Application of OsCOST1 gene in plant breeding regulation

Abstract

The invention belongs to the field of genetic engineering and botany, and particularly relates to application of an OsCOST1 gene in regulation and control of plant breeding. By constructing a rice OsCOST1 gene overexpression and expression inhibition plant, it is found that the rice plant height and biomass can be controlled by regulating and controlling the expression level of the OsCOST1 gene, and it is indicated that the gene can be used as a marker for regulating and controlling the plant type and increasing the plant yield to be applied to plant type and high-yield crop breeding. Therefore, the OsCOST1 gene provides a powerful means and tool for molecular marker-assisted breeding and cultivation of different plant shapes and high-yield new varieties of rice by using a genetic engineering method, and has huge application potential.

Description

Technical Field

[0001] The present invention belongs to the fields of genetic engineering and botany, and particularly relates to the application of an OsCOST1 gene in plant breeding regulation. Background Art

[0002] Rice (Oryza sativa L.) is one of the three most important food crops. Rice is grown in about 120 countries around the world, and about half of the world's population takes rice as the staple food (Khush G S. Challenges for meeting the global food and nutrient needs in the new millennium [J]. Proceedings of the Nutrition Society, 2001, 60(1): 15 - 26.). China is one of the original places of rice. In China, rice is the largest food crop, and 60% of the population takes rice as the staple food (Luo Runliang, Wu Jinghua. Hybrid rice and its development [J]. Science, 2000, 52(6): 51 - 53.). As an important food crop, rice plays an important role in food security, and it is crucial to monitor the growth status of rice. Biomass, as a parameter reflecting the dry matter accumulation of rice, can not only be used for rice yield estimation but also for rice growth monitoring (Zhang Can. Research on the estimation of rice biomass based on multiple characteristic parameters [D]. Wuhan University, 2021.).

[0003] The above - ground biomass of crops is one of the most important indicators for diagnosing and monitoring agricultural ecosystems. Biomass estimation is not only closely related to the monitoring of crop yield and production but also contributes to the study of the carbon cycle process and global climate change. Data on the spatio - temporal changes of specific crop parameters, such as above - ground biomass, plant length, and leaf area index at a specific location, helps to make appropriate management decisions (Feng X, Tang L, Xu M. Estimating the biomass of rice by combining GF - 1 and RADARSAT - 2 data [J]. Arabian Journal of Geosciences, 2021, 14: 1 - 11.).

[0004] COST1 is a member of the plant-specific DUF641 (Domain of unknown function 641) family of proteins. Chinese Patent CN108949821A discloses a method for improving plant drought tolerance by inhibiting the expression of the COST1 gene. As an important regulatory factor, COST1 participates in the balanced regulation between plant growth and stress response by directly regulating the autophagy pathway in plants (Bao Y, Song WM, Wang P, Yu X, Li B, Jiang C, Shiu SH, Zhang H, Bassham DC. COST1 regulates autophagy to control plant drought tolerance. Proceedings of the National Academy of Sciences. 2020 Mar 31;117(13):7482-93.).

[0005] Chinese Patent CN108949821A discloses a method for improving plant drought tolerance by inhibiting the expression of the COST1 gene. Homologous genes of the COST1 gene include the tomato SlCOST1 gene, the rice OsCOST1 gene, the poplar PtCOST1 and PtCOST2 genes, and other genes in other species with a homology of more than 40% to any nucleotide or protein region fragment of COST1. This patent also discloses that COST1, as an important regulatory factor, participates in the balanced regulation between plant growth and stress response by directly regulating the autophagy pathway in plants. In this patent, plant drought tolerance is improved by knocking out the COST1 gene (or the OsCOST1 gene) or inhibiting the expression of the COST1 gene (or the OsCOST1 gene).

[0006] However, the prior art does not involve methods for increasing rice biomass. Summary of the Invention

[0007] Based on the current situation in the prior art that lacks methods for increasing rice biomass through genetic techniques, the purpose of the present invention is to provide an application of the OsCOST1 gene in plant breeding regulation.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] The present invention first provides an application of the OsCOST1 gene in plant breeding regulation. The nucleotide sequence of the OsCOST1 gene is shown as SEQ ID No.1; the plant breeding regulation refers to regulating the expression level of the gene OsCOST1 in plants to control plant plant height and biomass.

