CN111197047B

CN111197047B - Soybean protein GmUBCa related to seed weight regulation and application of soybean protein GmUBCa and related biological material thereof

Info

Publication number: CN111197047B
Application number: CN201811375625.0A
Authority: CN
Inventors: 张劲松; 陈受宜; 胡杨; 张万科; 韦伟; 林晴; 阴翠翠; 何锶洁
Original assignee: Institute of Genetics and Developmental Biology of CAS
Current assignee: Institute of Genetics and Developmental Biology of CAS
Priority date: 2018-11-19
Filing date: 2018-11-19
Publication date: 2022-03-01
Anticipated expiration: 2038-11-19
Also published as: CN111197047A

Abstract

The invention discloses soybean protein GmUBCa related to seed weight regulation and application of a related biological material thereof. The application is the application of GmUBCa or related biological materials thereof in regulating and controlling the grain weight of seed plants; the GmUBCa is protein with an amino acid sequence shown as SEQ ID No. 2; the biological material is any one of the following materials: B1) a nucleic acid molecule encoding said GmUBCa; B2) an expression cassette comprising the nucleic acid molecule of B1); B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2); B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector; B5) a molecular marker of the GmUBCa gene. The GmUBCa and related biological materials thereof can be used for improving the crop yield and cultivating high-yield varieties.

Description

Soybean protein GmUBCa related to seed weight regulation and application of soybean protein GmUBCa and related biological material thereof

Technical Field

The invention relates to soybean protein GmUBCa related to seed weight regulation in the field of molecular biology and application of a related biological material thereof.

Background

Soybean is an important traditional crop, contains rich nutritional value, is an important economic crop for providing grain oil and feed, and has a plurality of applications in industrial production, such as biofuel, surfactant, softener and the like. China was the world's largest soybean producing country, however, in recent years, soybean production in China only accounts for one fourth of the demand, so China becomes the world's largest soybean importing country, and the total import amount is half of the total export amount of soybeans in the world. The soybean production is far behind the development pace of other domestic food crops and can not meet the national needs. In the last 50 years, soybean production has increased only 62%, while other food crops have increased more than 5 times. Therefore, the improvement of the yield per unit of soybean becomes a problem to be solved at present.

The weight of seeds (grain weight) is an important indicator in crop production and is one of the important agronomic traits affecting crop yield. The plant can achieve the purpose of increasing yield by increasing the grain weight.

The soybean yield is composed of plant type, pod bearing rate, pod number, seed weight per hundred and other factors, wherein the weight of the seed is the highest factor of heritability. The influence of grain weight on yield is not limited to leguminous plants, but is also an important factor of yield potential for other monocotyledonous and dicotyledonous plants, so that the grain weight is an important selection trait to be considered in the process of breeding crop varieties. Existing studies have shown that grain weight is influenced by the cultivation environment and genetics. Under normal cultivation conditions, inheritance, i.e., the relevant gene, plays an important role. Therefore, the research of molecular mechanism related to thousand kernel weight becomes a hot spot.

Disclosure of Invention

The invention aims to solve the technical problem of how to improve the grain weight of the seed plants.

In order to solve the technical problems, the invention firstly provides seed plant grain weight related protein and related biological materials thereof.

The seed plant grain weight related protein provided by the invention is named as GmUBCa, is derived from soybean (Glycine max (L.) Merrill), and is protein A1) or A2) or A3) as follows:

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

A3) a protein which is obtained by substituting and/or deleting and/or adding more than one amino acid residue for the protein shown in A1) or A2), has more than 90% of identity with the protein shown in A1) or A2), and is related to the grain weight of seed plants;

the biological material is any one of the following B1) to B5):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector;

B5) a molecular marker of the GmUBCa gene.

In the above protein, the protein tag (protein-tag) refers to a polypeptide or protein that is expressed by fusion with a target protein using in vitro recombinant DNA technology, so as to facilitate expression, detection, tracking and/or purification of the target protein. The protein tag may be a Flag tag, a His tag, an MBP tag, an HA tag, a myc tag, a GST tag, and/or a SUMO tag, among others.

In the above proteins, identity refers to the identity of amino acid sequences. The identity of the amino acid sequences can be determined using homology search sites on the Internet, such as the BLAST web pages of the NCBI home website. For example, in the advanced BLAST2.1, by using blastp as a program, setting the value of Expect to 10, setting all filters to OFF, using BLOSUM62 as a Matrix, setting Gap existence cost, Per residual Gap cost, and Lambda ratio to 11, 1, and 0.85 (default values), respectively, and performing a calculation by searching for the identity of a pair of amino acid sequences, a value (%) of identity can be obtained.

