Salt-tolerant bacillus zanthoxyli and application thereof

Abstract

The invention discloses salt-tolerant bacillus zanthoxyli and application thereof, and belongs to the technical field of microorganisms. The preservation number of the bacillus zanthoxyli RX10 is CCTCC M 20242733, and the bacillus zanthoxyli RX10 integrates multiple functions of salt resistance, growth promotion, nitrogen fixation, phosphorus dissolution, potassium dissolution, siderophore production, indoleacetic acid production, grape powdery mildew prevention and control, soil improvement and the like, is a multifunctional plant endophyte, and has important significance on growth promotion, disease prevention and soil improvement of plants under soil salinization conditions.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, and in particular to a salt-tolerant Zanthoxylum bungeanum strain and application thereof. Background Art

[0002] Soil salinization is the process in which soluble salts accumulate in the soil, causing the soil properties to deteriorate and the quality to decline. Soil salinization has seriously affected agricultural development. When crops are subjected to salt stress, the osmotic pressure and ion homeostasis in the plant body are unbalanced, resulting in the obstruction of plant photosynthesis, slow growth and development, metabolic disorders, and ultimately resulting in reduced crop yields, reduced quality, increased risk of pests and diseases, and even death.

[0003] Plant endophytes refer to a class of microorganisms that live in various tissues or organs of healthy plants for a certain stage or all stages of their life cycle without causing obvious plant diseases. Plant endophytes can improve the osmotic balance and ion toxicity of plant tissues from the aspects of plant antioxidant system, osmotic regulation, mineral element absorption and photosynthesis, thereby alleviating the damage of saline-alkali stress to plants. However, the actual efficacy of microbial agents is affected by many variables, especially environmental variables, including temperature, humidity, pH and soil texture. These variable factors not only pose challenges to the survival and proliferation of strains, but also may interfere with the interaction between strains and plants. In salinized soils, high-salt environments are extreme conditions for most microorganisms, and only a very small number of microorganisms can adapt. Therefore, it is very difficult to screen out microbial strains that can adapt to the salinized soil environment and can normally perform growth-promoting and disease-resistant functions under salt stress conditions. Summary of the invention

[0004] In view of the above prior art, the purpose of the present invention is to provide a salt-tolerant Bacillus zanthoxylum and its application. The present invention isolates a Bacillus zanthoxylum RX10 from young grape fruits, which can promote plant growth, improve plant photosynthesis, reduce plant disease occurrence, and improve plant stress resistance under salt stress.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides a strain of Bacillus zanthoxyli RX10, which has been deposited in the China Center for Type Culture Collection (CCTC) on December 5, 2024, and the deposit address is: Wuhan University, Bayi Road, Wuchang District, Wuhan City, Hubei Province; its deposit number is: CCTCC M 20242733.

[0007] Compared with the Bacillus zanthoxyli reported previously, the Bacillus zanthoxyli RX10 of the present invention has the following characteristics:

[0008] (1) It is a multifunctional plant endophyte that integrates multiple functions such as salt tolerance, growth promotion, nitrogen fixation, phosphate solubilization, potassium solubilization, iron carrier production, indoleacetic acid production, prevention and control of grape powdery mildew and soil improvement. It is of great significance for plant growth promotion, disease prevention and soil improvement under soil salinization conditions.

[0009] (2) The strain of the present invention is derived from young Cabernet Sauvignon grapes, is non-pathogenic to humans and animals, and is safe to use.

[0010] The second aspect of the present invention provides a bacterial agent, wherein the bacterial agent contains the above-mentioned Bacillus zanthoxyli RX10.

[0011] Preferably, in the bacterial agent, Bacillus zanthoxyli RX10 exists in the form of cultured live bacteria, bacterial suspension or fermentation liquid.

[0012] Furthermore, the bacterial suspension is prepared by the following method:

[0013] Bacillus zanthoxyli RX10 was inoculated into LB liquid culture medium, cultured in a constant temperature shaking incubator at 37° C. and 180 rpm for 24 h, centrifuged, the bacteria were collected, and resuspended in sterile distilled water to prepare a bacterial suspension.

