Application of rice photosynthetic state conversion key gene OsSTN7 in improvement of plant photosynthetic rate and biomass

Abstract

The invention discloses application of a rice photosynthetic state conversion key gene OsSTN7 in improving the photosynthetic rate and biomass of plants, and belongs to the technical field of genetic engineering. In order to improve the photosynthetic rate or / and biomass of the plant, the invention provides application of the OsSTN7 protein or a biological material related to the OsSTN7 protein in improving at least one character of the photosynthetic rate, the biomass and the effective tiller number of the plant. Experiments prove that the encoding gene of the OsSTN7 protein is introduced into a target plant to obtain a transgenic plant, and the net photosynthesis rate and biomass of the transgenic plant are higher than those of the target plant under natural conditions; the net photosynthesis rate and the biomass of the transgenic plant are higher than those of the target plant under continuously changing light intensity. The method provides available data for other crops and production practice, and is of great significance in theory and practice.

Description

Technical Field

[0001] This application belongs to the field of genetic engineering technology, specifically involving the application of the key gene OsSTN7 for photosynthetic state transition in rice in improving plant photosynthetic rate and biomass. Background Technology

[0002] Photosynthesis is the most important chemical reaction on Earth, a major source of food and energy for humans, and the foundation for crop yields. Photosynthesis is the collective term for the chemical reactions in which photosynthetic organisms convert light energy into chemical energy. Improving the efficiency of crops in utilizing light energy is a crucial way to increase their yield. While traditional breeding methods have improved the photosynthetic efficiency of rice to some extent, progress has been slow. Therefore, it is necessary to utilize modern biotechnology to deeply explore and utilize high-photosynthetic-efficiency genes in rice, and to introduce these superior genes into cultivated rice through molecular breeding techniques, thereby cultivating new rice varieties with higher yields.

[0003] In oxygen-evolving photosynthetic organisms, photosynthesis involves photosynthetic electron transport coupled with oxidative phosphorylation via photosystem II (PSII) and photosystem I (PSI). Photosynthetic electron transport is divided into two modes: linear electron transport and cyclic electron transport. Linear electron transport is completed jointly by both PSII and PSI, ultimately producing high-energy products ATP and NADPH for carbon fixation. Cyclic electron transport, under certain light intensity conditions, occurs when PSII is over-excited, resulting in electron transport mediated solely by PSI. The final product of this cyclic electron transport is only ATP, without NADPH. Plants can adapt to changes in light intensity or quality by adjusting the energy distribution between PSII and PSI. Linear and cyclic electron transport can interconvert, a process known as photosynthetic state switching.

[0004] STN7 kinase is a key protein kinase in plant photosynthesis, belonging to the serine / threonine protein kinase family, and is mainly involved in the regulation of photosynthetic state transition. Regulating STN7 activity may be a target for improving crop light energy utilization efficiency, which is of great significance for increasing the light energy utilization efficiency and yield of rice. Summary of the Invention

[0005] The technical problem this application aims to solve is: how to increase the photosynthetic rate and / or biomass of plants. To solve this technical problem, this application provides the following technical solution: This application provides the use of OsSTN7 protein or biomaterials related to said OsSTN7 protein in at least one of the following: A1) Application in improving plant photosynthetic rate; A2) Application in the preparation of products that improve the photosynthetic rate of plants; A3) Application in increasing plant biomass; A4) Application in the preparation of products that increase plant biomass; A5) Application in increasing the number of effective tillers in plants; A6) Application in the preparation of products that increase the number of effective tillers in plants; A7) Application in improving the height of plant plants; A8) Application in the preparation of products that increase plant height; The OsSTN7 protein may be at least one of the following proteins: B1) Proteins with amino acid sequences as shown in SEQ ID NO:4; B2) A protein with the same function as the protein shown in B1) obtained by substituting, deleting and / or adding amino acid residues of the amino acid sequence shown in B1). B3) Proteins that have more than 70% amino acid sequence identity with those shown in B1) or B2) and have the same function; B4) A fusion protein obtained by linking a protein tag to the N-terminus and / or C-terminus of any one of B1) to B3).

[0006] In this application, the protein may be derived from rice.

[0007] The proteins described in this application can be synthesized artificially, or the encoding genes can be synthesized first and then expressed biologically.

[0008] The protein tag described in this application refers to a polypeptide or protein fused with a target protein using in vitro DNA recombination technology for expression, detection, tracing, and / or purification of the target protein. The protein tag may be a Flag protein tag, His protein tag, MBP protein tag, HA protein tag, myc protein tag, GST protein tag, and / or SUMO protein tag, etc.

[0009] In this application, the biomaterial may include at least one of the following: C1) The nucleic acid molecule encoding the OsSTN7 protein described above; C2) An expression cassette containing the nucleic acid molecule described in C1); C3) A recombinant vector containing the nucleic acid molecule described in C1) or a recombinant vector containing the expression cassette described in C2); C4) Recombinant microorganisms containing the nucleic acid molecules described in C1), recombinant microorganisms containing the expression cassette described in C2), or recombinant microorganisms containing the recombinant vector described in C3); C5) Transgenic plant cells containing the nucleic acid molecules described in C1), transgenic plant cells containing the expression cassette described in C2), or transgenic plant cells containing the recombinant vector described in C3); C6) Transgenic plant tissue containing the nucleic acid molecule described in C1), transgenic plant tissue containing the expression cassette described in C2), or transgenic plant tissue containing the recombinant vector described in C3); C7) A transgenic plant organ containing the nucleic acid molecule described in C1), a transgenic plant organ containing the expression cassette described in C2), or a transgenic plant organ containing the recombinant vector described in C3); C8) A transgenic plant containing the nucleic acid molecule described in C1), a transgenic plant containing the expression cassette described in C2), or a transgenic plant containing the recombinant vector described in C3).

[0010] In this application, the nucleic acid molecule described in C1) may be a DNA molecule as described in at least one of the following: D1) A DNA molecule whose coding sequence is shown in SEQ ID NO:3; D2) DNA molecules that have more than 70% similarity to the DNA molecules described in D1) and encode the OsSTN7 protein described above; C2) The expression cassette contains a promoter and an enhancer for enhanced transcription, the nucleotide sequence of the promoter being shown in SEQ ID NO:1 and the nucleotide sequence of the enhancer being shown in SEQ ID NO:2.

[0011] This application also provides the aforementioned OsSTN7 protein and / or biological materials.

