Application of sorghum SbDRP5B in improving photosynthesis inhibition herbicide stress resistance of plants

Abstract

The invention relates to an application of sorghum SbDRP5B in improving plant photosynthesis inhibition herbicide stress resistance. The application comprises application of sorghum chloroplast split protein SbDRP5B and a coding gene thereof in genetic breeding for regulating plant photosynthesis inhibition herbicide stress resistance and / or improving plant tolerance to photosynthesis inhibition herbicides. Researches show that the sorghum chloroplast division protein SbDRP5B can regulate and control stress response of rice to photosynthesis inhibition herbicides. By expressing the SbDRP5B gene in the rice, the rice can show good tolerance to photosynthesis inhibition herbicides, the damage of the photosynthesis inhibition herbicides to the growth and development of the rice is effectively reduced, and the expression of the SbDRP5B does not influence the agronomic traits of the rice. Therefore, the sorghum chloroplast split protein SbDRP5B can improve the resistance of rice to photosynthesis inhibition herbicides, and is used for molecular breeding of photosynthesis inhibition herbicide resistant rice.

Description

Technical Field

[0001] The invention belongs to the field of agricultural biotechnology, and particularly relates to application of sorghum SbDRP5B in improving plant resistance to photosynthesis-inhibiting herbicide stress. Background Art

[0002] Weeds in rice fields severely impact rice production, resulting in yield losses of 15% to 30%, and in severe cases, up to 50%. Currently, chemical weed control remains the primary method for weed control in rice fields. Photosynthesis inhibitory herbicides, in particular, exert their weed-killing effects by interfering with the weed photosynthetic system. Their mechanisms of action include blocking electron transfer from QA to QB in photosystem II, competitively intercepting NADP+ electrons, inhibiting photosynthetic phosphorylation, and interfering with chlorophyll synthesis. Over 60% of newly developed herbicides work by interfering with chloroplast function, highlighting the importance of photosynthesis inhibitory herbicides in weed control. However, while these herbicides are highly effective in controlling weeds, they often also affect rice photosynthesis, resulting in varying degrees of phytotoxicity. Therefore, cultivating rice varieties resistant to photosynthesis inhibitory herbicides is of great value.

[0003] The chloroplast division protein of sorghum (Sorghum bicolor), a dynamin-related protein (DRP) associated with chloroplast division, is a member of the plant-specific DRP5B / ARC5 subfamily. Sorghum DRP5B significantly influences plant photosynthesis efficiency by regulating normal chloroplast division and maintaining chloroplast structural integrity. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide an application of sorghum SbDRP5B in improving plant resistance to photosynthesis-inhibiting herbicide stress. By regulating the expression of the gene encoding the sorghum chloroplast division protein SbDRP5B in plants, the tolerance of plants to photosynthesis-inhibiting herbicides can be effectively improved, the damage of photosynthesis-inhibiting herbicides to plants can be effectively reduced, and the growth and development of plants under photosynthesis-inhibiting herbicide stress conditions can be promoted.

[0005] The first aspect of the present invention is to provide the use of a gene encoding a sorghum chloroplast division protein SbDRP5B in regulating plant resistance to photosynthesis-inhibiting herbicide stress, wherein the nucleotide sequence of the encoding gene is as shown in SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is as shown in SEQ ID NO: 1.

[0006] The second aspect of the present invention is to provide the use of sorghum chloroplast division protein SbDRP5B in regulating plant resistance to photosynthesis-inhibiting herbicide stress. The amino acid sequence of the sorghum chloroplast division protein SbDRP5B is shown in SEQ ID NO: 1.

[0007] The third aspect of the present invention is to provide a use of a sorghum chloroplast division protein SbDRP5B or a gene encoding it in genetic breeding for improving plant tolerance to photosynthesis-inhibiting herbicides, wherein the amino acid sequence of the sorghum chloroplast division protein SbDRP5B is shown in SEQ ID NO: 1;

[0008] The nucleotide sequence of the coding gene is shown as SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is shown as SEQ ID NO: 1.

[0009] The fourth aspect of the present invention is to provide an overexpression vector inserted with a gene encoding sorghum chloroplast division protein SbDRP5B, wherein the nucleotide sequence of the encoding gene is shown in SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is shown in SEQ ID NO: 1.

