Application of perphenazine in prevention and treatment of rice blast

Abstract

The invention relates to the field of rice blast prevention and treatment, in particular to application of perphenazine in rice blast prevention and treatment. At present, perphenazine has not been reported in literatures and can be used for preventing and treating rice blast. The technical problem to be solved by the invention is to provide the application of perphenazine in preventing and treating rice blast. Experiments prove that the perphenazine has the effect of inhibiting the magnaporthe oryzae, the vegetative growth of the magnaporthe oryzae is obviously inhibited along with the increase of the concentration, and the pathogenicity of the magnaporthe oryzae is almost completely lost under the interference of the perphenazine with a certain concentration. Therefore, perphenazine can be used as a novel antifungal agent for controlling rice blast.

Description

Technical Field

[0001] The present invention relates to the field of rice blast control, and particularly to the application of perphenazine in the control of rice blast. Background Art

[0002] Magnaporthe oryzae is a filamentous ascomycete fungus that can cause rice diseases. This pathogen is distributed in all grain-producing areas of the world, and the average annual loss of rice yield caused by rice blast is sufficient to feed more than 60 million people. In addition to rice, Magnaporthe oryzae can also infect gramineous plants such as wheat, barley, and sorghum, and is considered to be one of the most important plant pathogenic fungi. The infection cycle of Magnaporthe oryzae begins with conidia, which are transmitted from the spore-forming site to the healthy host plant tissue through wind or water droplets. After the conidia land on the surface of the host plant, they germinate to produce germ tubes under suitable conditions, and then the germ tubes are specifically differentiated into a spherical infection structure - appressorium. The appressorium further differentiates into a hard penetration structure (infection peg), penetrates the cuticle of the susceptible host plant, successfully invades and colonizes, and finally causes lesions at the infection site.

[0003] Discovering new uses of existing drugs has the characteristics of high efficiency, speed, and cost savings, and practice has proved that this is a feasible method. Perphenazine (PPZ), also known as perphenazine, is an organic compound with the chemical formula C 21 H 26 ClN3OS, which is a drug used clinically to treat mental illnesses. There is no literature report that perphenazine can be used to control rice blast. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide the application of perphenazine in the control of rice blast.

[0005] The present invention is realized as follows: The present invention provides the application of perphenazine in the control of rice blast.

[0006] Specifically, the application of perphenazine in the preparation of a drug for controlling rice blast.

[0007] Furthermore, the drug for controlling rice blast is a drug with perphenazine as a single component or a composition composed of perphenazine and other pharmaceutically acceptable components as a drug.

[0008] Still further, in the drug for controlling rice blast, the concentration of perphenazine is greater than 50 μg / mL.

[0009] Preferably, the concentration of perphenazine is 50 - 100 μg / mL. The present invention has the following advantages: The present invention has confirmed the effect of perphenazine in inhibiting Magnaporthe oryzae through experiments. As the concentration increases, the vegetative growth of Magnaporthe oryzae is significantly inhibited. Under the interference of a certain concentration of perphenazine, the pathogenicity of Magnaporthe oryzae is almost completely lost. Therefore, perphenazine can be used as a new antifungal agent for controlling rice blast. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described below with reference to the accompanying drawings in conjunction with embodiments.

[0011] Figure 1 Effect of PPZ on wild-type strain of Magnaporthe oryzae.

[0012] Wherein: Sensitivity of wild-type strain to different concentrations of PPZ. The fungus was cultured on CM medium supplemented with the specified concentration of PPZ for 10 days. B. Analyze the effect of PPZ on the pathogenicity of Magnaporthe oryzae ( M. oryzae ). The fungal spore suspension (5×10 ^4 spores / mL) was treated with DMSO, 50 μg / mL and 100 μg / mL PPZ respectively, and then sprayed on 3-week-old susceptible CO39 rice seedlings. Observation and photography were carried out on the 7th day (dpi) after inoculation.

[0013] C. Formation of appressoria of Magnaporthe oryzae ( M. oryzae ) after treatment with ddH2O, DMSO and 50 μg / mL PPZ for 8 hours.

[0014] D. After inoculating rice leaf sheaths with conidial suspensions of Magnaporthe oryzae supplemented with ddH2O, DMSO and 50 μg / mL PPZ respectively for 48 h, the infection grade of Magnaporthe oryzae was statistically analyzed under a microscope (Type I is appressorium, Type I is primary infection hypha, Type III is multi-branched infection hypha, Type IV is infection hypha extending to adjacent cells). Scale bar = 10 µm. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Those not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0016] I. Materials and Methods: Strains (1) The wild-type strain of Magnaporthe oryzae used in this study is Guy11.

[0017] (2)Rice variety CO39.

[0018] Common culture media (per liter) (1)CM medium: 6 g each of yeast extract and acid-hydrolyzed casein, 10 g of sucrose, 20 g of agar powder.

[0019] (2)Rice bran medium: 40 g of rice bran, 20 g of agar powder, pH 6.0 - 6.5.

