Plant source metabolite for preventing and treating wheat scab

Abstract

The invention belongs to the technical field of biological prevention and treatment, and particularly relates to a plant source metabolite-para aminobenzoic acid for preventing and treating wheat scab. A high-expression secondary metabolite of the medium-scab-resistant wheat variety Lianmai 12 after being infected for 72 hours is obtained through a UPLC-MS / MS test, and the effective component is determined to be p-aminobenzoic acid through test and optimization. The solvent is 0.4% dimethyl sulfoxide, and the solute concentration is 2g / L. The plant source metabolite for preventing and treating wheat scab, provided by the invention, can effectively improve the resistance of wheat to the wheat scab and reduce the disease spikelet rate by being sprayed to wheat ears at the early flowering stage, and the prevention and treatment effect is good; compared with a chemical agent, the plant source metabolite p-aminobenzoic acid is derived from a secondary metabolite of gibberellic-disease-resistant wheat, is more environment-friendly and safer to people and livestock, and has important application value in prevention and treatment of wheat gibberellic disease through p-aminobenzoic acid.

Description

Technical Field

[0005] The invention belongs to the technical field of biological control, and in particular relates to a plant-derived metabolite for preventing and controlling wheat scab. Background Art

[0006] Wheat fusarium head blight is one of the most destructive diseases affecting wheat yield and quality, and is particularly serious in humid and semi-humid areas of temperate and subtropical wheat-producing regions. The disease is mainly caused by Fusarium fungi, which produce mycotoxins such as deoxynivalenol that accumulate in wheat grains, posing a serious threat to human and animal health.

[0007] At present, wheat production still uses traditional chemical control as the main means to prevent fusarium head blight. However, due to the long-term and large-scale use of pesticides to control wheat fusarium head blight, fusarium head blight has developed resistance in some areas. For example, the resistance of fusarium head blight strains to carbendazim in many places in Henan Province is on the rise and spreading. The emergence of pathogen resistance has brought tremendous pressure to the long-term green prevention and control of wheat fusarium head blight. Therefore, the exploration of new and efficient wheat fusarium head blight control agents is not only related to the yield and quality of wheat, but also plays a key role in the sustainable development of agriculture and food safety. Summary of the invention

[0008] The purpose of the present invention is to provide a plant-derived metabolite for preventing and controlling wheat fusarium scab, so as to improve the prevention and control effect of wheat fusarium scab in a more environmentally friendly manner.

[0009] The invention obtains highly expressed secondary metabolites of the moderately resistant wheat variety "Lianmai 12" 72 hours after fusarium infection by UPLC-MS / MS test, and determines the inhibition efficiency of each secondary metabolite on hyphae growth and spore expansion of fusarium pathogen by a method of drug administration and culture in a solid culture medium and a liquid culture medium, and conducts a wheat fusarium prevention and control effect test on wheat fusarium in the field with a secondary metabolite with a stronger inhibition rate.

[0010] A plant-derived metabolite for preventing and treating wheat fusarium head blight, wherein the active ingredient of the plant-derived metabolite is p-aminobenzoic acid.

[0011] Preferably, the solvent of the p-aminobenzoic acid solution is 4‰ dimethyl sulfoxide, and the mass fraction of p-aminobenzoic acid is 2 g / L.

[0012] The method for preparing the plant-derived metabolite for preventing and controlling wheat fusarium head blight comprises dissolving 2 g of p-aminobenzoic acid in 4 mL of dimethyl sulfoxide, adding water to make the volume to 1 L after the solution is fully dissolved, and obtaining a p-aminobenzoic acid solution with a mass fraction of 2 g / L.

[0013] The method for applying the plant-derived metabolites for preventing and controlling wheat fusarium head blight comprises spraying p-aminobenzoic acid uniformly on the wheat ears for two consecutive days at the early stage of wheat flowering.

[0014] Compared with the prior art, the present invention has the following excellent effects: the plant-derived metabolites for preventing and controlling wheat fusarium rust provided by the present invention have good prevention and control effects on wheat fusarium rust, can significantly inhibit the hyphae growth and spore propagation of fusarium rust pathogens, reduce the diseased spikelet rate of susceptible wheat ears, and improve the disease resistance of wheat to fusarium rust. The preparation is simple and environmentally friendly, and is of great significance for the prevention and control of wheat fusarium rust. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It shows the inhibitory effect of different concentrations of p-aminobenzoic acid solution on the mycelial growth of Fusarium fusarium pathogen.

