Screening and application of magnaporthe oryzae MOHS1 gene siRNA

Abstract

The invention provides screening and application of siRNA of a magnaporthe oryzae MOHS1 gene, and relates to the technical field of biology. The siRNA is used for carrying out targeted silence on the MOHS1 gene (MGG08523) of the magnaporthe oryzae; the siRNA molecule can delay and inhibit the formation of magnaporthe oryzae appressorium, so that the pathogenicity of magnaporthe oryzae is reduced, and a new method for preventing and treating magnaporthe oryzae is provided. The siRNA molecule of the targeted MOHS1 gene is prepared into a nucleic acid pesticide, and the nucleic acid pesticide is sprayed on leaves of rice, so that leaf rice blast scab and scab area are effectively reduced, the siRNA molecule can be further used for preventing and treating rice blast, and the tedious process of cultivating transgenic crops and the worry of consumer groups can be avoided.

Description

[0001] This application is a divisional application of the parent case, the parent case application number is: 202411087506.0 (authorization announcement number: CN118620899 B), and the application date is August 9, 2024. Technical Field

[0002] The invention relates to the field of biotechnology, and mainly relates to the screening and application of siRNA of rice blast fungus MOHS1 gene. Background Art

[0003] Rice blast, bacterial leaf blight and sheath blight are known as the three major diseases of rice. Among them, rice blast is caused by the rice blast fungus Magnaporthe oryzae. The rice blast fungus can infect multiple parts of rice. According to the time or tissue of disease occurrence, it can be divided into seedling blast, node blast, leaf blast and ear neck blast, among which ear neck blast is the main cause of rice yield loss. In addition to rice, M. oryzae can also infect more than 50 kinds of grass crops, including economically and agriculturally important cash crops such as wheat (Triticum spp.), barley (Hordeum vulgare), corn (Zea mays) and grass weeds.

[0004] The infection of rice blast fungus starts with conidia. When they are scattered on the leaf surface of plants such as rice, under suitable temperature and humidity conditions, conidia germinate and grow germ tubes. The top of the germ tube swells and forms a special infection structure, that is, a hemispherical appressorium. As the appressorium forms and matures, a melanin layer is formed between the cell membrane and the cell wall, and a large amount of osmotic substances (such as glycerol) accumulate inside the appressorium, causing the turgor pressure inside the appressorium to gradually increase. Under the combined action of the melanin layer and the high turgor pressure, the high turgor pressure is converted into mechanical pressure to penetrate the host surface, forming an infection nail at the base of the appressorium, and penetrating the host plasma layer to form primary infection hyphae. The rice blast fungus needs the melanin layer in the appressorium to produce and maintain the high turgor pressure required for plant penetration, and the synthesis of melanin requires the participation of multiple enzymes.

[0005] In recent years, RNAi pesticides (nucleic acid pesticides) developed based on RNAi have become a hot topic of research at home and abroad. dsRNA or siRNA is sprayed on the surface of plants, and then directly or indirectly absorbed by target biological cells, causing RNAi reactions in the body, and then silencing the target gene. This technology is also called spray-induced gene silencing (SIGS). SIGS technology avoids the complex process and potential ecological risks of crop genetic modification, showing greater development potential.

[0006] So far, although there have been many attempts to use SIGS technology to control pathogenic fungi, there are very few nucleic acid molecules developed based on the key pathogenic genes of rice blast fungus, and no products have been reported, which in turn limits the application of SIGS technology in the control of rice blast fungus. Summary of the invention

[0007] In view of the above problems, the present invention designs siRNA with MGG_08523 (MOHS1), a gene related to melanin synthesis in rice blast fungus, as the target, and the obtained siRNA is subjected to antibacterial effect analysis, and then applied to rice leaves in the form of spray to inhibit the pathogenicity of rice blast fungus, thereby achieving the purpose of preventing and controlling rice blast.

[0008] To achieve the above object, the present invention adopts the following scheme:

[0009] In one aspect, the present invention provides an siRNA for controlling rice blast fungus, wherein the siRNA targets and silences the MOHS1 gene of rice blast fungus, wherein the MOHS1 gene has a nucleotide sequence as shown in the sequence table SEQ ID NO: 1. Screening of siRNA targeting key genes for growth and development of rice blast fungus revealed that siMohs-10 targeting and silencing the MOHS1 gene of rice blast fungus can significantly reduce the proportion of appressorium formation of rice blast fungus.