[0012] In this application, the recombinant microorganisms may specifically be yeast, bacteria, algae, and fungi.

[0013] In this application, the plant tissue may be derived from roots, stems, leaves, flowers, fruits, seeds, pollen, embryos, and anthers.

[0014] In this application, the genetically modified plant organs may be the roots, stems, leaves, flowers, fruits, and seeds of the genetically modified plant.

[0015] In this application, the transgenic plant cell lines, transgenic plant tissues, and transgenic plant organs may or may not include propagation material.

[0016] This application also provides a transgenic plant containing the expression cassette described in C2) or the recombinant vector described in C3).

[0017] The transgenic plants can be prepared by introducing the aforementioned expression cassettes or recombinant vectors into recipient plants.

[0018] In one embodiment of this application, the expression cassette described above is introduced into the recipient plant in the form of a recombinant vector.

[0019] In one embodiment of this application, the recombinant vector is transferred into the recipient plant via Agrobacterium-mediated transformation.

[0020] In this application, the transgenic plant may have at least one of the following traits: E1) has a higher photosynthetic rate compared to the recipient plant; E2) has a higher biomass compared to the recipient plant; E3 plants have a higher number of effective tillers compared to the recipient plants.

[0021] This application also provides a method for improving at least one of the following traits in a recipient plant: photosynthetic rate, biomass, plant height, and number of effective tillers. The method may include introducing the aforementioned traits into the recipient plant. OsSTN7 The protein-coding gene or expression cassette is used to enhance at least one of the following traits in recipient plants: photosynthetic rate, biomass, plant height, and effective tiller number.

[0022] This application also provides a method for preparing a target plant with improved photosynthetic rate, biomass, plant height, and effective tiller number. The method may include introducing the encoding gene or expression cassette of the OsSTN7 protein mentioned above into a recipient plant to obtain a target plant with improved photosynthetic rate, biomass, plant height, and effective tiller number.

[0023] In the above method, the encoding gene is at least one of the following: D1) A DNA molecule whose coding sequence is shown in SEQ ID NO:3; DNA molecules that have more than 70% similarity to the DNA molecules described in D2) and encode the aforementioned OsSTN7 protein.

[0024] In the above method, the expression cassette further contains a promoter and an enhancer for enhanced transcription, the nucleotide sequence of the promoter is shown in SEQ ID NO:1, and the nucleotide sequence of the enhancer is shown in SEQ ID NO:2.

[0025] In this application, the plant may be a monocotyledonous plant.

[0026] In this application, the monocotyledonous plant may be a grass family plant.

[0027] In this application, the grasses mentioned may be cereal plants.

[0028] In this application, the cereal plant may be rice.

[0029] In this application, the photosynthetic rate can be obtained by detecting a photosynthesis instrument.

[0030] In this application, the biomass can be evaluated by the plant dry weight, i.e., the dry weight of a single plant. The dry weight of a single plant is the total dry weight of the aboveground parts of a single plant.

[0031] The experiments presented in this application demonstrate that introducing the gene encoding the OsSTN7 protein into a target plant yields transgenic plants. These transgenic plants exhibit higher net photosynthetic rate, biomass, plant height, and effective tiller number under natural conditions than the target plant. Furthermore, the transgenic plants also demonstrate higher net photosynthetic rate, biomass, and effective tiller number under continuously varying light intensities. This provides usable data for other crops and production practices, and is of significant theoretical and practical importance. Attached Figure Description

[0032] Figure 1 For rice OsSTN7 Cloning of the gene CDS.

[0033] Figure 2 for OsSTN7 Cloning of the promoter segment.

[0034] Figure 3 plant expression vector pCSiSTN7 Restriction enzyme digestion map.

[0035] Figure 4 Hygromycin resistance gene in transgenic rice plants Hyg PCR detection.

[0036] Figure 5 The target gene for transgenic rice plants OsSTN7 PCR detection.

[0037] Figure 6 The target gene for transgenic rice plants OsSTN7 The expression level was detected.

[0038] Figure 7 for OsSTN7 Measurement of net photosynthetic rate of transgenic rice under natural growth conditions. Detailed Implementation

[0039] I. Terms used in this application: Examples of resources describing many of the molecular biology-related terms used in this article can be found in the following literature: Alberts et al., Molecular Biology of The Cell, 5th ed., Garland Science Publishing, Inc.: New York, 2007; Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed., Springer-Verlag: New York, 1991; King et al., A Dictionary of Genetics, 6th ed., Oxford University Press: New York, 2002; and Lewin, GenesIX, Oxford University Press: New York, 2007.

[0040] Any references cited in this article, including, for example, all patents, published patent applications and non-patent publications, are incorporated in their entirety by reference.

[0041] For ease of understanding this application, several terms and abbreviations used herein are defined as follows: In this application, "identity" refers to the similarity of amino acid or nucleotide sequences. The similarity of amino acid sequences (or nucleotide sequences) can be determined using homology search sites on the Internet, such as the BLAST page on the NCBI homepage. For example, in Advanced BLAST 2.1, by using blastp as the program, setting the Expect value to 10, setting all filters to OFF, using BLOSUM62 as the matrix, and setting the Gap existence cost, Perresidue gap cost, and Lambda ratio to 11, 1, and 0.85 (default values) respectively, and performing a search for the similarity of a pair of amino acid sequences, the similarity value (%) can be obtained.

[0042] Specifically, the consistency of 70% or more can be 75% or more. Specifically, the consistency of 75% or more can be 80% or more. Specifically, the consistency of 80% or more can be 85% or more. Specifically, the consistency of 85% or more can be 90% or more. Specifically, the consistency of 90% or more can be 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or more. More specifically, the consistency of 70% or more can be at least 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% consistency.

[0043] When used in a list of two or more items, the term "and / or" means that any of the listed items can be used alone or in combination with any one or more of the listed items. For example, the expression "A and / or B" is intended to mean either or both of A and B, i.e., A alone, B alone, or a combination of A and B. The expression "A, B and / or C" means A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B and C.

[0044] The term "comprising" is not intended to be restrictive, but rather inclusive and implies the presence of other elements besides those listed, and can be interpreted as "including but not limited to". The term "comprising" also encompasses the terms "consisting of" and "substantially consisting of". In this document, the terms "including" and "comprise" are used interchangeably.