[0016] Figure 2 It shows the inhibitory effect of different concentrations of p-aminobenzoic acid solution on the spore proliferation of Fusarium fusarium pathogen.

[0017] Figure 3 The control effect of p-aminobenzoic acid on wheat fusarium head blight in the field environment. (A) Effect on the diseased spikelet rate of wheat varieties "Lianmai 7", "Huai Mai 33" and "Zhou Mai 18" that are highly susceptible to fusarium head blight, "Huai Mai 20" that are moderately susceptible to fusarium head blight, and "Lianmai 12" that are moderately resistant to fusarium head blight; (B) Control effect on wheat varieties "Lianmai 7" and "Huai Mai 33" that are highly susceptible to fusarium head blight. DETAILED DESCRIPTION

[0018] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but the implementation of the present invention is not limited thereto.

[0019] Example 1 UPLC-MS / MS analysis of the metabolome of “Lianmai 12” in response to scab

[0020] The wheat variety "Lianmai 12" with medium resistance to ergot was inoculated with 10 μL of spore solution at the early stage of flowering, and the control group was inoculated with the same amount of sterile water as a simulated inoculation. Each group had 10 spikelets, with 3 replicates. The spikelets were harvested at the same time after 72 hours, and the spikelet samples were frozen with liquid nitrogen and stored at -80°C.

[0021] The inoculated spikelets were freeze-dried and ground into powder. 0.1 g of spikelet powder was injected into 1.2 mL of pre-cooled 70% methanol solution for metabolite extraction; the dissolved sample was placed at 4°C for 12 h, vortexed 6 times during the period; centrifuged at 12000 rpm for 10 min, and the supernatant was collected and filtered with a microporous membrane filter (pore size 0.22 μm).

[0022] Ultra-high performance liquid chromatography was performed using a Shimadzu Nexera X2 system and an Agilent SB-C18 column. The column temperature was 40°C and the flow rate was 0.35 mL / min. The mobile phase included phase A (0.1% formic acid dissolved in ultrapure water) and phase B (0.1% formic acid dissolved in acetonitrile). The elution gradient was as follows: the initial proportion of phase B was 5%, which increased linearly to 95% within 9 minutes and was maintained at 95% for 1 minute. At 10-11.1 minutes, the proportion of phase B dropped to 5%, and the equilibrium was maintained under this condition for 14 minutes. Tandem mass spectrometry analysis was performed using a Biosystems 4500QTRAP. The electrospray ionization temperature was 550°C and the ion spray voltage was 5500 V (positive ion mode) / -4500 V (negative ion mode). Metabolites were quantified using the multiple reaction monitoring mode of a triple quadrupole mass spectrometer. The highly expressed metabolites in the ear after 12-72 hours of infection of fusarium head blight spores are shown in Table 1.

[0023] Table 1

[0024]

[0025] It can be seen that compared with the control group inoculated with sterile water, there are 12 metabolites with a difference of more than 3 and annotated with CAS numbers after inoculation with Fusarium spores.

[0026] Example 2 Inhibitory effect of p-aminobenzoic acid on hyphae growth of fusarium scurf pathogen

[0027] Add p-aminobenzoic acid at concentrations of 0.1 mg / mL, 0.2 mg / mL, 0.4 mg / mL, and 0.8 mg / mL to potato dextrose agar medium, respectively, and the solvent is 4‰ dimethyl sulfoxide to make solid plates. Blank potato dextrose agar medium and medium with only solvent added were used as controls. Use a 5 mm diameter circular puncher to obtain pathogenic bacteria blocks from the growing edge of a colony plate, and then inoculate 5 mm diameter bacteria blocks into the corresponding culture medium, and the experiment is repeated 3 times. The culture dish was cultured in the dark at 25 ° C for 3 days. The colony diameter was measured every day, and the mycelial growth inhibition rate was calculated.

[0028] The results are as follows Figure 1 shown.

[0029] It can be seen that there is no significant difference in the mycelial growth inhibition rate between the blank control medium and the solvent control medium (P>0.05), indicating that 4‰ dimethyl sulfoxide as a solvent has no significant effect on mycelial growth. Compared with the two control groups, the medium with p-aminobenzoic acid significantly inhibited the growth of mycelial growth of the Fusarium fusogen (P<0.001). At the same time, the concentration of p-aminobenzoic acid was positively correlated with the inhibition rate of mycelial growth of the pathogen. The inhibition rates of different Fusarium fusogen strains at 0.4 mg / mL and 0.8 mg / mL were 25.4%-31.4% and 42.87%-52.48%, respectively, indicating that p-aminobenzoic acid can significantly inhibit the mycelial growth of Fusarium fusogen.