[0010] The fifth aspect of the present invention is to provide a host cell, wherein the host cell contains the overexpression vector as described above.

[0011] In some embodiments, the host cell is Agrobacterium.

[0012] The sixth aspect of the present invention is to provide the use of the above-mentioned overexpression vector or the host cell in genetic breeding for regulating plant resistance to photosynthesis-inhibiting herbicide stress and / or improving plant tolerance to photosynthesis-inhibiting herbicides.

[0013] In some embodiments, the plant comprises rice, sugarcane, or soybean, preferably rice.

[0014] In some embodiments, the photosynthesis-inhibiting herbicide is selected from at least one of diquat and fluazifop-propyl.

[0015] The seventh aspect of the present invention is to provide a biological preparation for improving plant tolerance to photosynthesis-inhibiting herbicides, wherein the active ingredient of the biological preparation comprises the overexpression vector and / or the host cell as described above.

[0016] The eighth aspect of the present invention is to provide a method for regulating plant resistance to photosynthesis-inhibiting herbicide stress, the method comprising regulating the expression of a gene encoding a sorghum chloroplast division protein SbDRP5B in a plant, wherein the nucleotide sequence of the encoding gene is as shown in SEQ ID NO: 2, or the nucleotide sequence encoding an amino acid sequence is as shown in SEQ ID NO: 1.

[0017] In some embodiments, the plant comprises rice, sugarcane, or soybean, preferably rice.

[0018] In some embodiments, the photosynthesis-inhibiting herbicide is selected from at least one of diquat and fluazifop-propyl.

[0019] In some embodiments, the method for regulating the expression of the gene encoding the sorghum chloroplast division protein SbDRP5B in plants includes Agrobacterium-mediated genetic transformation, gene gun method, CRISPR / dCas9 activation method, and chemical induction method.

[0020] The present invention has discovered that the sorghum chloroplast fission protein SbDRP5B can regulate rice's stress response to photosynthesis-inhibiting herbicides. By utilizing the promoter of the rice homologous gene OsDRP5B, the expression of the SbDRP5B gene in rice was successfully driven. It was found that compared with wild-type rice, the root length and shoot length of rice seedlings expressing the sorghum chloroplast fission protein SbDRP5B were significantly reduced under photosynthesis-inhibiting herbicide stress, and the rice seedlings showed good tolerance to photosynthesis-inhibiting herbicides, effectively reducing the damage caused by photosynthesis-inhibiting herbicides to rice growth and development. Moreover, in a growth environment without photosynthesis-inhibiting herbicide stress, the plant height, number of panicles, and panicle length of rice expressing the sorghum chloroplast fission protein SbDRP5B were not significantly different from those of wild-type rice, indicating that the expression of the sorghum chloroplast fission protein SbDRP5B does not affect the agronomic traits of rice. Therefore, the sorghum chloroplast division protein SbDRP5B can improve the resistance of rice to photosynthesis-inhibiting herbicides and be used for molecular breeding of photosynthesis-inhibiting herbicide-resistant rice. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Protein characteristics and sequence analysis of SbDRP5B and homologous proteins from different species.

[0022] Figure 2 Cluster analysis of homologous proteins of SbDRP5B in different species.

[0023] Figure 3 The expression of SbDRP5B gene in SbDRP5B-positive rice plants No. 1 to 7.

[0024] Figure 4 The relative expression levels of OsDRP5B gene under stress at different times after Zhonghua No. 11 was sprayed with different photosynthesis-inhibiting herbicides.

[0025] Figure 5 This is the tolerance of SbDRP5B-positive rice to diquat during seed germination.

[0026] Figure 6 This is the tolerance of SbDRP5B-positive rice to fluazifop-butyl during seed germination.

[0027] Figure 7 These are the agronomic traits of SbDRP5B-expressing rice and wild-type rice Zhonghua 11. DETAILED DESCRIPTION

[0028] To facilitate understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the present disclosure more thorough and comprehensive.

[0029] Experimental procedures in the following examples, where specific conditions are not specified, generally followed conventional conditions, such as those in Molecular Cloning: A Laboratory Manual (4th edition, edited by Green and Sambrook, published in 2013), or according to manufacturer recommendations. All commonly used chemical reagents used in the examples were commercially available.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Furthermore, as used herein, the term "or" is inclusive and equivalent to the term "and / or," unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on other factors not described, unless the context clearly dictates otherwise. Furthermore, throughout this specification, the meanings of "a," "an," and "the" include plural referents. The meaning of "in" includes "in" and "on."

