Soybean rhizosphere growth-promoting strain and application thereof

Abstract

The invention provides a soybean rhizosphere growth promoting strain, which is named Acinetobacter sp.A11, is preserved in the China Center for Type Culture Collection (CCTCC), has the preservation number of CCTCC NO: M20242725, and has the preservation date of December 04, 2024, the preservation number of CCTCC NO: M20242725, and the preservation number of CCTCC NO: M20242725 is CCTCC NO: M20242725. The nucleotide sequence of the 16S rRNA is as shown in SEQ ID NO. 1. The invention also provides an application of the soybean rhizosphere growth-promoting strain, and the soybean rhizosphere growth-promoting strain is used for fixing nitrogen, dissolving organic phosphorus, dissolving inorganic phosphorus and dissolving potassium. And soybean growth can be promoted. The strain disclosed by the invention has strong functions of fixing nitrogen, dissolving organic phosphorus and inorganic phosphorus, dissolving potassium and the like, provides high-quality strain resources for development of microbial fertilizers, microbial agents and the like, and is of great significance in improving soil, increasing crop yield, realizing sustainable development of ecological environment and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of soybean rhizosphere growth-promoting bacteria, and specifically relates to a soybean rhizosphere growth-promoting bacterial strain and application thereof. Background Art

[0002] Plant Growth Promoting Rhizobacteria (PGPR) refers to a type of beneficial microorganisms that live in the soil near the roots of plants or are attached to the roots of plants, can significantly promote plant growth and development and their absorption and utilization of mineral nutrients, and can alleviate the external environment's stress on plants and improve the ability of plants to resist diseases and pests. As the direct interface for the exchange of substances and energy between plants and soil, the plant rhizosphere is the most active area of ​​microbial activity. In recent years, the huge potential of the rhizosphere microbiome has been confirmed in relevant studies. In recent years, the huge potential of the rhizosphere microbiome has been confirmed in relevant studies. The biggest feature of this type of microorganism is its functional diversity. It can not only promote plant growth and development directly or indirectly by promoting material circulation, synthesizing and regulating plant hormones, and alleviating plant environmental pressure, but also maintain soil stability and improve the rhizosphere microbial network. With the development of modern agriculture, the ecological planting of crops has gradually received attention. In modern agricultural practice, many problems such as soil compaction, soil salinization, heavy metal pollution, and destruction of soil microbial diversity caused by the long-term application of chemical fertilizers and pesticides are becoming increasingly serious. As a new type of fertilizer, microbial fertilizer has rhizosphere growth-promoting bacteria as its main functional ingredient. It can fix nitrogen in the atmosphere and release fixed phosphorus and potassium in the soil, so that the nutrient potential of the environment can be fully utilized. It also creates a good soil microbial environment for crop growth and is of great significance in reducing the use of chemical fertilizers, reducing environmental pollution, and improving the quality of crops. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a multifunctional soybean rhizosphere growth-promoting strain and its application in view of the deficiencies of the above-mentioned prior art. The strain has strong functions of nitrogen fixation, solubilization of organic phosphorus and inorganic phosphorus, and potassium solubilization. It not only enriches the local microbial growth-promoting bacteria resource library in Xinjiang, but also lays an important research foundation for the development and application of microbial fertilizers and agents related to soybean cultivation in Xinjiang, which is of great significance to soil improvement, increasing crop yields, and achieving sustainable development of the ecological environment.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a soybean rhizosphere growth-promoting strain, the soybean rhizosphere growth-promoting strain is named Acinetobacter sp.A11, preserved in the China Type Culture Collection, the preservation address is Wuhan University, Wuhan, China, the preservation number is CCTCC NO: M20242725, and the preservation date is December 4, 2024; the nucleotide sequence of 16S rRNA of the soybean rhizosphere growth-promoting strain is shown in SEQ ID NO.1.

[0005] The application of the soybean rhizosphere growth-promoting strain of the present invention is that the soybean rhizosphere growth-promoting strain is used for nitrogen fixation, dissolving organic phosphorus, dissolving inorganic phosphorus, and dissolving potassium; the soybean rhizosphere growth-promoting strain is used for promoting soybean growth.

[0006] Preferably, the soybean rhizosphere growth-promoting strain is used to improve the germination rate of soybean seeds and increase the length of soybean embryos.