[0010] Among them, the amino acid sequence of the OsCOST1 protein expressed by the OsCOST1 gene is shown in SEQ ID No. 2.

[0011] In one embodiment of the present invention, the plant is a monocotyledonous or dicotyledonous plant containing the DUF641

[0012] (Pfam: PF04859; InterPro: IPR006943) protein domain.

[0013] In one embodiment of the present invention, the plant is a gramineous plant.

[0014] In one embodiment of the present invention, the gramineous plant is at least one of wheat, corn or rice.

[0015] Furthermore, the gramineous plant is rice.

[0016] In one embodiment of the present invention, the application of overexpressing the gene OsCOST1 in increasing the biomass of rice and cultivating high-yield rice varieties.

[0017] In one embodiment of the present invention, the application of overexpressing the gene OsCOST1 in cultivating rice varieties with increased plant height and increased biomass of rice.

[0018] In one embodiment of the present invention, the application of regulating the expression level of OsCOST1 in cultivating plants with different plant types.

[0019] In one embodiment of the present invention, the application of a plant expression vector containing a fragment of the gene OsCOST1 in regulating plant biomass and cultivating high-yield rice varieties, for example, in cultivating rice varieties with increased plant height and increased biomass of rice.

[0020] In one embodiment of the present invention, the application of a host cell containing a fragment of the gene OsCOST1 in regulating plant biomass and cultivating high-yield rice varieties, for example, in increasing the biomass of rice and cultivating high-yield rice varieties.

[0021] In one embodiment of the present invention, the application of a host cell containing the gene OsCOST1 in cultivating rice varieties with increased plant height and increased biomass of rice.

[0022] The present invention also provides a method for increasing the biomass of rice, which includes the step of overexpressing the gene OsCOST1 in rice.

[0023] In one embodiment of the present invention, overexpressing the gene OsCOST1 in rice includes:

[0024] Insert the gene OsCOST1 into a basic vector to construct a recombinant vector containing the gene OsCOST1;

[0025] Transform the recombinant vector containing the gene OsCOST1 into crop tissues or cells.

[0026] Furthermore, the basic vector includes a crop transformation vector, and the crop transformation vector includes one of a binary Agrobacterium vector and a vector applicable to crop microprojectile bombardment. The binary Agrobacterium vector includes one of pCAMBIA1301 and pCAMBIA2301, etc.

[0027] Furthermore, the transformation method includes microinjection, genetic transformation of Agrobacterium, and one of a Ti plasmid, an Ri plasmid, or a viral vector.

[0028] Furthermore, the overexpression of the gene OsCOST1 in rice specifically includes:

[0029] Obtain a gene fragment with a nucleotide sequence as shown in SEQ ID NO.1;

[0030] Insert the gene fragment into an expression vector containing a strong promoter through a recombination reaction

[0031] In pCAMBIA1301 - 35SN, use the marker gene on the expression vector to screen for positive clones to obtain the recombinant expression vector OsCOST1 - OE;

[0032] Transfer the recombinant expression vector OsCOST1 - OE into Agrobacterium EHA105, and use the characteristics of the expression vector and the Agrobacterium itself to screen for positive Agrobacterium strains that can be used to infect rice tissues;

[0033] Infect rice callus with the positive Agrobacterium strain, and perform dark culture on a selection medium containing hygromycin to obtain positive transgenic callus;

[0034] Differentiate, root, and transplant the positive callus to obtain T0 - generation transgenic plants;

[0035] Obtain T1 - generation plants with increased rice plant height and increased biomass through conventional molecular marker detection and rice cultivation methods.

[0036] The present invention provides the gene OsCOST1 for increasing biomass, and the gene OsCOST1 has a nucleotide sequence as shown in SEQ ID NO.1.