In the above protein, the 90% or more identity may be at least 91%, 92%, 95%, 96%, 98%, 99% or 100% identity.

Among the above proteins, the GmUBCa may be derived from soybean.

In the above protein, SEQ ID No.2 (SEQ ID NO: 2 in the sequence Listing) is composed of 148 amino acid residues.

In the above biological material, the nucleic acid molecule may be DNA, such as cDNA, genomic DNA or recombinant DNA; the nucleic acid molecule may also be RNA, such as mRNA or hnRNA, etc.

In the above biological material, the nucleic acid molecule encoding GmUBCa in B1) may be a GmUBCa gene (GmUBCa). The GmUBCa gene can be a DNA molecule with a coding sequence shown in SEQ ID No.1 (sequence 1 in a sequence table).

Wherein, SEQ ID No.1 consists of 447 nucleotides, and the coding sequence is nucleotides 1 to 447 of SEQ ID No.1 and codes protein shown in SEQ ID No. 2.

In the above-mentioned biological material, the expression cassette described in B2) means a DNA capable of expressing GmUBCa in a host cell, and the DNA may include not only a promoter which initiates transcription of the GmUBCa gene but also a terminator which terminates transcription of the GmUBCa gene. Further, the expression cassette may also include an enhancer sequence. Promoters useful in the present invention include, but are not limited to: constitutive promoters, tissue, organ and development specific promoters, and inducible promoters. Examples of promoters include, but are not limited to: the constitutive promoter of cauliflower mosaic virus 35S; the wound-inducible promoter from tomato, leucine aminopeptidase ("LAP", Chao et al (1999) Plant Physiol 120: 979-992); chemically inducible promoter from tobacco, pathogenesis-related 1(PR1) (induced by salicylic acid and BTH (benzothiadiazole-7-carbothioic acid S-methyl ester)); tomato proteinase inhibitor II promoter (PIN2) or LAP promoter (both inducible with jasmonic acid ester); heat shock promoters (U.S. patent 5,187,267); tetracycline-inducible promoters (U.S. Pat. No. 5,057,422); seed-specific promoters, such as the millet seed-specific promoter pF128(CN101063139B (Chinese patent 200710099169.7)), seed storage protein-specific promoters (e.g., phaseolinThe promoters of napin, oleosin and soybean beta conglycin (Beachy et al (1985) EMBO J.4: 3047-3053)). They can be used alone or in combination with other plant promoters. All references cited herein are incorporated by reference in their entirety. Suitable transcription terminators include, but are not limited to: agrobacterium nopaline synthase terminator (NOS terminator), cauliflower mosaic virus CaMV 35S terminator, tml terminator, pea rbcS E9 terminator and nopaline and octopine synthase terminators (see, e.g., Odell et al (I)⁹⁸⁵) Nature 313: 810; rosenberg et al (1987) Gene,56: 125; guerineau et al (1991) mol.gen.genet,262: 141; proudfoot (1991) Cell,64: 671; sanfacon et al Genes Dev.,5: 141; mogen et al (1990) Plant Cell,2: 1261; munroe et al (1990) Gene,91: 151; ballad et al (1989) Nucleic Acids Res.17: 7891; joshi et al (1987) Nucleic Acid Res, 15: 9627).

In the biological material, a plant expression vector can be used for constructing a recombinant expression vector containing the GmUBCa gene expression cassette. The plant expression vector can be a Gateway system vector or a binary agrobacterium vector and the like, such as pGWB411, pGWB412, pGWB405, pBin438, pCAMBIA1302, pCAMBIA2301, pCAMBIA1301, pCAMBIA1300, pBI121, pCAMBIA1391-Xa or pCAMBIA 1391-Xb. When the GmUBCa is used for constructing a recombinant expression vector, any one of enhanced, constitutive, tissue-specific or inducible promoters, such as a cauliflower mosaic virus (CAMV)35S promoter, a ubiquitin gene Ubiqutin promoter (pUbi) and the like, can be added in front of the transcription initiation nucleotide, and can be used alone or combined with other plant promoters; in addition, when the gene of the present invention is used to construct plant expression vectors, enhancers, including translational or transcriptional enhancers, may be used, and these enhancer regions may be ATG initiation codon or initiation codon of adjacent regions, etc., but must be in the same reading frame as the coding sequence to ensure proper translation of the entire sequence. The translational control signals and initiation codons are widely derived, either naturally or synthetically. The translation initiation region may be derived from a transcription initiation region or a structural gene.