[0007] Compared with the prior art, the present invention has the following advantages:

[0008] The soybean rhizosphere growth-promoting strain of the present invention is aimed at the excavation of indigenous rhizosphere growth-promoting bacteria in the arid environment of Xinjiang, which not only enriches the local microbial growth-promoting bacteria strain resource library in Xinjiang, but also lays an important research foundation for the development and application of microbial fertilizers and microbial agents related to soybean cultivation in Xinjiang. The application of this strain provides an important scientific basis for alleviating plant environmental stress, promoting plant growth and development, improving crop quality, maintaining soil stability, improving soil rhizosphere environment, reducing fertilizer use, and reducing environmental pollution.

[0009] The present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the determination of the nitrogen fixation function of the A11 strain in Example 1 of the present invention.

[0011] Figure 2 This is the determination of the ability of the A11 strain in Example 1 of the present invention to dissolve organic phosphorus.

[0012] Figure 3 This is the determination of the ability of the A11 strain in Example 1 of the present invention to decompose inorganic phosphorus.

[0013] Figure 4 This is the determination of the potassium solubilizing ability of the A11 strain in Example 1 of the present invention.

[0014] Figure 5 This is the colony morphology of the A11 strain on LB solid culture medium in Example 1 of the present invention.

[0015] Figure 6It is a growth curve diagram of the A11 strain in Example 1 of the present invention.

[0016] Figure 7 This is the Gram staining result of the A11 strain under an optical microscope in Example 1 of the present invention.

[0017] Figure 8 This is a hemolysis test diagram of the A11 strain in Example 1 of the present invention.

[0018] Fig. 9 It is a phylogenetic tree diagram of the A11 strain in Example 1 of the present invention based on 16S rRNA phylogeny.

[0019] Fig.10 This is a test chart of the soybean seed germination rate using strain A11 in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] Example 1

[0021] The test culture medium formulas in this embodiment are as follows:

[0022] LB medium: tryptone 10.0 g / L, yeast extract 5.0 g / L, NaCl 10.0 g / L, agar 18 g / L, pH 7.0-7.2.

[0023] Ashby nitrogen-free medium: mannitol 10.0 g / L, KH2PO4 0.2 g / L, MgSO4·7H2O 0.2 g / L, NaCl 0.2 g / L, CaCO3 5 g / L, CaSO4 0.1 g / L, pH 6.8-7.0.

[0024] Montana organic phosphorus medium (for verification of solubilized organic phosphorus function): MnSO4·H2O 0.03g / L, FeSO4·7H2O 0.03g / L, CaCO35.0 g / L, glucose 10.0g / L, (NH4)2SO40.5 g / L, lecithin 0.2g / L, NaCl0.3g / L, KCl 0.3g / L, yeast extract 0.4g / L, agar 18g / L, pH7.0-7.2

[0025] Inorganic phosphorus culture medium: glucose 10.0 g / L, MgCl2·6H2O 5.0 g / L, MgSO4·7H2O 0.25 g / L, KCL 0.2 g / L, (NH4)2SO4 0.1 g / L, Ca3(PO4) 25.0 g / L, pH 6.8-7.0.

[0026] Potassium-dissolving culture medium: glucose 10 g / L, Na2HPO4 0.2 g / L, MgSO4·7H2O 0.2 g / L, NaCl 0.2 g / L, CaSO4 0.2 g / L, CaCO3 5 g / L, potassium feldspar 2.5 g / L, agar 18 g / L, pH 7.0-7.2.

[0027] The isolation, purification and identification of Acinetobacter sp.A11 strain are as follows:

[0028] (I) Isolation and purification of strains

[0029] The soil sample collection point for strain isolation is located in the wild soybean plant distribution area of ​​Burqin County, Altay, Xinjiang Uygur Autonomous Region, Xinjiang (E 87.29818675, N 47.81434647). The soil texture of this planting area is sandy loam, with poor texture and very low organic matter and nutrient content. The rhizosphere soil (including the nodule soil) was collected and diluted to 10 with sterile water. -4 , spread on LB medium. Culture at 28℃, pick single colonies with different colors and shapes, and repeatedly streak to separate until purified.