[0037] The present invention also provides an OsCOST1 protein, and the amino acid sequence of the OsCOST1 protein is as shown in SEQ ID NO.2.

[0038] The present invention also provides a recombinant vector comprising the gene OsCOST1.

[0039] Furthermore, the recombinant vector includes the recombinant expression vector OsCOST1-OE.

[0040] The present invention also provides a transformant and a transgenic line comprising the recombinant vector.

[0041] The present invention also provides the use of the gene OsCOST1, the recombinant vector, the transformant and the transgenic line in the cultivation for increasing the biomass of rice.

[0042] The gene OsCOST1 described in the present invention, in addition to the gene OsCOST1 itself, also includes analogous genes and homologous genes of OsCOST1. That is to say, the solution of the present application also protects the use of analogous genes and homologous genes of OsCOST1 in plant breeding regulation.

[0043] Among them, the analogous gene of OsCOST1 refers to a DNA fragment with a homology of more than 40% (preferably more than 50%, more preferably more than 60%, more preferably more than 70%, more preferably more than 80%, more preferably more than 90%) in any region of the OsCOST1 sequence; the analogous gene of OsCOST1 also includes an amino acid sequence encoded by it with a homology rate of more than 40% (preferably more than 50%, more preferably more than 60%, more preferably more than 70%, more preferably more than 80%, more preferably more than 90%) in any region of the amino acid sequence encoded by the gene OsCOST1. Among them, the analogous gene of OsCOST1 can be cloned from the genome of any organism, or can be artificially synthesized or amplified in vitro by PCR.

[0044] The homologous gene of OsCOST1 refers to other genes homologous to OsCOST1, such as the rice OsCOST1 gene, the poplar PtCOST1 and PtCOST2 genes, and genes homologous to COST1 in other species.

[0045] The present application has successfully cloned the gene OsCOST1, which is involved in regulating the plant height and biomass of rice, thereby increasing the yield of rice, and can be widely applied to the cultivation of new high-yield rice varieties. By increasing the expression level of OsCOST1, the biomass of rice can be increased.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] By constructing an overexpression plant of the rice OsCOST1 gene, it is found that increasing the expression of the OsCOST1 gene can increase the plant height of normal rice, indicating that this gene can be used as a marker for increasing rice biomass and applied to the breeding of high-yield rice crops. Therefore, the OsCOST1 gene can be used to promote rice growth and increase rice biomass in rice breeding. The OsCOST1 gene provides a powerful means and tool for cultivating new high-yield rice varieties by using molecular marker-assisted breeding and genetic engineering methods, and has great application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. The drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0049] Figure 1 is the phylogenetic tree analysis of the COST family in Arabidopsis thaliana and rice;

[0050] Figure 2 is the effect of different expression levels of Arabidopsis AtCOST1 on plant size and biomass;

[0051] Figure 3 is the effect of different expression levels of rice OsCOST1 on plant height and biomass.

[0052] The sequences involved in the present invention are as follows:

[0053] SEQ ID No.1: Nucleotide sequence of gene OsCOST1

[0054]

[0055] SEQ ID No.2: Amino acid sequence of protein OsCOST1

[0056] MVLPGSKESQNYDSNNQKVHPQPIDENMNQNMGSMDTMIGRIFNNISSLKSAYIQLQEAHTPYDPDKIQAADQLVIEELTKLSELKHAYREKNPKPVAATPQDARLLSEIQEQQNLLKTYEVMVKKFQSQIQTRDTEITHLQQQIDEAKLRKSKLEKKLKQRGLLNKESEESDDEDNYFSIELTPSLFTSAVDNAYQSIHDFSKPLINMMKAAGWDLDAAANAIEPAVVYTRRAHKKYAFESYICQRMFGGFQEESFSVKAANITVSNEAFFHQFLAVRAMDPLDVLSQNPDSVFGKFCRSKYLLLVHPKMEGSFFGNMDQRNYVMSGGHPRTPFYQAFLKLAKSIWLLHRLAYSFDPKVKVFQVKKGSDFSEIHMESVVKNIILDEGAERPKVGLMVMPGFLIGTSVIQSRVYLSGVKSAD Detailed implementation manners

[0057] The present invention will be specifically described below in combination with the detailed implementation manners and examples, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these detailed implementation manners and examples are used to illustrate the present invention, rather than limiting the present invention.