In order to facilitate the identification and screening of transgenic plant cells or plants, plant expression vectors to be used may be processed, for example, by adding a gene encoding an enzyme or a luminescent compound which can produce a color change (GUS gene, luciferase gene, etc.), an antibiotic marker having resistance (gentamicin marker, kanamycin marker, etc.), or a chemical-resistant marker gene (e.g., herbicide-resistant gene), etc., which can be expressed in plants.

In order to solve the technical problem, the invention also provides any one of the following applications:

u1, the GmUBCa or the biological material in the preparation of seed plant grain weight regulation products.

Use of U2, the GmUBCa or the biological material in plant breeding.

Use of U3, the GmUBCa or the biological material for growing high-weight seed plants.

Use of U4, the GmUBCa or the biological material for the preparation of a product for growing high-weight seed plants.

In the above application, U2 may be specifically a plant containing said GmUBCa or said biological material (e.g. GmUBCa gene) to be crossed with other plants for plant breeding.

In order to solve the above technical problems, the present invention further provides the following two methods:

m1, a method for breeding high-weight seed plants, comprising increasing the expression level of the GmUBCa or the coding gene thereof in the target seed plants to obtain high-weight seed plants; the high grain weight seed plant has a grain weight higher than the grain weight of the seed plant of interest.

M2, a method for breeding a transgenic seed plant of high grain weight comprising introducing into a recipient seed plant a gene encoding said GmUBCa resulting in a transgenic seed plant of higher grain weight than said recipient seed plant.

In the method, the coding gene can be a DNA molecule with a coding sequence shown as a sequence 1 in a sequence table.

In M2, the gene encoding GmUBCa introduced into a recipient seed plant may be introduced into a recipient seed plant via a plant expression vector carrying GmUBCa of the present invention. The plant expression vector carrying the GmUBCa of the present invention can transform plant cells or tissues by using conventional biological methods such as Ti plasmid, Ri plasmid, plant virus vector, direct DNA transformation, microinjection, conductance, agrobacterium-mediated transformation, etc., and culture the transformed plant cells or tissues into plants.

The plant expression vector carrying the GmUBCa can be pGWB 411-GmUBCa. pGWB411-GmUBCa is a GmUBCa gene expression vector obtained by recombining a DNA molecule shown in a sequence 1 in a sequence table into a vector pGWB 411.

As used herein above, the seed plant, seed plant of interest and recipient seed plant may each be a dicotyledonous plant, such as a plant of the Brassicaceae family.

Experiments prove that the grain weight of transgenic arabidopsis seeds obtained by transferring GmUBCa genes into wild arabidopsis is obviously higher than that of wild arabidopsis (the thousand seed weights of seeds of wild arabidopsis control, GmUBCa overexpression strains OE2, OE5, OE9, OE20, OE25 and OE26 are respectively 14.7 +/-1.8, 19.5 +/-0.2, 17.4 +/-0.5, 16.8 +/-1.1, 18.2 +/-0.5, 21.8 +/-0.7 and 17.3 +/-1.5 milligrams), which indicates that the grain weight of plant seeds can be regulated and controlled by the GmUBCa and coding genes thereof, and the grain weight of the plant seeds is improved after overexpression. The GmUBCa and related biological materials thereof can be used for improving the crop yield and cultivating high-yield varieties.

The present invention will be described in further detail with reference to specific examples.

Drawings

FIG. 1 shows the expression characteristics of GmUBCa in various organs of soybean.

FIG. 2 is a cloning vector

A physical map of (a).

FIG. 3 is a schematic structural diagram of a plant expression vector pGWB 411-GmUBCa.

FIG. 4 shows molecular characterization of a pure line of GmUBCa-overexpressing Arabidopsis thaliana.

FIG. 5 shows thousand kernel weight comparison of GmUBCa transgenic lines and control seeds.

Detailed Description

The present invention is described in further detail below with reference to specific embodiments, which are given for the purpose of illustration only and are not intended to limit the scope of the invention. The examples provided below serve as a guide for further modifications by a person skilled in the art and do not constitute a limitation of the invention in any way.

