Rice bacterial leaf blight effector gene m4337 and application thereof

Abstract

The application provides a rice rhizoctonia solani effector gene m4337 and application thereof, the nucleotide sequence of the gene is shown as SEQ ID NO:1; the amino acid sequence of the protein encoded by the gene is shown as SEQ ID NO:2; and the HIGS (Host-induced gene silencing) silencing segment is shown as SEQ ID NO:3. It is found that overexpression of m4337 in rice can reduce the resistance of rice to rhizoctonia solani by rhizoctonia solani phenotype identification, and the resistance of rice to rhizoctonia solani can be enhanced by silencing the gene by using the HIGS technology. Through cloning of the rhizoctonia solani effector gene and functional analysis, the application provides a new theoretical basis for developing new biological pesticides and cultivating rice varieties resistant to rhizoctonia solani.

Description

Technical Field

[0001] This invention belongs to the field of plant genetic engineering technology, specifically the m4337 effector gene of rice sheath blight pathogen and its application. Background Technology

[0002] Rice is a core food crop globally, and ensuring stable and high rice yields is of great significance for maintaining food security. Rice sheath blight is a major global fungal disease of rice caused by Rhizoctonia solani AG1-IA. The disease is particularly severe under conditions of high temperature and humidity, high fertilizer and dense planting, and has become a key technical bottleneck restricting the high quality and high yield of rice.

[0003] Currently, the control of rice sheath blight relies excessively on chemical agents. Long-term, high-dose use of these agents easily leads to problems such as pathogen resistance, farmland pollution, and excessive pesticide residues in rice, while significantly increasing planting costs, which is inconsistent with the requirements of green agriculture development. At the same time, there is a lack of major rice varieties with high resistance to sheath blight, a shortage of disease-resistant germplasm resources, and slow progress in disease-resistant breeding, making it impossible to achieve long-term control at the source of the disease. Therefore, elucidating the molecular mechanisms of pathogenicity, identifying core pathogenic genes, and developing targeted green control technologies are the core paths to solving the current challenges in disease control.

[0004] Effector proteins are key small-molecule proteins secreted by pathogenic fungi during host infection. They are core functional factors for pathogens to overcome host immunity, establish colonization, and cause disease. They are also key targets for elucidating the pathogen-host interaction mechanism and developing disease-resistant breeding and green control technologies. Rice sheath blight pathogens, by secreting specific effector proteins, inhibit host innate immunity, interfere with host cell metabolism, and disrupt the host's defense barrier, thereby achieving infection and pathogenicity. The genes encoding these effector proteins directly determine the pathogen's virulence and host adaptability.

[0005] With the development of genome sequencing technology, the whole genome of rice sheath blight fungus strain AG1-IA has been completed. The scientific community has preliminarily screened and verified a small number of candidate effector protein genes, clarifying that some genes can regulate the pathogenic process of the pathogen by inhibiting host immunity and inducing cell death. However, existing technologies have significant shortcomings: the number of identified functional effector protein genes is extremely small, and a large number of highly conserved, novel core effector genes with strong pathogenicity have not yet been discovered; the pathogenic mechanisms and interaction pathways of reported genes with the rice host are still unclear; and practical technologies such as disease-resistant breeding, precise pathogen detection, and targeted biological control based on effector genes are extremely scarce, far from meeting the needs of production applications.

[0006] In summary, existing technologies lack the ability to discover novel, high-functionality effect genes of rice sheath blight pathogens, and there are no mature and supporting application technologies. This results in a serious disconnect between research on the pathogen's pathogenic mechanism and its production application, making it difficult to improve the green disease control system. To address these shortcomings in existing technologies, discovering novel effect genes and clarifying their functions and application scenarios is crucial for overcoming the bottlenecks in rice sheath blight control and promoting the upgrading of disease-resistant breeding and green control technologies. This is also the core technical problem that this patent aims to solve. Summary of the Invention

[0007] Objective: To address the shortcomings of existing technologies, this invention provides a rice sheath blight effector gene, m4337. Through sheath blight phenotypic identification, this invention discovered that overexpression of the m4337 gene in rice reduces rice resistance to sheath blight, while silencing this gene using HIGS technology enhances rice resistance. This indicates that m4337 is an important pathogenic gene of rice sheath blight pathogens. Cloning and functional analysis of this gene will provide a new theoretical basis for the targeted development of novel biological pesticides.

