A priestia megaterium ls-71strain and the use thereof in promoting plant growth and improving crop tolerance to adverse environment

Abstract

This invention relates to a rice endophytic bacterium strain, *Priestia megaterium* LS-71, and a method for promoting plant growth and improving crop tolerance to stress. The method involves spraying a bacterial solution of *Priestia megaterium* LS-71 onto the leaves or sowing seeds that have been soaked and inoculated with it. Inoculation with *Priestia megaterium* of this invention can effectively stimulate the expression of growth-related genes in the target crop, thereby improving crop growth and stress tolerance.

Claims

1. The use of a rice endophytic bacterium, *Priestia megaterium* LS-71 strain (accession number BCRC911293), for promoting plant growth, wherein the *Priestia megaterium* promotes seed germination, root growth, biomass accumulation, and / or increases crop yield by accelerating the decomposition of starch in plants or stimulating the accumulation of hydrogen peroxide in roots.

2. As described in item 1, wherein the Priestia megaterium LS-71 strain is used to regulate the expression of plant starch-degrading genes or auxin-related genes.

3. As described in item 1, wherein the Priestia megaterium LS-71 strain is used to increase the accumulation of beneficial activated oxygen (ROS) in plant roots.

4. The use of a rice endophytic bacterium, *Priestia megaterium* LS-71 strain (accession number BCRC911293), for stimulating the accumulation of hydrogen peroxide in roots and increasing aerenchyma, thereby improving the crop's tolerance to stress, wherein the stress includes flooding.

5. As described in item 4, wherein the Priestia megaterium LS-71 strain is used to combine with plants to form a functional bacterial community, thereby enhancing the plant's ability to resist environmental adversity.

6. An inoculation method for promoting plant tolerance to flooding stress, comprising: disinfecting crop seeds and soaking them in a bacterial solution containing 1x106-5x106 CFU / mL of Priestia megaterium LS-71 (accession number BCRC911293) until the seeds germinate; draining the germinated seeds and germinating them in a high-humidity, dry environment for 16-20 hours until they are ready for sowing; and planting the germinated seedlings in the subsequent growth environment.

7. The method as described in item 6, wherein the crop includes grasses, cucurbits, cruciferous crops and solanaceous crops.

8. The method as described in item 6, wherein the method comprises disinfecting the seeds and then immersing them in a bacterial solution of *Priestia megaterium* LS-71 containing 1 x 10⁶ to 2 x 10⁶ CFU / mL until germination.

9. The method as described in item 6, wherein the seed disinfection step includes disinfection with 2.5% hypochlorous acid solution for 30-40 minutes.

10. The method as described in item 6, wherein the seed disinfection step comprises disinfecting with a 2000-fold dilution of the field fungicide Tebuconazole for 16-18 hours.

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