[0032] The present invention is further described in detail below with reference to specific embodiments.

[0033] The amino acid sequence of the sorghum chloroplast division protein SbDRP5B of the present invention is shown in SEQ ID NO: 1:

[0034]

[0035]

[0036] The nucleotide sequence of the gene encoding the sorghum chloroplast division protein SbDRP5B is shown in SEQ ID NO: 2.

[0037]

[0038]

[0039] The present invention is further described in detail below with reference to specific embodiments.

[0040] The Escherichia coli DH5α used in the following examples is a commonly used commercially available strain; the rice variety is wild-type Zhonghua No. 11 (a publicly available rice variety). The primers used were synthesized by Shenzhen BGI Genomics Co., Ltd., and sequencing was performed at Shenzhen BGI Genomics Co., Ltd.

[0041] The quantitative tests in the following examples were all repeated three times, and the results were averaged.

[0042] Example 1 Construction of SbDRP5B gene overexpression vector

[0043] 1. Obtaining the Sorghum SbDRP5B Gene Fragment

[0044] The coding region of the sorghum SbDRP5B gene was obtained from NCBI (the nucleotide sequence is shown in SEQ ID NO: 2, and the amino acid sequence is shown in SEQ ID NO: 1). The protein sequence length is 757 aa, and the nucleotide sequence length is 2274 bp.

[0045] 2. Analysis and prediction of SbDRP5B homologous proteins

[0046] The DRP5B protein (amino acid sequence as shown in SEQ ID NO: 1) was searched for homologous proteins from multiple species by BLAST search database, and the sequences of homologous proteins from multiple species and SbDRP5B were compared using DNAMAN software. Figure 1As shown, this protein is widely present in various plants, and the DLP1 domain in its protein sequence is highly conserved. In order to further determine the evolutionary relationship of the DRP5B gene (nucleotide sequence shown in SEQ ID NO: 2), the DRP5B amino acid sequences of species such as reed, millet, broomcorn millet, corn, carrot, lotus, silver fir, rice, barley, and Urartu wheat were used to further analyze the homology of these proteins with SbDRP5B using MEGA11.0 software. Figure 2 As shown, the sorghum SbDRP5B gene is highly conserved with the DRP5B genes of C4 plants foxtail millet, broomcorn millet, and maize, and DRP5B shows a certain degree of differentiation in C3 plants and C4 plants, indicating that the gene may have undergone functional changes during evolution.

[0047] 3. Construction of the pCAMBIA1300-OsDRP5B-SbDRP5B recombinant vector containing the above target gene

[0048] (1) Primer design and amplification

[0049] In order to better express the sorghum gene SbDRP5B in rice, the rice homologous gene OsDRP5B promoter was used to drive the expression of SbDRP5B, that is, the pCAMBIA1300-OsDRP5B-SbDRP5B recombinant vector was constructed. Adapter primers were designed based on the OsDRP5B promoter sequence: F1: 5'-TATGACATGATTACGAATTCCCCCTGACACGAAATAGCCATTTAT-3' (SEQ ID NO: 3), R1: 5'-TGCGATTGGGTCACGCGTGGTTTAGGAGGGGTTTCGAAGTGCG-3' (SEQ ID NO: 4); adapter primers were designed based on the SbDRP5B coding sequence (CDS region, as shown in SEQ ID NO: 2): F2: 5'-CCACGCGTGACCCAATCGCAATGGCGACGCCGGTCCCGGC-3' (SEQ ID NO: 5), R2: 5'-TGGTCTTTGTAGTCCTGCAGCTGCCTAACCTGAAGAGAATTGAGCT-3' (SEQ ID NO: 6). The OsDRP5B promoter sequence and SbDRP5B coding sequence were amplified separately. The PCR reaction system is shown in Table 1.

[0050] Table 1 Target gene PCR reaction system

[0051]

[0052] The amplification program was as follows: 98°C for 3 minutes, 32 cycles of 98°C for 30 seconds, 58°C for 30 seconds, and 68°C for 3 minutes, and finally 60°C for 6 minutes. After completion, the electrophoresed fragment was excised and the target fragment was recovered using the Tiangen Biochemical Technology Co., Ltd. Agarose Gel DNA Recovery Kit (DP209-03) according to the kit instructions.