[0008] The present invention also provides the application of the rice sheath blight effector gene m4337.

[0009] Technical solution: In order to achieve the above objective, the rice sheath blight pathogen effector gene m4337 of the present invention has the nucleotide sequence of the gene m4337 as shown in SEQ ID NO. 1 and the amino acid sequence it encodes as shown in SEQ ID NO. 2.

[0010] The silencing region of the rice sheath blight bacterium effector gene m4337 described in this invention has the nucleotide sequence shown in SEQ ID NO: 3.

[0011] The present invention relates to recombinant vectors, recombinant microorganisms, or transgenic plant cell lines containing the m4337 gene described above.

[0012] The application of the gene m4337 described in this invention, the silent segment described in claim 2, or the recombinant vector, recombinant microorganism, or transgenic plant cell line described in claim 3 in regulating resistance to rice sheath blight.

[0013] Overexpression of the m4337 gene reduces rice's resistance to sheath blight, while silencing the m4337 gene enhances rice's resistance to sheath blight.

[0014] The present invention relates to the application of cDNA or genomic DNA molecules that have 75% or more identity with the m4337 gene, or that hybridize with the m4337 gene and encode the m4337 protein, in regulating the resistance of rice to sheath blight.

[0015] The application of the m4337 gene or its silenced segment, or the recombinant vector, recombinant microorganism, or transgenic plant cell line described in this invention in designing pesticide molecular targets and cultivating rice varieties resistant to rice sheath blight.

[0016] The vector may be a plasmid, granule, bacteriophage, or viral vector; the microorganism may be yeast, bacteria, algae, or fungi, such as Agrobacterium; the transgenic plant cell line does not include propagation material.

[0017] The method for cultivating transgenic rice with reduced or increased resistance to sheath blight according to the present invention includes enhancing or reducing the expression level and / or activity of m4337 protein in recipient rice during infection with sheath blight pathogen, thereby obtaining transgenic rice; the disease resistance of the transgenic rice is lower or higher than that of the recipient rice, and the m4337 protein is encoded by the gene shown in SEQ ID NO. 1.

[0018] The disease resistance of the transgenic rice is higher / lower than that of the recipient rice, as evidenced by the fact that the length of the sheath blight lesions in the transgenic rice is smaller / longer than that in the recipient rice.

[0019] The method for enhancing or reducing the expression level and / or activity of the m4337 protein in the recipient rice is achieved by overexpressing or silencing the gene encoding the m4337 protein in the recipient rice.

[0020] The application of the m4337 gene or m4337 protein, or the recombinant vector, recombinant microorganism, or transgenic plant cell line described in this invention in the cultivation of transgenic rice with enhanced resistance to sheath blight.

[0021] The method for cultivating transgenic rice with reduced or increased resistance to rice sheath blight, as described in this invention, is applied in the creation of new rice germplasm resistant to rice sheath blight.

[0022] In this invention, the rice variety described above can specifically be Nipponbare (NIP).

[0023] This invention identifies an effector gene, m4337, using bioinformatics methods. This gene is a key gene for the pathogenicity of rice sheath blight pathogen. Sheath blight resistance identification results show that silencing the m4337 gene increases rice resistance to sheath blight, while overexpression of m4337 significantly weakens rice resistance to sheath blight. These results indicate that m4337, as a key gene for the pathogenicity of rice sheath blight pathogen, can be used to control rice sheath blight pathogen and to prepare control products for rice sheath blight pathogen.

[0024] In the application described in this invention, the disease resistance can be sheath blight resistance; the regulation is specifically manifested in the following ways: when the activity and / or content of m4337 protein during the infection of rice by *Rhizoctonia solani* decreases, the plant's resistance to sheath blight increases; when the activity and / or content of m4337 protein during the infection of rice by *Rhizoctonia solani* increases, the plant's resistance to sheath blight decreases.

[0025] Specifically, the plant breeding mentioned above may involve creating new germplasm resistant to rice sheath blight.

