Application of monopalmitoylglycerol and its derivatives in plant disease prevention and control

Abstract

The present invention relates to the technical field of plant disease prevention and control, and in particular to the application of monopalmitoyl glycerol and its derivatives in plant disease prevention and control. The present invention has a significant effect on preventing and controlling plant diseases caused by plant pathogens, can induce and enhance the resistance of the plant itself, and also has good antibacterial properties; in particular, it has a significant effect on inhibiting the growth of Fusarium solani and reducing the lesion area of ​​Alternaria ginseng, can effectively prevent and control root rot and black spot, and provides a new prevention and control agent for preventing and controlling plant diseases, and meets the requirements of sustainable development, and has broad research and market application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of plant disease prevention and control, in particular to application of monopalmitoyl glycerol and its derivatives in plant disease prevention and control. Background Art

[0002] The root rot of Panax notoginseng is a typical soil-borne disease. There are two common symptoms in the field: one is that the aboveground leaves are not in the right color at the beginning, the leaves wilt, turn yellow and fall off, and the underground part rots; the other is that the roots are damaged, and the leaves droop to one side and wilt. The root rot symptoms of Panax notoginseng are diverse, mainly including yellow rot type, dry crack type, pith rot type, acute stem withering type, and base dry type. The pathogenic factors of root rot are complex, and can be caused by a variety of pathogenic bacteria, fungi, and nematodes alone or in combination. However, fungi are the main ones. Among them, the root rot caused by Fusarium solani causes some of the root fibrous roots and lateral roots to turn brown and rot in the early stage, and gradually spread to the taproot. After the taproot becomes ill, the cortex of the root begins to rot, turn brown and fall off, and the xylem vascular bundle also turns brown. In severe cases, the entire root rots.

[0003] The current prevention and control methods mainly include soil fumigation, addition of organic matter, biological control, and rotation of non-host crops. The rotation period is generally required to be more than 30 years, which is difficult to implement on a large scale in actual production. The application of chemical pesticides is only one of the means to temporarily alleviate plant diseases and insect pests, and the prevention and control effect is not stable. It will also cause serious pollution to the ecological environment and cannot solve the problem from the root. It may even lead to soil acidification and salinization. Soil fumigation and other treatment methods seriously affect the quality of medicinal materials, destroy soil structure, and inhibit the reproduction of microorganisms in the soil. Due to the complexity of root rot and the limitations of various prevention and control measures, the prevention and control of root rot has become an urgent problem to be solved in Panax notoginseng production.

[0004] Panax notoginseng black spot disease is a common disease in Panax notoginseng cultivation and production, with a high incidence rate, which seriously restricts the development of Panax notoginseng planting industry. At present, it is believed that the pathogen of Panax notoginseng black spot disease is mainly Alternaria panax Whetze, which mainly causes the disease by infecting the leaves of Panax notoginseng. Its stems, flower axes and young and tender parts of fruit stalks can all be affected, which has a serious impact on the yield and quality of Panax notoginseng. At present, chemical control is mainly used for Panax notoginseng black spot disease, but excessive reliance on fungicides and the continuous increase in their use are more likely to cause excessive pesticide residues in Panax notoginseng and deteriorate its quality, and also reduce the sensitivity of the disease to some commonly used fungicides.

[0005] Due to the complexity of plant diseases such as root rot and black spot and the limitations of current prevention and control measures, especially the reduced sensitivity of Panax notoginseng pathogens to many commonly used preparations, there is an urgent need to find a new substance that has a significant effect on preventing and controlling Panax notoginseng root rot and black spot. Summary of the invention

[0006] The present invention unexpectedly discovered during the planting process of Panax notoginseng that, compared with other conventional growth environments, when Panax notoginseng is planted together with some tree species, it can effectively prevent and control common diseases such as root rot and black spot caused by plant pathogens that occur during the growth of Panax notoginseng. In order to further explore the reasons, the present invention detected and analyzed a large number of metabolites secreted from the roots of relevant tree species and found that monopalmitoyl glycerol or its pharmaceutically acceptable derivatives have a significant effect on preventing and controlling Panax notoginseng tree diseases caused by plant pathogens. In view of this, the present invention is specially proposed.