[0045] The terms “protein,” “peptide,” and “polypeptide” are used interchangeably herein and refer to polymers of amino acid residues linked together by peptide (amide) bonds. These terms refer to proteins, peptides, or polypeptides of any size, structure, or function. Typically, proteins, peptides, or polypeptides are at least 3 amino acids in length. Proteins, peptides, or polypeptides can refer to a single protein or a collection of proteins. One or more amino acids in a protein, peptide, or polypeptide can be modified, for example, by adding chemical entities such as carbohydrate groups, hydroxyl groups, phosphate groups, farnesyl groups, isofarnesyl groups, fatty acid groups, linkers for conjugation, functionalization, or other modifications. Proteins, peptides, or polypeptides can also be single molecules or can be multi-molecular complexes. Proteins, peptides, or polypeptides can simply be fragments of naturally occurring proteins or peptides. Proteins, peptides, or polypeptides can be naturally occurring, recombinant, or synthetic, or any combination thereof. Any protein provided herein can be produced by any method known in the art. For example, the proteins provided herein can be produced by recombinant protein expression and purification, which is particularly suitable for fusion proteins containing peptide linkers.

[0046] The terms "nuclear localization signal," "nuclear localization sequence," or "NLS," used interchangeably in this article, refer to the amino acid sequence that "tags" a protein for transport into the nucleus via nuclear transport. Typically, this signal consists of a short sequence of one or more positively charged lysine or arginine residues exposed on the protein surface. Different nuclear localization proteins may share the same NLS. The NLS functions in the opposite way to the nuclear export signal, aiming to expel the protein from the nucleus.

[0047] As used in this article, the term "fusion protein" refers to a hybrid polypeptide containing protein domains from at least two different proteins. One protein may be located at the N-terminal (N-terminal) portion or the C-terminal (C-terminal) portion of the fusion protein, thus forming an "N-terminal fusion protein" or a "C-terminal fusion protein," respectively.

[0048] The term "biomaterial" refers to any material that carries genetic information and is capable of self-replication or replication within a biological system, such as genes, plasmids, microorganisms, animals, and plants.

[0049] The term "plant" refers to an organism that can sustain itself by using photosynthesis to synthesize carbohydrates and proteins from inorganic substances such as water, carbon dioxide, and inorganic salts, and that does not typically move.

[0050] As used in this article, "plant" includes explants, plant parts, seedlings, plantlets, or whole plants at any stage of regeneration or development.

[0051] As used in this article, “cereals” refers to monocotyledonous crops of the Poaceae or Gramineae family, and is typically harvested for their seeds, including, for example, corn, wheat, rice, millet, barley, sorghum, oats, and rye.

[0052] As used herein, "plant part" can refer to any organ or intact tissue of a plant, such as meristematic tissue, bud organs / structures (e.g., leaves, stems, or nodes), roots, flowers or floral organs / structures (e.g., flowers, bracts, sepals, petals, stamens, carpels, anthers, and ovules), seeds (e.g., embryo, endosperm, and seed coat), fruits (e.g., mature ovaries), propagules, or other plant tissues (e.g., vascular tissue, dermal tissue, ground tissue, etc.) or any part thereof. The plant part in this application can be viable, non-viable, renewable, and / or non-renewable. "Propagule" can include any plant part that can grow into a whole plant.

[0053] Plant cells are biological cells of plants, derived from plants or derived from cultures obtained by culturing cells taken from plants. As used herein, “transgenic plant cell” means any plant cell transformed with a stably integrated recombinant DNA molecule, construct, expression cassette, or sequence. Transgenic plant cells can include original transformed plant cells, transgenic plant cells regenerated or developed from R0 generation transgenic plant cells, transgenic plant cells cultured from another transgenic plant cell, or transgenic plant cells from any progeny or offspring of a transformed R0 generation plant, including cells of plant seeds or embryos, or cultured plant cells, callus cells, etc.

[0054] As is commonly understood in the art, the term "promoter" generally refers to a DNA containing an RNA polymerase binding site, a transcription start site, and / or a TATA box that assists or promotes the transcription of transcribed DNA. Promoters can be artificially synthesized, modified, or derived from known or naturally occurring promoters. Promoters can also include chimeric promoters comprising combinations of two or more heterologous sequences. Therefore, the promoters of this application may include variants of promoter sequences that are compositionally similar but not identical to other promoter sequences provided herein.

[0055] Promoters can be classified according to various criteria related to the expression patterns of the associated coding or transcribed sequences or genes (including transgenes) operably linked to them, such as constitutive, developmental, tissue-specific, and inducible promoters. A promoter that drives expression in all or most tissues of a plant is called a "constitutive" promoter. A promoter that drives expression at certain times or stages of development is called a "developmental" promoter. A promoter that drives enhanced expression in certain tissues of a plant relative to other tissues is called a "tissue-enhancing" or "tissue-preferred" promoter. Therefore, a "tissue-preferred" promoter elicits relatively high or preferential expression in a specific tissue of the plant, but lower expression levels in other tissues. A promoter that is expressed in a specific tissue of the plant but rarely or not expressed in other tissues is called a "tissue-specific" promoter. An "inducible" promoter is a promoter that initiates transcription in response to environmental stimuli (e.g., cold, drought, or light) or other stimuli (e.g., injury or chemical application). Promoters can also be classified according to their origin, such as heterologous, homologous, chimeric, synthetic, etc.

[0056] The term "transcribed DNA" refers to DNA that can be transcribed into RNA molecules.

[0057] The term "operationally ligated" can refer to a functional connection between a promoter and transcribed DNA, enabling the promoter to function and initiate transcription of the transcribed DNA. The term "operationally ligated" can also refer to a functional connection between other regulatory elements and a target gene to regulate the transcription and / or expression of the target gene.

[0058] The term "construct" refers to any recombinant DNA or recombinant RNA molecule. Recombinant DNA molecules can be plasmids, granules, viruses, bacteriophages, or linear or circular DNA. Constructs typically include one or more expression cassettes.

[0059] As used herein, an "expression cassette" refers to a cassette containing at least transcribed DNA operatively linked to one or more regulatory elements, typically at least a promoter and a 3' UTR (such as a terminator).

[0060] As used herein, the term "vector" refers to any construct that can be used for transformation purposes, i.e., to introduce heterologous DNA into a host cell. Examples include plasmids, granules, viruses, bacteriophages, or linear or circular DNA.