[0010] Furthermore, the siRNA has SEQ ID NOs: 38-39 (siMohs-1), SEQ ID NOs: 40-41 (siMohs-2), SEQ ID NOs: 42-43 (siMohs-3), SEQ ID NOs: 44-45 (siMohs-4), SEQ ID NOs: 46-47 (siMohs-5), SEQ ID NOs: 48-49 (siMohs-6), SEQ ID NOs: 50-51 (siMohs-7), SEQ ID NOs: 52-53 (siMohs-8), SEQ ID NOs: 54-55 (siMohs-9), SEQ ID NOs: 16-17 (siMohs-10), SEQ ID NOs: 56-57 (siMohs-11), SEQ ID NOs: 58-59 (siMohs-12), SEQ ID NOs: 60-61 (siMohs-13), SEQ ID NOs: 62-63 (siMohs-14), SEQ ID NOs: 64-65 (siMohs-15), SEQ ID NOs: 66-67 (siMohs-16), SEQ ID NOs: 68-69 (siMohs-17), SEQ ID NOs: 70-71 (siMohs-18), SEQ ID NOs: 72-73 (siMohs-19), SEQ ID NOs: 74-75 (siMohs-20), SEQ ID NOs: 76-77 (siMohs-21), SEQ ID NOs: 78-79 (siMohs-22), SEQ ID NOs: 80-81 (siMohs-23), SEQ ID NOs: 82-83 (siMohs-24), SEQ ID NOs: 84 Any one or more of SEQ ID NOs: 62-63 (siMohs-14), SEQ ID NOs: 64-65 (siMohs-15), SEQ ID NOs: 66-67 (siMohs-16) and SEQ ID NOs: 68-69 (siMohs-17).

[0011] Preferably, the siRNA has any one or more of SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 16-17, SEQ ID NOs: 58-59 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

[0012] Preferably, the siRNA has SEQ ID NOs: 16 to 17 as shown in the nucleotide sequence table.

[0013] After siMohs molecules were incubated with rice blast fungus for 4 hours, the formation of rice blast fungus appressorium was blocked and the morphology was smaller when siMohs-7 (SEQ ID NO: 50-51) and siMohs-10 (SEQ ID NO: 16-17) molecules were applied, compared with siMohs-6 (SEQ ID NO: 48-49), siMohs-12 (SEQ ID NO: 58-59) and siMohs-17 (SEQ ID NO: 68-69); the inhibitory effect of siMohs-10 was better than that of siMohs-7. In short, siMohs-10 molecules had the most obvious inhibitory effect on rice blast fungus.

[0014] In another aspect, the present invention provides a nucleic acid pesticide for controlling rice blast fungus, wherein the nucleic acid pesticide comprises siRNA that targets and silences the MOHS1 gene of rice blast fungus.

[0015] Furthermore, the working concentration range and working time of the siRNA are 6.25-25 μM and 8 h, respectively. Rice blast fungus was treated with different concentrations of siMohs-10 to explore the effects of different concentrations of siRNA on the formation of rice blast fungus appressorium. The results showed that when the siRNA concentration was 25 μM and the rice blast fungus was treated for 4 h, the inhibitory effect on the formation of rice blast fungus appressorium was the most obvious, and the inhibitory effect on the growth of rice blast fungus could last for 8 h.

[0016] Furthermore, the siRNA is wrapped by nanomaterials, and after being assembled with the nanomaterials, the inhibitory effect of siMohs-10 on rice blast fungus is prolonged.

[0017] In another aspect, the present invention provides a method for controlling rice blast fungi, the method comprising applying a siRNA solution to leaves of a plant, wherein the siRNA is as described above. In order to further explore the control effect of siMohs-10 on rice blast, siMohs-10 and spores of rice blast fungi were mixed and inoculated on rice leaves, and it was found that the lesion area of ​​rice treated with siMohs-10 was smaller than that of the control, indicating that siRNA targeting the MOHS1 gene can reduce the pathogenicity of rice blast fungi, further proving that siMohs-10 can be used to control rice blast.

[0018] In another aspect, the present invention provides use of the MOHS1 gene as a target gene for controlling rice blast fungus, wherein the MOHS1 gene has a nucleotide sequence as shown in SEQ ID NO: 1 in the sequence listing.