[0007] The present invention firstly provides application of monopalmitoyl glycerol or its pharmaceutically acceptable derivatives in preventing and treating plant diseases caused by plant pathogenic bacteria.

[0008] At present, monopalmitoyl glycerol is usually used in the fields of food industry, daily chemical industry and pharmaceutical industry. In the prior art, it includes the following three application directions: (1) used as an emulsifier in bread, cakes, steamed buns, moon cakes, functional foods and health products; (2) used for the preservation of dairy products and fruit and vegetable products to extend the shelf life of food; (3) used in baked foods to improve the quality of rice and flour products. However, the present invention unexpectedly found that it has a better effect on preventing and treating plant diseases caused by plant pathogens, can inhibit plant pathogens, and can also induce plants to produce or enhance disease resistance.

[0009] The present invention further provides the use of monopalmitoylglycerol or its pharmaceutically acceptable derivatives as a preparation for preventing and treating plant diseases caused by plant pathogens.

[0010] Preferably, the controlling of plant diseases caused by plant pathogens is inhibiting plant pathogens.

[0011] Preferably, the prevention and control of plant diseases caused by plant pathogens is to induce plants to produce or enhance disease resistance.

[0012] Preferably, the plant diseases include root rot or black spot.

[0013] More preferably, the plant pathogenic bacteria include Fusarium solani or Alternaria alternata.

[0014] Preferably, the plant belongs to the genus Panax.

[0015] More preferably, the plant is Panax notoginseng.

[0016] In the art, the pathogens of Panax plants are similar to those of Panax notoginseng, such as Alternaria panax, F. solani, Phytophthora cactorum and other pathogens, all of which can cause root rot of Panax notoginseng. The art is based on monopalmitoyl glycerol or its pharmaceutically acceptable derivatives, which can prevent and control diseases caused by Fusarium solani or Alternaria ginseng in Panax notoginseng, and can be applied to other Panax plants except Panax notoginseng to prevent and control the above-mentioned pathogens according to actual needs.

[0017] The invention also provides a bacteriostatic agent for plant pathogenic bacteria, which contains monopalmitoyl glycerol or a pharmaceutically acceptable derivative thereof.

[0018] Preferably, in the antibacterial agent, the concentration of the monopalmitic acid glycerol or its pharmaceutically acceptable derivative is above 50 ppm.

[0019] In the present invention, the antibacterial agent containing monopalmitic acid glycerol or its pharmaceutically acceptable derivatives can be administered by root irrigation or other conventional methods in the art.

[0020] The invention also provides a plant resistance inducer, which contains monopalmitoyl glycerol or a pharmaceutically acceptable derivative thereof.

[0021] Preferably, the concentration of monopalmitoyl glycerol or its pharmaceutically acceptable derivatives is above 0.1 ppm.

[0022] Based on the above technical solution, the beneficial effects of the present invention are:

[0023] (1) The present invention proposes for the first time the use of monopalmitoyl glycerol or its pharmaceutically acceptable derivatives as a method for preventing and treating plant diseases caused by plant pathogens, and determines the concentrations used for antibacterial and resistance induction, respectively.

[0024] (2) The present invention has a significant effect on preventing and controlling plant diseases caused by plant pathogens, can induce and enhance the resistance of the plant itself, and also has good antibacterial properties; in particular, it has a significant effect on inhibiting the growth of Fusarium solani and reducing the lesion area of ​​Alternaria ginseng, and can effectively prevent and control root rot and black spot disease, providing a new control agent for the prevention and control of plant diseases, and meeting the requirements of sustainable development. It has broad research and market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are 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.