[0058] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention pertains. In case of conflict, this specification shall prevail.

[0059] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present invention can be obtained through market purchase or by existing methods.

[0060] The scientific terms related to the present invention are as follows:

[0061] "Target gene" refers to rice OsCOST1 and a series of its homologous genes.

[0062] "Similar gene" refers to any DNA fragment (gene fragment) with a homology of more than 40% to any region in the coding sequence of the "target gene", or any DNA fragment (gene fragment) whose encoded amino acid sequence has a homology rate of more than 40% to any region in the amino acid sequence encoded by the "target gene". The "similar gene" can be cloned from the genome of any organism, or can be artificially synthesized or amplified in vitro by PCR.

[0063] "Gene fragment" refers to any DNA fragment with a homology rate of more than 40% to any domain region in the DNA sequence of the "target gene" or "similar gene" with a length of more than 300 base pairs (bp), or any DNA fragment encoding more than 100 amino acids, whose encoded amino acid sequence has a homology of more than 40% to any region in the amino acid sequence encoded by the "target gene" or "similar gene". The gene fragment can be cloned from the genome of any organism, or can be artificially synthesized or amplified in vitro by PCR.

[0064] "Recipient plant" refers to monocotyledonous and dicotyledonous plants.

[0065] "Transgene" refers to a foreign double-stranded deoxyribonucleotide (DNA) fragment introduced into a plant individual by any method, which can be free outside the chromosome or integrated into the genome of the recipient plant chromosome; it can be passed on to offspring through the reproductive process or not. The foreign gene can be cloned from the genome of any organism, or can be artificially synthesized or amplified in vitro by PCR.

[0066] The rice in the following examples is cultivated according to normal management methods: First, fresh rice seeds need to be soaked and germinated. After the seeds show white tips, they can be sown in the prepared seedling fields, and the seedlings can be transplanted to the fields when they reach the four-leaf and one-heart stage.

[0067] The technical solution of the embodiment of this application to solve the above technical problems is generally as follows:

[0068] 1. Using bioinformatics, the amino acid sequence of the DUF641 domain of Arabidopsis COST1 was used to mine the members of the DUF641 family to which Arabidopsis and rice belong. In Arabidopsis, there are 11 members of the DUF641 family, namely: AT2G45260.1|COST1, AT4G33320.1|COST2, AT4G34080.1|COST3, AT4G36100.1|COST4, AT3G14870.1|COST5, AT1G53380.1|COST6, AT1G29300.1|COST7, AT2G32130.1|COST8, AT2G30380.1|COST9, AT3G60680.1|COST10, AT5G58960.1|COST11. In rice, there are 9 members of the DUF641 family, namely: Os10g23220.1, Os10g36400.1, Os01g10680.1, Os01g60850.1, Os03g61040.1, Os12g02230.1, Os05g11650.1, Os11g02270.1, Os11g14490.1. The protein sequence of AtCOST1 was homologously aligned with the proteins of the DUF641 member family in rice, and the gene Os10g23220.1 with the highest sequence similarity to the AtCOST1 sequence was obtained. That is, phylogenetic analysis of rice DUF641 members found that OsCOST1 (Os10g23220) is the orthologous gene of Arabidopsis COST1 (At2G45260) gene ( Figure 1 ).

[0069] 2. Then, functional analysis of the 9 members of the rice DUF641 family was carried out. Specifically, the double digestion and ligation method (the primers used are shown in Table 1) was used to construct overexpression pCambia binary vectors 35S:OsCOST1s-YFP (hygromycin resistance) of the 9 rice DUF641 members, which were introduced into the GV3101 strain of Agrobacterium tumefaciens, and introduced into the flowers of Arabidopsis cost1 mutants by the floral dip method. After the fruit pods matured, transgenic seeds were collected from individual plants. Positive seedlings overexpressing the OsCOSTs-YFP gene were screened by antibiotics and YFP fluorescence, and they were grown under the same culture conditions as the cost1 mutants and wild-type Arabidopsis plants, and the growth conditions were observed. In the gene function analysis of DUF641 members, it was found that only OsCOST1s successfully complemented the phenotype of Arabidopsis cost1 mutants, and other genes could not complement its phenotype, indicating that OsCOST1 is the orthologous gene of Arabidopsis COST1.

