Application of Pyrazolotriazine in Controlling Rice Diseases

Abstract

The present invention relates to the application of pyrazolotriazine in the preparation of agents for controlling rice diseases. The present invention proves that pyrazolotriazine has inhibitory effects on both plant pathogenic Xanthomonas and Magnaporthe oryzae. At the same time, pyrazolotriazine has inhibitory effects on different species and pathogenic variants of Xanthomonas. The present invention provides a method for using pyrazolotriazine (pseudoiodinine) as an antibacterial substance to control rice diseases, breaking through the bottleneck of difficult control of bacterial diseases caused by Xanthomonas, and laying a theoretical foundation for the subsequent development and creation of green biological pesticides.

Description

Technical Field

[0001] The present invention belongs to the field of biological pesticides, and particularly relates to the application of pyrazolotriazine in controlling rice diseases. Background Art

[0002] Rice bacterial blight and bacterial leaf streak are important bacterial diseases causing disasters in the world's rice-growing areas. Rice bacterial blight is caused by Xanthomonas oryzae pv. oryzae (Xoo), and rice bacterial leaf streak is caused by another variant (X. oryzae pv. oryzicola, Xoc). Xoo invades through water pores or wounds at the leaf tips and margins of rice, and mainly colonizes and multiplies in the xylem of the vascular bundles, causing systemic leaf blight symptoms. Xoc invades through the stomata or wounds of rice leaves, mainly infects the parenchyma cell tissue of rice, cannot infect the xylem tissue, and is restricted by parallel leaf veins, producing water-soaked necrotic streak symptoms ( -Liu, D.O., Ronald, P.C., Bogdanove, A.J. Xanthomonas oryzae pathovars: model pathogens of a model crop[J]. Molecular plant pathology. 2006, 7(5): 303-324.).

[0003] Rice blast caused by Magnaporthe oryzae is the most devastating rice disease worldwide and is also one of the top ten fungal diseases threatening global food security. Rice blast generally reduces rice yield by 10%-30%, and can lead to crop failure in severe cases. All above-ground parts of rice are susceptible to Magnaporthe oryzae. Among them, panicle neck blast is the most harmful. When infecting rice, an appressorium that closely adheres to the surface of host cells must be developed first. Subsequently, an infection peg is produced at the bottom of the appressorium, and it penetrates into the host tissue relying on huge turgor pressure, thereby achieving invasion and forming necrotic spots on the leaves (Dean R, Van Kan JA, Pretorius ZA, Hammond-Kosack KE, Di Pietro A, Spanu PD, Rudd JJ, Dickman M, Kahmann R, Ellis J et al. 2012. The Top 10 fungal pathogens in molecular plant pathology. Molecular plant pathology 13: 414-430.).

[0004] At present, the control measures for these three rice diseases mainly include the cultivation of disease-resistant varieties and chemical control (Zhu Xiaofen. Monitoring of resistance to thicyazuron and streptomycin in Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola and indoor risk assessment of drug resistance. Nanjing Agricultural University. 2010.). However, due to the lack of disease-resistant gene resources and the loss of resistance, most rice varieties are susceptible to diseases, especially hybrid rice is highly susceptible to the two bacterial diseases. Long-term and large-scale use of chemical pesticides can cause environmental safety problems such as pesticide residues and rhizosphere microecological disorders, and also make pathogens produce drug resistance or resistance. Biological control has good control effects on crop diseases, is not easy to produce drug resistance and environmental pollution problems, and has the advantages of high targeting, good specificity and environmental friendliness (Su Qin. Analysis of the advantages and disadvantages of chemical control and biological control [J]. Inner Mongolia Agricultural Science and Technology. 2011(6):84-85.).

[0005] The research on biological control mainly focuses on the excavation of antibacterial substances. Pseudomonas can produce a variety of antibacterial secondary metabolites, including enzymes (protease, chitinase, etc.), hydrogen cyanide, syringomycin, pyoluteorin, 2,4-diacetylphloroglucinol, pyrrolnitrin, phenazine and cyclic lipopeptides, etc., and has great potential in biological control and the development and application of biocontrol agents (Sahu B, Singh J, Shankar G, Pradhan A: Pseudomonas fluorescens PGPR bacteria as well as biocontrol agent: A review. IJCS 2018, 6(2):01-07.). Therefore, the discovery of antibacterial active compounds from biocontrol Pseudomonas has received increasing attention. In view of this, achieving efficient and green control of rice bacterial and fungal diseases has become an important research direction.

