Salt-tolerant xanthomonas new species R10 and application thereof

Abstract

This invention discloses a novel salt-tolerant fungal strain, *Luteimonas sp.* R10, its prepared microbial agent, and its applications. The strain was isolated from the rhizosphere soil of cotton in saline-alkali land in Xinjiang. The microbial agent was obtained through fermentation. Treatment of wheat seeds with the *Luteimonas sp.* R10 microbial agent provided by this invention significantly improved wheat germination rate, budding rate, plant height, chlorophyll content, and phenylalanine hydrolase activity, increasing these by 26.67%, 21.28%, 41.34%, 98.73%, and 61.48%, respectively, compared to the control. When applied to cotton seed soaking, the cotton germination rate, plant height, and fresh weight increased by 200.00% compared to the control. 、 The concentrations of 31.50% and 9.37% indicate that the microbial inoculant prepared from the salt-tolerant new bacterium Luteimonas sp. R10 provided by this invention has a significant promoting effect on plant growth and early maturity, can increase plant disease resistance, and has good application prospects as a bio-fertilizer.

Description

Technical Field

[0001] This invention belongs to the field of microbial and its preparation application technology, specifically involving the application of salt-tolerant new fungus Luteimonas sp. R10 and its microbial inoculants in plant growth. Background Technology

[0002] Xinjiang is located in an arid and semi-arid region with low rainfall, abundant sunshine, and strong evaporation. Soil salinization is a major factor restricting agricultural development in the region.

[0003] Currently, the main methods for improving saline-alkali soils are physical, chemical, biological, and water-based measures, each with its own applicable scope and conditions. Biological methods, such as exogenous inoculation with salt-tolerant growth-promoting bacteria, are considered relatively effective and environmentally friendly. Salt-tolerant growth-promoting bacteria possess a certain resistance to stress conditions such as salinity, high temperatures, etc., accelerating soil formation, participating in soil nutrient transformation, and alleviating osmotic stress caused by high salt content to some extent, while also scavenging reactive oxygen species. Furthermore, they can effectively improve the resistance of crops to saline-alkali stress and increase the biotransformation rate of soil nutrients. Among salt-tolerant growth-promoting bacteria, some can utilize their own 1-aminocyclopropane-1-carboxyl (ACC) deaminase to decompose ACC in the roots and body of host plants into α-butanone and ammonia, thereby reducing the ethylene content produced by plants under abiotic stress conditions (salt-alkali, drought, heavy metals, and pesticide pollution, etc.), promoting the growth of host plants, and are a class of growth-promoting bacteria with broad application potential. Therefore, inoculating salt-tolerant growth-promoting bacteria that produce ACC deaminase into the plant rhizosphere has the advantages of being pollution-free, fast-acting, and sustainable, and can improve the survival ability of plants under adverse stress. It is therefore widely used in soil improvement, fertilizer efficiency reduction, and biological control. However, the current bottleneck in the development of my country's microbial fertilizer industry is the breeding of highly efficient strains. Given the advantages of microbial agents in promoting drought resistance and plant growth, and the limited number of existing drought-tolerant growth-promoting bacteria, there is an urgent need to screen for more new microbial strains with superior performance. Furthermore, there is a lack of literature and patent records regarding the current technological status of *Gastrodinium luteum* in promoting salt tolerance and plant growth. Summary of the Invention