[0070] 3. According to the results in Steps 1 and 2, using the cDNA of rice as a template, PCR amplification is carried out with the primers shown in Table 1 to obtain a gene fragment with a nucleotide sequence as shown in SEQ ID NO.1; in other embodiments, the gene fragment with a nucleotide sequence as shown in SEQ ID NO.1 can be directly synthesized without using the cDNA of rice as a template.

[0071] In the present invention, by differentially expressing the OsCOST1 gene in rice, it is found that: after overexpressing OsCOST1 in wild-type rice plants, the biomass at the mature stage is significantly greater than that of the wild type, indicating that OsCOST1 is closely related to the biomass of rice; increasing the expression level of OsCOST1 can increase the yield of rice. The functional domain of OsCOST1 is highly conserved in other important food crops (such as wheat, corn, etc.), indicating that this gene may have a similar molecular mechanism in regulating the yield of other crops. Therefore, OsCOST1 can also be tried to be applied to improving the yield of other crops.

[0072] Therefore, according to a typical embodiment of the present invention, a gene OsCOST1 is provided, and the gene OsCOST1 has a nucleotide sequence as shown in SEQ ID NO.1.

[0073] The gene OsCOST1 has the following characteristics: the nucleotide sequence shown in SEQ ID NO.1 consists of 1269 bases and contains only one exon.

[0074] According to another typical embodiment of the present invention, an OsCOST1 protein is provided, a protein involved in regulating the biomass of rice. In order to facilitate the research and utilization of the OsCOST1 protein, a tag can be connected to the amino terminus or carboxyl terminus of the protein sequence. The amino acid sequence of the OsCOST1 protein is as shown in SEQ ID NO.2.

[0075] OsCOST1 is a gene that can significantly increase the plant height and biomass of rice, thereby increasing the yield of rice, and is of great significance in the cultivation of high-yield rice varieties.

[0076] According to still another typical embodiment of the present invention, a method for increasing the biomass of rice is provided, and the method includes:

[0077] Overexpressing the OsCOST1 gene in rice, wherein the nucleotide sequence of the OsCOST1 gene is as shown in SEQ ID NO.1.

[0078] In the above technical solution, the overexpression of the OsCOST1 gene in rice includes:

[0079] Insert the OsCOST1 gene into a basic vector to construct a recombinant vector containing OsCOST1;

[0080] Transform the recombinant vector containing OsCOST1 into crop tissues or cells.

[0081] The basic vector includes a crop transformation vector, and the crop transformation vector includes one of a binary Agrobacterium vector and a vector applicable to crop microprojectile bombardment. The binary Agrobacterium vector includes one of pCAMBIA1301 and pCAMBIA2301; the transformation method includes microinjection, Agrobacterium-mediated genetic transformation, and one of through a Ti plasmid, an Ri plasmid or a viral vector.

[0082] In order to achieve the purpose of using the OsCOST1 gene to modify crop yields, when constructing the vector, any promoter that helps to change the expression of the OsCOST1 gene can be added before the gene start site, such as the cauliflower mosaic virus (CAMV) 35S promoter, the ubiquitin (Ubiquitin) gene promoter (pUbi), etc. In addition, the purpose of differential expression can be achieved by adding an enhancer. No matter which method is adopted, the correctness of the coding sequence must be ensured to obtain the correct OsCOST1 protein structure.

[0083] Vectors containing marker genes such as the GUS gene, the GFP gene, the hygromycin resistance gene, the herbicide resistance gene, etc. can be used to construct the recombinant vector, which is more conducive to experimental operations and subsequent crop screening and selection.