[0014] The third aspect of the present invention provides the use of the above-mentioned Bacillus zanthoxyli RX10 or bacterial agent in at least one of the following (1)-(3):

[0015] (1) Improve the photosynthetic capacity of plants in salt stress environments;

[0016] (2) Promote plant growth under salt stress conditions;

[0017] (3) Improve soil enzyme activity under salt stress conditions.

[0018] In the above application, preferably, the plant is grape or corn.

[0019] In the above application, the soil enzyme is one or more of sucrase, urease, FDA hydrolase, alkaline phosphatase and neutral protease.

[0020] The fourth aspect of the present invention provides the use of the above-mentioned Bacillus zanthoxyli RX10 or bacterial agent in the following (1) or (2):

[0021] (1) Prevent and control grape powdery mildew;

[0022] (2) Preparation of a drug for preventing and treating grape powdery mildew.

[0023] Beneficial effects of the present invention:

[0024] (1) The Bacillus zanthoxyli RX10 of the present invention has excellent salt tolerance and can fix nitrogen, dissolve phosphorus, dissolve potassium, produce siderophores and produce indoleacetic acid.

[0025] (2) The Bacillus zanthoxyli RX10 of the present invention can improve the photosynthesis of plants in a salt stress environment and promote plant growth.

[0026] (3) The Bacillus zanthoxyli RX10 of the present invention can improve the activities of soil sucrase, urease, FDA hydrolase, alkaline phosphatase and neutral protease under salt stress conditions, and has the effect of improving soil.

[0027] (4) The Bacillus zanthoxyli RX10 of the present invention can also effectively prevent and treat grape powdery mildew. In particular, under saline-alkali stress conditions, the disease caused by grape powdery mildew can be aggravated. However, the Bacillus zanthoxyli RX10 of the present invention can still play the role of preventing and treating grape powdery mildew under salt stress conditions.

[0028] (5) The Bacillus zanthoxyli RX10 of the present invention is a plant endophyte derived from young Cabernet Sauvignon grapes. It does not cause any harm to plants, can coexist well with various crops, is non-pathogenic to humans and animals, and is highly safe to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a colony diagram of the RX10 strain of the present invention on LB solid culture medium.

[0030] Figure 2 It is the Gram staining picture of the RX10 strain of the present invention.

[0031] Figure 3 The phylogenetic tree constructed.

[0032] Figure 4 This is the colony picture of Bacillus zanthoxylum RX10 after being cultured in combined nitrogen fixation medium for one day.

[0033] Figure 5 This is the colony picture of Bacillus zanthoxylum RX10 after being cultured in silicate medium for one day.

[0034] Figure 6 This is a picture of the colonies of Bacillus zanthoxylum RX10 after being cultured in inorganic phosphate medium for 4 days.

[0035] Figure 7 This is a picture of the colonies of Bacillus zanthoxylum RX10 after being cultured in CAS detection medium for 4 days.

[0036] Figure 8 This is the color development of Bacillus zanthoxylum RX10 under the Salksowski colorimetric method.

[0037] Fig. 9 This is the quantitative determination result of IAA production by Bacillus zanthoxylum RX10.

[0038] Fig.10 This is a graph showing the growth characteristics of the grape seedling potted plant experiment in Experimental Example 1.

[0039] Fig.11 This is the result diagram of the photosynthetic capacity of the grape seedling potted experiment in Experimental Example 1.

[0040] Fig.12 This is a graph showing the results of measuring the active oxygen scavenging system in the grape seedling potted plant experiment in Experimental Example 1.

[0041] Fig.13 This is the result of soil enzyme determination in the grape seedling pot experiment in Experimental Example 1.

[0042] Fig.14 This is the result of the corn seedling pot experiment in Experimental Example 2.