[0006] Chinese Patent CN108998389A discloses a Pseudomonas with antagonistic effects on Xanthomonas oryzae and Magnaporthe oryzae and its application. The strain is isolated from the rhizosphere soil of rice in Fengxian District, Shanghai, and the preservation name is: Pseudomonas mosselii 923, preservation number: CCTCC No: M 2018252. This patent proves that Pseudomonas shows significant inhibitory effects on Xanthomonas oryzae, and at the same time has strong inhibitory ability on other plant pathogenic bacteria of the genus Xanthomonas and Magnaporthe oryzae, and has the value of biological control application. However, this patent does not disclose what substances play the antagonistic effects on Xanthomonas oryzae and Magnaporthe oryzae.

[0007] Pseudoiodinine is a heterocyclic molecule containing multiple nitrogen atoms, purple, a polar molecule, and it belongs to the family of natural products in the Pyrazolo[4,3-e][1,2,4]triazine class.

[0008] To date, research on the biological functions of pseudoiodinine has mainly focused on its derivatives, which have anti-cancer, anti-viral and anti-tumor activities. It itself also has anti-viral and anti-tumor activities, can be used as a drug against human sarcoma, and is predicted to be able to treat atherosclerosis (Dembitsky, V.M., Gloriozova, T.A., Poroikov, V.V. Pharmacological and predicted activities of natural azocompounds[J]. Natural products and bioprospecting. 2017, 7(1): 151-169.). Since pseudoiodinine is a purine analogue, by modifying its structure, it can inhibit the activities of multiple enzymes. Utilizing the visible spectral characteristics of these derivatives, it can be used for the chemotherapy of cancer and viruses, and has great application value in the fields of biological research and pharmacological research (Mojzych, M., Rykowski, A., Wierzchowski, J. Pyrazolo[4,3-e][1,2,4]triazines: Purine analogues with electronic absorption in the visible region[J]. Molecules. 2005, 10(10): 1298-1306.).

[0009] Currently, research on the biological functions of pseudoiodinine mainly includes anti-viral and anti-tumor activities, but its research in antibacterial aspects is still relatively limited. Summary of the Invention

[0010] Based on the current situation in the prior art where there is no use of pseudoiodinine to prevent and control rice diseases, the present invention provides an application of pseudoiodinine in preventing and controlling rice diseases.

[0011] The present invention uses pseudoiodinine as an antibacterial substance to prevent and control rice diseases, thereby solving the bottleneck of the difficult prevention and control of bacterial diseases caused by Xanthomonas at present.

[0012] The purpose of the present invention can be achieved by the following technical solutions:

[0013] The present invention provides application of pyrazole triazine in preparing a medicament for preventing and treating rice diseases.

[0014] In one embodiment of the present invention, pyrazole triazine is used in the preparation of a medicament for inhibiting plant pathogenic Xanthomonas.

[0015] In one embodiment of the present invention, pyrazole triazine is used in the preparation of an agent for inhibiting rice blast fungus.

[0016] In one embodiment of the present invention, pyrazole triazine is used in the preparation of an agent for inhibiting plant pathogens Xanthomonas and Rice blast fungi.

[0017] In one embodiment of the present invention, the plant pathogenic Xanthomonas include Xanthomonas oryzae and Xanthomonas leaf stripe pathogen.

[0018] The present invention has found that pyrazolotriazine has an inhibitory effect on plant pathogens Xanthomonas and rice blast fungus.

[0019] In one embodiment of the present invention, the pyrazole triazine has an inhibitory effect on different species and pathogenic species of Xanthomonas.

[0020] The present invention found that the MIC values of pyrazolotriazine against Xanthomonas oryzae and Pseudomonas oryzae were 0.5 μg / mL and 4 μg / mL, respectively, and the EC 50 The MIC values and EC values of the blast fungus were 0.17 μg / mL and 1.36 μg / mL, respectively. 50 The values were 8 μg / mL and 4.43 μg / mL, respectively.

[0021] In one embodiment of the present invention, the pyrazole triazine is prepared into a liquid or solid powder for being configured into a sprayable agent.

[0022] In one embodiment of the present invention, the pyrazole triazine is prepared as a sprayable agent.

[0023] The invention also provides a method for preventing and controlling rice diseases, which comprises spraying pyrazole triazine on rice leaves.

[0024] In one embodiment of the present invention, pyrazole triazine at a concentration of 0.5 μg / mL is sprayed on rice leaves to prevent and control rice bacterial blight.