[0084] As a specific implementation method, the overexpression of the OsCOST1 gene in rice specifically includes:

[0085] Obtain a gene fragment with the nucleotide sequence shown in SEQ ID NO.1; specifically, the gene fragment with the nucleotide sequence shown in SEQ ID NO.1 can be directly synthesized; insert the gene fragment into the expression vector pCAMBIA1300-35S-YFP containing a strong promoter through a recombination reaction, and screen positive clones using the marker gene on the expression vector to obtain the recombinant expression vector OsCOST1-OE; transfer the recombinant expression vector OsCOST1-OE into Agrobacterium tumefaciens GV3101, and screen positive Agrobacterium strains that can be used to infect rice tissues using the characteristics of the expression vector and the Agrobacterium itself; infect the rice callus with the positive Agrobacterium strains, and perform dark culture on a screening medium containing hygromycin to obtain positive transgenic callus; perform differentiation, rooting, and transplantation culture on the positive callus to obtain T0 generation transgenic plants;

[0086] The T1 generation plants with increased rice plant height and biomass are obtained through conventional molecular marker detection and rice cultivation methods. The high-yield and high-light-efficiency gene OsCOST1, the recombinant vector, the transformant, and the transgenic line can all be applied in the cultivation for increasing rice biomass.

[0087] The following will combine examples and experimental data to elaborate in detail on a method for increasing rice biomass of this application.

[0088] Example 1

[0089] Evolutionary relationship analysis and functional verification of DUF641 family members in rice and Arabidopsis

[0090] To systematically study the DUF641 family members in rice and Arabidopsis, using the amino acid sequence corresponding to the DUF641 domain of the Arabidopsis COST1 protein as the target sequence, homologous sequence searches were performed on Arabidopsis (version Araport11) and rice (version ITAG4.0) in Phytozome 13 (https: / / phytozome-next.jgi.doe.gov). The evolutionary analysis of DUF641 family members in rice and Arabidopsis was carried out using the evolutionary analysis software MEGA X. First, the amino acid sequences were aligned with default parameters by the ClustalW method, and then a phylogenetic tree was constructed using the output file, with a neighbor-joining tree, and 1000 times of bootstrap analysis was performed. Gene annotations were extracted from the gff3 file, and the gene structures were visually presented through Toolbox for biologists (TBtools) ( Figure 1 ).

[0091] To identify whether these nine members of the DUF641 family in rice (Os10g23220.1, Os10g36400.1, Os01g10680.1, Os01g60850.1, Os03g61040.1, Os12g02230.1, Os05g11650.1, Os11g02270.1, Os11g14490.1) have similar functions or functional redundancy, the double digestion and ligation method (the primers used are shown in Table 1) was used to construct overexpression pCambia binary vectors 35S:OsCOSTs-YFP (hygromycin resistance) of five rice DUF641 members, which were introduced into the GV3101 strain of Agrobacterium tumefaciens and introduced into Arabidopsis cost1 mutants by the floral dip method during the full bloom period. After the fruit pods matured, transgenic seeds were harvested from each individual plant. After sterilization, the seeds were sown on a medium containing hygromycin for screening, and at the same time, further confirmation was carried out using the YFP fluorescence tag carried by the transgenic plants with a fluorescence microscope. Positive seedlings overexpressing the OsCOSTs gene, cost1 mutants, and wild-type Arabidopsis plants were grown under consistent culture conditions, and their growth conditions were observed.

[0092] Table 1. Primers used to construct the 35S:OsCOSTs-YFP binary expression vector

[0093]

[0094]

[0095] Note: The underlined sequences indicate the restriction enzyme sites. CCCGGG is Sma I, and ACTAGT is Spe I.

[0096] Through genome-wide mining and evolutionary analysis of the DUF641 family members in rice and Arabidopsis, it was found that there are nine DUF641 members in rice (see Figure 1 ), fewer than the 11 in Arabidopsis, and they may have lower functional redundancy. Among them, OsCOST1 is an orthologous gene of the Arabidopsis COST1 gene. The functional verification results showed that only OsCOST1 successfully complemented the phenotype of the Arabidopsis cost1 mutant, and other genes could not complement its phenotype, indicating that OsCOST1 is a gene with a similar function to Arabidopsis COST1, and there are functional differences between the other 48 DUF641 members in rice and OsCOST1.