[0019] In another aspect, the present invention provides use of siRNA for preparing an agent for interfering with the appressorium development or pathogenicity of rice blast fungus, wherein the siRNA is a siRNA targeting silencing the MOHS1 gene of rice blast fungus.

[0020] The beneficial effects of the present invention include:

[0021] 1. The present invention explores the effects of multiple siRNA molecules targeting key genes for the growth and development of rice blast fungus on the formation of rice blast fungus appressoria. After comparison, siRNA targeting silencing the MOHS1 gene has the best effect.

[0022] 2. A target gene MOHS1 that plays a role in the prevention and control of rice blast fungus is provided, and the optimal working concentration of the siRNA molecule designed based on this target gene is 25μM, and it effectively inhibits the formation of rice blast fungus appressorium within 8 hours. The packaging of nanomaterials can prolong the action time of siRNA.

[0023] 3. The siRNA molecules for resisting rice blast infection provided by the present invention can be prepared into nucleic acid pesticides and sprayed on rice leaves, avoiding the cumbersome process of cultivating transgenic crops and the concerns of consumer groups, thereby providing a new method for preventing and controlling rice blast. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 :Absorption of siRNA in vitro by rice blast fungus (fluorescence signal distribution diagram); scale bar = 20 μm

[0026] Figure 2 :The effects of siRNA targeting different genes of Magnaporthe oryzae on Magnaporthe oryzae; Scale bar = 20 μm, data differences were analyzed by t-test, ****P<0.0001; DDW, siGFP-255 and siMcherry-362 were negative controls

[0027] Figure 3:Distribution map of different siRNA positions on the target gene sequence

[0028] Figure 4 :Comparison of the inhibitory effects of different siRNA fragments on rice blast fungus; Scale bar = 20 μm

[0029] Figure 5 :Appressorium formation rate of Magnaporthe grisea after treatment with different concentrations of siRNA for different time periods

[0030] Figure 6 :Effects of siRNA encapsulated by nanomaterials on appressorium formation of Magnaporthe grisea

[0031] Figure 7 :Effects of siRNA spraying on the pathogenicity of rice blast fungus DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and specific examples of the specification. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0033] Although the Mohs in the drawings provided by the present invention and MOHS1 in the specification are inconsistent in wording, they are named by the inventor according to his habit, and the two are essentially the same and have the same meaning.

[0034] Example 1: The rice blast fungus has the ability to absorb siRNA molecules from the external environment

[0035] In order to determine whether the rice blast fungus can take up RNA molecules in the external environment, the present example uses siRNA with a fluorescent marker to treat the spores of the rice blast fungus (using siGFP-255 as an example, the specific sequence is shown in the sequence table).

[0036] Preparation of siRNA with fluorescent marker: Entrust Genema Biotechnology Co., Ltd. to synthesize a siRNA (taking siGFP-255 as an example) and add a fluorescent marker to the 5' end of the sense strand. Dissolve the siRNA with fluorescent marker to a final concentration of 20 μM and store for later use.

[0037] Collection of spores of rice blast fungus: Wash the culture plate of rice blast fungus (Guy11) grown for 8-10 days with sterile water, filter it into a centrifuge tube, centrifuge at 7,000 rpm for 4 minutes, and discard the supernatant. Use a hemocytometer to adjust the spore concentration to 1×10 5 Pieces / mL.

[0038] Appressorium induction: The hydrophobic membrane was rinsed with sterile water, then wiped with 70% ethanol, and the dried hydrophobic membrane was placed in a moisturizing box. The fluorescently labeled siGFP was mixed with rice blast fungus spores and then spotted on the hydrophobic membrane. They were incubated in vitro for 4h, 8h, and 12h, respectively. After incubation, the surface liquid of the hydrophobic membrane was aspirated and observed under a fluorescence microscope.

[0039] The results are as follows Figure 1 As shown in the figure, after siRNA carrying fluorescent markers was incubated with spores in vitro for 2 hours, the fluorescent signal was already enriched on the germ tube of the spores, and the fluorescent signal in the germ tube could reach 40%. From 4 to 8 hours, the fluorescent signal in the appressorium continued to increase, but from 8 to 12 hours, the fluorescent signal began to decrease, indicating that siRNA has a certain validity period. The results show that the spores of rice blast fungus can take up siRNA from the time they germinate the germ tube. In addition, the fluorescent signal is mainly concentrated on the surface of the germ tube and the early appressorium, with a small amount of fluorescence enrichment inside the appressorium, but no fluorescence enrichment in the spores.

