Sphingolipid sp. W6 strain for promoting plants to adapt to low-phosphorus environment and application of spingolipid sp. W6 strain

Abstract

The invention discloses a sphingobium sp. W6 strain for promoting plants to adapt to a low-phosphorus environment and application of the sphingobium sp. W6 strain, and relates to the technical field of microorganisms, the preservation number of the sphingobium sp. W6 is GDMCCNO: 66821, and the sphingobium sp. W6 is preserved in the Guangdong Microbial Culture Collection Center on August 7th, 2025, and the preservation address is the 5th floor, No. 59 building, No. 100 Courtyard, Xianlie Middle Road, Guangzhou. The invention also provides application of the sphingolipid bacteria W6 in improving the plant phosphorus absorption efficiency and preparing a product for improving the plant phosphorus absorption efficiency. The sphingolipid strain W6 has high IAA yield and can significantly promote plant root growth, so that the phosphorus utilization efficiency of plants in a low-phosphorus environment is improved, and the sphingolipid strain W6 has a great promotion effect on plant growth.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a sphingolipid strain W6 that promotes plant adaptation to low-phosphorus environments and its applications. Background Technology

[0002] Phosphorus (P) is an essential element for plant growth and development, but the scarcity of available phosphorus in soil is one of the main factors limiting crop production. Plants utilize phosphorus by converting phosphorus fixed in the soil into usable phosphorus, either by themselves or through soil microorganisms. Maize (Zea mays L.) is a globally important food, feed, and industrial raw material crop, and its high and stable yields are crucial for ensuring food security. Modern maize production widely utilizes hybrid maize varieties bred through hybrid vigor, which typically exhibit stronger stress resistance and nutrient utilization efficiency. However, under low-phosphorus soil conditions, even high-yielding hybrid maize still faces problems such as limited growth and decreased biomass, restricting the realization of its advantages.

[0003] Currently, research on efficient phosphorus utilization in maize mainly focuses on genetic improvement and fertilizer management, while strategies for synergistically enhancing phosphorus uptake efficiency in maize using functional microorganisms (such as phosphate-solubilizing bacteria and rhizosphere growth-promoting bacteria) have not been fully developed. The rhizosphere microbiome, hailed as the "second genome" of plants, plays a crucial role in plant growth and development. Different plant genotypes improve their survival performance by specifically recruiting microorganisms. Hybrid maize may possess unique root exudates or signaling molecules due to its genetic heterozygosity, attracting or activating specific beneficial microorganisms. Microorganisms may help maize adapt to low phosphorus stress by regulating plant hormones or inducing systemic resistance.

[0004] Although some phosphate-solubilizing strains (such as *Pseudomonas* and *Bacillus*) have been reported to promote phosphorus utilization in crops, the most promising approach is to specifically regulate phosphorus uptake in hybrid maize through microorganisms, thereby maximizing hybrid vigor. Highly efficient strains selected through microbial regulation can be developed into biofertilizers and used in conjunction with hybrid maize varieties to form a combined "variety-microorganism" solution. This technology aligns with the needs of ecological agriculture, reducing chemical fertilizer inputs and minimizing non-point source pollution. Furthermore, these findings can provide new targets for crop stress-resistance breeding. Therefore, by regulating hybrid vigor through microorganisms, the goal of "low input, high output, and environmentally friendly" agricultural production can be achieved, yielding significant ecological, economic, and social benefits. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a sphingolipid strain W6 that promotes plant adaptation to low-phosphorus environments and its application. The sphingolipid strain W6 of the present invention has a high IAA yield, which can significantly promote plant root growth, thereby improving the phosphorus utilization efficiency of plants in low-phosphorus environments and having a significant promoting effect on plant growth.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a sphingobium sp. W6 that promotes plant adaptation to low phosphorus environment is provided, which has the accession number GDMCC No: 66821 and was deposited on August 7, 2025 at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0007] This invention also provides the application of the above-mentioned sphingolipid bacterium W6, which promotes plant adaptation to low phosphorus environments, in improving the efficiency of plant phosphorus absorption.

[0008] This invention also provides the application of the above-mentioned sphingolipid bacterium W6, which promotes plant adaptation to low phosphorus environments, in the preparation of products that improve the efficiency of plant phosphorus absorption.

[0009] Furthermore, the plant mentioned above is corn.

[0010] Furthermore, the aforementioned plants are hybrid varieties of maize.

[0011] Furthermore, the above products are microbial agents or bio-fertilizers.

[0012] The present invention also provides a microbial agent for promoting plant adaptation to low phosphorus environments, including the above-mentioned Sphingolipidus W6.