[0097] Example 2

[0098] 1. Obtaining the full-length fragment of the OsCOST1 gene

[0099] Using rice cDNA as a template, primers OsCOST1-F / R were designed and corresponding recombination sequences were added to their respective 5' ends. The primer sequences are shown in Table 2. PCR amplification was performed, and the products were subjected to sequencing analysis. The nucleotide sequence of the amplified gene fragment is as shown in SEQ ID NO.1. In other embodiments, a gene fragment with the nucleotide sequence as shown in SEQ ID NO.1 can be directly synthesized.

[0100] Table 2 - Primer Sequences

[0101] Primer name Primer sequence (5'-3') OsCOST1-F <![CDATA[CGC CCCGGG ATGGTACTGCCAGGCTCTAAGGA]]> OsCOST1-R <![CDATA[GCG ACTAGT ATCAGCAGACTTGACACCTGAAA]]>

[0102] 2. Construction of the OsCOST1 Gene Overexpression Vector

[0103] The gene fragment with the nucleotide sequence as shown in SEQ ID NO.1 was inserted into the expression vector pCAMBIA1300 - 35S - YFP containing a strong promoter through enzymatic digestion and ligation reactions. Positive clones were screened using the marker gene on the vector to obtain the recombinant expression vector OsCOST1 - OE.

[0104] 3. Obtaining of OsCOST1 Gene Overexpression Transgenic Plants

[0105] The constructed OsCOST1 - OE vector can be transferred into Agrobacterium tumefaciens GV3101 by electroporation or heat shock methods. Positive Agrobacterium strains that can be used to infect rice tissues were screened using the characteristics of the vector and Agrobacterium itself. Rice calli were infected with the recombinant Agrobacterium strain containing the recombinant plasmid OsCOST1 - OE and were cultured in the dark on a selection medium containing 50 mg / L hygromycin to obtain positive transgenic calli. The positive calli were differentiated, rooted, and transplanted to obtain T0 generation transgenic plants. T1 generation plants were obtained through conventional molecular marker detection and rice cultivation methods.

[0106] 4. Yield Detection of OsCOST1 Gene Overexpression Plants

[0107] (1) Detection of the expression level of the OsCOST1 gene by qRT - PCR:

[0108] The 35S promoter, as a strong plant promoter, can increase the expression level of the target gene in plants. Total RNA of OsCOST1 overexpression plants and wild - type plants was obtained using conventional RNA extraction methods, and the corresponding cDNA was obtained using a reverse transcription kit (purchased from Vazyme). The expression level of OsCOST1 was detected by qRT - PCR using the primer pair OsCOST1 - RT - F / R; the PCR product of the primer pair Actin - RT - F / R was used as an internal reference; the above primer sequences are shown in Table 3.

[0109] Table 3 - Primer Sequences

[0110] Primer name Primer sequence (5'-3') OsCOST1-RT-F GCAGGAAGCTCACACCCCATA OsCOST1-RT-R GCCTCATCGATTTGCTGCTGT Actin-RT-F TGTATGCCAGTGGTCGTACCA Actin-RT-R CCAGCAAGGTCGAGACGAA

[0111] (2) Statistics of plant height and biomass of transgenic plants:

[0112] The over - expressed transgenic materials and wild - type seeds were soaked, germinated, and transplanted by conventional methods. When the ears of the materials were fully developed, the materials were harvested for seeds respectively. Then, the over - expressed transgenic materials and wild - type materials were examined for seeds, and the

[0113] Performance of grains and yield of the OsCOST1 over - expressed materials at the mature stage was as Figure 3 shown, indicating that OsCOST1 can increase biomass and thus increase rice yield.