[0026] The main steps of reducing the expression level and / or activity of the m4337 gene in the recipient rice in the above method are as follows: (1) Similar sequences were compared using the si-fi tool, and a 500bp specific fragment was selected for constructing an RNAi vector, named m4337-HIGS. Primers with corresponding restriction sites on the RNAi vector were designed using Primer 3 Plus, named m4337-HIGS-F / m4337-HIGS-R respectively. (2) The RNAi fragment was amplified by PCR using Rhizoctonia solani YN-7 cDNA as a template and m4337-HIGS-F / m4337-HIGS-R as primers. The PCR product was detected by 1% agarose gel and recovered using the PCR product purification kit (DC301-1) of Novizan Biotechnology Co., Ltd. (3) The recovered m4337-HIGS fragment was ligated with the pGEM-T-Easy vector overnight at 4℃, and then transformed into Escherichia coli DH5α competent cells. Positive TA clones were obtained by double digestion with KpnⅠ and BamHI and sent to Qingke Biotechnology Co., Ltd. for sequencing. The TA clone with the correct sequence was named TA-m4337-HIGS. (4) TA-m4337-HIGS and RNAi vector pDS1301 were double digested with KpnⅠ and BamHI. The positive m4337-HIGS fragment and the digested vector pDS1301 were recovered by gel digestion. The recovered fragment and vector were ligated overnight at 4℃ and then transformed into E. coli DH5α competent cells. Positive clones were obtained by double digestion with KpnⅠ and BamHI and named pDS1301-m4337-HIGS-1. (5) TA-m4337-HIGS and RNAi vector pDS1301-m4337-HIGS-1 containing the positive fragment were double digested with SacⅠ and SpeⅠ. The reverse-directed m4337-HIGS fragment and vector were recovered from the gel, ligated overnight at 4°C, and then transformed into *E. coli* DH5α competent cells. Double digestion with BamHI / KpnI and SacI / SpeI was used to select the correct single clone, which was named pDS1301-m4337-HIGS-2. Finally, pDS1301-m4337-HIGS-2 was transformed into *Agrobacterium tumefaciens* EHA105 and sent to Weimi Biotechnology Co., Ltd. for rice genetic transformation.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0028] This invention clones an effector gene m4337 of rice sheath blight and its target fragment. This gene is a key gene for the pathogenicity of rice sheath blight. Studies have shown that this gene is significantly induced to express in the early stage of rice infection by rice sheath blight. Overexpression of m4337 in rice significantly reduces rice resistance to rice sheath blight. Silencing m4337 during rice infection using HIGS technology significantly reduces the pathogenicity of rice sheath blight, and transgenic plants resistant to rice sheath blight can be obtained.

[0029] Furthermore, the method for constructing transgenic plants resistant to rice sheath blight provided by this invention only expresses a small fragment of a gene in the plant, without producing products such as proteins, and does not pose the potential risks associated with transgenic foods. Therefore, the rice sheath blight effector gene m4337 and its target fragment have broad application prospects in the control of rice sheath blight, the preparation of rice sheath blight control agents, and the construction of transgenic plants resistant to rice sheath blight. Attached Figure Description

[0030] Figure 1 This represents the induced expression pattern of the m4337 gene.

[0031] Figure 2 To validate the function of the m4337 protein signal peptide. A is a schematic diagram of the m4337 gene structure; B is the result of the yeast secretion experiment of the m4337 protein signal peptide.

[0032] Figure 3 The phenotypes of in vitro sheath blight resistance in climate chambers are shown for m4337 gene overexpression lines, RNA-silenced lines, and wild-type controls. A represents the in vitro phenotype in the climate chamber; B represents the lesion length 7 days after in vitro inoculation in the climate chamber.

[0033] Figure 4 The results of Western Blot analysis are for the m4337 gene overexpression lines.

[0034] Figure 5 The results show the detection results of RNA silencing lines for the m4337 gene. A shows the qRT-PCR detection results of the m4337 gene 48 hours after inoculation of the RNA silencing lines. B shows the small RNA sequencing results of the RNA silencing lines. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] The conventional rice variety NIP used in this invention was provided by Yangzhou University;

[0037] The moderately pathogenic Rhizoctonia solani strain YN-7 (Lee DY et al., Comparative genome analyses of four rice-infecting Rhizoctonia solani isolates reveal extensive enrichment of homogalacturonan modification genes. BMC Genomics. 2021 Apr 7;22(1):242.) was provided by Yangzhou University.

[0038] Nipponbare (NIP Japan Sunny Day) was provided by Yangzhou University.

[0039] TA-m4337-HIGS and RNAi vector pDS1301 were provided by Huazhong Agricultural University (Chen X, et al. A secreted fungal effector suppresses rice immunity through host histonehypoacetylation. New Phytol. 2022;235(5):1977-1994.).