[0030] (II) Determination of the growth-promoting function of strains

[0031] The isolated strains (A-5-1, A-5-2, A-5-3, A-5-4, A9, A11, A-11-1-2) were inoculated on different functional culture media. The specific determination methods were as follows (1)-(4). A strain A11 with the functions of nitrogen fixation, organic phosphorus solubilization and potassium solubilization was obtained. The diameter of the transparent zone for organic phosphorus solubilization was 0.5, and the diameter of the transparent zone for potassium solubilization was 1.3. The specific results are shown in Table 1. Figure 1-4 shown.

[0032] (1) Determination of nitrogen-fixing function of strains

[0033] Ashby nitrogen-free medium was used to determine the nitrogen fixation ability of bacterial isolates. The purified strains were inoculated on Ashby nitrogen-free medium and cultured at 28°C for 7 days. Whether the bacteria could grow normally on Ashby nitrogen-free medium was used to determine whether the bacteria had the ability to fix nitrogen, and the size of the nitrogen fixation ability was determined based on the diameter of the colony growth.

[0034] The results of the nitrogen fixation experiment are as follows Figure 1 As shown, strain A11 can grow normally on Ashby nitrogen-free medium after constant temperature culture, indicating that strain A11 has nitrogen fixation function.

[0035] (2) Determination of dissolved organic phosphorus function

[0036] Qualitative determination method of organic phosphorus solubility: inoculate the purified strain on the Montana organic phosphorus medium, culture it in a constant temperature incubator at 28℃ for 5-7 days, and measure its phosphorus solubility circle diameter (D) and colony diameter (d). Phosphatase secreted by the strain with phosphorus solubilization function during growth can decompose organic phosphorus compounds such as lecithin into phosphoric acid and other products, making the organic phosphorus in the culture medium soluble, thus forming a transparent area around the colony. The size of the transparent circle directly reflects the ability of bacteria to decompose organic phosphorus and the activity of phosphatase. Therefore, the larger the ratio of the phosphorus solubility circle diameter (D) to the colony diameter (d) of the organic phosphorus degrading bacteria, the better the organic phosphorus degradation effect.

[0037] Quantitative experiment of dissolved organic phosphorus: The bacterial suspension was inoculated at a 1% (v / v) inoculation rate into 50 mL of organic phosphorus liquid culture medium at 30°C and 180 r / min for 3 days. The supernatant was collected after centrifugation at 10,000 r / min for 15 min, and the effective phosphorus content in the supernatant was determined by molybdenum blue colorimetry.

[0038] like Figure 2 As shown, the qualitative experimental results showed that the organic phosphorus degradation index of strain A11 was 1.7; the quantitative test results showed that the conversion amount of phosphatidylcholine by strain A11 reached 3.96 mg / L after 3 days of cultivation.

[0039] (3) Determination of the function of dissolving inorganic phosphorus

[0040] Qualitative determination method for inorganic phosphorus decomposition: Inoculate the purified strain on the inorganic phosphorus culture medium, culture it in a constant temperature incubator at 28℃ for 5-7 days, and measure its phosphorus dissolution circle diameter (D) and colony diameter (d). The formation of the phosphorus dissolution transparent circle is due to the fact that the phosphorus dissolution bacteria convert the insoluble phosphorus in the culture medium into soluble phosphorus through acidification, chelation, exchange reaction and polymer formation, so that the phosphate in the culture medium can be released and diffused to form a transparent circle. Therefore, the larger the ratio of the phosphorus dissolution circle diameter (D) of the inorganic phosphorus degrading bacteria to the colony diameter (d), the better the inorganic phosphorus degradation effect.

[0041] Quantitative experiment of dissolved inorganic phosphorus: The bacterial suspension was inoculated at a 1% (v / v) inoculation rate into 50 mL of inorganic phosphorus liquid culture medium at 30°C and 180 r / min for 3 days. The supernatant was collected after centrifugation at 10,000 r / min for 15 min, and the effective phosphorus content in the supernatant was determined by molybdenum blue colorimetry.

[0042] The results of inorganic phosphorus functional determination are as follows Figure 3 As shown, the qualitative experimental results showed that the inorganic phosphorus decomposition index of strain A11 was 1.8; the quantitative test results showed that the conversion amount of calcium phosphate by strain A11 reached 32.96 mg / L after 3 days of cultivation.