[0043] Fig.15 This is a diagram showing the antagonistic effect of Test Example 3 on grape powdery mildew. DETAILED DESCRIPTION

[0044] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0045] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with specific embodiments. If the specific experimental conditions are not specified in the embodiments, they are usually in accordance with conventional conditions or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following embodiments, unless otherwise specified, can be obtained through commercial channels. Among them:

[0046] M9 glucose medium: 1 g ammonium chloride, 0.13 g magnesium sulfate, 3 g potassium dihydrogen phosphate, 6 g disodium hydrogen phosphate, and 0.338 g glucose are dissolved in 1 L distilled water and sterilized at 115°C for 20 min.

[0047] Example 1: Isolation and purification of strains

[0048] The surface attachments of Cabernet Sauvignon grapes from the Cabernet Sauvignon grape experimental field (116.16'N, 36.17'E) of the Horticultural Experiment Station of Shandong Agricultural University were washed with running water, and 1g of grape samples were weighed, disinfected with 75% alcohol for 30s, washed with sterile distilled water for 3-5 times, placed in 0.1% mercuric chloride solution for 1min, and washed with sterile distilled water for 5 times. The sterilized and cleaned Cabernet Sauvignon grapes were placed in a high-temperature sterilized mortar, and an appropriate amount of sterilized quartz sand and 9mL sterile water were added to grind the plant samples. After grinding, the samples were allowed to stand for 30min, and then 100μL of the supernatant was spread on M9 glucose medium and cultured at 28℃.

[0049] Single colonies with different morphological characteristics were selected for purification, and the salt tolerance of the purified strains was tested using LB culture medium containing different NaCl concentrations. The strain with the best salt tolerance (which could still grow on LB culture medium with a NaCl concentration of 10%) was selected, named RX10, and stored in glycerol tubes.

[0050] Example 2: Identification of strains

[0051] 1. Morphological, physiological and biochemical identification of strains:

[0052] The colony morphology of strain RX10 on LB solid plate is round, milky white, opaque, with rough and convex surface, sticky texture, and no halo ( Figure 1 ).

[0053] Take the stable phase strain RX10 for Gram staining, which is purple ( Figure 2 ), proving that it is a Gram-positive bacterium. The morphology is rod-shaped under an optical microscope. The growth temperature of strain RX10 is 23-37°C, the pH range is 4-9, the optimal growth temperature is 37°C, and the optimal pH is 7.

[0054] 2. 16S rDNA identification of strains:

[0055] The three-zone line method was used to pick single colonies on the plate and activate them in LB medium, and then the bacterial solution was sent to Shanghai Biotech Sequencing Company for sequencing. After sequencing, the sequencing results were submitted to NCBI (https: / / www.ncbi.nlm.nih.gov / ) for BLAST sequence comparison. The 16S rRNA sequences of strains of similar species to the sequence were obtained from GenBank, and 6-8 sequences with more than 98% homology were selected. The phylogenetic tree was constructed using the neighbor-joining method using the software MEGA64. Phylogenetic analysis was performed and it was found that the strain had the highest sequence similarity with Bacillus zanthoxyli ( Figure 3 ).

[0056] Combined with the results of morphological, physiological and biochemical identification and 16S rDNA identification of the strain, strain RX10 was identified as Bacillus zanthoxyli and a biological deposit was made under the patent procedure. The deposit information is as follows:

[0057] Reference biological material (strain): RX10;

[0058] Suggested taxonomic name: Bacillus zanthoxyli;

[0059] Accession number: CCTCC M 20242733.

[0060] Example 3: Study on the growth-promoting performance of Bacillus zanthoxylum RX10

[0061] 1. Test method:

[0062] The purified RX10 single colony was inoculated into LB liquid medium and cultured under shaking conditions of 37°C and 180rpm for 24-48h for activation and then the growth-promoting ability was determined. The main growth-promoting indicators measured include: nitrogen fixation ability, potassium solubilization ability, phosphorus solubilization ability, iron carrier production ability, and IAA production ability.