[0026] Figure 1 The monopalmitoyl glycerol provided by the present invention has an inhibitory effect on Panax notoginseng Fusarium solani;

[0027] Figure 2 It is a plate photo of the monopalmitoyl glycerol provided by the present invention inhibiting the growth of Panax notoginseng Fusarium solani; wherein, from left to right, the first plate is a control group, and the remaining plates are plate photos of the effects of monopalmitoyl glycerol at concentrations of 50ppm, 25ppm, 12.5ppm, and 6.25ppm on Fusarium solani from left to right;

[0028] Figure 3 This is the result of the induction of resistance of monopalmitoyl glycerol to Panax notoginseng black spot disease provided by the present invention;

[0029] Figure 4 This is the inhibitory effect of spermidine in comparative example 1 on Fusarium solani;

[0030] Figure 5 This is the result of the induced resistance of stearic acid to Panax notoginseng black spot disease in Example 2.

[0031] In the above figure, CK is the control group. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0034] Example 1 Antibacterial effect of monopalmitoyl glycerol

[0035] This example provides the verified effect of monopalmitoyl glycerol in inhibiting the growth of Fusarium solani. The specific steps include:

[0036] 1. Place 200 ml of PDA culture medium (40 g of potato, 3 g of agar, 4 g of glucose, and 200 ml of water) in a high-pressure steam autoclave for sterilization for 15 min at 121°C. After sterilization, place it in a clean bench for UV sterilization for 20 min.

[0037] 2. Prepare the compound into a solution: Dissolve 0.4 g of monopalmitoyl glycerol in 4 ml of methanol to prepare a mother solution ①

[0038] Take 2ml① and add 2ml methanol→②

[0039] Take 2ml② and add 2ml methanol →③

[0040] Take 2ml③ and add 2ml methanol→④

[0041] 3. Use a pipette to take 50μl of each of ④-① and add them to 100ml of culture medium to obtain culture medium with concentrations of 6.25ppm, 12.5ppm, 25ppm and 50ppm respectively. Take 50μl of methanol solution in the control group and add it to 100ml of culture medium. After shaking well, put it into a high-pressure steam sterilizer for sterilization. After sterilization, take it out, cool it slightly and pour it into a plate, and cool it. Use a 5mm diameter puncher to punch the pathogen Fusarium solani isolated from the root of Panax notoginseng into a cake of about 5mm in size. Use an inoculation needle to inoculate the cake into the culture medium containing the compound solution, place it in an incubator at 26-28℃ for 7d, observe the colony morphology and measure the colony diameter after 7d.

[0042] Results Figure 1 and Figure 2 .

[0043] like Figure 1 , Figure 2 As shown, the results showed that monopalmitic acid glycerol promoted the growth of Fusarium at low concentrations. As the concentration increased, it inhibited the growth of Fusarium at 50 ppm, indicating that monopalmitic acid glycerol has the effect of promoting Fusarium at low concentrations and inhibiting Fusarium at high concentrations.

[0044] Example 2 Anti-inducing effect of monopalmitoylglycerol

[0045] This example provides the resistance effect of monopalmitoyl glycerol to black spot disease through potted plant experiments. The specific experimental steps are:

[0046] 1. Prepare the compound into a solution: Dissolve 1g of monopalmitoylglycerol in 100ml of methanol to prepare a mother solution①

[0047] Take 1ml① and add 19ml methanol→②

[0048] Take 10ml② and add 10ml methanol →③

[0049] Take 0.1ml① and add 9.9ml methanol→④

[0050] 2. Take 1 ml of each of ①-④ and add 1L of water. Mix well and add 100 ml to each tissue culture bottle and place them in a white transparent storage box.

[0051] 3. After carefully cleaning the soil from the roots of Panax notoginseng with water, rinse with sterile water, and place in a tissue culture bottle containing the compound, with 5 Panax notoginseng plants in each bottle. After 24 hours, when the growth of Panax notoginseng is stable, inoculate the Panax notoginseng black spot disease cake (5mm in diameter) on the leaves of Panax notoginseng away from the main veins, with two leaves for each Panax notoginseng plant. After the inoculation is completed, spray sterile water to keep the Panax notoginseng moist, cover the box lid and culture at 25-26℃ for 5 days. After 5 days, the Panax notoginseng leaves will be diseased, remove the cake, take down the leaves, and scan the leaf lesions with a scanner. After the scan is completed, use Adobe Photoshop software to calculate the lesion size.