[0004] Given the advantages of microbial inoculants in promoting salt tolerance and plant growth, and the limited number of existing salt-tolerant bacteria, there is an urgent need to screen for more and better-performing microbial strains. Furthermore, there is a lack of literature and patent records regarding the current state of technology for the application of *Luteimonas* in promoting salt tolerance and plant growth. This invention aims to provide a novel salt-tolerant bacterium, *Luteimonas* sp. R10, its prepared microbial inoculant, and its applications. This invention isolates and screens a novel salt-tolerant bacterium, *Luteimonas* sp. R10, from the rhizosphere soil of cotton in saline-alkali land in Xinjiang. This strain is fermented to obtain a microbial inoculant. Treatment of wheat seeds with the *Luteimonas* sp. R10 microbial inoculant provided by this invention significantly improves the germination rate, scape rate, plant height, chlorophyll content, and phenylpropanoid content of wheat. The activity of amino acid hydrolase was increased by 26.67%, 21.28%, 41.34%, 98.73%, and 61.48% respectively compared with the control. When applied to cotton seed soaking, the germination rate, plant height, and fresh weight of cotton increased by 200.00%, 31.50%, and 9.37% respectively compared with the control. This indicates that the microbial agent prepared by the salt-tolerant new bacterium Luteimonas sp. R10 provided by this invention has a significant promoting effect on plant growth and early maturity, can increase plant disease resistance, and has good application prospects as a bio-fertilizer.

[0005] To achieve the above technical effects, the present invention is implemented through the following technical solution.

[0006] The salt-tolerant bacterium *Luteimonas* sp. R10 provided by this invention was isolated from the rhizosphere soil of cotton in saline-alkali land in Xinjiang. Phylogenetic and morphological analysis of its 16S rRNA sequence confirmed that strain R10 belongs to *Luteimonas* sp. Gene sequencing of this strain and BLAST alignment analysis on the NCBI website showed that the 16S rRNA gene sequence of strain R10 had 96.24%-94.29% homology with the standard type bacterium of this genus. Specifically, it shares similarities with *Luteimonas yindakuii* S-1072. T The highest homology was observed, with a similarity of 96.24%. A phylogenetic tree of 16S rRNA was constructed using sequences with high homology. Strain R10 and Luteimonasyindakuii S-1072 showed similarity. T The strain clustered on one branch with a confidence level of 77%. A series of molecular-level identifications confirmed that strain R10 is a novel Luteimonasp. species, exhibiting typical characteristics of new species.

[0007] The salt-tolerant new bacterium *Luteimonas sp.* R10 provided by this invention has been identified at the molecular level using well-known and recognized strain systems in the art. Combined with morphological identification, physiological and biochemical characteristics, and chemical characteristics, multiphase classification system analysis revealed several differences between *Luteimonas sp.* R10 and the standard type strain with the closest homology in the genus. This confirms that *Luteimonas sp.* R10 is a new species of *Luteimonas sp.*, and it has been named *Luteimonas sp.*. It has been deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 24213, on December 29, 2021.

[0008] The gene sequence of the salt-tolerant new bacterium Luteimonas sp. R10 is shown in SEQ ID NO: 1.

[0009] In this invention, the isolation medium for the salt-tolerant new bacterium Luteimonas sp. R10 is (g / L): peptone 10.0, beef meal 3.0, NaCl 20.0, agar 15.0-20.0, pH 7.3±0.1.

[0010] In this invention, the purification medium for the salt-tolerant new bacterium Luteimonas sp. R10 is (g / L): peptone 10.0, beef meal 3.0, NaCl 20.0, pH 7.2±0.2.

[0011] This invention provides a Luteimonas sp. R10 microbial inoculant, which is prepared by fermentation of the salt-tolerant new bacterium Luteimonas sp. R10.

[0012] Meanwhile, this invention provides a method for preparing a Luteimonas sp. R10 microbial inoculant, specifically including the following steps: a single colony of Luteimonas sp. R10 is inoculated into NB liquid fermentation medium and cultured at 30°C and 180 rpm for 18 h to obtain a seed culture; the seed culture is inoculated into NB liquid fermentation medium containing 2% NaCl at a volume ratio of 1:100 and fermented at 30°C and 200 rpm for 24 h to obtain a Luteimonas sp. R10 microbial inoculant.

[0013] The viable count of the above-mentioned Luteimonas sp. R10 microbial inoculant reached 8.6 × 10⁶. 9CFU / mL.