[0061] II. Implementation Examples The present application will now be described in further detail with reference to specific embodiments. The embodiments given are merely illustrative of the present application and are not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the present application in any way.

[0062] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0063] In the following embodiments pCAMBIA1300 / Ubi The biomaterial is owned by the inventor and is described in the literature "OsJAZ13Negatively Regulates Jasmonate Signaling and Activates Hypersensitive CellDeath Response in Rice. International Journal of Molecular Sciences. 2020, 21, 4379; doi:10.3390 / ijms21124379". The public can obtain this biomaterial from the applicant; the obtained biomaterial can only be used to verify the technical solution of this application.

[0064] Unless otherwise specified, the quantitative experiments in the following examples were performed in triplicate, and the results were averaged.

[0065] Example 1 OsSTN7 The acquisition of genetically modified rice 1. Rice OsSTN7 Cloning of genes According to the MSU Version 7.0 database (http: / / rice.plantbiology.msu.edu / index.shtml), OsSTN7 The annotations yielded OsSTN7 Gene information: This gene is located on chromosome 5 (27249448-27245246), and its name is LOC_Os05g47560. Sequence information shows that its full-length CDS is 1680 bp, encoding a protein of 559 amino acids. BLASTN analysis of the OsSTN7 protein sequence did not reveal any other proteins with high homology, indicating that this gene is a single-copy gene in rice.

[0066] right OsSTN7 Full-length CDS primers stF and stR were designed for the promoter. Using cDNA reverse transcribed from total RNA in the flag leaf of MH86 rice during the grain-filling stage as a template, and stF and stR as primers, amplification was performed using high-fidelity DNA polymerase. The amplified bands are shown below. Figure 1 As shown, the sequencing vector T-easy was used for sequencing confirmation, ultimately yielding a result containing... OsSTN7The full-length coding sequence is 1680 bp (CDS, nucleotide sequence see SEQ ID NO:3). OsSTN7 CDS sequencing vector OsSTN7 The 1680 bp coding sequence is similar to that of Nipponbare rice. OsSTN7 The gene sequence differs by two bases, but neither of them changes the encoded amino acid sequence.

[0067] Genomic DNA was extracted from MH86 rice leaves and used as a template. Primers PstF and PstR were designed, and the DNA was amplified using high-fidelity DNA polymerase. OsSTN7 The promoter sequence approximately 2 Kb upstream of CDS amplifies the band as follows: Figure 2 As shown, the sequence was confirmed by sequencing using the T-easy sequencing vector, yielding a promoter sequence of 1985 bp (from rice, nucleotide sequence shown in SEQ ID NO:1). OsSTN7 CDS sequencing vector.

[0068] The primer sequences used in the above operations are as follows: stF: 5'-ATGGCCACCGGTAGCCTTG-3'; stR: 5' - CTACTCCTCCTTTGGTATC -3'; PstF: 5'-TTGGGCACTAATGGTGGT-3'; PstR: 5'-ATGCGGCTCACACTATTTC-3'; 2. Construction of plant expression vectors by OsSTN7 Using the CDS sequencing vector as a template, primers stFB and stRK were designed, and the primer sequences were modified accordingly. Bam HI and Kpn The corresponding restriction enzyme cleavage site adapter sequence (lowercase letter format) for I OsSTN7 The full-length CDS was amplified to obtain CDS with enzyme recognition sites. OsSTN7 The full-length CDS fragment was ligated into the sequencing vector T-easy for sequencing to ensure the CDS sequence was correct.

[0069] by OsSTN7 Using the promoter sequencing vector as a template, primers Pst FP and Pst RS were designed, and the primer sequences were modified accordingly. Pme I and Sal I. Corresponding restriction enzyme cleavage site adapter sequence (lowercase letters), for OsSTN7 Amplification of the promoter region yields a sample containing enzyme recognition sites. OsSTN7 The promoter fragment is ligated into the sequencing vector T-easy for sequencing to ensure the promoter sequence is correct.

[0070] Artificially synthesized containing Ubiquitin First intron ( ubi1 intron Using plasmids containing omega transcription-translation enhancer sequences as templates, primers Intron FS and Intron RB were designed, with the following added to the primer sequences: Sal I and Bam The corresponding HI restriction enzyme cleavage site adapter sequence (lowercase letter format) is used for transcriptional translation enhancement elements (the transcriptional translation enhancement elements in the examples below). Ubiquitin First intron ( ubi1 intron The nucleotide sequence (as shown in SEQ ID NO:2) and omega sequence are collectively referred to as enhancers. Enhancer fragments with enzyme recognition sites are amplified and ligated into the sequencing vector T-easy for sequencing to ensure the sequence is correct.

[0071] The nucleotide sequences of the primers are as follows: stF: 5'-CGggatccACAATGGCCACCGGTAGCCTTG-3'; stRK: 5'-GGggtaccCTACTCCTCCTTTGGTATC-3'; PstFP: 5'-GCTgtttaaacTTGGGCACTAATGGTGGT-3'; PstRS: 5'-GACgtcgacATGCGGCTCAACTATTTC-3'; IntronFS: 5'-CGCgtcgacGTACGCCGCTCGTCCTCCC-3'; IntronRB: 5'-CGggatccTGTAATTGTAAATAGTAATTG-3'.

[0072] by Bam HI / Kpn I. Double enzyme digestion of plasmid pCAMBIA1300 / Ubi and OsSTN7 Full-length CDS clip, obtained by linking pC1300STN7T Intermediate carrier. Then... Sal I / Bam HI double digestion of enhancer fragments with restriction enzyme recognition sites and pC1300STN7T Intermediate carrier skeleton, connected to obtain pC1300iSTN7T intermediate carrier; finally used Pme I / Sal I double digestion of enzymes containing enzyme recognition sites OsSTN7 promoter fragments and pC1300iSTN7T Intermediate vector, ligated to obtain the final plant expression vector pCSiSTN7T .

[0073] After enzyme digestion and identification, the results are as follows: Figure 3 As shown: where 1 is pCSiSTN7T plasmid, 2 is Pme I / Sal I enzyme digestion fragment, 3 is Sal I / Bam HI digestion fragment, 4 Bam HI / Kpn The enzyme digestion fragment, as shown in the figure, yielded a positive plant expression vector. pCSiSTN7T .