[0063] Method for determining the nitrogen fixation, potassium solubilization, phosphate solubilization and iron carrier production abilities of the strain: Activate the RX10 strain on LB solid culture medium, pick a single colony and inoculate it into the purchased culture medium for observation.

[0064] Nitrogen fixation ability assay (combined nitrogen-fixing bacteria culture medium, product number HB8541), potassium solubilization ability assay (silicate bacteria culture medium, product number HB8548-1), phosphorus solubilization ability assay (inorganic phosphorus bacteria culture medium, product number HB8549-2), and iron carrier production ability assay (CAS detection culture medium, product number HB9132); all were purchased from Qingdao Haibo Biotechnology Co., Ltd.

[0065] Method for determining IAA production capacity:

[0066] (1) Qualitative determination:

[0067] The isolated and purified RX10 strain was inoculated into a medium containing 200 mg L-tryptophan. -1 LB liquid medium was cultured in a shaker at 28°C and 180 rpm. After 4 days, the bacterial solution was taken out and thoroughly mixed with Salksowski colorimetric solution at a ratio of 1:2. At the same time, a positive control was set up, i.e., 50 mg·L -1 IAA is added to the Salksowski colorimetric solution. After 30 minutes of color development at room temperature in the dark, observe. If pink appears, it means that IAA is produced.

[0068] (2) Quantitative determination:

[0069] The IAA yield was determined by UV spectrophotometry. First, draw an IAA standard curve: add 2 mL of IAA series concentration standard solution to each test tube, number them, then add 8 mL of Salksowski colorimetric solution, color for 30 minutes in the dark, and measure the OD with a spectrophotometer. 530 Then, the concentration of IAA standard solution was used as the horizontal axis and the OD 530 The standard curve is drawn with y as the vertical axis.

[0070] Then, samples were taken every 12 hours, and the bacterial solution was centrifuged at 10,000 rpm for 10 minutes. The supernatant was added with the same volume of Salkowski colorimetric solution, and placed in the dark for 30 minutes for color development, and its absorbance at a wavelength of 530 nm was measured.

[0071] 2. Test results:

[0072] The results of the nitrogen fixation ability test of strain RX10 are as follows Figure 4 As shown in Figure 1, the strain RX10 of the present invention can grow well on the combined nitrogen fixation medium (commercially available medium) and has a good nitrogen fixation effect. Figure 5 As shown, strain RX10 was inoculated in silicate-dissolving medium (commercially available medium), and the colony morphology was transparent oil droplets, indicating that the strain RX10 of the present invention has a good potassium-dissolving effect. Figure 6 As shown in the figure, the strain of the present invention can grow on the inorganic phosphorus dissolving medium, and there is an obvious phosphorus dissolving circle around the colony, which has a good phosphorus dissolving effect. Figure 7 As shown, strain RX10 can grow on CAS detection medium, and there is an obvious orange ring around the colony, which has the ability to produce siderophores.

[0073] The present invention also uses the Salksowski colorimetric method to qualitatively determine the IAA production capacity of strain RX10, using LB liquid medium containing 200 mg / L L-tryptophan without inoculation as a blank control and IAA as a positive control. The results are as follows: Figure 8 As shown, the solution was pink, proving that the strain had the ability to produce IAA. Then, the IAA production capacity was quantitatively determined. After 72 hours, the amount of IAA secreted by strain RX10 was about 57.67 mg / L ( Fig. 9 ).

[0074] Example 4: Preparation of Bacillus zanthoxylum RX10 bacterial suspension

[0075] The purified strain RX10 was inoculated into LB liquid medium at a volume fraction of 1%, and cultured in a constant temperature shaking incubator at 37°C and 180 rpm for 24 h. The fermentation broth was transferred to a sterilized centrifuge tube and centrifuged at 10,000 rpm for 10 min at room temperature. The supernatant was then carefully discarded, and the cells were resuspended in sterile distilled water for 3 times. The OD was measured. 600 , adjust the absorbance at 600 nm to 1, and prepare the Bacillus zanthoxylum RX10 bacterial suspension.