[0014] Furthermore, this invention provides an application of Luteimonas sp. R10 in promoting plant salt tolerance and growth, which can significantly enhance the salt tolerance of plants while promoting plant growth, and has broad development and application prospects in plant growth promotion.

[0015] Meanwhile, this invention provides an application of Luteimonas sp. R10 microbial inoculant in plant drought resistance and growth promotion, which significantly enhances plant drought resistance while promoting plant growth, and has broad development and application prospects in plant growth promotion.

[0016] Through the above technical solutions, the present invention achieves the following technical effects:

[0017] (1) This invention provides a salt-tolerant Luteimonas sp. R10. After molecular-level identification using well-known and recognized strain systems in the field, combined with morphological identification, physiological and biochemical characteristics, chemical characteristics and other multi-phase classification system identification and analysis, strain Luteimonas sp. R10 has several differences from the standard type strain of the genus with the closest homology. It is confirmed to be a new strain of Luteimonas sp., and it is confirmed that the strain number R10 obtained in the Luteimonas sp. category is a typical new strain. Therefore, it is necessary to preserve it in accordance with legal requirements.

[0018] (2) In the salt-alkali stress test, wheat treated with the Luteimonas sp. R10 microbial agent provided by the present invention showed that, compared with the control group, the germination rate of wheat increased by 26.67%, the grafting rate increased by 15%, the fresh weight increased by 21.28%, the plant height increased by 41.34%, the chlorophyll content of wheat increased by 98.73%, and the phenylalanine ammonia-lyase (PAL) activity increased by 61.48%. This indicates that the new salt-tolerant Luteimonas sp. R10 microbial agent provided by the present invention has a significant promoting effect on the early maturity and growth of wheat, and has broad development and application prospects in agricultural bio-fertilizers.

[0019] (3) In the salt-alkali stress test, cotton treated with the Luteimonas sp. R10 microbial agent provided by the present invention showed that, compared with the control group, the germination rate of cotton increased by 200%, the plant height increased by 31.50%, and the fresh weight increased by 9.37%, indicating that the Luteimonas sp. R10 microbial agent provided by the present invention has a significant promoting effect on cotton growth and has broad development and application prospects in agricultural bio-fertilizers. Attached Figure Description

[0020] Figure 1 The diagram shown is a phylogenetic tree based on the 16S rRNA gene sequence of the salt-tolerant new bacterium Luteimonas sp. R10CGMCC No.24213.

[0021] Figure 2 The image shows colony and cell images of the salt-tolerant new bacterium Luteimonas sp. R10CGMCC No.24213. In the image, A is a colony image and B is a cell image.

[0022] Figure 3 The figure shows the effect of seed soaking with salt-tolerant new fungus Luteimonas sp. R10 microbial agent on wheat growth.

[0023] Figure 4 The image shows the effect of salt-tolerant Luteimonas sp. R10 microbial inoculant on wheat chlorophyll content.

[0024] Figure 5 The image shows the effect of salt-tolerant Luteimonas sp. R10 microbial inoculant on the activity of phenylalanine ammonia-lyase in wheat plants.

[0025] Figure 6 The image shows the effect of salt-tolerant Luteimonas sp. R10 microbial inoculant on cotton growth in saline-alkali soil. Detailed Implementation

[0026] The present invention will now be illustrated with examples; however, the present invention is not limited to the examples described below. All raw and auxiliary materials used in the present invention, as well as the selected microbial culture methods, are well known in the art. All percentages mentioned in the present invention are volume percentages unless otherwise specified.

[0027] DF medium (g / L): KH₂PO₄ 4.0, Na₂HPO₄ 6.0, MgSO₄·7H₂O 0.2, glucose 2, sodium gluconate 2, citric acid 2, (NH₄)₂SO₄ 2.0, 0.1 mL each of component one and component two trace element solutions. Add samples one by one, dissolve thoroughly, and autoclave at 121℃ for 20 min. Trace element solutions: Component one: H₃BO₃ 10 mg, MnSO₄·H₂O 11.19 mg, ZnSO₄·7H₂O 124.6 mg, CuSO₄·5H₂O 78.22 mg, MoO₃ 10 mg, dissolved in 100 mL sterile distilled water. Component two: 100 mg FeSO₄·7H₂O dissolved in 100 mL sterile distilled water.

