Application of diterpenoid progesterone in prevention and treatment of apple rot

Abstract

The invention belongs to the technical field of prevention and treatment of apple rot, and relates to application of diterpenoid progesterone in prevention and treatment of apple rot, and the molecular formula of the diterpenoid progesterone is C21H30O2; the apple rot disease is caused by infection of fungus black beetle shell fungus; when the concentration of the diterpenoid compound progesterone is 2.5 mu g / mL to 12.5 mu g / mL, the growth of black beancurd skin hyphae is inhibited; the progesterone is a diterpenoid compound, and the progesterone content in a Xinjiang malus sieboldii plant is up-regulated and expressed by 5.77 times after being infected by black beetle shell fungi; the progesterone is used as a plant endogenous antifungal terpenoid, the development and utilization of the progesterone can fill the vacancy of the antifungal terpenoid, and a new resource is provided for resisting apple rot.

Description

Technical Field

[0001] The present invention belongs to the technical field of preventing and controlling apple canker, and particularly relates to the application of a diterpenoid compound progesterone in preventing and controlling apple canker. Background Art

[0002] Plant diseases seriously threaten the safety of agricultural production, and their prevention and control methods can be mainly divided into the following types:

[0003] (1) Agricultural control, including field management means such as germplasm screening, reasonable arrangement of tillage time, and timely removal of weeds.

[0004] (2) Chemical control, at different growth stages of crops, using means such as irrigation and spraying to apply chemical agents to kill bacteria, pests or fungi.

[0005] (3) Biological control, which refers to using antagonistic microorganisms, natural enemies, etc. to inhibit the growth and reproduction of pathogenic bacteria or pests, and is considered a more environmentally friendly disease prevention and control measure.

[0006] The ancestral species of modern cultivated apples, Malus sieversii, is distributed in the Tianshan Mountains of Xinjiang in China. It is a national second-class protected plant and a precious tertiary relict plant. As an important global fruit, the planting and production of apples are closely related to the healthy development of the global agricultural economy. However, apple canker caused by the ascomycete Cytospora mali can infect Malus sieversii and cultivated apples, resulting in weakened tree vigor and even death of fruit trees.

[0007] After Cytospora mali infects fruit trees, its disease occurrence patterns can be divided into two types: ulcer type and dead-branch type [1]. In the initial stage of the ulcer type, reddish-brown water-soaked round spots are formed on the main trunk, and the diseased part further ulcerates as the disease progresses, hindering the nutrient transport of fruit trees. The dead-branch type is more common on small branches. After the disease occurs, the lesions are in the shape of irregular black-brown or reddish-brown wheel patterns and gradually dry out.

[0008] At present, the prevention and control measures for apple canker are still relatively limited, mainly relying on field management and chemical control. The field management methods for preventing and controlling apple canker include seedling management prevention and manually scraping the diseased parts of fruit trees after the disease occurs. Chemical control refers to the large-area spraying of antifungal agents such as chlorothalonil and thiophanate-methyl. Currently, the existing prevention and control methods for apple canker have problems such as high consumption of manpower and financial resources and environmental pollution caused by excessive use of chemical agents.

[0009] Natural products refer to substances extracted from animals, plants, microorganisms themselves or their secondary metabolites, including alkaloids, flavonoids, terpenoids, fatty acids and other substances. Due to their more environmentally friendly nature, natural products have become a research hotspot for new biological pesticides in recent years, and the antibacterial potential of terpenoid compounds has also been extensively studied. There are a wide variety of terpenoid compounds, which are widely present in plants. However, the antibacterial ability of terpenoid compounds against fungi has been rarely studied and reported. Summary of the Invention

[0010] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an application of the diterpenoid compound progesterone in the prevention and control of apple canker.

[0011] In order to achieve the purpose of the present invention, the following technical solutions are adopted for implementation.

[0012] An application of a diterpenoid compound progesterone in the prevention and control of apple canker, wherein the molecular formula of the diterpenoid compound progesterone is C 21 H 30 O 2 ; the apple canker is caused by the infection of the fungus Valsa mali.

[0013] As a preferred embodiment of the present invention, the progesterone is an endogenous diterpenoid compound in plants.

[0014] As a preferred embodiment of the present invention, when the concentration of the diterpenoid compound progesterone is 2.5 μg / mL to 12.5 μg / mL, it inhibits the growth of Valsa mali hyphae.