[0040] Example 1

[0041] Cloning of the m4337 CDS region of the effector gene of rice sheath blight fungus

[0042] 0.1 g of mycelium of *Rhizoctonia solani* YN-7 was weighed, and total RNA was extracted from leaves of 4-5 leaf stage NIP seedlings using the Trizol method (Invitrogen). Total cDNA was synthesized using the PrimeScript RT reagent Kit With gDNA Eraser (TaKaRa). Primers were designed based on sequence information: m4337-CDS-F: 5'-ATGAAATTCACCATCGCTGC-3' and m4337-CDS-R: 5'-AGGACAGAAGGTAAGGGTGT-3'. The gene was cloned using YN-7 cDNA as a template. The nucleotide sequence encoded by the rice m4337 gene of this invention is shown in SEQ ID NO.1, and the amino acid sequence is shown in SEQ ID NO.2.

[0043] Example 2

[0044] Expression analysis of the m4337 gene, an effector of rice sheath blight fungus, during rice infection.

[0045] NIP was cultured under normal conditions until the booting stage. The inlay method was used (Zuo Shimin et al., Establishment and improvement of field rice sheath blight resistance identification system [J]. Journal of Yangzhou University: Agriculture and Life Sciences Edition. 2007 (27): 57-61). NIP was inoculated with sheath blight fungus strain YN-7. A piece of wood bark 1 cm long and 2 mm wide (covered with mycelium) was carefully embedded into the leaf sheath 1 cm-2 cm below the second leaf from the top of the rice plant. The rice leaf sheaths 1 cm above and below the inoculation were cut before inoculation (0 h) and 8 h, 16 h, 24 h and 32 h after inoculation and stored in liquid nitrogen.

[0046] Following the instructions in the manufacturer's manual (Invitrogen), total RNA was extracted from each rice sample using Trizol. The total RNA was then digested with DNase I (RNase-free, Promega) to remove genomic DNA contamination (see the DNase I manual for the method). Subsequently, the total RNA was reverse transcribed into the first strand of cDNA using reverse transcriptase (TaKaRa) (see the reverse transcriptase manual for the method). The reaction conditions were: 37°C for 30 min; 85°C for 5 sec; 4°C for forever. Using cDNA as a template and the GAPDH gene of *Rhizoctonia solani* as an internal reference gene (GAPDH gene amplification primers F1: 5'-GGTCGGCAAAGTCATACCAT-3' and R1: 5'-CTGCGTCCTTCTTGGAGATA-3'), real-time quantitative PCR was performed using m4337 gene-specific quantitative primers (qRT-m4337-F: 5'-ACAACGCTTGTCCCTTCACC-3' and qRT-m4337-R: 5'-GGCCTCCCAACCAGTCTCGA-3'). The reaction conditions were: 95℃ pre-denaturation for 2 min, followed by the following cycles: 95℃ for 15 sec, 60℃ for 10 sec, and 72℃ for 10 sec, for a total of 40 cycles. The results showed that the expression level of gene m4337 increased significantly 8 h after infection. Figure 1 ).

[0047] Example 3

[0048] The m4337 signal peptide was predicted to be the N-terminal amino acid 1-20 of the protein using the SignalIP-6.0 website. Figure 2A). To determine whether the signal peptide (SP) of this protein possesses functional activity, a yeast sucrase exocytosis experiment was performed. The m4337-encoding signal peptide region was cloned into the pSUC2 vector, with α-factor as a positive control and Mg87 as a negative control. Subsequently, the constructed vector was transformed into the yeast sucrase-deficient strain YTK12 (wild-type strain) and cultured in CMD-W and YPRAA solid media, respectively. The results showed that ( Figure 2 B), the YTK12 strain without plasmid transformation could not grow on CMD-W medium, while the other strains with plasmid transformation could grow. YTK12 strains transformed with the empty vector and Mg87SP could not grow on YPRAA medium because they lacked a signal peptide and therefore could not secrete sucrase normally. Strains transformed with α-factor and m4337 signal peptides, however, could grow normally on YPRAA medium, indicating that both strains successfully secreted sucrase in vitro. Furthermore, the colorimetric reaction further verified that the enzyme activity product glucose produced by the strain transformed with m4337 signal peptide turned TTC solution red, while neither the wild-type strain nor the strain transformed with the empty vector could catalyze this reaction, indicating that the m4337 signal peptide does indeed have the function of guiding protein excretion. Figure 2 B).