[0074] Further sequencing analysis of the vector revealed that it contained the correct... OsSTN7 Promoter, enhancer OsSTN7 The CDS and T-nos terminators are specifically replaced with a DNA fragment whose nucleotide sequence is shown in SEQ ID NO:1. pCAMBIA1300 / Ubi carrier Pme I and Sal The small fragment between I and II should be replaced with a DNA fragment whose nucleotide sequence is shown in SEQ ID NO:2. pCAMBIA1300 / Ubi carrier Sal I and Bam The small fragments between HI should be replaced with the DNA fragment whose nucleotide sequence is shown in SEQ ID NO:3. pCAMBIA1300 / Ubi carrier Bam HI and Kpn The short segments between I, keep pCAMBIA1300 The other nucleotide sequences of the vector remain unchanged. Plant expression vector. pCSiSTN7T It can express the OsSTN7 protein with the amino acid sequence SEQ ID NO:4.

[0075] 3. Genetic transformation of MH86 rice and field cultivation of regenerated plants (1) Preparation of bacterial cells The positive plant expression vectors obtained above pCSiSTN7T Agrobacterium tumefaciens was introduced via electroporation. Agrobacterium tumefaciensIn EHA105, plating was performed on YEB solid selection medium (composed of 5 g / L beef extract, 1 g / L yeast extract, 5 g / L peptone, 5 g / L sucrose, 0.5 g / L MgSO4·7H2O, and 15 g / L agar, pH 7.2) containing 50 mg / L each of rifamycin (Rf) and kanamycin (Kan). The medium was incubated at 28°C in the dark for approximately 36 to 48 hours. The resulting colonies were then liquid cultured, and plasmids were extracted for enzyme digestion and identification to obtain the correct clones. These clones were then re-streaked onto YEB selection medium and incubated at 28°C in the dark. The resulting colonies were stored at 4°C and transposed approximately once a month. For long-term storage, 30% glycerol was added to the bacterial culture and the culture was stored at -70°C.

[0076] (2) Preparation of plant materials After threshing and dehulling mature rice seeds of MH86 and sterilizing them, the seeds were dried with sterile filter paper, spread evenly on induction medium, and exposed to light at 30°C for 7 days to induce callus formation at the mature embryo. The callus was collected for Agrobacterium infection and transformation.

[0077] (3) Transformation process Will pCSiSTN7T Agrobacterium was streaked on YEB plates three days in advance. A match head-sized colony was picked and placed in YEB liquid medium containing the corresponding antibiotic. The culture was incubated overnight at 28°C and 200 rpm for 16 h. The next day, 0.1 mL of the bacterial culture was transferred to 50 mL of YEB liquid medium, and AS (acetylsyl syringone) was added to a final concentration of 150 μM. The culture was then incubated at 28°C and 200 rpm for about 4 h. When the OD600 reaches approximately 0.5, centrifuge at 6000 rpm for 10 min to collect the bacterial cells. Discard the supernatant, add 4 mL of AAM medium (containing 300 μM AS) to the centrifuge tube, gently resuspend the bacterial cells, and then resuspend the bacterial cells in AAM solution. Adjust the OD600 to 0.4 to 0.5. Soak the collected rice callus in the collected bacterial solution and gently shake at 120 rpm for 30 min at 28℃. Then transfer the callus to a sterile gauze to air dry. Finally, spread the callus evenly on a co-culture medium containing filter paper and incubate in the dark at 25℃ for three days.

[0078] (4) Screening, rooting and field culture of transformation materials After three days of co-culture, the callus was transferred to an Erlenmeyer flask. Agrobacterium bacteria on the outside of the callus were rinsed with sterile water until the sterile water was clear. The callus was then left to stand in sterile water for 30 minutes, rinsed twice with sterile water, and then washed with sterile water containing 200 mg / L carboxybenzene. After standing for 15 minutes, the callus was dried and transferred to a pre-medium without hygromycin resistance. The callus was then incubated in the dark at 30°C for 3 to 4 days.

[0079] All calluses from the pre-culture medium were transferred to a single-sieve medium and cultured for two weeks at 30°C in a room with a 14-hour light-to-dark cycle. Fresh, yellow, resistant calluses were selected and transferred to a new selection medium. After two more weeks of culture, the calluses were transferred to a triple-sieve medium and subcultured for another two weeks. The resistant calluses were then transferred to a pre-differentiation medium and cultured for 7 to 10 days. Once green spots appeared on the calluses, they were transferred to a differentiation medium and cultured for about four weeks to differentiate into seedlings. The resistant seedlings were then transferred to a rooting medium, and rooted resistant seedlings were obtained after three weeks. The resistant seedlings were hardened off and planted in a greenhouse. During this period, molecular identification of the transgenic plants was performed to obtain transgenic rice seeds.

[0080] Rice callus induction medium: N6 macroelements + B5 microelements + MS iron salts + B5 organic + hydrolyzed casein 0.3 g / L + glutamine 0.5 g / L + proline 2.8 g / L + 2,4-D 2 mg / L + sucrose 30 g / L + plant gel 4.5 g / L, pH 5.8.

[0081] AAM medium: N6 macroelements + B5 microelements + MS iron salts + B5 organic + hydrolyzed casein 0.3 g / L + proline 2.8 g / L + 2,4-D 2 mg / L + sucrose 68.5 g / L + glucose 30 g / L + plant gel 4.5 g / L + AS 300 μM, pH 5.2.

[0082] Co-culture medium: N6 macroelements + B5 microelements + MS iron salts + B5 organic + hydrolyzed casein 0.3 g / L + glutamine 0.5 g / L + proline 2.8 g / L + 2,4-D 2 mg / L + sucrose 30 g / L + glucose 10 g / L + plant gel 4.5 g / L + AS 100 μM, pH 5.2.

[0083] Pre-culture medium: N6 macroelements + B5 microelements + MS iron salts + B5 organic + hydrolyzed casein 0.3 g / L + glutamine 0.5 g / L + proline 2.8 g / L + 2,4-D 2 mg / L + sucrose 30 g / L + plant gel 4.5 g / L + carbenicillin 0.2 g / L + cephalosporin 0.5 g / L, pH 5.8.

[0084] Screening medium: N6 macroelements + B5 microelements + MS iron salts + B5 organic + hydrolyzed casein 0.3 g / L + glutamine 0.5 g / L + proline 2.8 g / L + 2,4-D 2 mg / L + sucrose 30 g / L + plant gel 4.5 g / L + carbenicillin 0.2 g / L + cephalosporin 0.4 g / L + hygromycin 50 mg / L, pH 5.8.