[0025] In one embodiment of the present invention, 4 μg / mL of pyrazole triazine is sprayed on rice leaves to prevent and control rice leaf streak disease.

[0026] In one embodiment of the present invention, the pseudoiodinine is prepared by fermenting Pseudomonas mosselii strain 923. The fermentation conditions of Pseudomonas mosselii strain 923 are as follows: ferment at 28 - 32 °C and 200 - 250 rpm in a culture medium for 30 - 40 h. The fermentation broth contains pseudoiodinine. Ethyl acetate is used to extract pseudoiodinine from the fermentation broth, and then the ethyl acetate organic phase is rotary evaporated and dried to obtain a crude extract of pseudoiodinine. The crude extract of pseudoiodinine is dissolved in methanol and C18 reverse-phase silica gel is added to make a methanol-silica gel homogenate. After loading it into a glass chromatography column, elution is carried out using a mobile phase. The purple phase is rotary evaporated and dried, and purified by HPLC to obtain a pure product of pseudoiodinine.

[0027] In the present invention, Pseudomonas mosselii 923 is deposited in the China Center for Type Culture Collection, and its deposit number is: CCTCC No: M 2018252. The deposit date is May 7, 2018, and the deposit address is within Wuhan University, No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province (opposite the First Affiliated Primary School of Wuhan University), the preservation center of Wuhan University, which is disclosed in patent CN108998389A.

[0028] In one embodiment of the present invention, the structure of the pseudoiodinine is shown as follows:

[0029]

[0030] Compared with the prior art, the present invention provides a method for preventing and controlling rice diseases by using pseudoiodinine as an antibacterial substance, breaking through the bottleneck of difficult prevention and control of bacterial diseases caused by Xanthomonas, and laying a theoretical foundation for the development and creation of subsequent green biological pesticides. Brief Description of the Drawings

[0031] Figure 1 : Antagonistic effect diagram of the antibacterial substance pseudoiodinine against Xanthomonas oryzae.

[0032] Figure 2: Determination of the MIC values of the antibacterial substance pseudoiodinine against different phytopathogenic Xanthomonas bacteria (The order of the 13 colonies on the plate from left to right is: X. campestris pv. phaseoli ICMP5834, X. campestris pv. malvacearum ATCC12131, X. campestris pv. musacearum ICMP287, X. axonopodis pv. glycines, X. citri subsp. citri 029-1, X. translucens pv. cerealis NXtc01, X. campestris pv. vesicatoria NCPPB701, X. axonopodis pv. allii LMG578, X. axonopodis pv. vignicola ATCC11648, X. arboricola pv. juglandis DW3F3, X. campestris pv. campestris 8004-WT).

[0033] Figure 3 : Determination of the MIC and EC values of the antibacterial substance pseudoiodinine against Magnaporthe oryzae R01-1. 50 Value determination.

[0034] Figure 4 : Antagonistic effect diagram of the antibacterial substance pseudoiodinine against 11 other phytopathogenic Xanthomonas bacteria.

[0035] Figure 5 : Field control effect of the antibacterial substance pseudoiodinine against Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola. Detailed implementation method

[0036] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The culture medium formula used in the following examples is as follows:

[0038] (1) Nutrient Agar Medium NA (g / L): Beef extract 3 g, Polypeptone 5 g, Sucrose 10 g, Yeast extract 1 g, Agar powder 15 g. Dissolve in water and finally make up the volume to 1000 mL. Adjust the pH to 7.0 - 7.2. After sub-packaging, sterilize by high pressure (121 °C, 20 min).

[0039] (2) Oatmeal Medium (OAM): Take 60 g of sugar-free oatmeal, add 1000 mL of pure water, and make it into a paste in a wall breaker. Sub-pack 300 mL into 500 mL conical flasks, add 4.5 g of agar powder, mix well, and sterilize by high pressure at 121 °C for 20 min.

[0040] In the following examples, pseudoiodinine was prepared by fermenting Pseudomonas mosselii 923 strain. Pseudomonas mosselii 923 was deposited in the China Center for Type Culture Collection, and its deposit number is: CCTCC No: M 2018252. The deposit date was May 7, 2018, and the deposit address was in the Wuhan University Preservation Center, opposite to the First Affiliated Primary School of Wuhan University, No. 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province, which was publicly disclosed in Patent CN108998389A.