[0028] ADF medium (g / L): KH₂PO₄ 4.0, Na₂HPO₄ 6.0, MgSO₄·7H₂O 0.2, glucose 2, sodium gluconate 2, citric acid 2, ACC (1-aminocyclopropane-1-carboxylate) 3.0 mmol, 0.1 mL each of component one and component two trace element solutions. Add samples one by one, dissolve thoroughly, and autoclave at 121℃ for 20 min. Trace element solutions: Component one: H₃BO₃ 10 mg, MnSO₄·H₂O 11.19 mg, ZnSO₄·7H₂O 124.6 mg, CuSO₄·5H₂O 78.22 mg, MoO₃ 10 mg, dissolved in 100 mL sterile distilled water. Component two: 100 mg FeSO₄·7H₂O dissolved in 100 mL sterile distilled water.

[0029] Example 1: Isolation, purification and identification of Luteimonas sp. R10CGMCC No. 24213

[0030] (I) Separation and purification

[0031] Microorganisms were isolated and purified using a gradient dilution method. 10g of sample was collected from the rhizosphere soil of cotton in saline-alkali land, Xinjiang. 100mL of sterile water was added, along with sterile glass beads. The mixture was shaken at 30℃ and 150rpm for 30min to ensure thorough dispersion. 100μL of the supernatant was then taken and diluted with 900μL of sterile water to a final concentration of 10 μL. -2 -10 -5 Diluents of various concentrations: Take 100 μL of each diluent and spread it on a plate of isolation medium using the conventional spreader method. Incubate at 30℃ for 72 h. After colonies grow on the plate, pick single colonies from the plate for purification culture until no contaminating colonies are found. Isolation medium (g / L): peptone 10.0, beef meal 3.0, NaCl 20.0, agar 15.0-20.0, pH 7.3±0.1. Purification medium (g / L): peptone 10.0, beef meal 3.0, NaCl 20.0, pH 7.2±0.2.

[0032] (II) Identification of 16S rRNA gene

[0033] 1. DNA extraction

[0034] The purified strain R10 was inoculated into a solid culture medium and cultured in a shaker at 30°C for 2 days. The bacterial cells were collected and total genomic DNA was extracted using a DNA extraction kit.

[0035] 2. PCR amplification

[0036] 16S rRNA sequence primers:

[0037] 27F: 5′-AGAGTTTGATCCTGGCTC-3′;

[0038] 1492R: 5′-CGGCTACCTTGTTACGACTT-3′.

[0039] Reaction system and conditions

[0040]

[0041] 3. Sequencing

[0042] The PCR amplification product was sequenced after electrophoresis and purification. The sequence length was 1435 bp, as shown in SEQ ID No: 1. A BLAST homology search was performed using NCBI, and a phylogenetic tree was constructed using the Neighbor-Joining method (1000 replicates) with MEGA 5.0 software, a commonly used tool in this field. The results are shown in the appendix. Figure 1 As shown, the obtained sequences were compared and analyzed on the NCBI website. The results showed that the 16S rRNA gene sequence of strain R10 had 96.24%-94.29% homology with the standard type strain of this genus. Specifically, it shared similarities with Luteimonas yindakuii S-1072. T The highest homology was observed, with a similarity of 96.24%. In the phylogenetic tree constructed based on the 16S rRNA gene sequence, the 16S rRNA sequence of strain R10 was similar to that of LuteimonasyindakuiiS-1072. T The strains clustered on one branch with a confidence level of 77, indicating that strain R10 has a very high support rate as a new species and exhibits excellent stability in the phylogenetic tree. Through a comprehensive judgment of the similarity and homology of the strains, it was confirmed that the obtained Luteimonas sp. R10 belongs to the Luteimonas genus and is a typical new Luteimonas species.