The experimental procedures in the following examples are conventional unless otherwise specified. Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

HN44 in the following examples is soybean Hei nong 44 (Heng Cheng qun et al, the influence of breeding and different planting modes of Hei nong 44, a new soybean variety, on its yield and variety, 5 th year in 2004, 1-5, a soybean variety approved by the Committee for examining varieties of crops in Hei Longjiang province in 2002 by the institute for Soybean, academy of agriculture, Hei Longjiang academy of sciences, first breeder was Du Wei Guang researcher, patent numbers are CNA20020216.2, and the examining number is Black trial bean 2002003)

The expression vector pGWB411(Tsuyoshi Nakagawa, et al, gateway Vectors for Plant Transformation, Plant Biotechnology,2009,26,275-284) in the examples described below was supplied by Dr. Tsuyoshi Nakagawa, publicly available from the institute of genetics and developmental biology, with the consent of Dr. Tsuyoshi Nakagawa, and this biomaterial was used only for the repetition of the experiments related to the present invention and was not used for other purposes.

Agrobacterium GV3101(Lee CW et al, Agrobacterium tumefaciens proteins mutant strain mutant in Arabidopsis thaliana, Plant Cell,2009,21(9),2948-62) in the examples described below, was publicly available from the institute of genetics and developmental biology, and this biomaterial was only used for repeating the experiments related to the present invention and was not used for other purposes.

Example 1 cDNA cloning of a Soybean-derived seed grain weight-related protein GmUBCa Gene (GmUBCa) and construction of a plant expression vector

The inventor obtains a high expression gene GmUBCa when performing transcriptome analysis on a soybean seed development process. The function of the gene was examined. The transcription of GmUBCa is highest in soybean flowers, followed by seeds and roots, and is very low in seedlings and pods, and very low in leaves (FIG. 1).

Total RNA of HN44 seedlings was extracted and reverse transcribed into cDNA using reverse transcriptase.

Based on the soybean genomic sequence of plantagdb and the information on the sequence of the GmUBCa full-length cDNA in the determined HN44 genomic sequence, primers were designed, the sequences of which were as follows:

GmUBCa-up：5’-ATGGCCTCCAAGCGGATT

GmUBCa-dp：5’-CTAGCCCATTGCATACTTCTGAGTC

and performing PCR amplification by using HN44cDNA as a template and GmUBCa-up and GmUBCa-dp as primers to obtain a PCR product of about 0.5 Kb. After sequencing, the PCR product is 447bp, and has the nucleotide shown in the sequence 1 in the sequence table, the gene shown by the nucleotide is GmUBCa, the coding sequence of the GmUBCa is the sequence 1 in the sequence table, the protein coded by the gene is GmUBCa, and the amino acid sequence of the protein is the sequence 2 in the sequence table.

Gene cloning was performed using the Gateway system provided by invitrogen, vector 3' -T overhang, for direct ligation of Taq enzyme amplified PCR products. The PCR product of the GmUBCa is connected with a cloning vector by using the principle of TA cloning

The recombinant vector pTOPO-GmUBCa was obtained as described above (FIG. 2). Both pTOPO-GmUBCa and the expression vector pGWB411 are provided with recombination sites attL1 and attL2, pTOPO-GmUBCa containing GmUBCa and the expression vector pGWB411 carry out LR recombination reaction under the action of recombinase, finally, the target gene GmUBCa is successfully constructed on the expression vector pGWB411, and the obtained recombination vector is named as pGWB411-GmUBCa (figure 3). pGWB411-GmUBCa is a GmUBCa gene expression vector obtained by recombining a DNA molecule shown in a sequence 1 in a sequence table into an expression vector pGWB 411.

Example 2 obtaining of GmUBCa overexpressing Arabidopsis thaliana

First, obtaining recombinant Agrobacterium

The recombinant vector pGWB411-GmUBCa containing the GmUBCa obtained in example 1 was introduced into Agrobacterium GV3101 by electroporation to obtain a recombinant Agrobacterium containing pGWB411-GmUBCa, which was designated as recombinant Agrobacterium