[0041] After Pseudomonas mosselii 923 (hereinafter referred to as strain 923 or P. mosselii 923) was taken out from the -80 °C refrigerator, it was activated by streaking on a TSB solid medium plate and cultured overnight in a 30 °C incubator. After single colonies grew out, single colonies were picked and inoculated into 4 mL of TSB liquid medium, and cultured at 30 °C and 220 rpm for 12 h to obtain the fermentation seed liquid of 923. The seed liquid was transferred to a 250 mL conical flask containing 50 mL of TSB liquid medium according to an inoculation amount of 1:100 by volume ratio, and cultured with shaking at 30 °C and 220 rpm for 36 h. Under room temperature conditions, the fermentation broth of 923 was extracted with equal volumes of ethyl acetate, petroleum ether and n-butanol respectively, continuously extracted 3 times according to a volume ratio of 1:1, mixed well, and after standing for 15 min, it was divided into organic phase and aqueous phase, and then the organic phases were combined and collected, and dried by rotary evaporation at 35 °C to obtain the crude extract. Then, the crude extract was separated by reverse-phase silica gel column chromatography for pseudoiodinine. The method is as follows:

[0042] (1) Sample mixing: The crude extract obtained by extracting with ethyl acetate phase above was dissolved in methanol, and an appropriate amount of C18 reverse-phase silica gel was added and stirred evenly, and dried by rotary evaporation at 35 °C.

[0043] (2) Column packing: Weigh about 30.0 g of C18 reversed-phase silica gel powder with a clean small beaker, add methanol with a volume twice that of the silica gel powder, and continuously stir with a glass rod during the process. After mixing evenly, a methanol-silica gel slurry is prepared.

[0044] Tightly compact the bottom of the glass chromatography column with cotton in advance to prevent silica gel leakage. Then, slowly pour the methanol-silica gel slurry into the chromatography column at one time, and gently stir with a thin iron wire while pouring. Pay attention not to generate bubbles during this process. When the methanol-silica gel slurry is filled to about 9 - 10 cm from the upper end of the column mouth, stop column packing.

[0045] (3) Equilibration: Use methanol with a concentration of 30% to equilibrate the silica gel column. Fix the glass chromatography column on a support and place it vertically overnight to allow the chromatography column to settle fully without any vibration during this period. To prevent methanol volatilization, seal the tube mouth of the chromatography column with a sealing film.

[0046] (4) Sample loading: Slowly add the powder prepared in step (1) to the tube mouth, and pay attention to ensuring the neatness of the column surface for subsequent gradient separation.

[0047] (5) Elution: Use a mobile phase of methanol:water (v / v) = 1:1 to elute successively, and control the flow rate at about 1 mL / min.

[0048] (6) Collection of components: According to the different colors of different compounds in the chromatography column, use 250 mL small conical flasks to collect the components eluted from each gradient respectively.

[0049] (7) TLC plate inspection: Perform TLC thin-layer chromatography plate inspection on each bottle of collected components. Appropriate sample merging can be carried out according to the migration positions of different components. After the collected samples are dried by rotary evaporation at 35°C, store them at -80°C for subsequent antibacterial and HPLC detections.

[0050] Based on the above method, pseudoiodinine used in the following examples is obtained.

[0051] The structure of pseudoiodinine is shown as follows:

[0052]

[0053] The structural information of pseudoiodinine is as follows:

[0054] Mp 120–123 °C (lit. 112 °C). 1H NMR (400 MHz, CD3OD, δ): 4.27 (s, 3H), 4.41 (s, 3H), 8.95 (s, 1H). 13C NMR (125 MHz, CD3OD, δ): 43.0, 57.6, 139.0, 142.6, 146.0, 160.7. IR (NaCl, thin film) (cm−1): 2988, 2924, 2851, 1586, 1537. UV (CH2Cl2) λmax (log ε): 230 (3.6), 255 (3.5), 295 (3.2), 533 (2.6). UV (EtOH) λmax (log ε): 220 (3.7), 254 (3.6), 295 sh (3.4), 520 (2.6). HRMS-ESI (m / z): [M + H]+ calcd for C6H8N5O, 166.0729; found, 166.0737.