[0052] The results are as follows Figure 3 As shown in the figure, the results of the Panax notoginseng bottle culture experiment showed that monopalmitic acid glycerol can significantly reduce the lesion area at 0.1ppm, indicating that monopalmitic acid glycerol can slow down the occurrence of black spot disease by enhancing the overall resistance of the plant.

[0053] Results Figure 3 .

[0054] like Figure 3 As shown in the figure, the results show that monopalmitic acid glycerol can significantly reduce the lesion area at a concentration of 0.1ppm and above, indicating that monopalmitic acid glycerol can slow down the occurrence of black spot disease by enhancing the overall resistance of plants.

[0055] Example 3

[0056] This example verifies the effect of monopalmitoyl glycerol on increasing the dry weight of Panax notoginseng plants.

[0057] The specific experimental steps are:

[0058] 1. Prepare the compound into a solution: Dissolve 0.1 g of monopalmitoyl glycerol in 10 ml of methanol to prepare a mother solution①

[0059] Take 1ml① and add 9ml methanol→②

[0060] Take 1ml② and add 1ml methanol →③

[0061] Take 1ml③ and add 1ml methanol→④

[0062] 2. Take 1 ml of each of ②-④ and add them to 1L of water. After mixing, add 50 ml of the compound to each pot according to the concentration. For the control, take 1 ml of methanol and add it to 1L of water. Then continue the root irrigation experiment for 6 weeks (once a week). After the Panax notoginseng continues to grow for two months, collect samples of the potted Panax notoginseng, wash them, and count the number of Panax notoginseng plants treated with each compound concentration gradient. Put them into envelopes, sterilize them at 115℃ for 30 minutes, and dry them at 60℃ for 3 days. Weigh the dry weight and calculate the dry weight.

[0063] The results are shown in Table 1. The experimental results show that root irrigation of monopalmitic acid glycerol can significantly increase the dry weight of Panax notoginseng plants.

[0064] Table 1 Comparison of dry weight of individual Panax notoginseng plants

[0065]

[0066] Comparative Example 1

[0067] This comparative example provides another substance detected in soil metabolic secretions - spermidine, and tests its inhibitory effect on Fusarium solani. The specific experimental steps are only different from those in Example 1 in that monopalmitoylglycerol is replaced by spermidine.

[0068] The results are as follows Figure 4 As shown, after adding spermidine, at concentrations above 25 ppm, the diameter of the bacterial cake on the plate was significantly higher than that of the control. The results showed that spermidine promoted the growth of Fusarium solani at concentrations of 25 ppm and above.

[0069] Comparative Example 2

[0070] This comparative example verifies the resistance effect of stearic acid, another substance detected in soil metabolic secretions, on black spot disease through a bottle culture experiment. The specific experimental steps are only different from those of Example 2 in that monopalmitoylglycerol is replaced by stearic acid.

[0071] The results are as follows Figure 5 As shown, the results showed that the lesion area of ​​the stearic acid treatment group was significantly higher than that of the control group. Therefore, stearic acid could not induce resistance to Panax notoginseng leaf black spot disease.

[0072] In addition to the compounds listed in the above comparative examples, the present invention also verified other numerous compounds obtained from soil metabolic secretions, and found that many other compounds were unable to simultaneously inhibit Fusarium solani and Rust fungi while inducing resistance to black spot disease, and they are not listed one by one here.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Application of monopalmitoyl glycerol in preventing and treating Panax notoginseng root rot caused by Fusarium solani, wherein the concentration of the monopalmitoyl glycerol is above 50 ppm.

2. Application of monopalmitic acid glycerol in preventing and treating Panax notoginseng black spot disease caused by Alternaria ginseng, wherein the concentration of the monopalmitic acid glycerol is 0.1ppm~0.5ppm.

3. Use of monopalmitic acid glycerol as a preparation for preventing and treating Panax notoginseng root rot caused by Fusarium solani, wherein the concentration of the monopalmitic acid glycerol is above 50 ppm.

4. Use of monopalmitic acid glycerol as a preparation for preventing and treating Panax notoginseng black spot disease caused by Alternaria ginseng, wherein the concentration of the monopalmitic acid glycerol is 0.1ppm~0.5ppm.

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