[0114] The plant diagram of the OsCOST1 over - expressed materials was as Figure 3 shown, indicating that OsCOST1 significantly increases rice biomass;

[0115] The plant height performance of the OsCOST1 over - expressed materials was as Figure 3 shown, indicating that OsCOST1 significantly increases rice plant height.

[0116] Examples of the present invention show that: Homologous genes of the COST1 gene include the OsCOST1 gene, the rice OsCOST1 gene, the poplar PtCOST1 and PtCOST2 genes, and other genes in other species with a homology of more than 40% to any nucleotide or protein region fragment of COST1 ( Figure 1 ). In Arabidopsis thaliana (L.) Heynh., the number of rosette leaves and leaf area of the AtCOST1 (At2G45260) over - expressed lines were significantly larger than those of wild - type plants ( Figure 2 ). Similarly in rice, the OsCOST1 (Os10g23220) over - expressed lines also had similar characteristics, with their plant height and yield both larger than those of wild - type plants ( Figure 3 ).

[0117] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non - exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0118] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0119] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. Application of the OsCOST1 gene in plant breeding regulation, characterized in that, The nucleotide sequence of the OsCOST1 gene is shown as SEQ ID No.1; the plant breeding regulation refers to regulating the expression level of OsCOST1 in the recipient plant to control plant height and biomass.

2. The application according to claim 1, wherein The recipient plant is a monocotyledonous or dicotyledonous plant containing the DUF641 (Pfam: PF04859; InterPro: IPR006943) protein domain in its genome.

3. The application according to claim 1, characterized in that, Use of overexpressing OsCOST1 in increasing rice plant height, biomass and cultivating high-yield rice varieties.

4. The application according to claim 1, wherein Use of regulating the expression level of the OsCOST1 gene in cultivating plants with different plant types.

5. The application according to claim 1, characterized in that Use of a plant expression vector containing an OsCOST1 gene fragment or a host cell containing an OsCOST1 gene fragment in regulating plant biomass and cultivating high-yield rice varieties.

6. The application according to claim 5, wherein Use of a plant expression vector containing an OsCOST1 gene fragment or a host cell containing an OsCOST1 gene fragment in cultivating varieties with different plant heights.

7. A method for increasing rice biomass, characterized in that, It includes the step of overexpressing OsCOST1 and its similar genes in rice, and the nucleotide sequence of the OsCOST1 gene is shown as SEQ ID No.

1.

8. A method for increasing rice biomass according to claim 7, characterized in that, Overexpressing the OsCOST1 gene in rice includes: Inserting the OsCOST1 gene into a basic vector to construct a recombinant vector containing the OsCOST1 gene; Transforming the recombinant vector containing the OsCOST1 gene into crop tissues or cells.

9. A method for increasing rice biomass according to claim 8, characterized in that, The basic vector includes a crop transformation vector, and the crop transformation vector includes one of a binary Agrobacterium vector and a vector available for crop particle bombardment. The binary Agrobacterium vector includes one of pCAMBIA1301 or pCAMBIA2301; The transformation method includes microinjection, genetic transformation of Agrobacterium, and one of Ti plasmid, Ri plasmid or virus vector.

10. A method for increasing rice biomass according to claim 7, characterized in that, The overexpression of the OsCOST1 gene in rice specifically includes: Obtaining a gene fragment with the nucleotide sequence shown as SEQ ID NO.1; Inserting the gene fragment into the expression vector pCAMBIA1301-35SN containing a strong promoter through a recombination reaction, and screening positive clones using the marker gene on the expression vector to obtain the recombinant expression vector OsCOST1-OE; Transferring the recombinant expression vector OsCOST1-OE into Agrobacterium EHA105, and screening to obtain a positive Agrobacterium strain that can be used to infect rice tissues using the characteristics of the expression vector and the Agrobacterium itself; Infecting rice callus with the positive Agrobacterium strain, and performing dark culture on a screening medium containing hygromycin to obtain positive transgenic callus; Performing differentiation, rooting and transplanting culture on the positive callus to obtain T0 generation transgenic plants; Obtaining T1 generation plants with increased rice plant height and improved biomass through conventional molecular marker detection and rice cultivation methods.

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