[0043] Example 2: Classification and identification of Luteimonas sp. R10 CGMCC No. 24213

[0044] (I) Colony morphology characteristics

[0045] The strain of *Luteimonas sp.* R10 to be observed was inoculated onto NA medium containing 2% NaCl and incubated at 30°C for 3 days. After the colonies had completely covered the plate, the colony characteristics were observed, recorded, and photographed. Scanning electron micrographs of the colonies were also recorded. The results are shown in the appendix. Figure 2 As shown.

[0046] From the appendix Figure 2 The results showed that when strain R10 was cultured in NA medium containing 2% NaCl at 30°C for 3 days, the colonies were round, opaque, raised, shiny, smooth, and golden yellow.

[0047] Based on the above biological characteristics, strain R10 was identified as Luteimonasp. This strain is deposited at the Budapest Treaty International Collection Unit for Microbial Cultures: China General Microbiological Culture Collection Center (CGMCC), located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, 100101, China, on December 29, 2021, with accession number CGMCC No. 24213.

[0048] (II) Physiological and Biochemical Characteristics

[0049] Strain R10 was inoculated onto NA medium containing 2% NaCl, and its physiological and biochemical characteristics were examined. The salt-tolerant new bacterium *Luteimonas sp.* R10 (CGMCC No. 24213) is Gram-negative, rod-shaped, approximately 2-3 mm in diameter, and does not produce spores. The cells can grow on NA and LB media containing 2% NaCl. The cells can grow at 4℃-50℃ under 0-8% NaCl conditions; optimal growth is observed at 20℃-30℃, pH 6.0-7.0, and 2% NaCl. The bacterial cell growth temperature range is 10-45℃, with an optimal growth temperature of 28℃; the pH growth range is 5.0-10, with an optimal pH of 7.0; it can tolerate 1-20% NaCl; it is positive for catalase reaction, can hydrolyze starch and gelatin, negative for VP reaction, does not produce acid in litmus milk, does not produce indole, is negative for nitrate reduction, and produces acid but not gas during glucose fermentation; in the GNIII test, it can utilize Tween 40, D-mannitol, methyl pyruvate, D-maltose, D-fructose, D-arabinol, β-formyl-D-glucosinolate, L-alanine, and D-trehalose. D-galactose, inositol, β-hydroxy-D,L-butyric acid, 3-formylglucose, glycerol, L-aspartic acid, α-keto-butyric acid, gentiobiose, N-acetyl-D-glucosamine, D-fructose, D-glucose-6-phosphate, L-glutamic acid, α-keto-glutarate, acetoacetic acid, sucrose, N-acetyl-β-D-mannosamine, L-fructose, D-fructose-6-phosphate, mucoacid, D-minobiose, L-rhamnose, L-pyroglutamic acid, quinic acid, L-malic acid, stachyose, N-acetylneuraminic acid, creatinine, D-serine, L-serine.

[0050] (III) Chemical Characteristics

[0051] 1. ACC deaminase production test

[0052] Luteimonas sp. R10 was inoculated into DF and ADF media (with ACC as the sole nitrogen source) and cultured at 37°C for 24-72 h. The growth of the strain was observed. After three subcultures, Luteimonas sp. R10 grew well on the medium with ACC as the sole nitrogen source, indicating that R10 is an ACC deaminase-positive strain.

[0053] 2. Salt tolerance test

[0054] The salt-tolerant strain *Luteimonas sp.* R10 (CGMCC No. 24213) was inoculated into NB liquid fermentation medium and cultured at 30°C and 180 rpm for 24 h. The bacterial suspension was then inoculated into NB liquid medium containing 1%, 2%, 5%, and 10% NaCl, respectively, and cultured at 30°C and 180 rpm with shaking for 24 h. The OD value at 600 nm was measured to observe the growth of *Luteimonas sp.* R10 and determine its salt tolerance.