[0085] Predifferentiation medium: MS salt + hydrolyzed casein 1 g / L + sucrose 30 g / L + sorbitol 20 g / L + plant gel 4.5 g / L + NAA (α-naphthaleneacetic acid) 0.5 mg / L + 6-BA (6-benzylaminopurine) 2 mg / L + KT (kinetin) 1 mg / L, pH 5.8.

[0086] Differentiation medium: MS salt + hydrolyzed casein 0.3 g / L + sucrose 10 g / L + sorbitol 20 g / L + plant gel 4.5 g / L + NAA (α-naphthaleneacetic acid) 0.5 mg / L + 6-BA (6-benzylaminopurine) 2 mg / L + KT (kinetin) 1 mg / L, pH 5.8.

[0087] Rooting medium: 1 / 2 MS salt + 15 g / L sucrose + 4.5 g / L plant gel + 30 mg / L hygromycin, pH 5.8.

[0088] 4. Molecular detection of transformed rice plants (1) Extraction of genomic DNA from rice leaves Genomic DNA was extracted from rice leaves using the CTAB method (Maguire et al., 1994). The method was as follows: Approximately 100 mg of rice leaf material was ground into a fine powder in liquid nitrogen and transferred to a centrifuge tube. 650 μL of CTAB extraction buffer preheated to 65°C was added and thoroughly mixed by inverting. The mixture was incubated in a 65°C water bath for 30 min, gently inverting three times during the incubation to prevent clumping. The mixture was then cooled to room temperature. An equal volume of chloroform:isoamyl alcohol (24:1) was added and thoroughly mixed by inverting. The mixture was centrifuged at 12,000 rpm for 15 min at room temperature. The supernatant was transferred to a new centrifuge tube, and an equal volume of isopropanol was added. The mixture was incubated at -20°C for 30 min to precipitate DNA. DNA was collected by centrifuging at 12,000 rpm for 10 min. The DNA precipitate was washed with 1 mL of 75% ethanol, dried at room temperature, dissolved in an appropriate amount of double-distilled water, and stored at -20°C for later use.

[0089] (2) PCR detection Using the total DNA extracted above (1) as a template, the hygromycin resistance gene ( Hyg PCR detection was performed using primers for the target gene ( ) to screen for positive plants; further PCR was performed using primers for the target gene ( ) STN7 Using full-length primers (CDS), PCR was performed on total DNA to obtain transgenic plants.

[0090] Hyg The amplification primers are: HYG1:5'-CGTTATGTTTATCGGCACTTT-3' HYG2:5'-CGGTCGGCATCTACTCTATT-3' STN7 The full-length CDS amplification primers are: stFB: 5'-CGGGATCCACAATGGCCACCGGTAGCCTTG-3' stRK: 5'-GGGGTACCCTACTCCTCCTTTGGTATC-3' Hyg The PCR reaction system was as follows: 1-2 μg genomic DNA template, 2 μL 2.5 mM dNTPs, 0.5 μL each of 10 μM primers, 2 μL 10× Taq buffer, and finally 0.5 μL Taq enzyme. The final volume was brought to 20 μL with double-distilled water. The reaction program was: 95℃ denaturation for 5 min; 95℃ for 30 s, 57℃ annealing for 30 s, 72℃ extension for 45 s, 33 cycles; then 72℃ for 10 min. 5 μL of the PCR product was analyzed by agarose gel electrophoresis. The results are shown below. Figure 4As shown, the number above each lane corresponds to the number of the resistant plant, where "+" indicates that it is a resistant plant. pCSiSTN7T The graph shows PCR amplification results using plasmids as templates; "-" indicates PCR amplification results using the MH86 genome as a template. The graph shows that most resistant plants were amplified. Hyg The gene-specific DNA fragment is 861 bp in length.

[0091] STN7 The PCR reaction system for the full-length CDS sequence was 20 μL: 1–2 μg genomic DNA template, 2 μL 2.5 mM dNTPs, 0.5 μL each of 10 μM primers, 2 μL 10 × Taq buffer, and finally 0.5 μL Taq enzyme. The final volume was brought to 20 μL with double-distilled water. The reaction program was: 95℃ denaturation for 5 min; 95℃ for 30 s, 57℃ annealing for 30 s, 72℃ extension for 90 s, 33 cycles; then 72℃ for 10 min. 5 μL of the PCR product was analyzed by agarose gel electrophoresis. The results are shown below. Figure 5 As shown, "+" indicates that... pCSiSTN7T The PCR amplification results using plasmids as templates, with "-" indicating PCR amplification results using the MH86 genome as a template. The figure shows that the target gene DNA fragment can be amplified in most hygromycin-resistant plants. [[ID= The CDS (Cell, Scale, and Spectrum) is 1680 bp, and the transgenic plants STN7-OX-37, STN7-OX-81 and STN7-OX-87 used subsequently are all transgenic positive plants.

[0092] (3) ​ RNA extraction and qRT-PCR detection in transgenic rice For transgenic rice plants at the jointing stage, the top two fully extended leaves were collected after two hours of light exposure. Total RNA was extracted from the leaves using the Invitrogen TRIzol reagent, with slight modifications: during the chloroform extraction stage, the extraction was repeated twice with 200 μL of chloroform to more thoroughly remove impurities. The concentration of the extracted RNA was measured using a spectrophotometer, and the quality of the RNA was assessed by 1.2% agarose gel electrophoresis. RNA samples were stored at -80℃ for later use.

[0093] qRT-PCR detection: Extracted RNA was treated with Invitrogen DNase I to digest and remove any potential genomic DNA, following the manufacturer's instructions; 2-4 μg of RNA was used for reverse transcription to obtain cDNA, and amplification was performed according to the Bio-Rad reverse transcription kit instructions; the real-time quantitative PCR (qPCR) reaction system used Bio-Rad's SYBR Green Supermix, with appropriate templates and primers (target gene) added. ​ The amplification primers were qSTN7F: 5'-CGTTATGAAGGTGAGGATAC-3' and qSTN7R: 5'-GCAGGTCTTGAACATCTC-3'; the internal reference gene was used. ​ (LOC_Os01g22490) The amplification primers were: qUBQ-F: 5'-ACCACTTCGACCGCCACTACT-3' and qUBQ-R: 5'-ACCCCTAAGCCTGCTGGTT-3', prepared in 20 μL reaction mixtures. Each sample was repeated three times in parallel. The reaction was performed on a Rocher LightCycler 480 quantitative PCR instrument. The amplification program was: 95℃ pre-denaturation for 5 min, followed by 45 cycles of 95℃ for 10 s, 58℃ for 10 s, and 72℃ for 10 s; then melting curve analysis was performed at 95℃ for 5 s and 65℃ for 1 min; finally, cooling was performed at 40℃ for 30 s. According to 2 -ΔΔCt The transcriptional levels of the corresponding genes were calculated (Schmittgen and Livak, 2008), and significance analysis was performed using SPSS statistical software. The results are as follows: ​ As shown: The transgenic plants tested ​ Gene transcription levels were significantly higher than those of the control MH86, mostly increasing by 2 to 8 times, and a few by 10 to 12 times.