[0076] Test Example 1: Growth promotion experiment on Cabernet Sauvignon grape seedlings

[0077] 1. Test method:

[0078] Vermiculite and vineyard soil were mixed in a mass ratio of 1:1 and sterilized to obtain mixed soil. One-year-old Cabernet Sauvignon seedlings were planted in the mixed soil, and when the seedlings grew to 5-6 functional leaves, Cabernet Sauvignon seedlings with the same growth and size were selected for treatment.

[0079] There are 4 treatment groups in the experiment, namely:

[0080] Single inoculation treatment (RX10): 500 mL of clean water was poured into each pot of seedlings once every 5 days; 3 days after pouring clean water, 50 ml of the Bacillus zanthoxylum RX10 bacterial suspension prepared in Example 4 was applied to each pot once a week, for a total of two pourings of bacterial suspension.

[0081] Single salt stress treatment (NaCl): 500 mL of 250 mM NaCl solution was poured into each pot of seedlings once every 5 days; 3 days after pouring the NaCl solution, 50 ml of clean water was applied to each pot once a week, for a total of two pours.

[0082] Salt stress + bacteria treatment (NaCl + RX10): 500 mL of 250 mM NaCl solution was poured into each pot of seedlings once every 5 days; 3 days after pouring the NaCl solution, 50 ml of the Zanthoxylum bungeanum RX10 bacterial suspension prepared in Example 4 was applied to each pot once a week for a total of two pours.

[0083] Control treatment (CK): 500 mL of clean water was poured into each pot of seedlings once every 5 days; 3 days after pouring clean water, 50 ml of clean water was added to each pot once a week, for a total of two pourings.

[0084] Pour 50 mL of clean water into each pot of seedlings once a week, for a total of two times.

[0085] Each treatment group had 14 biological replicates and was treated for 28 days.

[0086] Sampling was taken to measure various indicators, including: plant height, stem diameter, root length, aboveground fresh weight, root fresh weight, aboveground dry weight, root dry weight, net photosynthetic rate, stomatal conductivity, intercellular CO2 concentration, transpiration rate, water use efficiency, chlorophyll a content, chlorophyll b content, total chlorophyll content, carotenoid content, MDA content, hydrogen peroxide content, superoxide anion content, ascorbate peroxidase activity, peroxidase activity, superoxide dismutase activity, and reduced glutathione content.

[0087] In addition, the sucrase activity, urease activity, catalase activity, FDA hydrolase activity, alkaline phosphatase, neutral protease activity, soil organic carbon content, soil organic matter content, soil available potassium content, soil available phosphorus content, soil alkaline nitrogen content, soil total potassium content and soil total phosphorus content of the treated soil were determined.

[0088] The determination methods of the above-mentioned indicators are all methods recorded in the prior art, or are detected using existing instruments or kits; for example: photosynthetic indicators are determined using a portable photosynthetic instrument TARGAS-1; hydrogen peroxide content (item number: G0168F), superoxide anion content (item number: G0129F), ascorbic acid peroxidase activity (item number: G0203F), peroxidase activity (item number: G0107F), superoxide dismutase activity (item number: G0103F), reduced glutathione content (item number: G0206F), sucrase activity (item number: G0302F), urease activity (item number: G0301F), Catalase activity (Cat. No.: G0303F), FDA hydrolase activity (Cat. No.: G0322F), alkaline phosphatase (Cat. No.: G0305F), and neutral protease activity (Cat. No.: G0315F) can be detected using the corresponding kits purchased from Suzhou Grace Biotechnology Co., Ltd.; soil organic matter content (potassium dichromate volumetric method-dilution heat method), soil available potassium content (flame photometry), soil effective phosphorus content (molybdenum-antimony-anticolorimetric method), soil alkaline nitrogen content (alkaline diffusion method), soil total potassium content (flame photometry), soil total phosphorus content (molybdenum-antimony-anticolorimetric method); the specific determination methods will not be described in detail here.