[0049] Example 4

[0050] Vector construction, genetic transformation and detection

[0051] 1. Steps for constructing a HIGS silencing vector targeting the effector gene m4337 of rice sheath blight pathogen:

[0052] (1) A specific 500bp fragment in SEQ ID NO.1 of Example 1 was screened as a silenced gene and used to construct an RNAi vector named m4337-HIGS, as shown in SEQ ID NO.3. Primers with corresponding restriction sites on the RNAi vector were designed using Primer 3 Plus and named m4337-HIGS-F: 5'-GACTAGTGGTACCCGTGTCTCAGCGGTGGCT-3' and m4337-HIGS-R5'-CGAGCTCGGATCCACCCTTACCTTCTGTCCT-3', respectively.

[0053] (2) RNAi fragments were amplified by PCR using Rhizoctonia solani YN-7 cDNA as a template and m4337-HIGS-F / m4337-HIGS-R as primers. The PCR products were detected by 1% agarose gel electrophoresis and recovered using the PCR product purification kit (DC301-1) from Novizan Biotechnology Co., Ltd.

[0054] (3) The recovered m4337-HIGS fragment was ligated with the pGEM-T-Easy vector overnight at 4°C, and then transformed into E. coli DH5α competent cells. Positive TA clones were obtained by double digestion with KpnⅠ and BamHI and sent to Qingke Biotechnology Co., Ltd. for sequencing. The TA clone with the complete correct sequence was named TA-m4337-HIGS.

[0055] (4) TA-m4337-HIGS and RNAi vector pDS1301 were digested with KpnⅠ and BamHI, and the positively oriented m4337-HIGS fragment and the digested vector pDS1301 were recovered by gel digestion. The recovered fragment and vector were ligated overnight at 16℃, and then transformed into E. coli DH5α competent cells. Positive clones were obtained by double digestion with KpnⅠ and BamHI and named pDS1301-m4337-HIGS-1.

[0056] (5) TA-m4337-HIGS and the RNAi vector pDS1301-m4337-HIGS-1 containing the forward fragment were digested with SacⅠ and SpeⅠ. The reverse m4337-HIGS fragment and the vector were recovered by gel digestion, ligated overnight at 16℃, and then transformed into E. coli DH5α competent cells. The correct single clone was selected by double digestion with BamHI / KpnⅠ and SacⅠ / SpeⅠ, respectively. The correct single clone was named pDS1301-m4337-HIGS-2. Finally, pDS1301-m4337-HIGS-2 was transformed into Agrobacterium tumefaciens EHA105, and Agrobacterium-mediated transformation was used to transform NIP callus of conventional japonica rice. Hygromycin was used for screening, resulting in 17 stable T0 transgenic seedlings. qRT-PCR was performed on the target gene m4337, and combined with small RNA sequencing results, two transgenic lines were obtained, named m4337-RNAi10 and m4337-RNAi17, respectively. Figure 3 , Figure 5 (As shown).

[0057] 2. The construction steps of the overexpression vector are as follows:

[0058] (1) Primers were designed using the total cDNA from Example 1: m4337-CDS-F: 5'-ATGAAATTCACCATCGCTGC-3' and m4337-CDS-R: 5'-AGGACAGAAGGTAAGGGTGT-3'. The gene was cloned using YN-7 cDNA as a template. The CDS sequence of m4337 was obtained by amplification with high-fidelity DNA polymerase. The nucleotide sequence is shown in SEQ ID NO.1, and the amino acid sequence is shown in SEQ ID NO.2. The PCR program was as follows: pre-denaturation: 95℃ for 5 min; denaturation: 95℃ for 30 s; annealing: 58℃ for 30 s; extension: 72℃ for 3 min; 35 cycles; total extension for 5 min. The product was stored at 4℃ after the reaction.

[0059] (2) The overexpression vector pCAMBIA1390 (Liu Xiuming et al., Study on transgenic cephalosporin AD (CAD) gene in alfalfa [J]. Journal of South China Agricultural University, 2012, 33(04):498-502.) with strong promoter Ubi was linearized by restriction endonuclease PstI (Takara).

[0060] (3) The target gene from step (1) and the linearized vector after enzyme digestion were ligated using homologous recombinase (Novizan ClonExpress II One Step Cloning Kit reagent).