GV3101/GmUBCa。

Second, obtaining and identifying GmUBCa transgenic arabidopsis thaliana

The recombinant Agrobacterium GV3101/GmUBCa was cultured to logarithmic phase, then transformed into Columbia ecotype Arabidopsis thaliana (Col-0) with a vacuum method (seed from Arabidopsis Biological Resource Center (ABRC)), and the seed was harvested after culturing (T)₁Passage), sowing seeds on MS screening culture medium containing kanamycin (50mg/L), and waiting for screening to obtain T₁When the generation plants grow to 4-6 leaves, the generation plants are transferred to vermiculite to grow, and T is harvested₁Generation of individual plant, seeds of each individual plant (T)₂Passage) were sown separately and continued screening with the same MS screening medium to observe T₂Segregation of generations, repeating the generations until genetically stable transgenic homozygous lines are obtained, obtaining 18 transgenic Arabidopsis pure lines (T) transformed with GmUBCa₅Generation). And 6 strains of 18 strains are randomly selected and named as OE2, OE5, OE9, OE20, OE25 and OE26 to carry out the detection of the expression quantity of the GmUBCa gene. Respectively extracting the total RNA of the seedlings of the 6 strains and Columbia ecotype arabidopsis (Col-0, used as a wild type arabidopsis control, for short, a control), carrying out reverse transcription, respectively taking cDNA obtained by the reverse transcription as a template, and taking primers as follows: GmUBCa-up: 5' -ATGGCCTCCAAGCGGATT and GmUBCa-dp: 5' -CTAGCCCATTGCATACTTCTGAGTC, Real Time-PCR identification. The arabidopsis AtActin2 gene is used as an internal standard, and the used primers are Primer-TF: 5' -ATGCCCAGAAGTCTTGTTCC, and Primer-TR: 5'-TGCTCATACGGTCAGCGATA-3' are provided. The relative expression level of the GmUBCa gene is determined by taking the expression level of the internal standard AtActin2 gene as 1. The experiment was repeated three times and the results averaged. The relative expression levels of GmUBCa in OE2, OE5, OE9, OE20, OE25 and OE26 were 0.17, 0.28, 0.18, 0.47, 0.16 and 0.25, respectively, and no expression level of GmUBCa was detected in the wild-type arabidopsis control (fig. 4).

The above results further demonstrate that GmUBCa is transferred into arabidopsis and expressed. 6 strains of OE2, OE5, OE9, OE20, OE25 and OE26 are GmUBCa overexpression strains.

Phenotypic analysis of transgenic Arabidopsis with GmUBCa gene

The control and 6 GmUBCa overexpressing strains OE2, OE5, OE9, OE20, OE25 and OE26 were first tested for phenotype under normal conditions. Under normal conditions, the phenotypes of the control and GmUBCa overexpression lines, such as rosette, plant height and the like, have no significant difference from the control.

Thousand kernel weight of seeds, i.e. of thoroughly dried seeds, of wild type arabidopsis thaliana controls, GmUBCa overexpressing lines OE2, OE5, OE9, OE20, OE25 and OE26 was measured.

20 seeds of each strain are taken, 200 seeds are weighed in each strain, the biological experiment is repeated three times, and the average value is +/-standard deviation.

The results are shown in FIG. 5, the thousand seed weights of wild type Arabidopsis control, GmUBCa overexpression lines OE2, OE5, OE9, OE20, OE25 and OE26 are 14.7 + -1.8, 19.5 + -0.2, 17.4 + -0.5, 16.8 + -1.1, 18.2 + -0.5, 21.8 + -0.7 and 17.3 + -1.5 mg, respectively.

The results show that the thousand seed weight of 6 GmUBCa over-expressing transgenic lines is significantly or very significantly higher than that of the wild-type control (fig. 5). In fig. 5, a significant difference from wild-type arabidopsis thaliana is shown; indicates a very significant difference compared to wild type arabidopsis thaliana.

The experiment shows that the overexpression of GmUBCa improves the thousand seed weight of the transgenic plant seeds, and the normal growth of the plants is not influenced while the weight (the seed weight) of the transgenic plant seeds is improved. Therefore, the gene can be used as a target gene for improving the seed yield of plants. GmUBCa is a protein related to seed weight.

The present invention has been described in detail above. It will be apparent to those skilled in the art that the invention can be practiced in a wide range of equivalent parameters, concentrations, and conditions without departing from the spirit and scope of the invention and without undue experimentation. While the invention has been described with reference to specific embodiments, it will be appreciated that the invention can be further modified. In general, this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. The use of some of the essential features is possible within the scope of the claims attached below.