[0043] (4) Screening of potassium-solubilizing strains

[0044] Qualitative experiment: The purified strain was inoculated onto the potassium-solubilizing medium, cultured in a constant temperature incubator at 28°C for 5-7 days, and its transparent zone diameter (D) and colony diameter (d) were measured. Potassium-solubilizing bacteria can dissolve insoluble potassium minerals in the culture medium by secreting organic acids, which diffuse in the culture medium and form transparent zones. The larger the ratio of the potassium-solubilizing zone diameter (D) to the colony diameter (d) of potassium-solubilizing bacteria, the more potassium ions the strain can release at the same growth scale, showing a stronger potassium-solubilizing ability. Therefore, the larger the D / d value, the better the potassium-solubilizing effect of the strain.

[0045] Quantitative experiment: Inoculate the prepared bacterial suspension at a 1% (v / v) inoculation volume into 50 mL of potassium-dissolving liquid culture medium without agar, culture at 30°C, 180 r / min for 3 days, centrifuge at 6000 r / min for 20 min, take the supernatant, and determine the potassium content in the supernatant using a flame spectrophotometer.

[0046] Potassium decomposition function test results Figure 4 As shown in the figure, the qualitative experimental results showed that the potassium-solubilizing index of strain A11 was 2.17; the quantitative test results showed that the conversion amount of potassium feldspar powder by strain A11 reached 5.91 mg / L after 3 days of cultivation.

[0047] Table 1 Results of functional assays of different strains

[0048] Strain number Nitrogen fixation capacity Organic phosphorus solution Solution of inorganic phosphorus Potassium-releasing function A-5-1 + - - - A-5-2 + - - - A-5-3 - - - - A-5-4 - - - - A9 ++ - - - A11 + D / d=0.5 / 0.3=1.7 D / d=0.9 / 0.5=1.8 D / d=1.3 / 0.6=2.17 A-11-1-2 + - - -

[0049] Note: "+" indicates that the strain has the corresponding function, and the more the number, the stronger the ability; "-" indicates that the strain does not have the corresponding function. "D" represents the diameter of the phosphate dissolution zone or transparent zone, and "d" represents the colony diameter. The larger the D / d ratio, the stronger the corresponding function.

[0050] The isolated strains were inoculated on different functional culture media, and a strain A11 with the functions of nitrogen fixation, organic phosphorus dissolution and potassium dissolution was screened. After 7 days of culture, its organic phosphorus dissolution index was 1.7, and the conversion amount to lecithin reached 3.96 mg / L; the inorganic phosphorus dissolution index was 1.8, and the conversion amount to calcium phosphate reached 32.96 mg / L; the potassium dissolution index was 2.17, and the conversion amount to potassium feldspar powder reached 5.91 mg / L.

[0051] (III) Morphological and physiological and biochemical identification of strains

[0052] Morphological identification: When the strains on the culture medium are clearly visible and growing well, refer to the Bergey's Bacterial Identification Manual to observe the morphological characteristics of the strains on the culture medium, such as colony color, shape, transparency, etc. Take a small amount of the strains and streak them on the LB medium, and pick the purified single colonies for Gram staining.

[0053] Salt tolerance test: LB culture medium with pH = 7.0 and NaCl content of 1%, 1.5%, 2%, 3%, 4% and 5% was prepared respectively, and the activated strain was streaked into LB culture medium with different NaCl concentration gradients, and cultured at 28°C for 3 days. The NaCl concentration tolerance of the strain was judged based on whether the strain could grow normally on the culture medium.

[0054] Alkali resistance test: The bacterial suspension was inoculated at 1% in an LB liquid medium with a NaCl concentration of 1% and different pH gradients (pH = 5, 6, 7, 8, 9). The shaking conditions were set at 30°C and 180 r / min. The OD was measured after 7 days. 600 The acid-base tolerance of the strain was determined.

[0055] Determination of strain growth curve: Pick a single colony of strain A11 cultured on the LB plate and place it in a 500mL conical flask containing 350mL LB liquid medium, place it in a shaker at 30℃, 180r / min for 3 days. Centrifuge the bacteria at 10000r / min, 4℃ for 10min, and make the collected bacteria into OD 600 =0.5 bacterial suspension, and then transferred to the same volume of culture medium at 5% inoculation volume. The sampling time was 0, 12, 24, 36, 48, 72, 96, 120 hours, and the cell concentration was measured at 600nm by UV spectrophotometer.