[0055] The results showed that Luteimonas sp. R10 could grow when the NaCl concentration was 1-10%, but the growth of bacteria decreased with increasing salt concentration.

[0056] Example 3: Preparation of Luteimonas sp. R10 microbial inoculant

[0057] Based on Examples 1-2, this embodiment provides a method for preparing Luteimonas sp. R10 microbial inoculant, specifically including the following steps: A single colony of Luteimonas sp. R10 is inoculated into NB liquid fermentation medium and cultured at 30°C and 180 rpm for 18 h to obtain Luteimonas sp. R10 seed culture; the Luteimonas sp. R10 seed culture is inoculated into NB liquid fermentation medium containing 2% NaCl at a volume ratio of 1:100 and fermented at 30°C and 200 rpm for 24 h to obtain Luteimonas sp. R10 microbial inoculant.

[0058] Example 4: Application of Luteimonas sp. R10 microbial inoculant

[0059] This embodiment applies the Luteimonas sp. R10 microbial agent provided by the present invention, based on embodiments 1-3.

[0060] Select plump wheat seeds (variety Xinchun 6) without obvious damage. Disinfect with 0.1% mercuric chloride for 5 minutes, rinse with sterile water, and then soak in sterile water containing 1% Luteimonas sp. R10 microbial agent for 4 hours. Two control treatments were designed: inoculated and uninoculated seeds. The uninoculated control seeds were soaked in sterile distilled water. Using a pot cultivation method, 20 seeds from both the Luteimonas sp. R10 microbial agent treatment and the control were sown in 20cm × 10cm pots containing 2.5kg of soil at a depth of 3cm. The plants were grown under natural conditions until maturity. Various morphological parameters of the wheat plants in the experimental and control groups were measured, including germination rate, grafting rate, plant height, aboveground fresh weight, leaf chlorophyll content, and phenylalanine ammonia-lyase activity. Detailed test results are shown in Table 2 and Appendix. Figure 3-5 As shown.

[0061] Table 2: Effects of microbial inoculant treatment on wheat growth according to the present invention

[0062] CK 75 15 0.470 18.820 R10 95 30 0.570 26.600

[0063] From Table 2 and Appendix Figure 3 Data shows that, compared with the control (CK) treatment, seed soaking with Luteimonas sp. R10 microbial inoculant provided by this invention significantly improved the germination rate of wheat by 26.67%. Simultaneously, the early maturity of wheat treated with Luteimonas sp. R10 microbial inoculant was investigated and statistically analyzed. The scion rate was recorded 5 days after the first wheat plant began scioning. The results indicate that seed soaking with Luteimonas sp. R10 microbial inoculant significantly promoted early maturity of wheat, increasing germination rate by 21.28% and plant height by 41.34% compared to the control.

[0064] Chlorophyll content is a physiological indicator for evaluating plant growth. Figure 4-5 This is a statistical result of the chlorophyll content and phenylalanine ammonia-lyase activity in wheat plants, from the appendix. Figure 4-5 The results showed that soaking wheat seeds in Luteimonas sp. R10 microbial inoculant significantly increased chlorophyll content, by 98.73% compared to the control. Phenylalanine ammonia-lyase (PAL) plays an important role in wheat growth, development, and resistance to insects and diseases. Soaking wheat seeds in Luteimonas sp. R10 microbial inoculant significantly increased PAL activity, by 61.48% compared to the control (CK) treatment.

[0065] Example 5: Application of Luteimonas sp. R10 microbial inoculant

[0066] This embodiment applies the Luteimonas sp. R10 microbial agent provided by the present invention, based on embodiments 1-3.