[0089] 2. Test results:

[0090] like Fig.10 As shown in the figure, under salt stress conditions, the biomass (fresh weight, dry weight, plant height, stem diameter, and root length) of Cabernet Sauvignon seedlings inoculated with Bacillus zanthoxyli suspension was significantly increased compared with Cabernet Sauvignon seedlings that were not inoculated. At the same time, the strain can significantly improve the photosynthesis of Cabernet Sauvignon seedlings ( Fig.11 ) and active oxygen scavenging system ( Fig.12 In addition, the inoculation of the strain significantly improved the soil environment under salt stress conditions ( Fig.13 ).

[0091] Test Example 2: Experiment on promoting growth of corn seedlings

[0092] 1. Test method:

[0093] Vermiculite and corn field soil were mixed in a mass ratio of 1:1 and then sterilized to obtain mixed soil. Corn seedlings were planted in the mixed soil, and when the seedlings grew to two leaves and one heart, corn seedlings with the same growth and size were selected for treatment.

[0094] There are 4 treatment groups in the experiment, namely:

[0095] Single inoculation treatment (RX10): At the beginning, the soil was irrigated with clean water. After 3 days, each pot of seedlings was irrigated with 20 mL of the Bacillus zanthoxylum RX10 suspension prepared in Example 4. The soil was irrigated once a week for a total of three times.

[0096] Single salt stress treatment (NaCl): At the beginning, the soil was irrigated with the same amount of NaCl solution (250 mM) as that of the single inoculum treatment. After 3 days, each pot of seedlings was watered with 20 mL of clean water once a week for a total of three times.

[0097] Salt stress + bacteria treatment (NaCl + RX10): At the beginning, the soil was irrigated with an equal amount of NaCl solution (250 mM) as in the single inoculation treatment. After 3 days, each pot of seedlings was irrigated with 20 mL of the Bacillus zanthoxylum RX10 bacterial suspension prepared in Example 4. The soil was irrigated once a week for a total of three times.

[0098] Control treatment (CK): At the beginning, the soil was irrigated with the same amount of clean water as that of the single inoculation treatment. After 3 days, each pot of seedlings was irrigated with 20 mL of clean water, once a week, for a total of three times.

[0099] Eight biological replicates were set for each treatment. Samples were taken on the 27th day after treatment to measure various indicators, including plant height, stem diameter, aboveground fresh weight, underground fresh weight, root length, dry weight, chlorophyll a content, chlorophyll b content, total chlorophyll content, and carotenoid content.

[0100] 2. Test results:

[0101] like Fig.14 As shown in the figure, the biomass (total fresh weight, fresh weight of aboveground part, fresh weight of underground part, dry weight, plant height, root length) of corn seedlings inoculated with Bacillus zanthoxyli suspension under salt stress conditions was significantly increased compared with corn seedlings without bacteria. In addition, inoculation of the strain significantly increased the content of photosynthetic pigments in corn seedlings under salt stress conditions.

[0102] Test Example 3: Antagonism experiment against grape powdery mildew

[0103] 1. Test method:

[0104] Vermiculite and vineyard soil were mixed in a mass ratio of 1:1 and sterilized to obtain mixed soil. One-year-old Cabernet Sauvignon seedlings were planted in the mixed soil, and when the seedlings grew to 5-6 functional leaves, Cabernet Sauvignon seedlings with the same growth and size were selected for treatment.

[0105] Preparation of powdery mildew pathogen spore suspension: The pathogen of grape powdery mildew is Uncinaria officinalis. Grape leaves infected with powdery mildew were collected, and the powdery mildew spores were gently brushed into sterilized water. After mixing, the spore suspension was obtained. The spore concentration in the suspension was adjusted to ≥3×10 6 / mL, set aside.