<110> institute of genetics and developmental biology of Chinese academy of sciences

<120> soybean protein GmUBCa related to seed weight regulation and application of related biological material thereof

<130> GNCFH182209

<160> 2

<170> PatentIn version 3.5

<210> 1

<211> 447

<212> DNA

<213> Glycine max (L.) Merrill of Glycine genus

<400> 1

atggcctcca agcggattct gaaggagctt aaggacctcc agaaagaccc tccaacctct 60

tgcagcgccg gtcctgtagc ggaagatatg tttcattggc aagcgactat aatgggtccc 120

cctgatagcc cttatgctgg gggtgttttt ctagttacta ttcattttcc tccggattat 180

ccattcaagc cacccaaggt tgcatttagg actaaagttt tccacccaaa tatcaacagc 240

aatggtagta tttgtcttga tatcttaaag gagcagtgga gccccgcctt gacaatatct 300

aaggttttgc tctccatttg ctccctattg acggatccaa acccagatga tcccttggtg 360

cctgaaattg ctcatatgta caagacagac aggtccaagt atgagacaac tgctaggagc 420

tggactcaga agtatgcaat gggctag 447

<210> 2

<211> 148

<212> PRT

<213> Glycine max (L.) Merrill of Glycine genus

<400> 2

Met Ala Ser Lys Arg Ile Leu Lys Glu Leu Lys Asp Leu Gln Lys Asp

1 5 10 15

Pro Pro Thr Ser Cys Ser Ala Gly Pro Val Ala Glu Asp Met Phe His

20 25 30

Trp Gln Ala Thr Ile Met Gly Pro Pro Asp Ser Pro Tyr Ala Gly Gly

35 40 45

Val Phe Leu Val Thr Ile His Phe Pro Pro Asp Tyr Pro Phe Lys Pro

50 55 60

Pro Lys Val Ala Phe Arg Thr Lys Val Phe His Pro Asn Ile Asn Ser

65 70 75 80

Asn Gly Ser Ile Cys Leu Asp Ile Leu Lys Glu Gln Trp Ser Pro Ala

85 90 95

Leu Thr Ile Ser Lys Val Leu Leu Ser Ile Cys Ser Leu Leu Thr Asp

100 105 110

Pro Asn Pro Asp Asp Pro Leu Val Pro Glu Ile Ala His Met Tyr Lys

115 120 125

Thr Asp Arg Ser Lys Tyr Glu Thr Thr Ala Arg Ser Trp Thr Gln Lys

130 135 140

Tyr Ala Met Gly

145

Claims

The application of GmUBCa or related biological materials thereof in regulating and controlling the grain weight of seed plants; the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

the biological material is any one of the following B1) to B4):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector.
Application of GmUBCa or related biological materials thereof in preparation of products for regulating and controlling seed plant grain weight;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

the biological material is any one of the following B1) to B4):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector.
Use of GmUBCa or a related biological material thereof in plant breeding;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

the biological material is any one of the following B1) to B4):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector.
Use of GmUBCa or a related biological material thereof for breeding high-grain weight seed plants;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

the biological material is any one of the following B1) to B4):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector.
Application of GmUBCa or related biological materials thereof in preparation of plant products for cultivating high-grain-weight seeds;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2;

the biological material is any one of the following B1) to B4):

B1) a nucleic acid molecule encoding said GmUBCa;

B2) an expression cassette comprising the nucleic acid molecule of B1);

B3) a recombinant vector containing the nucleic acid molecule of B1) or a recombinant vector containing the expression cassette of B2);

B4) a recombinant microorganism containing B1) the nucleic acid molecule, or a recombinant microorganism containing B2) the expression cassette, or a recombinant microorganism containing B3) the recombinant vector.
6. Use according to any one of claims 1 to 5, characterized in that: the nucleic acid molecule is a DNA molecule with a coding sequence shown as SEQ ID No. 1.
7. A method for breeding high-grain-weight seed plants comprises the steps of improving the expression level of GmUBCa or a coding gene thereof in target seed plants to obtain high-grain-weight seed plants; the grain weight of the high grain weight seed plant is higher than the grain weight of the seed plant of interest;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) and (3) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2.
8. A method of breeding a transgenic seed plant of high grain weight comprising introducing into a recipient seed plant a gene encoding GmUBCa to yield a transgenic seed plant of higher grain weight than said recipient seed plant;

the GmUBCa is the protein of the following A1) or A2):

A1) protein with amino acid sequence shown as SEQ ID No. 2;

A2) and (3) a fusion protein obtained by connecting a protein tag to the carboxyl terminal or/and the amino terminal of the protein shown in SEQ ID No. 2.
9. The method according to claim 7 or 8, characterized in that: the coding gene is a DNA molecule with a coding sequence shown as SEQ ID No. 1.