[0056] Catalase test: Use a sterilized inoculation loop to take an appropriate amount of activated bacteria and smear it on a glass slide. Add 2-3 drops of 3% hydrogen peroxide solution to perform a catalase test and observe whether bubbles are generated. If bubbles are generated, it proves that the catalase reaction is positive, otherwise it is negative.

[0057] like Figure 5-7 As shown, the colony morphology of the target strain A11 in LB solid medium is as follows Figure 5 As shown, the color is light yellow, the colonies are round, the surface is smooth and moist, the edges are neat, and the Figure 6 The growth curve of strain A11 shows that it reaches the late logarithmic growth stage after about 72 hours of growth. Figure 7 As shown, the Gram staining result was negative, the bacterial morphology was rod-shaped, and there were no spores. The salt-alkali tolerance experiment showed that strain A11 could tolerate 1.5% (w / v) NaCl concentration and grow well in the range of pH 5 to pH 9. The cell concentration OD 600 = 1.0 or above, and the best growth was in the medium containing 1% NaCl (w / v) and pH 7. The result of the catalase assay reaction was positive.

[0058] (IV) Strain hemolysis test

[0059] The purified A11 strain was inoculated into TSA medium containing 5% sheep blood and cultured in a constant temperature incubator at 28°C for 3 days to observe whether a transparent circle is produced. If a transparent circle is produced, it is a positive reaction, and if no transparent circle is produced, it is a negative reaction. Figure 8 shown.

[0060] From the results of the hemolysis test, it can be seen that the A11 strain does not produce a transparent circle on the plate, indicating that the hemolysis reaction result of the strain is negative.

[0061] (V) Molecular identification

[0062] Use a sterile inoculation loop to pick a single colony of the purified strain, add 200 μL of 5% (w / v) BT-chelex100 resin (prepared with distilled water, sterilized at 121°C for 30 min), boil in a boiling water bath for 15 min, quickly freeze at -20°C, thaw at room temperature, and spin at 4°C, 6000 r / min. -1 Centrifuge for 3 minutes, and take 2 μL of the supernatant as template DNA. The template DNA was amplified using the universal primers 27F (5'-AGA GTTTGATCCTGGCTCAG-3') and 1492R (5'-GGTTACCTTGTTACGACTT-3') of the bacterial 16S rRNA gene.

[0063] The total volume of the PCR reaction was 25 μL, including 2.0 μL DNA template, 0.5 μL upstream and downstream primers, 9.5 μL ddH2O, and 12.5 μL Green tapMix enzyme. The PCR reaction program was: 95°C, 5 min pre-denaturation; 94°C, 1 min denaturation, 55°C, 1 min annealing, 72°C, 1.5 min extension, 35 cycles; 72°C, 10 min extension, and 4°C storage. After 1.0% agarose gel electrophoresis, the PCR product was sent to Shanghai Sangon Biotechnology Co., Ltd. for sequencing. The sequencing results were compared and analyzed in the bacterial and archaeal 16SrRNA gene database EZBioCloud (https: / / www.ezbiocloud.net / ), and it was found that the A11 strain was similar to Acinetobacterpittii CIP 70.29 T The similarity was 99.65%. MEGA 11.0 software was used to construct the phylogenetic tree.

[0064] The 16S rRNA gene sequence of strain A11 obtained by sequencing was 1409 bp in size. The sequence of the strain was subjected to homology comparison analysis on EZBioCloud. Based on the homology comparison results, a phylogenetic tree was constructed using MEGA 11.0. The results are as follows: Fig. 9As shown in the 16S rRNA gene phylogenetic tree, strain A11 belongs to Acinetobacter strains, which is similar to Acinetobacter pittii CIP 70.29. T (APQP01000001), AcinetobactergeminorumJ00019 T (MT380471) is in the same branch. Comparison and analysis in the EzBioCloud database found that the sources of the strains closely related to A11 were mostly some medical-related strains, which were quite different from the A11 isolated from the rhizosphere of soybeans in arid areas in this study. In addition, A11 has good growth-promoting function and no hemolytic reaction, and is suspected to be a new species or subspecies produced during the evolution of the strain. This result is consistent with the conclusion of previous studies that explored phosphate-solubilizing microorganisms through systematic genetic analysis of prokaryotic strain genotypes, pointing out that Acinetobacter is considered to be one of the six most promising phosphate-solubilizing bacteria in the future.

