Application of natural stilbene compound in preparation of medicament for preventing and treating plant fungal diseases

Abstract

The invention discloses application of a natural stilbene compound in preparation of a medicament for preventing and treating plant fungal diseases. A bacteriostatic activity research result shows that the natural stilbene compound provided by the invention specifically comprises pterostilbene, dihydroresveratrol, resveratrol trimethyl ether, polydatin and pine stilbene, and the polygonum multiflorum glycoside has bacteriostatic activity on four plant pathogenic fungi specifically comprising cacumen biotae, gleditsia sinensis wilt, walnut kernel mildew and rot bacteria and orange sour rot bacteria. Accurate toxicity determination results show that the toxicity of pterostilbene to the four pathogenic fungi is higher than that of commercially available medicaments such as prochloraz and chlorothalonil. Pharmacodynamic test results show that pterostilbene has good prevention and protection effects on citrus reiculata acid rot, and the prevention and treatment effects are significantly higher than those of prochloraz and chlorothalonil. Therefore, the natural stilbene compound provided by the invention is expected to be used for preparing a medicament for preventing and treating plant fungal diseases.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticides, and particularly relates to the application of natural stilbene compounds in the preparation of agents for preventing and controlling plant fungal diseases. Background Art

[0002] Chemical pesticides are a conventional means for preventing and controlling plant diseases. However, with the extensive use of chemical pesticides, many drawbacks of using chemical pesticides for plant disease control have gradually emerged. Long-term overuse not only disrupts the ecological balance, leading to a sharp decline in biodiversity, but also the pollution of soil and water sources by pesticide residues seriously affects the quality and safety of agricultural and forestry crops. These harmful substances enter the human body through the food chain, posing a potential threat to health and even increasing the risk of cancer. More seriously, the abuse of chemical pesticides has accelerated the evolution of pest and disease resistance, making traditional control methods gradually ineffective and increasing the difficulty and cost of control. In addition, the phenomenon of accidental killing by chemical pesticides has also exacerbated the imbalance of the ecosystem, causing irreversible damage to natural enemies and non-target organisms. Botanical control agents, with their natural and environmentally friendly characteristics, have become ideal substitutes for chemical pesticides, being widely sourced, renewable, environmentally friendly, and not easily polluting the soil and water sources. Botanical antibacterial active substances are diverse in types and action mechanisms, which enables botanical control agents to slow down the generation of pathogen resistance. In addition, compared with chemical pesticides, botanical control agents have the characteristics of low toxicity and low residue, with less impact on natural enemies and non-target organisms, helping to maintain the balance of the ecosystem and being conducive to ensuring the quality and safety of agricultural and forestry products.

[0003] Natural stilbene compounds refer to compounds with a parent structure of two benzene rings connected by a vinyl group, such as polydatin, polygonumin, pterostilbene, and pinosylvin, etc., which can be classified as secondary metabolites of plant polyphenols and have a wide distribution range in nature.

[0004] Existing studies have proven that natural stilbene compounds have a wide range of pharmacological effects such as anti-cardiovascular diseases, anti-inflammatory, antibacterial, anti-aging, anti-hypercholesterolemia, anti-atherosclerosis, and liver protection. The antibacterial effect is one of the biological activities that natural stilbene compounds have been focused on. However, the reported studies on the antibacterial activity of natural stilbene compounds mainly focus on medical pathogens, and mostly on pathogenic bacteria, and there are few related reports on their application to the inhibitory activity of plant pathogenic fungi. Summary of the Invention

[0005] Aiming at the technical problems existing in the background art, the purpose of the present invention is to provide the application of natural stilbene compounds in the preparation of agents for preventing and controlling plant fungal diseases.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides the use of natural stilbene compounds in the preparation of agents for preventing and controlling plant fungal diseases, and the natural stilbene compounds are dihydroveratrol, trimethoxyresveratrol, polydatin, pinosylvin stilbene or polygonum multiflorum glycoside.

[0008] Preferably, the plant fungal diseases are cercospora leaf blight of Platycladus orientalis, fusarium wilt of Gleditsia sinensis, mold rot of walnut kernels or sour rot of oranges.