[0061] (4) The ligation product was introduced into competent DH5α cells, and positive single clones were selected and sequenced on LB medium containing kanamycin. After verification, the construction of the m4337-OE vector was completed. The above plant expression vector was transformed into rice variety NIP using the Agrobacterium-mediated transformation method. Two transgenic lines were obtained by Western blotting and named m4337-OE1 and m4337-OE2. Figure 3 , Figure 4 (As shown).

[0062] Example 5

[0063] Identification of sheath blight resistance in genetically modified rice

[0064] Resistance to sheath blight was identified in wild-type (WT), silent lines (m4337-RNAi10 and m4337-RNAi17), and overexpression lines (m4337-OE1 and m4337-OE2) using an in vitro inoculation method.

[0065] When rice plants in the field reached the early heading stage, detached stem samples were taken. The rice stems were cut off, leaving only the flag leaf and the second leaf from the top. The samples were then placed in water overnight to allow the rice to acclimate to the climatology chamber environment and prevent water loss. The next day, inoculation was performed using the same embedding method. A 1 cm long and 2 mm wide piece of bark (covered with mycelium) containing *Rhizoctonia solani* hyphae was carefully placed 1 cm below the leaf sheath of the second leaf from the top. After inoculation, the stems were inserted into test tube racks containing floral foam and then transferred to a nutrient solution. The plants were then placed in an environment with 14 hours of light (30℃), 10 hours of darkness (24℃), and 90% humidity. The length of lesions was assessed 7 days after inoculation.

[0066] like Figure 3 The average lesion length of the two transgenic overexpression lines (10.65 cm and 11.5 cm, respectively) was significantly longer than that of the wild type (7.36 cm), while the average lesion length of the two RNA-silenced lines (5.28 cm and 5.37 cm, respectively) was significantly shorter than that of the wild type (7.36 cm). Figure 3 A, B). These results indicate that the gene m4337 is an important pathogenic gene of rice sheath blight pathogen, and gene silencing can significantly enhance the rice's resistance to sheath blight.

Claims

1. An effector gene m4337 of rice sheath blight fungus, characterized in that, The nucleotide sequence of the gene m4337 is shown in SEQ ID NO. 1, and the amino acid sequence it encodes is shown in SEQ ID NO.

2.

2. A silenced region of the m4337 gene of *Rhizoctonia solani*, the causal agent of rice sheath blight, as described in claim 1, characterized in that... Its nucleotide sequence is shown in SEQ ID NO:

3.

3. A recombinant vector, recombinant microorganism, or transgenic plant cell line containing the m4337 gene as described in claim 1.

4. The application of the gene m4337 of claim 1, the silent segment of claim 2, or the recombinant vector, recombinant microorganism, or transgenic plant cell line of claim 3 in regulating resistance to rice sheath blight.

5. The application according to claim 4, characterized in that, Overexpression of the m4337 gene reduces rice resistance to sheath blight, while silencing the m4337 gene enhances rice resistance to sheath blight.

6. The application of the m4337 gene of claim 1, the silenced segment of claim 2, or the recombinant vector, recombinant microorganism, or transgenic plant cell line of claim 4 in designing pesticide molecular targets and cultivating rice varieties resistant to rice sheath blight.

7. A method for cultivating transgenic rice with reduced or increased resistance to sheath blight, comprising enhancing or reducing the expression level and / or activity of m4337 protein in recipient rice during infection with sheath blight pathogen, thereby obtaining transgenic rice; wherein the transgenic rice has lower or higher disease resistance than the recipient rice, and the m4337 protein is encoded by the gene shown in SEQ ID NO.

1.

8. The method according to claim 7, characterized in that, The disease resistance of the transgenic rice is higher / lower than that of the recipient rice, as evidenced by the fact that the length of the sheath blight lesions in the transgenic rice is less / longer than that in the recipient rice.

9. The method according to claim 7 or 8, characterized in that: The method for enhancing or reducing the expression level and / or activity of the m4337 protein in recipient rice is achieved by overexpressing or silencing the gene encoding the m4337 protein in the recipient rice.

10. The use of the m4337 gene of claim 1, the silenced segment of claim 2, or the recombinant vector, recombinant microorganism, or transgenic plant cell line of claim 4 in the cultivation of transgenic rice with enhanced resistance to sheath blight.

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