[0030] Example 3 Inhibitory Effect of p-Aminobenzoic Acid on Spore Proliferation of Fusarium Scab Pathogen

[0031] Prepare 200mL of 6% mung bean soup liquid culture medium with concentrations of 0.1mg / mL, 0.2mg / mL, 0.4mg / mL, and 0.8mg / mL p-aminobenzoic acid, and inoculate the mung bean soup liquid culture medium with the same amount of sterile water or solvent as the control group. Inoculate the same amount of Fusarium mycelium blocks respectively, and set up 3 groups of replicates for the experiment. After shaking and culturing at 200rpm and 25℃ for 2 days, measure the spore concentration with a hemocytometer.

[0032] The results are as follows Figure 2 shown.

[0033] It can be seen that with the increase of the concentration of p-aminobenzoic acid, the concentration of conidia of the Fusarium fusarium pathogen decreased significantly, indicating that p-aminobenzoic acid can inhibit the production of conidia of the pathogen.

[0034] Example 4: The control effect of p-aminobenzoic acid on wheat scab in the field

[0035] The wheat varieties with high susceptibility to ergot disease, “Lianmai 7”, “Huaimai 33”, and “Zhoumai 18”, the wheat variety with moderate ergot disease, “Huaimai 20”, and the wheat variety with moderate ergot disease resistance, “Lianmai 12” were used as test objects. At the early stage of flowering, 10 ears of similar size were selected, and each ear was treated with 10 μL of 1×10 5 / mL conidia suspension was inoculated on the middle floret, with 3 replicates. The inoculated wheat ears were kept moisturized in plastic bags for 3 days, sprayed with 2g / L p-aminobenzoic acid for the first time, and then sprayed with the same concentration of p-aminobenzoic acid again the next day. The wheat in the control group was sprayed with sterile water or solvent. The diseased spikelet rate on the inoculated ears was recorded 21 days after inoculation.

[0036] The results are as follows Figure 3 shown.

[0037] Figure 3A shows that the diseased spikelet rate of wheat sprayed with p-aminobenzoic acid was significantly lower than that of the blank control sprayed with water or the solvent control group sprayed with solvent (P<0.05), and the diseased spikelet rate of each variety of wheat was reduced by 30.67% to 57.99% and 29.54% to 55.89% compared with the blank control and solvent control, respectively. This shows that p-aminobenzoic acid can significantly improve the resistance of wheat to fusarium head blight in the field environment. Figure 3 B shows that after spraying p-aminobenzoic acid on the highly susceptible wheat varieties "Lianmai No. 7" and "Huaimai 33", only the spikelets near the pathogen inoculation point were infected, indicating that p-aminobenzoic acid has a good preventive and control effect on wheat ergot in the field environment.

[0038] It can be concluded from Examples 1-4 that p-aminobenzoic acid can show good inhibitory effects on fusarium fusarium pathogens on wheat varieties with different fusarium fusarium resistance both in in vitro culture tests and in field application tests. Therefore, it is believed that p-aminobenzoic acid can improve wheat resistance to fusarium fusarium. The plant-derived metabolite p-aminobenzoic acid proposed for the first time in the present invention has broad application prospects for preventing and controlling wheat fusarium fusarium.

Claims

1. A plant-derived metabolite for preventing and controlling wheat scab, characterized in that: The active ingredient of the plant-derived metabolite is p-aminobenzoic acid.

2. The para-aminobenzoic acid for preventing and treating wheat scab according to claim 1, characterized in that: The solvent of the p-aminobenzoic acid solution is 4‰ dimethyl sulfoxide, and the mass fraction of p-aminobenzoic acid is 2g / L.

3. The method for preparing p-aminobenzoic acid for preventing and treating wheat scab according to claims 1 and 2, characterized in that: Dissolve 2 g of p-aminobenzoic acid in 4 mL of dimethyl sulfoxide. After fully dissolved, add water to make the volume to 1 L to obtain a p-aminobenzoic acid solution with a mass fraction of 2 g / L.

4. The method for applying the plant-derived metabolites for preventing and controlling wheat scab according to claims 1 and 2, characterized in that: At the beginning of wheat flowering, spray p-aminobenzoic acid evenly on the wheat ears for two consecutive days.

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