[0009] The second aspect of the present invention provides the use of pterostilbene in the preparation of agents for preventing and controlling plant fungal diseases, and the plant fungal diseases are cercospora leaf blight of Platycladus orientalis, fusarium wilt of Gleditsia sinensis, mold rot of walnut kernels or sour rot of oranges.

[0010] The present invention has the following beneficial effects:

[0011] By investigating the antibacterial activities of natural stilbene compounds, specifically pterostilbene, dihydroveratrol, trimethoxyresveratrol, polydatin, pinosylvin stilbene, polygonum multiflorum glycoside, against four plant pathogenic fungi (cercospora leaf blight of Platycladus orientalis, fusarium wilt of Gleditsia sinensis, mold rot of walnut kernels or sour rot of oranges), the results show that the natural stilbene compounds provided by the present invention have antibacterial activities against the above four pathogenic fungi. The precise virulence determination results show that the virulence of pterostilbene against the above four pathogenic fungi is higher than that of the commercially available agents prochloraz and chlorothalonil. The efficacy test results show that pterostilbene has a good preventive and protective effect on sour rot of Wogan oranges, and the control effect is significantly higher than that of prochloraz and chlorothalonil. Therefore, the natural stilbene compounds provided by the present invention are expected to be prepared into agents for preventing and controlling plant fungal diseases in the fields of agricultural and forestry disease prevention and control, etc., which lays a foundation for the development and utilization of stilbene-based plant-derived control agents. Detailed implementation manners

[0012] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should understand that the present invention can also be implemented in other embodiments without these specific details.

[0013] Example 1

[0014] 1. Experimental materials

[0015] The polydatin, resveratrol trimethyl ether and polygonum multiflorum glycoside required for the experiment were purchased from Shanghai Macklin Biochemical Co., Ltd. Pterostilbene, dihydroresveratrol and pinosylvin were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The 450 g / L prochloraz aqueous emulsion was purchased from Shandong Tiandao Bioengineering Co., Ltd. The 75% chlorothalonil wettable powder was purchased from Shandong Bainong Sida Biotechnology Co., Ltd. The plant pathogenic fungi Alternaria tenuissima, Thyronectria austroamericana, Geotrichum candidum and Colletotrichum gloeosporioides required for the experiment were all isolated from diseased plants or fruits.

[0016] 2. Research on the Inhibitory Activity of Natural Stilbenoids against Plant Pathogenic Fungi

[0017] (2.1) Preliminary Toxicity Determination of the Inhibitory Activity of Natural Stilbenoids against Plant Pathogenic Fungi

[0018] Experimental method: Using pterostilbene, dihydroresveratrol, resveratrol trimethyl ether, polydatin, pinosylvin and polygonum multiflorum glycoside as test agents, and using four strains of plant pathogenic fungi, Alternaria tenuissima, Thyronectria austroamericana, Geotrichum candidum and Colletotrichum gloeosporioides, prepare a mixed-toxicity medium with a natural stilbenoid content of 1.8 mmol / L (0.41 - 0.73 g / L), conduct the cultivation of plant pathogenic fungi, set a solvent control, incubate at a constant temperature of 25 °C for 5 days, measure the colony diameter, and calculate the inhibition rate. The results are shown in Table 1.

[0019] Table 1. Results of Preliminary Toxicity Determination of the Inhibitory Activity of Natural Stilbenoids against Plant Pathogenic Fungi

[0020]

[0021] As can be seen from the results in Table 1, natural stilbene compounds (pterostilbene, dihydroveratrol, trimethoxyresveratrol, polydatin, piceatannol, polygonum multiflorum glycoside) with a concentration of 1.8 mmol / L (0.41 - 0.73 g / L) have certain inhibitory effects on four tested plant pathogenic fungi (Gleditsia wilting pathogen, Platycladus orientalis leaf blight pathogen, walnut kernel mildew pathogen, orange sour rot pathogen). Among them, pterostilbene has the highest antibacterial activity, and the inhibition rate can reach 84% - 100%. Its inhibition rates against Gleditsia wilting pathogen and walnut kernel mildew pathogen can both reach 100%, and the inhibition rate against Platycladus orientalis leaf blight pathogen can reach 90.26%; the inhibition rate of piceatannol can reach 50.00% - 79.40%.