[0040] Example 2: Screening of siRNA targeting key genes of rice blast fungus

[0041] Design and synthesis of siRNA: Based on the results of the above examples, this example uses the key genes that regulate the growth and development of rice blast fungus as target genes, and refers to the method of designing siRNA on the website (http: / / siDirect2.rnai.jp) to design siRNA. Combining bioinformatics and gene data analysis, the possibility of targeting the rice genome and other genes of rice blast fungus is reduced, and siRNA (siChs1-1, siChs1-3, siChs3-1, siChs3-2, siChs3-3, siChs3-4, siChs3-5, siChs3-6, siChs3-7, siChs3-8, siChs3-9, siChs4-10, siChs4-11, siChs4-12, siChs4-13, siChs4-14, siChs4-15, siChs4-16, siChs4-17, siChs4-18, siChs4-19, siChs4-21, siChs4-23, siChs4-27, siChs4-28, siChs4-29, siChs4-30, siChs4-31, siChs4-32, siChs4-33, siChs4-34, siChs4-35 iChs3-2, siChs7-1959, siMohs-10, siBuf1-156, siBuf1-624, siMGG_04732-488, siMGG_04732-1172, siMGG_04876-381, siMGG_04876-480, siHtfg-1318, siRgs4-989, siRgs7-795, siRgs7-1595, see the sequence table for specific sequences). The siRNA double-stranded molecule of the present invention was directly synthesized by a biological company (Shanghai Jierui), and the synthesized product was dissolved in water to a final concentration of 10 μM and stored in aliquots.

[0042] The collection of rice blast fungus spores is as described in Example 1.

[0043] Co-incubation of siRNA and rice blast fungus: Clean the hydrophobic membrane that induced the formation of appressorium in advance, then wipe it with 70% ethanol, and place the wiped hydrophobic membrane in a moisturizing box. Mix siRNA with rice blast fungus spore liquid and then spot it on the center of the treated hydrophobic membrane. At this time, the final concentration of siRNA is 5μM. After incubation for 4 hours, observe and record the formation of appressorium.

[0044] The results are as follows Figure 2 As shown, compared with the negative control (DDW, siGFP-255 and siMcherry-362) and siRNA targeting other genes, siRNA targeting MOHS1 gene of rice blast fungus (siMohs-10, SEQ ID NO: 16-17) can significantly reduce the proportion of rice blast fungus appressorium formation, and the rice blast fungus appressorium formation rate is reduced by about 25%; at the same time, the spore morphology of rice blast fungus after treatment for 4 hours was observed. Compared with the control, the germ tube of rice blast fungus treated with siMohs-10 was elongated, the appressorium morphology was smaller, and the melanin layer of the appressorium was shallower. The results of this example show that exogenously added siMohs-10 targeting MOHS1 gene of rice blast fungus can inhibit the morphological construction of appressorium of rice blast fungus.

[0045] Example 3: Design of siRNA targeting MOHS1 gene

[0046] According to the results of the above-mentioned Example 2, it is shown that the MOHS1 gene is an effective target gene for controlling rice blast fungus. Therefore, in order to select the best siRNA for targeting and silencing the MOHS1 gene, this example designs siRNA for the target silencing region present in the full length of the MOHS1 gene (the specific sequence is shown in the sequence table, and the position is shown in the sequence table). Figure 3 As shown), a total of 17 pairs of siRNAs were obtained (including the siRNA siMohs-10 involved in Example 2). The design principles of siRNAs are as described in Example 2.

[0047] Example 4: Comparison of the inhibitory effects of different siRNAs targeting the MOHS1 gene on rice blast fungus

[0048] Four siRNAs designed in Example 3 (siMohs-6, siMohs-7, siMohs-12 and siMohs-17) were randomly selected to compare their antibacterial effects with the siRNA siMohs-10 in Example 2. The effects on the rice blast fungus were observed and recorded for 4 hours. Figure 4As shown. At 4h, compared with other siRNAs, the formation of appressorium of rice blast fungus with siMohs-7 and siMohs-10 molecules was blocked, and the appressorium morphology was smaller; however, the inhibitory effect of siMohs-10 was better than that of siMohs-7. The results of this example show that siMohs-10 is the best siRNA molecule targeting MOHS1 gene.