[0015] Beneficial Effects

[0016] Progesterone is a diterpenoid compound, and the content of progesterone in Malus sieversii plants in Xinjiang shows a 5.77-fold up-regulation after being infected by Valsa mali; as an endogenous antifungal terpenoid compound in plants, the development and utilization of progesterone can fill the gap of antifungal terpenoid compounds and provide new resources for the prevention and control of apple canker. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the inhibition of Valsa mali growth by progesterone described in the present invention, wherein: Figure A is a broken line graph of the growth area of Valsa mali hyphae; Figure B is the growth situation of Valsa mali hyphae;

[0018] Figure 2 It is a schematic diagram of the inhibition of Valsa mali growth by spraying progesterone on tissue culture seedlings described in the present invention, wherein: Figure A is the disease situation of Malus sieversii tissue culture seedlings; Figure B is the fungal content of Malus sieversii tissue culture seedlings; Figure C is the statistics of the lesion length of Malus sieversii tissue culture seedlings, CK: 0.5% DMSO, Pg: Progesterone, progesterone;

[0019] Figure 3 This is the quantitative map of resistance genes after progesterone spraying according to the present invention. Specific embodiments

[0020] The present invention will be further described in conjunction with the accompanying drawings and embodiments.

[0021] Preliminary verification of the ability of progesterone to resist Valsa mali

[0022] Through the joint analysis of the metabolome and transcriptome data of tissue-cultured rooting seedlings of Malus sieversii inoculated with Valsa mali in Xinjiang, the terpene metabolite progesterone was selected for verification of its antibacterial ability. A concentration gradient with an initial concentration of 0.08 μg / mL and a maximum concentration of 20 μg / mL was set. 4 mg of progesterone compound powder was dissolved in 1 ml of dimethyl sulfoxide (DMSO) to obtain a stock solution, and then the stock solution with the highest concentration was gradually diluted 2-fold with DMSO to 0.16 mg / ml. For the 9 kinds of stock solutions with the concentrations obtained in the previous step, 500 μl was respectively pipetted into 100 ml of potato dextrose agar medium (PDA) that had been sterilized and cooled slightly. 15 g / L of agar had been previously added to the medium. Pour the plates before it solidified. About 20 ml of the medium was poured into each petri dish, and 100 ml could be divided into 5 replicates. The Valsa mali strain C.mali EGI 1 was provided by the State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography. After the plates cooled, a mycelial disc with a diameter of 5 mm was attached to the center position of the medium, and the plates were incubated upside down. Then, observations and photographs were taken continuously for 7 days.

[0023] Verification of the ability of progesterone to resist rot disease by spraying tissue-cultured seedlings

[0024] One-month-old tissue-cultured seedlings of Malus sieversii (plant height 3 cm) were cut and laid flat on a moist sterilized filter paper, and stabbed 10 times with the needle attached to a disposable syringe. The Valsa mali pathogen EGI1 that had grown on PDA for 5 days was prepared, and the mycelial disc was attached to the wound. After 20 h, the mycelial disc was removed, and the wound had started to show slight disease. A progesterone aqueous solution was prepared at a final concentration of 20 μg / ml. Similar to the previous experiment, progesterone powder was first dissolved in DMSO and then diluted with sterilized water. The progesterone aqueous solution was sprayed onto the tissue-cultured seedlings using a 15 mL small spray bottle, spraying 2 times on each seedling, and supplemented with spraying once at a fixed time every day (interval 24 h). Samples were taken and photographed continuously for 3 days. The relative expression levels of the classical resistance genes MsPR5, MsPR8, and MsPR10 were extracted and measured, as shown in Figures A and B in Figure 1 as follows.

[0025] Prepare an aqueous solution of progesterone at a concentration of 20 μg / mL and spray it on the tissue culture seedlings. Progesterone can inhibit the infection of tissue culture seedlings of Malus sieversii by rot pathogens, which is consistent with the results of preliminary verification. After spraying progesterone, the plaque length on the Malus sieversii seedlings is significantly reduced compared with the wild type, and the bacterial content is also significantly lower than that of the wild type and the blank control, as shown in Figure 2 Figures A, B, and C in

[0026] After spraying progesterone, the expression levels of PR5 and PR8 show an upward trend. When inoculating with rot pathogens while spraying, the expression levels of PR5, PR8, and PR10 are significantly higher than those of the blank control group, as shown in Figure 3 shown.

[0027] The preferred embodiments of the embodiments of the present application have been described above with reference to the accompanying drawings. However, this does not limit the scope of the rights of the embodiments of the present application. Any modifications, equivalent replacements, and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall fall within the scope of the rights of the embodiments of the present application.

Claims

1. An application of a diterpenoid compound progesterone in the prevention and treatment of apple rot, characterized in that: The molecular formula of the diterpenoid progesterone is C 21 H 30 O2; The apple rot disease is caused by infection by the fungus Solanum odoratum.

2. The use of a diterpenoid compound progesterone in the prevention and treatment of apple rot according to claim 1, characterized in that: The progesterone is a diterpenoid compound endogenous to plants.

3. The use of a diterpenoid compound progesterone in the prevention and treatment of apple rot according to claim 1, characterized in that: The diterpenoid compound progesterone inhibits the growth of black rot mycelium when the concentration is 2.5 μg / mL to 12.5 μg / mL.

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