arabidopsis thaliana and transgenic Arabidopsis thaliana lines overexpressing the cultivated soybean allele GmSW18.1 and the wild soybean allele GsSW18.1, respectively. 1000 seeds were randomly selected from each line, and their thousand-seed weight was measured. 100 seeds were selected for observation and measurement of seed length and width using a depth-of-field stereomicroscope (DVM6a). Results showed that the thousand-seed weight of wild-type Arabidopsis thaliana was 22.83 mg, while the thousand-seed weights of Arabidopsis thaliana overexpressing the cultivated soybean allele GmSW18.1 were 24.75 mg, 25.50 mg, and 26.16 mg, respectively. The thousand-seed weight was significantly larger, with a maximum increase of 14.59%. Simultaneously, both seed length and width were significantly increased. Figure 5 The thousand-seed weights of Arabidopsis thaliana overexpressing the wild soybean allele GsSW18.1 were 21.13 mg, 21.72 mg, and 21.26 mg, respectively, all significantly lower than those of the wild type. Seed length and width were also significantly reduced. Figure 5Heterologous overexpression experiments confirmed that overexpression of cultivar GmSW18.1 promoted seed enlargement, while overexpression of wild-type GsSW18.1 inhibited seed development, indicating that the two alleles have opposite regulatory effects on seed size.
[0070] The above examples demonstrate that, combined with the results of gene localization, gene editing verification, and Arabidopsis heterologous overexpression experiments, the cultivated soybean allele GmSW18.1 can be identified as a positive functional gene regulating the 100-seed weight of soybean, and can be applied to high-yield molecular breeding of soybean.
[0071] sequence list
[0072] SEQ ID NO: 1 SW18.1 amino acid sequence (244 AA) Glycine max Wm82.a2.v1
[0073] MGKGSFQDSVKALEADIQYANTLALGYPRDKDGGCFQMRISYSPAAPLFLFLVQWTDYRLAGALGLLRILIYVTYGNGKNTMSIYERKASIRQFYSIIFPALLQLEKGITDLEERKQKEVYA LRYQRKSEFNERRQSEIDIEREEECGVCLEVKAKVVLPNCCHYMCLKCYRDWCQRSQSCPFCRDSLKRTNSGDLWIYTDTSDIVDVGTIFKENCKMLFLYIEKLPLIVPDPRYVFYDPLLR.
[0074] SEQ ID NO: 2 SW18.1CDS sequence (732 bp) Glycine max Wm82.a2.v1
[0075] ATGGGAAAGGGATCTTTTCAGGACTCTGTTAAAGCTCTGGAAGCTGACATTCAGTATGCTAATACCCTGGCATTAGGCTATCCAAGGGACAAAGATGGAGGATGCTTTCAGATGAGGATATCATACAGTCCAGCAGCCCCTCTTTTTCTGTTTCTTGTTCAATGGACCGATTACCGCCTCGCCGGTGCTCTGGGTTTGCTGAGAATTCTAATTTATGTGACTTATGGAAATGGGAAGAATACTATGTCAATATATGAAAGGAAAGCAAGCATTAGACAATTTTACTCGATTATATTTCCTGCTCTGTTGCAACTTGAGAAAGGCATCACAGATTTGGAGGAAAGGAAACAGAAAGAAGTATATGCCCTTAGATACCAAAGGAAAAGTGAGTTCAATGAGAGAAGACAATCTGAAATTGACATTGAAAGAGAAGAGGAATGTGGAGTGTGCTTGGAGGTGAAAGCAAAAGTTGTGCTTCCTAATTGCTGCCACTACATGTGTTTGAAGTGCTACAGAGATTGGTGTCAGAGGTCTCAGTCTTGCCCCTTTTGCCGGGATAGCCTGAAGAGAACCAACTCTGGGGACCTTTGGATTTACACTGACACCAGTGACATTGTTGATGTTGGGACAATTTTCAAAGAGAATTGTAAGATGCTGTTTCTGTACATAGAGAAGCTGCCTCTAATTGTTCCAGATCCCAGATATGTGTTCTATGATCCACTTCTGAGATGA。
[0076] SEQ ID NO: 3 Genomic DNA sequence (2996 bp) Glycine max Wm82.a2.v1
[0077]
Claims
1. The application of the SW18.1 gene, its encoded protein, or biological materials containing this gene in regulating soybean seed traits, characterized in that, The amino acid sequence of the protein encoded by the SW18.1 gene is shown in SEQ ID NO: 1; the CDS sequence of the SW18.1 gene is shown in SEQ ID NO: 2; and its full-length nucleotide sequence is shown in SEQ ID NO:
3.
2. The application according to claim 1, characterized in that, The biological material is a recombinant vector expressing sgRNA that targets and knocks out the SW18.1 gene; the sgRNA is a guide RNA that targets and knocks out the SW18.1 gene; the sgRNA sequence of the SW18.1 gene is shown in SEQ ID NO: 4 and SEQ ID NO:
5.
3. A method for identifying the type of gene editing in soybean SW18.1, characterized in that, The procedure includes the following steps: performing PCR on soybean genomic DNA using the primer sequences shown in SEQ ID NO: 6~9, sequencing the PCR product, comparing the sequencing results with the original sequence of the wild-type unedited soybean SW18.1 gene, and determining the type of gene editing mutation.
4. A method for regulating the grain traits of plants, characterized in that, Transgenic plants were obtained by regulating the expression of the SW18.1 gene in plants, thereby achieving directional regulation of the seed traits of the plants; the CDS sequence of the SW18.1 gene is shown in SEQ ID NO:
2.
5. The method for regulating plant grain traits according to claim 4, characterized in that, The grain characteristics include at least one of the following: 100-grain weight, grain length, grain width, and grain thickness.
6. The method for regulating plant grain traits according to claim 4, characterized in that, The regulation of the SW18.1 gene is achieved by overexpressing the SW18.1 gene.
7. The method for regulating plant grain traits according to claim 4, characterized in that, The primer sequences for gene amplification and vector construction of the transgenic plants are shown in SEQ ID NO: 44~47.
8. The method for regulating plant grain traits according to claim 4, characterized in that, The plant is either soybean or Arabidopsis thaliana.
9. A method for identifying traits of soybean seeds, characterized in that, PCR was performed on soybean genomic DNA using the primer sequences shown in SEQ ID NO: 6~9. The PCR products were sequenced, and the sequencing results were compared with the original sequence of the wild-type unedited soybean SW18.1 gene to determine the gene editing mutation type. If the identification result was wild-type, the grain traits were superior; if the identification result was mutant, the grain traits were inferior.
10. An allele regulating soybean seed traits, characterized in that, The allele is located on soybean chromosome 18, 5828967~5831963 bp, with a total genome length of 2996 bp and a coding region of 732 bp. The sequence of the allele is shown in SEQ ID NO:
3. A base mutation on the 4th exon of the allele results in the coding amino acid changing from serine to threonine.