[0013] The present invention has the following beneficial effects:

[0014] 1. The Sphingolipid W6 provided by this invention has a high IAA yield, which can significantly promote plant root growth, thereby improving the phosphorus utilization efficiency of plants in low phosphorus environments and having a significant promoting effect on plant growth (especially maize hybrids). Attached Figure Description

[0015] Figure 1 Phylogenetic sequence alignment information for Sphingolipidus W6;

[0016] Figure 2 The graph shows the IAA production capacity test results for different strains;

[0017] Figure 3 A comparison chart of IAA production by different strains;

[0018] Figure 4 Phenotypic diagram of maize growth promotion experiment;

[0019] Figure 5 A comparison chart of biomass in maize growth promotion experiments;

[0020] Figure 6 This is a comparative diagram of the root systems of maize hybrids. Detailed Implementation

[0021] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0022] Example 1: Isolation and Identification of Strains

[0023] The phosphorus content in low-phosphorus soil (soil:sand ratio = 1:1 mixture) taken from the University of Hohenheim, Germany, was 13.8 mg·kg⁻¹. -1 Four weeks after planting maize, the roots were collected and high-throughput screening was used to identify strains enriched in a low-phosphorus environment. After purification and three-times culture in 1 / 2 TSB medium, Sphingobium sp. W6 was isolated. Species classification was identified by first-generation sequencing. The phylogenetic sequence alignment information of strain W6 (denoted as WX6) is as follows: Figure 1 As shown.

[0024] Example 2 Functional Verification

[0025] Single colonies isolated in Example 1 were inoculated into 1 / 2 TSB liquid medium for enrichment and culture for three days. 50 μL of each colony was then inoculated into 1 mL of 1 / 2 TSB liquid medium supplemented with tryptophan (1 g / L), with uninoculated medium serving as a control. Each treatment was performed in triplicate. The cultures were incubated at 28°C and 180 rpm for three days using a shaker. 800 μL of the culture was then transferred to a 1.5 mL centrifuge tube and centrifuged at 4°C and 12000 rpm. 100 μL of the supernatant was added to a 96-well plate containing 100 μL of Salkowski's reagent (1 mL of 0.5 mol / L ferric chloride dissolved in 49 mL of 35% perchloric acid). The mixture was thoroughly mixed and incubated at room temperature in the dark for 30 minutes. Observation revealed that the supernatant of IAA-producing strains mixed with Salkowski's reagent showed a red or pink color, while tryptophan showed a yellow or colorless reaction. The IAA production capacity of different strains was tested as follows: Figure 2 and Figure 3 As shown.

[0026] The results showed that the W6 (WX6) bacterial solution turned red after being mixed with the reagent, and this strain could significantly increase the IAA yield (reaching 23.78 μg / mL).

[0027] Example 3: Hybrid Low-Phosphorus Soil Growth Promotion Experiment

[0028] Sterilized soil was obtained by sterilizing low-phosphorus soil. Different genotypes of maize seeds were cultured under aseptic conditions for 3 days. After germination and root growth to approximately 2 cm, seeds with uniform growth were selected and inoculated with a solution of *Sphingobacterium sphingolipidae* W6 (WX6) with an OD value of 0.01, and physiological saline (soaked for 2 hours) as a control. Four biological replicates were set up for each group. Four weeks after planting, the aboveground biomass of maize was measured. The phenotypic results and biomass measurement results of the maize hybrid growth promotion experiment are shown in the figures below. Figure 4 and Figure 5 As shown.

[0029] Depend on Figure 4 and Figure 5 It can be seen that the growth of maize plants inoculated with Sphingobacterium sphingolipidum W6 (WX6) was significantly better than that of maize plants not inoculated with the bacterial solution; the biomass statistics show that Sphingobacterium sphingolipidum W6 has a significant effect on promoting the growth of maize hybrids.

[0030] Root systems of maize hybrids, for example Figure 6 As shown, sphingolipid-rich bacteria W6 significantly promoted root development in maize hybrids. The results indicate that W6 promotes plant growth by enhancing phosphorus absorption efficiency through root development.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sphingobium sp. W6 that promotes plant adaptation to low-phosphorus environments, characterized in that, Its accession number is GDMCC No: 66821. It was deposited on August 7, 2025 at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

2. The application of the sphingolipid bacterium W6 described in claim 1 in improving the efficiency of phosphorus absorption in plants.

3. The application of the sphingolipid bacterium W6 described in claim 1, which promotes plant adaptation to low-phosphorus environments, in the preparation of products that improve the efficiency of plant phosphorus absorption.

4. The application as described in claim 3, characterized in that, The plant in question is corn.

5. The application as described in claim 3, characterized in that, The plant in question is a maize hybrid.

6. The application as described in claim 3, characterized in that, The product is a microbial agent or bio-fertilizer.

7. A microbial agent for promoting plant adaptation to low-phosphorus environments, characterized in that, Includes the sphingolipid W6 as described in claim 1.

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