[0020] II. Basic phenotypic analysis of Magnaporthe oryzae: The following experiments were repeated more than three times.

[0021] 1 Measurement of growth rate Cut fresh mycelial blocks of the wild type, mutant, and complementary strains of the same size, and inoculate them in the center of a 9-cm CM solid medium. Five parallel replicates were set for each strain, and they were cultured upside down at 28 °C for 7 d. The colony diameter was measured and photographed.

[0022] 2 Observation of conidia germination and appressorium formation Filter the spore suspension through two layers of lens paper, adjust the spore suspension concentration to 1×104 - 3×104 spores, take 20 μL and drop it in the center of a hydrophobic glass slide, and culture it in the dark with humidity for 2 h, 4 h, 8 h, and 16 h. Observe the conidia germination and appressorium formation by microscopy or confocal microscopy and take pictures.

[0023] 3 Observation of rice pathogenicity Filter the spore suspension through two layers of lens paper, adjust the spore suspension concentration to 2×10 4 -5×10 4 , add 0.02% Tween 20, mix well and spray inoculate rice CO39 at the three-leaf and one-heart stage. After culturing in the dark with humidity for 24 h, transfer it to natural conditions with humidity for 4 - 6 d. After the wild type shows lesions, investigate the rice samples and scan and save them.

[0024] III. Test results: In the prevention and control of Magnaporthe oryzae on rice, we first detected the sensitivity of the wild-type strain of Magnaporthe oryzae to PPZ. The results showed that after 7 days of culture, the growth rate of the wild-type strain on DMSO in the negative control group was similar to that in the blank group Mock, and the diameter reached about 57 mm. However, when different concentrations of PPZ were added, the wild-type strain showed dose-dependent sensitivity to PPZ. As the concentration increased, the vegetative growth of Magnaporthe oryzae was significantly inhibited. After calculation, the EC 50 value of PPZ was 41 μg / mL ( Figure 1 in A).

[0025] To determine the effect of PPZ on the infectivity of Magnaporthe oryzae, we pretreated the spore suspension of the Guy11 strain with 50 μg / mL and 100 μg / mL of PPZ respectively, and then sprayed it on the CO39 rice seedlings. The results showed that obvious spindle-shaped lesions appeared on the rice leaves in the DMSO group, while there were almost no significant lesions on the rice leaves treated with 50 μg / mL and 100 μg / mL of PPZ, only a small number of hypersensitive necrotic lesions were presented, and the pathogenicity of Magnaporthe oryzae was almost completely lost ( Figure 1 in B), indicating that PPZ interfered with the pathogenicity of Magnaporthe oryzae.

[0026] To clarify the specific mechanism by which PPZ affects the infectivity of Magnaporthe oryzae, we first observed the effect of PPZ on the appressorium germination process. The results showed that after 8 h of induced germination, the appressorium germination rate of the conidia of Magnaporthe oryzae in the Mock group and the DMSO group reached more than 98%, while the conidia of Magnaporthe oryzae treated with 50 μg / mL of PPZ could hardly germinate to form appressoria, indicating that PPZ inhibited the appressorium germination process of Magnaporthe oryzae ( Figure 1 in C).

[0027] The invasive hyphae are the invasive organs differentiated after Magnaporthe oryzae penetrates into rice cells. The expansion ability of Magnaporthe oryzae can be quantified according to the grades of invasive hyphae in different proportions. Among them, Type I is the appressorium of Magnaporthe oryzae that has not penetrated into rice cells, Type II is the invasive hyphae that form single or initially branched hyphae, Type III is the invasive hyphae with multiple branches but not infecting the lower cells, and Type IV is the invasive hyphae that infect other cells. Statistical analysis showed that most of the invasive hyphae in the Mock group and the DMSO group were Type IV invasive hyphae after 48 h of inoculation, while most of the sheath groups treated with 50 μg / mL of PPZ were Type I invasive hyphae, indicating that PPZ inhibited the penetration and expansion ability of Magnaporthe oryzae ( Figure 1 in D). By comparing the grades of invasive hyphae with the control group, the higher the grade, the stronger the infectivity, and the more low-grade invasive hyphae, the more limited the infectivity. It can be shown that after using PPZ, the infectivity of Magnaporthe oryzae is restricted and it cannot effectively infect rice, that is, the control effect is achieved.

[0028] In summary, the above results indicate that PPZ can be used as a new antifungal agent for controlling rice blast.

[0029] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. Application of perphenazine in the prevention and treatment of rice blast.

2. The use according to claim 1, characterized in that: The application of perphenazine in preparing medicine for preventing and treating rice blast.

3. The use according to claim 2, characterized in that: The drug for preventing and treating rice blast is a single component of perphenazine as a drug or a composition of perphenazine and other pharmaceutically acceptable components as a drug.

4. The use according to claim 2, characterized in that: In the drug for preventing and treating rice blast, the concentration of perphenazine is greater than 50 μg / mL.

Images