[0067] Select plump cotton seeds (variety Xinluzao 77) without obvious damage, wash them with sterile water, and soak them overnight in sterile water containing 1% Luteimonas sp. R10 microbial inoculant. Two experimental treatments were designed: inoculated and uninoculated cotton seeds. The uninoculated control seeds were soaked in sterile distilled water. Pot cultivation was used. Twenty seeds of both Luteimonas sp. R10 and the control were sown in pots with a diameter of 20 cm containing 2.5 kg of moderately saline-alkali soil (pH 7.95, total salt content 7.8 g / kg) at a depth of 3 cm. The plants were allowed to grow naturally until maturity. The effects of the Luteimonas sp. R10 microbial inoculant treatment provided in this invention on the growth performance of cotton plants were measured, specifically the germination rate, plant height, and above-ground fresh weight of the cotton plants. Detailed test results are provided in the appendix. Figure 6 As shown.

[0068] From the appendix Figure 6 Data shows that the Luteimonas sp. R10 microbial inoculant provided by this invention can significantly improve the germination rate of cotton by 200.00% compared with the CK treatment; plant height increased by 31.50% and fresh weight increased by 9.37%.

[0069] The above data analysis shows that wheat and cotton seeds treated with the Luteimonas sp. R10 microbial agent provided by this invention significantly increased parameters such as germination rate, budding rate, fresh weight, and plant height of wheat. Simultaneously, the chlorophyll content and phenylalanine ammonia-lyase activity of wheat were also significantly improved. The germination rate, plant height, and fresh weight of cotton were significantly increased compared to the control group. This indicates that the Luteimonas sp. R10 microbial agent provided by this invention can not only reduce the amount of chemical fertilizer used but also promote plant growth, exhibiting good ecological and social benefits and broad development and application prospects in agricultural bio-fertilizers.

[0070] In summary, the above embodiments are merely descriptions of preferred embodiments of this experiment and are not intended to limit the scope of this experiment. Without departing from the spirit of this experiment design, all modifications and improvements made by those skilled in the art to the technical solutions of this experiment should fall within the protection scope determined by this experiment.

Claims

1. A new salt-tolerant fungus, *Gastrodinium luteolinum* ( Luteimon sp.)R10, characterized in that, The luteomyces ( Luteimon sp.) R10 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 24213; the *Glaucoma lutea* (sp.) Luteimon The 16S rRNA gene sequence of sp.)R10 is shown in SEQ ID NO:

1.

2. A strain of *Gastrodinium luteum* as described in claim 1 (… Luteimon sp.) R10 microbial inoculant, characterized in that, This microbial agent is composed of the salt-tolerant new bacterium *Glaucoma luteolyticus* (… Luteimon R10 was prepared by fermentation.

3. A type of *Gastrodinium luteum* as described in claim 2 (… Luteimon sp.) R10 microbial inoculant, characterized in that, The preparation method of this microbial agent specifically includes the following steps: preparing the strain of salt-tolerant new fungus *Gastrodinium luteum* (… Luteimon A single colony of *Gastrodinium sp.* R10 was inoculated into NB liquid fermentation medium and cultured at 30°C and 180 rpm for 18 h to obtain a seed culture. This seed culture was then inoculated into NB liquid fermentation medium containing 2% NaCl at a 1:100 volume ratio and fermented at 30°C and 200 rpm for 24 h to obtain *Gastrodinium luteum* (sp.). Luteimon R10 microbial inoculant (sp.) 4. A type of *Gastrodinium luteum* as described in claim 2 (… Luteimon Application of R10 microbial inoculant (sp.) in wheat growth promotion.

5. The salt-tolerant new bacterium *Gastrodinium luteum* as described in claim 1 (… Luteimon Application of sp.)R10 in wheat growth promotion cultivation.

6. A type of *Gastrodinium luteum* as described in claim 2 (… Luteimon Application of R10 microbial inoculant (sp.) in cotton growth promotion.

7. The salt-tolerant new bacterium *Gastrodinium luteum* as described in claim 1 (… Luteimon Application of sp.)R10 in cotton growth promotion cultivation.

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