[0053] (2) Homologous recombination vector ligation and transformation

[0054] Ligation: The target fragment and the linearized vector were homologously recombined using the Gibson assembly mix seamless cloning method. The homologous recombination ligation reaction system is shown in Table 2.

[0055] Table 2 Homologous recombination ligation reaction

[0056]

[0057]

[0058] Transformation: (1) Take a tube of 100 μL DH5α E. coli competent cells and mix with 5 μL ligation product, and place on ice for 30 minutes; (2) Place in a 42°C constant temperature water bath, heat shock for 90 seconds, and place on ice for 2 minutes; (3) Add 500 μL LB liquid culture medium and mix well; (4) Incubate at 37°C and 200 rpm for 45 minutes to allow the cells to return to normal growth state; (5) Spread the bacterial solution evenly on a Kana-resistant LB solid culture medium plate; (6) After 30 minutes, place in a 37°C constant temperature incubator and culture overnight.

[0059] Colony PCR Verification: Colony PCR verification was performed using primer pair F3: 5'-TGTTTGGTAGAGGTGGTGGA-3' (SEQ ID NO: 7); R3: 5'-CGTCCCCTGTTGCAGAGAG-3' (SEQ ID NO: 8). The reaction system is shown in Table 3. The amplification program was as follows: 95°C for 5 min; 25 cycles of 95°C for 30 s, 55°C for 30 s, and 72°C for 2 min; and 72°C for 4 min.

[0060] Table 3 Colony PCR amplification system

[0061]

[0062] Plasmid Extraction: Colonies that were positive for PCR were cultured and purified using the OMEGA Plasmid Miniprep Kit (D6943) according to the kit instructions. The quality of the plasmid extract was verified by 1% agarose gel electrophoresis and Sanger sequencing.

[0063] Sequencing results showed that the SbDRP5B gene fragment shown in SEQ ID NO: 2 was inserted between the two restriction enzyme sites of the vector pCAMBIA1300-OsDRP5B. The resulting recombinant vector was named pCAMBIA 1300-OsDRP5B-SbDRP5B.

[0064] 4. Rice genetic transformation

[0065] The pCAMBIA1300-OsDRP5B-SbDRP5B recombinant vector was transformed into multiple Zhonghua No. 11 rice calli using the Agrobacterium-mediated method to obtain SbDRP5B-expressing rice plants No. 1-7.

[0066] Example 2 Screening and Verification of Positive Expression Rice

[0067] Using the wild-type variety Zhonghua 11 as a control, the expression of the SbDRP5B gene in rice plants 1-7, which showed positive expression, was verified. A rapid extraction method was used to extract DNA from leaves of the identified plants and Zhonghua 11: an extraction buffer containing 0.1M Tris-HCl (pH 9.5), 0.25M KCl, and 0.01M EDTA was prepared. Approximately 0.1g of leaves were cut and completely disrupted with 200μL of extraction buffer. The leaves were heated at 100°C for 10 minutes and immediately cooled to -20°C for at least 5 minutes. 200μL of 3% BSA (w / v) and 400μL of sterile water were added. The leaves were centrifuged at 4000rpm for 10 minutes. The supernatant contained the rice DNA. The DNA was used as a template, and the SbDRP5B sequence was amplified using primers F4: 5'-CCGTGCTGGATTGAGACACT-3' (SEQ ID NO: 9) and R4: 5'-TGCCCTGTCCTGTTTGTTGT-3' (SEQ ID NO: 10); and the internal reference gene UBQ2 sequence was amplified using primers F5: 5'-TGCTATGTACGTCGCCATCCAG-3' (SEQ ID NO: 11) and R5: 5'-AATGAGTAACCACGCTCCGTCA-3' (SEQ ID NO: 12). Figure 3 As shown, both the wild-type and overexpressing rice can amplify the UBQ2 (Actin) sequence, indicating that the DNA quality is qualified; the wild-type rice cannot amplify the SbDRP5B sequence, indicating that it does not contain SbDRP5B, while the plants 1-7 to be identified all have bands, indicating that the sorghum SbDRP5B gene is successfully expressed in the rice, and are SbDRP5B-positive rice plants. The SbDRP5B-3 line was selected for subsequent experiments.