[0094] Homozygous lines of STN7-OX-81 or STN7-OX-87 obtained from two generations of continuous self-pollination were used for phenotypic determination.

[0095] Example 2 ​ Trait studies of transgenic organisms For the two obtained ​ Net photosynthetic rates were measured in plants from the transgenic homozygous lines STN7-OX-81-1 and STN7-OX-87-1. Molecular identification revealed that the two lines exhibited... ​ Transcription levels were significantly higher than MH86 ( ​ ).

[0096] two ​ Transgenic homozygous lines STN7-OX-81-1 and STN7-OX-87-1 and recipient rice MH86 were planted and phenotyped under the following conditions: The test plants for phenotypic determination under natural conditions were planted in the field in rows, with each line planted in 3 rows, with a row spacing of 20cm, 8 plants per row, and a plant spacing of 16.6cm.

[0097] The plants to be tested, whose phenotypes were determined under continuously varying light intensity, were planted in a greenhouse in rows, with each line planted in 3 rows, with a row spacing of 20 cm, 8 plants per row, and a plant spacing of 16.6 cm.

[0098] 1. Transfer ​ Detection of net photosynthetic rate (Pn) of genetically modified rice under natural conditions For those grown in the field under natural conditions ​ The net photosynthetic rate of the top two leaves of transgenic rice at both the jointing and booting stages was measured using a LI-6400XT photosynthesis system from LI-COR (USA). Measurements were performed according to the instrument's instruction manual, and the light intensity was set to 500 μmol·m⁻¹. -2 ·s -1 The CO2 concentration is 400 μmol·mol⁻¹ -1 The measurement results are shown in Table 1. ​ As shown, two ​ The Pn values ​​of transgenic rice at the jointing stage were higher than those of MH86, increasing by 3.4% and 3.9% respectively; at the booting stage, the Pn values ​​of STN7-OX-81-1 and STN7-OX-87-1 were 3.1% and 5.5% higher than those of MH86 respectively.

[0099] Table 1, Transfer ​ Detection of net photosynthetic rate of genetically modified rice under natural conditions

[0100] Note: The values ​​in the table are average ± SE (n = 6 to 8).

[0101] 2. Transfer ​ Detection of net photosynthetic rate of genetically modified rice under continuously varying light intensity Rice seedlings of two transgenic lines and the control MH86 were first cultured in incubators. When the seedlings reached the four-leaf stage, they were transferred to a greenhouse for hardening-off treatment. Five days later, they were transplanted, with eight individual plants planted for each line. After the seedlings recovered, they were subjected to continuously varying light intensity treatment using a Philips LED top light module and production module: light / dark time was 14 h / 10 h. During the light phase, the light intensity was 800 μmol·m⁻². -2 ·s-1 Irradiated for 10 min under light intensity, followed by 150 μmol·m -2 ·s -1 Irradiation was performed at a light intensity of 10 min, followed by alternating irradiation (Yamori et al., 2016) until the end of the grain-filling period. At the jointing stage, the net photosynthetic rate of the top two leaves of each line was measured using a LI-6400XT photosynthesis system from LI-COR (USA). Measurements were performed according to the instrument's instruction manual. Each leaf was measured at 800 μmol·m⁻² light intensity. -2 ·s -1 and 150 μmol·m -2 ·s -1 The measurement was performed under light intensity of 400 μmol·mol⁻¹. -1 .

[0102] Table 2, Transfer ​ Detection of net photosynthetic rate in genetically modified rice under continuously varying light intensities

[0103] Note: Values ​​in the table are mean ± SE (n = 6 to 8). Analyzed using SPSS. P A value < 0.05 is considered statistically significant and is indicated by an asterisk. P < 0.01 indicates a highly significant difference, indicated by two asterisks.

[0104] In summary, the results of Pn measurements under natural conditions and under continuously varying light intensities indicate that... ​ Genetically modified rice showed certain improvements compared to MH86, particularly under continuously varying light intensity. ​ The increase in Pn is more pronounced in genetically modified rice.

[0105] Example 3 ​ Statistics on agronomic traits of genetically modified rice 1. Transfer ​ Statistics on agronomic traits of genetically modified rice under natural conditions Grown under natural conditions ​ The statistical results of agronomic traits at maturity of transgenic rice are shown in Table 3. Two ​ The overexpression transgenic rice had one more effective tiller than the control, and the dry weight per plant (above-ground plant dry weight) of STN7-OX-81-1 and STN7-OX-87-1 was increased by 15.3% and 12.6% respectively compared to the control. These statistics indicate that under natural conditions, ​ The agronomic traits of the transgenic rice were generally similar to those of the control, and the yield traits of the STN7-OX-81-1 and STN7-OX-87-1 overexpressing rice showed potential for increased yield.

[0106] Table 3. Under natural growth conditions ​ Statistical analysis of traits in genetically modified rice

[0107] 2. Transfer ​ Statistical analysis of agronomic traits in genetically modified rice under continuously varying light intensities Processing of strong and weak light ​ A preliminary statistical analysis of the yield traits of transgenic rice at maturity was conducted, and the results are shown in Table 4. ​ The biomass of the overexpression lines was increased to some extent: First, the number of effective spikes in both overexpression lines was significantly higher than that in MH86, and the overexpression lines had at least one more effective tiller than the control; second, the dry weight of individual plants in the overexpression lines was increased to varying degrees, with STN7-OX-81-1 and STN7-OX-87-1 increasing by 15.8% and 12.9%, respectively. Analysis of the composition of the dry weight of individual plants revealed (see Table 5) that the spike dry weight of STN7-OX-81-1 increased by 8.7%, while the stem and sheath dry weight of the two transgenic plants increased by 33.3% and 14.7%, respectively, and the leaf dry weight increased by 25.4% and 15.9%, respectively.