[0022] (2.2) Precise virulence determination of pterostilbene against plant pathogenic fungi

[0023] Experimental method: Prochloraz and chlorothalonil, two commercially available agents, were used as positive controls, and a mixed solvent composed of 0.1% Tween 80 and 0.1% acetonitrile in equal proportions was used as a control. The test agent was prepared into a liquid medicine with a concentration of 9 mmol / L using the above mixed solvent, and then serially diluted into liquid medicines with concentrations of 0.9, 0.09, 0.009, and 0.0009 mmol / L. The commercially available agents were prepared into a liquid medicine with a concentration of 0.5 g / L with water, and then serially diluted to 0.25, 0.125, 0.0625, and 0.03125 g / L. The above liquid medicines were respectively added with 4 times of PDA to prepare a mixed medicine culture medium for antibacterial activity determination. The biological level was repeated 5 times. With the logarithm of the agent concentration as the abscissa and the probit value of the average inhibition rate as the ordinate, the antibacterial virulence equation of the test agent was constructed, and the median effective concentration EC 50 . The results are shown in Table 2.

[0024] Table 2. Results of precise virulence determination of pterostilbene against four plant pathogenic fungi

[0025]

[0026] The data in the table are EC 50 . Data are EC 50 .

[0027] As shown by the results in Table 2, pterostilbene, as well as two commercially available chemical agents, prochloraz and chlorothalonil, have inhibitory effects on four tested plant pathogenic fungi (Platycladus orientalis leaf blight pathogen, Gleditsia wilting pathogen, walnut kernel mildew pathogen, orange sour rot pathogen). With the logarithm of the agent concentration as the abscissa and the probit value of the average inhibition rate as the ordinate, the goodness of fit of the virulence equation of the test agent constructed can reach 0.90 - 1.00, indicating that the goodness of fit of the virulence equation is good. Based on this, EC 50 was calculated. It can be seen that the EC 50The content of pterostilbene was 0.04 - 6.14 mg / L. Moreover, the virulence of pterostilbene against the above four plant pathogenic fungi was higher than that of two commercially available agents, prochloraz and chlorothalonil. The virulence was 3.40 - 46.78 times that of prochloraz and 12.78 - 713.17 times that of chlorothalonil respectively.

[0028] 3. Control efficacy test of pterostilbene against sour rot of Wogan oranges

[0029] To control the sour rot of Wogan oranges, a 9 mmol / L (2.31 g / L) pterostilbene solution was sprayed. The biological level was repeated 3 times. The results are shown in Table 3.

[0030] The results in Table 3 show that the control efficacy of pterostilbene spray reached 86.96% after 4 days and still reached 78.57% after 6 days, which was higher than that of the control agents prochloraz and chlorothalonil. The above results indicate that pterostilbene has a good preventive and protective effect on the sour rot of Wogan oranges.

[0031] Table 3. Control efficacy results of pterostilbene against sour rot of Wogan oranges

[0032]

[0033] The present invention is not limited to the above specific embodiments. Those of ordinary skill in the art, starting from the above concepts and without creative labor, can make various transformations, all of which fall within the protection scope of the invention.

Claims

1. Use of natural stilbene compounds in the preparation of agents for controlling phytogenic fungal diseases, characterized in that: The natural stilbene compound is dihydroveratrol, trimethoxyresveratrol, polydatin, piceatannol or polygonum multiflorum glycoside.

2. Use of the natural stilbene compound according to claim 1 in the preparation of a medicament for controlling phytogenic fungal diseases, characterized in that: The plant fungal disease is cercospora leaf blight of Platycladus orientalis, fusarium wilt of Gleditsia sinensis, mold rot of walnut kernel or sour rot of orange.

3. Application of pterostilbene in preparing medicament for preventing and treating plant fungal diseases, characterized in that: The plant fungal disease is cercospora leaf blight of Platycladus orientalis, fusarium wilt of Gleditsia sinensis, mold rot of walnut kernel or sour rot of orange.

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