[0068] Example 3 Real-time fluorescence quantitative test after treatment of rice with photosynthesis-inhibiting herbicides

[0069] Prepare diquat A (6g / hm 2 ) and B(27g / hm 2 ), fluazifop-butyl A (4g / hm 2 ) and B(97g / hm 2 ) solution was sprayed on 25-day-old Zhonghua 11 plants, four leaves old. Water was used as a control. Six hours after treatment, RNA was extracted from aerial parts of rice (OMEGA Cat# R6827-02) and reverse-transcribed into cDNA (Takara, PrimeScript RTreagent Kit with gDNA Eraser). Real-time quantitative PCR was then performed to detect OsDRP5B gene expression.

[0070] Real-time quantitative PCR was performed using primers F6: 5'-TAGAGACCCTTGTTCGTGCG-3' (SEQ ID NO: 13) and R6: 5'-ACATCAGAGGCTCGTGCAAA-3' (SEQ ID NO: 14). UBQ2 was used as an internal reference gene, and primers F5 and R5 were used. The PCR reaction system (20 μL) was performed using SYBR Green Real-Time PCR Master Mix reagent (Takara) according to the product instructions. The specific system is shown in Table 4.

[0071] Table 4 Fluorescence quantitative PCR reaction system

[0072]

[0073] The amplification program was as follows: 95°C for 180 s; 95°C for 10 s, 60°C for 15 s, 40 cycles; 72°C for 30 s; 95°C for 10 s, 65°C for 60 s, and 97°C for 1 s.

[0074] The data were processed using the comparative Ct method, ΔCt = Ct(OsDRP5B)-Ct(UBQ2), with 2 -ΔΔCt The expression of OsDRP5B gene in the samples was analyzed and compared. Figure 4 As shown in the figure, after 6 hours of induction treatment with either high or low concentrations of diquat or fluazifop-propyl, the expression of OsDRP5B in the aboveground part of rice was significantly downregulated compared with the control group treated with pure water, indicating that both diquat and fluazifop-propyl could inhibit the expression of OsDRP5B.

[0075] Example 4 Resistance test of SbDRP5B-positive rice to different photosynthesis-inhibiting herbicides

[0076] Observe the growth of rice during the germination period in the presence of diquat or fluazifop-butyl. Prepare MS medium: Add 15g of sucrose and 2.215g of M&S basal medium with vitamins to 500mL of secondary water. Adjust the pH to 5.7 with NaOH and aliquot 80mL into each tissue culture flask. Add 0.28g of Phytagel and sterilize with high-temperature steam. When the temperature drops to approximately 60°C, add diquat to a final concentration of 0.05μM or fluazifop-butyl to a final concentration of 0.0023μM. Mix thoroughly and cool until solidified before use. Use MS medium without the added drugs as the untreated control. Seeds of wild-type Zhonghua No. 11 and SbDRP5B-overexpressing rice were revived at 49°C for 3-4 days. Before planting tissue culture seedlings, the seeds were disinfected: first, washed three times with 75% ethanol diluted in sterile water for 3 minutes each. Then, they were washed twice with a 30% sodium hypochlorite solution (with 1-2 drops of Tween 20 added to facilitate adhesion of the disinfectant to the seed surface), for 3 minutes and 20 minutes respectively. During washing, the seeds were shaken rapidly to remove impurities adhering to the surface, reducing the possibility of subsequent contamination. Finally, they were repeatedly washed with sterile water before being planted on the aforementioned MS medium. During the initial culture period (approximately 5 days), the seeds were incubated in the dark at 28°C. After emergence, they were transferred to normal conditions (light / dark = 14 hours / 10 hours, 28°C) and cultured for another 10 days. Growth after different treatments was recorded.

[0077] The results showed that under untreated conditions (no diquat or fluazifop-propyl was added to the MS culture medium), there was no significant difference in the length of the shoots and roots between the SbDRP5B-positive rice and the wild-type Zhonghua 11, indicating that overexpression of the SbDRP5B gene did not affect the growth and development of rice during the germination period. However, with the addition of herbicides, the symptoms of herbicide damage began to appear, but the stress conditions of the SbDRP5B-positive rice and the wild-type rice were different: under diquat stress, the shoot length and root length of the SbDRP5B-positive seedlings were significantly longer than those of the wild-type rice ( Figure 5 ); Under fluazifop-butyl stress, the shoot length of SbDRP5B-expressing seedlings was significantly longer than that of wild-type rice, while the root length was not affected by the herbicide at all ( Figure 6 The above results indicate that the SbDRP5B gene confers good tolerance to photosynthesis-inhibiting herbicides in rice, effectively reduces the damage of photosynthesis-inhibiting herbicides to rice, and promotes the growth and development of rice under photosynthesis-inhibiting herbicide stress conditions.