[0055] Example 1 Determination of the antagonistic activity of the antibacterial substance pyrazolotriazine (pseudoiodinine)

[0056] Nine different strains of Xanthomonas oryzae pv. oryzicola (Xoc: RS105, JSB1-39, YNB01-3, ZJB01-25, HNB3-17, RS85, HNB8-47, AHB3-7, and HANB12-26), Xanthomonas oryzae pv. oryzae (Xoo: PXO99 A , YC18, YC11, YC2, XZ35, LYG46, AH1, JL1, and JL3), and 11 Xanthomonas pathogens from other plants were inoculated into NA liquid medium and cultured at 28 °C and 220 r / min. The bacterial concentration was adjusted to an OD600 of 2.0. After mixing 200 μL of the bacterial suspension thoroughly with the NA medium, it was allowed to cool and solidify naturally. Oxford cups with a diameter of 7 mm were placed in the center of the NA plates, and 10 μL of pyrazolotriazine (pseudoiodinine) at a concentration of 0.5 mM was added to each Oxford cup. Three replicates were set for each strain, and the cultures were incubated at 28 °C for 24 - 48 h. The size of the inhibition zone and the relative inhibition rate were measured, the data were analyzed, and the pictures were sorted out. The results are as Figure 1 , Table 1, Table 2, and Table 3 show.

[0057] Table 1 Antibacterial effect of the antibacterial substance pyrazolotriazine (pseudoiodinine) against different strains of Xanthomonas oryzae pv. oryzicola

[0058]

[0059]

[0060] Table 2 Bacteriostatic Effects of the Antibacterial Substance Pyrazolotriazine (Pseudoiodinine) on Different Rice Bacterial Blight Pathogens

[0061]

[0062] Table 3 Bacteriostatic Effects of the Antibacterial Substance Pyrazolotriazine (Pseudoiodinine) on Different Phytopathogenic Xanthomonas Bacteria

[0063]

[0064]

[0065] Example 2 Method for Determining the Minimum Inhibitory Concentration of the Antibacterial Substance Pyrazolotriazine (Pseudoiodinine)

[0066] The minimum inhibitory concentration (MIC) is the minimum concentration that inhibits colony growth. The determination method is as follows: Dissolve pyrazolotriazine (pseudoiodinine) at different concentrations in methanol, mix it evenly with NA medium, and prepare indicator plates with the following different concentration gradients. The final concentrations of the target compound are set to 0.25 μg / mL, 0.5 μg / mL, 0.6 μg / mL, 1 μg / mL, 2 μg / mL, 4 μg / mL, 5 μg / mL, 8 μg / mL, 10 μg / mL, 16 μg / mL, 32 μg / mL, 48 μg / mL, and 64 μg / mL in sequence. According to the previous culture method, different species of Xanthomonas bacteria are cultured in NB medium to prepare a bacterial suspension with an OD 600 of 1.0, uniformly diluted 3 times, and then 2 μL of each is taken and spotted onto the solid plates containing the compound with different concentration gradients in sequence. After static culture at 28 °C for 36 h, observe the growth of the bacteria. The results are as Figure 2 shown in Table 4.

[0067] Example 3 Method for Determining the Median Lethal Concentration of the Antibacterial Substance Pyrazolotriazine (Pseudoiodinine)

[0068] (1) For pathogenic bacteria, the method for determining the median lethal concentration (EC 50 ) is based on the inhibition of colony growth. The method is as follows: Inoculate a single colony of the test indicator bacteria into NB culture medium and culture overnight at 28 °C, 220 rpm. Take 10 μL of the bacterial solution and transfer it to a 10 mL conical flask containing 5 mL of NB culture medium. Add PSD according to an arithmetic or geometric gradient, with final concentrations of 0, 0.0125 μg / mL, 0.025 μg / mL, 0.05 μg / mL, 0.1 μg / mL, 0.2 μg / mL, and 0.4 μg / mL. Wait until the OD of the control (without adding PSD) bacterial solution600 When it reaches 1.0, simultaneously detect the OD of the bacterial solution treated with different concentrations of PSD 600 value, and calculate the bacteriostatic rate of PSD against the indicator bacteria; convert the bacteriostatic rate with the probability value table, use it as the ordinate, take the logarithm of the different concentration values of the compound with Log 10 as the abscissa, draw a standard curve, set 3 replicates for each concentration. When the probability value is 5.0, substitute it into the formula to calculate the EC50. The results are shown in Table 4

[0069] Table 4 MIC and EC of the antibacterial substance pyrazolotriazine (pseudoiodinine) 50 Determination results

[0070]

[0071]