[0049] Example 5: Effects of different concentrations of siRNA on appressorium formation of rice blast fungus

[0050] Combined with the results of Example 3 and Example 4, this example selected siMohs-6, siMohs-7, siMohs-10, siMohs-12 and siMohs-17 as research objects to explore the effects of different concentrations of siRNA on the formation of rice blast appressorium. The dissolution and storage methods of siRNA molecules are the same as those of Example 1.

[0051] In this example, siRNA was first prepared into mother solutions with initial concentrations of 50 μM, 25 μM, and 12.5 μM, and then mixed with the adjusted concentration of rice blast fungus spore solution in Example 3 to form siRNA with final concentrations of 25 μM, 12.5 μM, and 6.25 μM. The siRNA was then dotted onto the center of the hydrophobic membrane and incubated for 4 h, 8 h, and 24 h, respectively, to observe and record the formation of appressorium. The results are shown in FIG. Figure 5 As shown. The formation rate of appressorium of rice blast fungus co-incubated with siMohs-10 for 4 hours was significantly lower than that of the control, and as the concentration of siMohs-10 increased, the formation rate of appressorium decreased, that is, the treatment with 25μM siMohs-10 had the best effect; after siMohs-10 and rice blast fungus were co-incubated for 8 hours, siRNA could still effectively inhibit the formation of appressorium of rice blast fungus compared with the control, but the inhibitory effect of siRNA of different concentrations was relatively consistent. By 24 hours, appressorium of rice blast fungus gradually formed, and the inhibitory effect of siMohs-10 gradually weakened. The results of this example show that the inhibitory effect of 25μM siMohs-10 treatment for 4 hours on the formation of appressorium of rice blast fungus is the most obvious; the inhibitory effect of siMohs-10 on the growth of rice blast fungus can last for 8 hours. The above experiment was also performed on siMohs-6, siMohs-7, siMohs-12 and siMohs-17, but the results were not as good as siMohs-10.

[0052] Example 6: Nanomaterials can prolong the duration of siRNA's inhibitory effect on rice blast fungus

[0053] Combined with the results of Example 5 above, this example uses nanomaterials (liposomes) to encapsulate and prolong the inhibitory effect of five siMohs molecules on the growth of rice blast fungus. First, the siRNA material is mixed with the nanomaterial, and then the mixture is diluted to 1mL for storage. At this time, the concentration of the siRNA mother solution is 5μM; the siRNA encapsulated by the nanomaterial is co-incubated with the rice blast fungus spores for 4h and 8h, and the formation of appressorium is observed and recorded. The results are shown in Figure 2. Figure 6 As shown in the figure, compared with the control, the formation of appressorium was significantly inhibited after the nanomaterial-encapsulated siMohs-10 was treated with rice blast fungus for 4h and 8h; the germ tube of rice blast fungus after 8h treatment was elongated, the appressorium was small in morphology, and the melanin layer was not formed normally. The experimental results show that nanomaterials can prolong the action time of siMohs-10. The above experiments were also carried out on siMohs-6, siMohs-7, siMohs-12 and siMohs-17, and similar conclusions were obtained.

[0054] Example 7: Control effect of siRNA spray on rice blast

[0055] In this example, the effect of siMohs on rice blast fungus was further explored by spray inoculation.

[0056] Planting of rice: soak and germinate the rice seeds, select rice (CO-39) seeds with consistent growth status, sow 22-25 seeds in each pot, wait for the rice to grow to the stage of three leaves and one heart, use a fresh-keeping bag to cover the rice plants to keep moisture and prevent liquid from overflowing during spraying.

[0057] Collection and acquisition of rice blast fungus spore liquid: Select a rice blast fungus (Guy11) plate grown to 10 days old, use sterile water and a disposable coating stick to scrape the surface mycelium, filter the obtained liquid, and the filtrate is the spore liquid. Then use a hemocytometer to adjust the spore liquid concentration to 2×10 5 Then, 0.3% gelatin solution was used to dilute it to 1×10 5 Pieces / mL.