[0078] Example 5 Agronomic traits of SbDRP5B-positive rice

[0079] Agronomic traits were investigated for wild-type Zhonghua 11 and SbDRP5B-expressing rice varieties based on the Zhonghua 11 background. Rice seedlings were cultured in a plant climate chamber and transplanted to a Hainan farm after reaching maturity (approximately 20-25 days). Topdressing or foliar fertilizer were regularly applied during the rice's fertilizer-demanding period. Plant height and panicle number were measured at harvest, and relevant phenotypic characteristics were photographed and recorded.

[0080] The results showed that the average plant height of wild-type rice and SbDRP5B-positive rice was 92.3 cm and 91.9 cm, the average number of panicles was 17 and 15, and the average panicle length was 20.65 cm and 19.39 cm, respectively. Figure 7 The expression of SbDRP5B in rice had no significant effect on the agronomic traits of Zhonghua 11, suggesting that SbDRP5B-positive rice varieties have the potential to become resistant to photosynthesis-inhibiting herbicides.

[0081] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. Application of the gene encoding sorghum chloroplast division protein SbDRP5B in regulating plant resistance to photosynthesis-inhibiting herbicide stress, characterized in that: The nucleotide sequence of the encoding gene is shown as SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is shown as SEQ ID NO:

1.

2. Application of sorghum chloroplast division protein SbDRP5B in regulating plant resistance to photosynthesis-inhibiting herbicide stress, characterized in that: The amino acid sequence of the sorghum chloroplast division protein SbDRP5B is shown in SEQ ID NO:

1.

3. Use of sorghum chloroplast division protein SbDRP5B or its encoding gene in genetic breeding for improving plant tolerance to photosynthesis-inhibiting herbicides, characterized in that: The amino acid sequence of the sorghum chloroplast division protein SbDRP5B is shown in SEQ ID NO: 1; The nucleotide sequence of the encoding gene is shown as SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is shown as SEQ ID NO:

1.

4. An overexpression vector having a gene encoding sorghum chloroplast division protein SbDRP5B inserted therein, characterized in that: The nucleotide sequence of the encoding gene is shown as SEQ ID NO: 2, or the nucleotide sequence encoding the amino acid sequence is shown as SEQ ID NO:

1.

5. A host cell, characterized in that The host cell contains the overexpression vector according to claim 4.

6. Use of the overexpression vector according to claim 4 or the host cell according to claim 5 in genetic breeding for regulating plant resistance to photosynthesis-inhibiting herbicide stress and / or improving plant tolerance to photosynthesis-inhibiting herbicides.

7. The use according to any one of claims 1 to 3 and 6, characterized in that: The plants include rice, sugarcane, soybean, preferably rice; and / or, The photosynthesis-inhibiting herbicide is selected from at least one of diquat and fluazifop-propyl.

8. A biological agent for increasing plant tolerance to photosynthesis-inhibiting herbicides, characterized in that: The active ingredient of the biological preparation comprises the overexpression vector according to claim 4 and / or the host cell according to claim 5.

9. A method for regulating plant resistance to photosynthesis-inhibiting herbicide stress, characterized in that: The method comprises regulating the expression of a gene encoding a sorghum chloroplast division protein SbDRP5B in a plant, wherein the nucleotide sequence of the encoding gene is shown in SEQ ID NO: 2, or the nucleotide sequence encoding an amino acid sequence is shown in SEQ ID NO:

1.

10. The method according to claim 9, wherein The plants include rice, sugarcane, soybean, preferably rice; and / or, And / or, the photosynthesis-inhibiting herbicide is selected from at least one of diquat and fluazifop-propyl. And / or, the method for regulating the expression of the gene encoding the sorghum chloroplast division protein SbDRP5B in plants includes Agrobacterium-mediated genetic transformation, gene gun method, CRISPR / dCas9 activation method, and chemical induction method.

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