[0072] (2) For pathogenic fungi, taking Magnaporthe oryzae as an example, cut the colonies with consistent growth on the OAM medium into mycelium blocks of 0.2 cm 2 and place them in the center of the solid medium plate containing different concentrations of PSD. The final concentrations of PSD are: 10, 15, 20, 25, 30, 35, 40, 45 and 50 μM. Incubate statically in a fungal incubator at 25 °C for 5 days, measure the growth diameter of the indicator bacteria colonies, and calculate the bacteriostatic rate according to the diameter of the indicator bacteria colonies cultured without drugs. According to the calculation method of bacterial EC 50 draw a standard curve and calculate the EC50. Repeat 3 times for each concentration and repeat the experiment 3 times. The results are as Figure 3 shown. The MIC value of pyrazolotriazine pseudoiodinine against Magnaporthe oryzae is 50 μM (8 μg / mL), and the EC 50 value is 26.86 ± 1.17 μM (4.43 ± 0.20 μg / mL).

[0073] Example 4 Rice field biocontrol experiment

[0074] Select healthy adult rice plants in the field and conduct field spray inoculation experiments according to the treatment method of spray inoculation, with the inoculation time interval set to 24 h. The specific method is as follows: The spray volume per rice plant is about 2 mL (the total amount of inoculated bacteria is about 1.4×10 8 CFU / mL). Collect the cells of the PXO99 A and RS105 bacterial solutions cultured to the logarithmic growth phase, wash them 2 times with sterile water after collection, and adjust to OD 600= 0.6, and the concentrations of pyrazolotriazine pseudoiodinine were taken as the MIC values for spray inoculation. After 15 days, the diseased areas of leaves under different treatments were observed, photographed, and statistically analyzed (the number of leaves ≥ 15). Five holes of rice were inoculated for each treatment, and the experiment was independently repeated twice. The diseased areas of rice leaves were classified and recorded. Referring to the plant disease classification standard, it is as follows:

[0075] Grade 0: No disease spots;

[0076] Grade 1: The diseased area accounts for less than 5% of the entire leaf area;

[0077] Grade 3: The diseased area accounts for 5% - 15% of the entire leaf area;

[0078] Grade 5: The diseased area accounts for 15% - 25% of the entire leaf area;

[0079] Grade 7: The diseased area accounts for 25% - 50% of the entire leaf area;

[0080] Grade 9: The diseased area accounts for 50% - 75% of the entire leaf area.

[0081] Grade 11: The diseased area accounts for more than 75% of the entire leaf area.

[0082] According to the investigation results, the disease index and control effect were calculated according to the following formulas (1) and (2).

[0083] (1) Disease index = (number of diseased leaves at each level × relative level value) / (total number of leaves investigated × 11) × 100%;

[0084] (2) Control effect = [(disease index of control group - disease index of treatment group) / disease index of control group] × 100%.

[0085] The results are as Figure 4 、 Figure 5 shown, indicating that under field trial conditions, pyrazolotriazine pseudoiodinine has a certain degree of control effect on both bacterial blight of rice and bacterial leaf streak of rice, and has good application prospects.

[0086] Therefore, the antibacterial substance pyrazolotriazine pseudoiodinine of the present invention can specifically control Xoo and Xoc of Xanthomonas oryzae, and also control some other plant pathogenic Xanthomonas, and has a good inhibitory effect on Magnaporthe oryzae, and has the activity of selectively killing Xanthomonas and the potential to be developed into a green biological pesticide.

[0087] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. The use of pyrazole triazine in the preparation of a medicament for preventing and treating rice diseases, wherein the structure of the pyrazole triazine is as follows: ； The rice disease prevention and control refers to the inhibition of rice leaf streak pathogen or the inhibition of rice bacterial blight pathogen.

2. The use of the pyrazole triazine according to claim 1 in preparing a medicament for preventing and treating rice diseases, characterized in that: The pyrazole triazine is prepared into a liquid or solid powder.

3. A method for preventing and controlling rice diseases, characterized in that: Spray pyrazole triazine liquid on rice leaves. The pyrazole triazine structure is shown below: ； The rice disease prevention and control refers to the inhibition of rice leaf streak pathogen or the inhibition of rice bacterial blight pathogen.

4. The method for preventing and controlling rice diseases according to claim 3, wherein: Pyrazole triazine at a concentration of 0.5 μg / mL was sprayed on rice leaves to control rice bacterial blight.

5. The method for preventing and controlling rice diseases according to claim 3, wherein: Pyrazole triazine at a concentration of 4 μg / mL was sprayed on rice leaves to control rice leaf streak disease.

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