[0065] (VI) Growth promotion test of strains

[0066] Preparation of bacterial suspension: After the test strain is activated, it is inoculated into a 250 mL conical flask containing 150 mL LB liquid medium, and cultured at 30 ° C and 180 r / min for 72 h; centrifuged at 8000 r / min for 10 min, the supernatant is discarded, the bacteria are collected, washed with sterile water twice, and resuspended in sterile water, and the OD of the bacterial suspension is adjusted. 600 =0.5, for standby use.

[0067] Seed germination test: Select Heinong 87 soybean seeds with full grains and the same size, and carry out surface disinfection (soak in 70% alcohol for 10 minutes, rinse with sterile water 3 times). The experiment has two treatments: CK (blank control group) and A11 (inoculated with A11 bacterial suspension), with 3 replicates for each treatment and 20 seeds for each replicate. Place 2 layers of sterilized filter paper in each sterile culture dish, and spread the sterilized and air-dried soybean seeds on the filter paper. Add 5 mL of sterile water to each culture dish of CK (control group), and add 5 mL of prepared bacterial suspension to each culture dish of the treatment group. Culture at 28°C in the dark for 3 days. During the culture process, add an appropriate amount of sterile water to keep the filter paper moist, and then calculate the germination rate and sprout length of the seeds. The specific results are shown in Table 2. Fig.10 shown.

[0068] Table 2 Seed germination rate test

[0069] deal with Germination rate (%) Germ length (cm) CK 70.0％ 1.60±0.36 A11 98.0％ 3.17±0.35

[0070] The results of the seed germination test showed that compared with CK, the germination rate of seeds inoculated with A11 increased by 28.6%, and the embryo length increased by 49.5%, with a significant growth-promoting effect.

[0071] The soybean rhizosphere growth-promoting strain was named Acinetobacter sp.A11, and was deposited in the China Type Culture Collection, with the deposit address at Wuhan University, Wuhan, China, the deposit number being CCTCC NO: M20242725, and the deposit date being December 4, 2024; the nucleotide sequence of 16S rRNA of the soybean rhizosphere growth-promoting strain is shown in SEQ ID NO.1.

[0072] The soybean rhizosphere growth-promoting strain of the present invention can be used for nitrogen fixation, dissolving organic phosphorus, dissolving inorganic phosphorus, and dissolving potassium, and has the effect of promoting the growth of soybeans, improving the germination rate of soybean seeds, and increasing the length of embryos.

[0073] The soybean rhizosphere growth-promoting strain of the present invention is aimed at the excavation of indigenous rhizosphere growth-promoting bacteria in the arid environment of Xinjiang. It has multiple growth-promoting functions such as strong nitrogen fixation, dissolution of organic phosphorus and inorganic phosphorus, and potassium solubility. It not only enriches the local microbial growth-promoting bacteria strain resource library in Xinjiang, but also provides high-quality strain resources for the development of microbial fertilizers and microbial agents. In addition, the multiple growth-promoting functions of the strain can help plants decompose and utilize insoluble silicate inorganic minerals such as insoluble phosphorus and potassium feldspar in the soil, converting them into soluble nutrients, which can effectively improve soil fertility, and provide important scientific basis for alleviating plant environmental stress, promoting plant growth and development, improving crop quality, maintaining soil stability, improving soil rhizosphere environment, reducing fertilizer use, and reducing environmental pollution.

[0074] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A soybean rhizosphere growth-promoting strain, characterized in that: The soybean rhizosphere growth-promoting strain is named Acinetobacter sp.A11, deposited in the China Center for Type Culture Collection, with a deposit number of CCTCC NO: M20242725 and a deposit date of December 4, 2024; the nucleotide sequence of 16S rRNA of the soybean rhizosphere growth-promoting strain is shown in SEQ ID NO.

1.

2. An application of the soybean rhizosphere growth-promoting strain as claimed in claim 1, characterized in that: The soybean rhizosphere growth-promoting strain is used for nitrogen fixation, dissolving organic phosphorus, dissolving inorganic phosphorus, and dissolving potassium; the soybean rhizosphere growth-promoting strain is used for promoting soybean growth.

3. The use according to claim 2, wherein the soybean rhizosphere growth-promoting strain is used to improve the germination rate of soybean seeds and increase the length of soybean embryos.

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