[0058] Rice leaf pathogenicity experiment: In this example, siRNA molecules were mixed with rice blast fungus spores for spray inoculation. siRNA and rice blast fungus spores were mixed in equal volumes, with a final concentration of siRNA of 5 μM. Each pot of rice was sprayed with 2 mL of siRNA and spore mixture. Then, the rice was placed in an incubator and cultured in the dark at 22°C for 2 days, and then at 25°C with light:dark = 10h:12h. The disease condition of rice leaves was observed, and leaves were cut to count the disease results.

[0059] The results are as follows Figure 7As shown in the figure, compared with the control, after being treated with siMohs-10, the size of the lesions on the rice leaves was significantly reduced, indicating that the pathogenicity of the spores of the rice blast fungus on the rice leaves was significantly reduced; siMohs-6, siMohs-7, siMohs-12 and siMohs-17 were also subjected to the above experiment, but the antibacterial effect of siMohs-10 was the best. The results of this example show that siMohs-10 targeting the key gene MOHS1 of the rice blast fungus can prevent and control the rice blast fungus, and the results provide a certain theoretical and experimental basis for SIGS to prevent and control the rice blast fungus.

[0060] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The use of MOHS1 gene as a target gene for controlling rice blast fungus, characterized in that: The MOHS1 gene has a nucleotide sequence as shown in SEQ ID NO: 1 in the sequence listing.

2. The use according to claim 1, characterized in that The use refers to using siRNA to target and silence the MOHS1 gene to achieve the purpose of preventing and controlling rice blast fungus.

3. The use according to claim 2, characterized in that The siRNA described in the use comprises any one or more of SEQ ID NOs: 38-39, SEQ ID NOs: 40-41, SEQ ID NOs: 42-43, SEQ ID NOs: 44-45, SEQ ID NOs: 46-47, SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 52-53, SEQ ID NOs: 54-55, SEQ ID NOs: 16-17, SEQ ID NOs: 56-57, SEQ ID NOs: 58-59, SEQ ID NOs: 60-61, SEQ ID NOs: 62-63, SEQ ID NOs: 64-65, SEQ ID NOs: 66-67 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

4. The use according to claim 2, characterized in that The siRNA described in the use has any one or more of SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 16-17, SEQ ID NOs: 58-59 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

5. A siRNA for controlling rice blast fungus, characterized in that: The siRNA targets and silences the MOHS1 gene of rice blast fungus, and the nucleotide sequence of the MOHS1 gene is shown in the sequence table as SEQ ID NO:

1.

6. The siRNA according to claim 1, wherein The siRNA comprises any one or more of SEQ ID NOs: 38-39, SEQ ID NOs: 40-41, SEQ ID NOs: 42-43, SEQ ID NOs: 44-45, SEQ ID NOs: 46-47, SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 52-53, SEQ ID NOs: 54-55, SEQ ID NOs: 56-57, SEQ ID NOs: 58-59, SEQ ID NOs: 60-61, SEQ ID NOs: 62-63, SEQ ID NOs: 64-65, SEQ ID NOs: 66-67 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

7. The siRNA according to claim 1, wherein The siRNA comprises any one or more of SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 58-59 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

8. Use of siRNA for preparing an agent that interferes with the development of appressorium or pathogenicity of rice blast fungus, characterized in that: The siRNA is a siRNA that targets and silences the MOHS1 gene of rice blast fungus. The nucleotide sequence of the MOHS1 gene is shown in the sequence table as SEQ ID NO:

1.

9. The use according to claim 8, characterized in that The siRNA comprises any one or more of SEQ ID NOs: 38-39, SEQ ID NOs: 40-41, SEQ ID NOs: 42-43, SEQ ID NOs: 44-45, SEQ ID NOs: 46-47, SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 52-53, SEQ ID NOs: 54-55, SEQ ID NOs: 56-57, SEQ ID NOs: 58-59, SEQ ID NOs: 60-61, SEQ ID NOs: 62-63, SEQ ID NOs: 64-65, SEQ ID NOs: 66-67 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

10. The use according to claim 8, characterized in that The siRNA comprises any one or more of SEQ ID NOs: 48-49, SEQ ID NOs: 50-51, SEQ ID NOs: 58-59 and SEQ ID NOs: 68-69 shown in the nucleotide sequence table.

Images