[0108] Under long-term varying light treatment, the overexpression lines showed strong adaptability: the number of final effective spikes in the two overexpression plants was more than one spike higher than the control on average (see Table 4); the dry weight of individual overexpression plants was increased, with STN7-OX-81-1 showing the greatest increase, up 15.0% compared to MH86, including a 28.3% increase in stem and sheath weight and a 25.4% increase in leaf dry weight (Table 5).

[0109] Table 4. Under strong and weak light conditions ​ Statistical analysis of traits in genetically modified rice

[0110] Note: SPSS analysis indicates a statistically significant difference (P < 0.05, indicated by one asterisk) and a highly statistically significant difference (P < 0.01, indicated by two asterisks). Values ​​in the table are mean ± SE (n = 6 to 8).

[0111] Table 5. Under strong and weak light conditions ​ Analysis of the dry weight composition of individual transgenic plants

[0112] Note: Analysis using SPSS P A difference less than 0.05 is considered statistically significant and is indicated by an asterisk. PA difference less than 0.01 is considered highly significant and is indicated by two asterisks. Values ​​in the table are mean ± SE (n = 6 to 8).

[0113] The above analysis shows that, ​ Overexpression in rice showed a certain degree of improvement in yield traits under natural light intensity. Under long-term varying light intensity treatment, ​ The number of effective tillers in the overexpression lines was significantly increased, and the dry weight of the plants was increased to a certain extent. Among them, the biomass of the rice in the overexpression lines was increased to a greater extent.

[0114] The present application has been described in detail above. Those skilled in the art will recognize that the present application can be implemented in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments are given in this application, it should be understood that further modifications can be made to the present application. In summary, in accordance with the principles of this application, this application is intended to include any changes, uses, or improvements to the present application, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. The use of OsSTN7 protein or biomaterials associated with said OsSTN7 protein in at least one of the following: A1) Application in improving plant photosynthetic rate; A2) Application in the preparation of products that improve the photosynthetic rate of plants; A3) Application in increasing plant biomass; A4) Application in the preparation of products that increase plant biomass; A5) Application in increasing the number of effective tillers in plants; A6) Application in the preparation of products that increase the number of effective tillers in plants; A7) Application in improving the height of plant plants; A8) Application in the preparation of products that increase plant height; The OsSTN7 protein is at least one of the following proteins: B1) Proteins with amino acid sequences as shown in SEQ ID NO:4; B2) A protein with the same function as the protein shown in B1) obtained by substituting, deleting and / or adding amino acid residues of the amino acid sequence shown in B1). B3) Proteins that have more than 70% amino acid sequence identity with those shown in B1) or B2) and have the same function; B4) A fusion protein obtained by linking a protein tag to the N-terminus and / or C-terminus of any one of B1) to B3).

2. The method according to claim 1, characterized in that: The biomaterial includes at least one of the following: C1) A nucleic acid molecule encoding the OsSTN7 protein as described in claim 1; C2) An expression cassette containing the nucleic acid molecule described in C1); C3) A recombinant vector containing the nucleic acid molecule described in C1) or a recombinant vector containing the expression cassette described in C2); C4) Recombinant microorganisms containing the nucleic acid molecules described in C1), recombinant microorganisms containing the expression cassette described in C2), or recombinant microorganisms containing the recombinant vector described in C3); C5) Transgenic plant cells containing the nucleic acid molecules described in C1), transgenic plant cells containing the expression cassette described in C2), or transgenic plant cells containing the recombinant vector described in C3); C6) Transgenic plant tissue containing the nucleic acid molecule described in C1), transgenic plant tissue containing the expression cassette described in C2), or transgenic plant tissue containing the recombinant vector described in C3); C7) A transgenic plant organ containing the nucleic acid molecule described in C1), a transgenic plant organ containing the expression cassette described in C2), or a transgenic plant organ containing the recombinant vector described in C3); C8) A transgenic plant containing the nucleic acid molecule described in C1), a transgenic plant containing the expression cassette described in C2), or a transgenic plant containing the recombinant vector described in C3).

3. The application according to claim 2, characterized in that: C1) The nucleic acid molecule is a DNA molecule that is at least one of the following: D1) A DNA molecule whose coding sequence is shown in SEQ ID NO:3; D2) A DNA molecule that has more than 70% similarity to the DNA molecule described in D1) and encodes the OsSTN7 protein described in claim 1; C2) The expression cassette contains a promoter and an enhancer for enhanced transcription, the nucleotide sequence of which is shown in SEQ ID NO:1 and the nucleotide sequence of which is shown in SEQ ID NO:

2.

4. The OsSTN7 protein and / or biological material according to any one of claims 1 to 3.

5. A transgenic plant, characterized in that: The transgenic plant contains the expression cassette as described in claim 2 or 3 (C2) or the recombinant vector as described in claim 3 (C3).

6. A method for improving at least one trait of a recipient plant, including photosynthetic rate, biomass, plant height, and effective tiller number, characterized in that: The method includes introducing the method of claim 1 into a recipient plant. OsSTN7 The protein-coding gene or expression cassette is used to enhance the photosynthetic rate, biomass, plant height, effective tiller number, and at least one of the traits in the recipient plant.

7. A method for preparing a target plant with improved photosynthetic rate, biomass, plant height, and effective tiller number, the method comprising introducing the method of claim 1 into a recipient plant. OsSTN7 The protein-coding gene or expression cassette is used to obtain a target plant with improved at least one of the following traits: photosynthetic rate, biomass, plant height, and effective tiller number.

8. The method according to claim 6 or 7, characterized in that: The encoding gene is at least one of the following: D1) A DNA molecule whose coding sequence is shown in SEQ ID NO:3; The DNA molecule described in D2) has more than 70% similarity to the DNA molecule described in D1) and encodes the OsSTN7 protein described in claim 1.

9. The method according to claim 6 or 7, characterized in that: The expression cassette also contains a promoter and an enhancer for enhanced transcription, the nucleotide sequence of which is shown in SEQ ID NO:1 and the nucleotide sequence of which is shown in SEQ ID NO:

2.

10. Any one of claims 1 to 9: characterized in that: The plant in question is a monocotyledonous plant.

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