[0106] There are 4 treatment groups in the experiment, namely:

[0107] Pathogen + bacterial agent treatment (powdery mildew + RX10): 500 mL of clean water was poured into each pot of seedlings, and 20 mL of powdery mildew pathogen spore suspension was sprayed on the front and back sides of the grape leaves. After 3 days, 50 mL of the Zanthoxylum RX10 bacterial suspension prepared in Example 4 was applied to each pot.

[0108] Salt stress + pathogen treatment (NaCl + powdery mildew): 500 mL of 250 mM NaCl solution was applied to each pot of seedlings, and 20 mL of powdery mildew pathogen spore suspension was sprayed on the front and back of the grape leaves. After 3 days, 50 ml of clean water was applied to each pot.

[0109] Salt stress + pathogen + bacterial agent treatment (NaCl + powdery mildew + RX10): 500 mL of 250 mM salt NaCl solution was applied to each pot of seedlings, and 20 mL of powdery mildew pathogen spore suspension was sprayed on the front and back of the grape leaves. After 3 days, 50 ml of the Bacillus zanthoxylum RX10 bacterial suspension prepared in Example 4 was applied to each pot.

[0110] Control treatment (CK+pathogen): 500 mL of clean water was poured into each pot of seedlings, and 20 mL of powdery mildew pathogen spore suspension was sprayed on the front and back sides of the grape leaves. After 3 days, 50 mL of clean water was applied to each pot.

[0111] Fourteen biological replicates were set up for each treatment group to observe the growth and resistance to powdery mildew of the plants in each treatment group.

[0112] 2. Test results:

[0113] The results are as follows Fig.15 As shown in the figure, under the condition of pathogen stress, the Cabernet Sauvignon seedlings inoculated with the suspension of Bacillus zanthoxylum RX10 had a significantly higher plant height than the uninoculated Cabernet Sauvignon seedlings, and the stress of powdery mildew was reduced. In addition, under the condition of salt stress, the damage of powdery mildew pathogens to Cabernet Sauvignon seedlings increased, but under the dual stress of salt stress + pathogen stress, the inoculation of the suspension of Bacillus zanthoxylum RX10 could still significantly reduce the stress of powdery mildew, and the plant height also increased significantly. The above results show that Bacillus zanthoxylum RX10 can improve the resistance of plants to powdery mildew under salt stress.

[0114] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A strain of Bacillus zanthoxyli RX10, whose deposit number is: CCTCC M20242733.

2. A bacterial agent, characterized in that The bacterial agent contains the Bacillus zanthoxyli RX10 described in claim 1.

3. The bacterial agent according to claim 2, characterized in that In the bacterial agent, Bacillus zanthoxyli RX10 exists in the form of cultured live bacteria, bacterial suspension or fermentation liquid.

4. The bacterial agent according to claim 3, characterized in that The bacterial suspension is prepared by the following method: Bacillus zanthoxyli RX10 was inoculated into LB liquid culture medium, cultured in a constant temperature shaking incubator at 37° C. and 180 rpm for 24 h, centrifuged, the bacteria were collected, and resuspended in sterile distilled water to prepare a bacterial suspension.

5. Use of the Bacillus zanthoxyli RX10 of claim 1 or the bacterial agent of any one of claims 2 to 4 in at least one of the following (1) to (3): (1) Improve the photosynthetic capacity of plants in salt stress environments; (2) Promote plant growth under salt stress conditions; (3) Improve soil enzyme activity under salt stress conditions.

6. The use according to claim 5, characterized in that: The plant is grape or corn.

7. The use according to claim 5, characterized in that: The soil enzyme is one or more of sucrase, urease, FDA hydrolase, alkaline phosphatase and neutral protease.

8. Use of the Bacillus zanthoxyli RX10 of claim 1 or the bacterial agent of any one of claims 2 to 4 in the following (1) or (2): (1) Prevent and control grape powdery mildew; (2) Preparation of a drug for preventing and treating grape powdery mildew.

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