Multiple Perspectives of Study on the Potential of Bacillus amyloliquefaciens JB20221020 for Alleviating Nutrient Stress in Lettuce.

Soil nutrient deficiency has become a key factor limiting crop growth. Plant growth-promoting rhizobacteria (PGPR) are vital in resisting abiotic stress. In this study, we investigated the effects of inoculation with Bacillus amyloliquefaciens JB20221020 on the physiology, biochemistry, rhizosphere microorganisms, and metabolism of lettuce under nutrient stress. Pot experiments showed that inoculation with B. amyloliquefaciens JB20221020 significantly promoted lettuce growth under nutrient deficiency. At the same time, the activities of the antioxidant enzymes superoxide dismutase, peroxidase, and catalase and the content of proline increased, and the content of Malondialdehyde decreased in the lettuce inoculated with B. amyloliquefaciens JB20221020. Inoculation with B. amyloliquefaciens JB20221020 altered the microbial community of the rhizosphere and increased the relative abundances of Myxococcales, Deltaproteobacteria, Proteobacteria, Devosia, and Verrucomicrobia. Inoculation also altered the rhizosphere metabolism under nutrient deficiency. The folate metabolism pathway was significantly enriched in the Kyoto Encyclopedia of Genes and Genomes enrichment analysis. This study explored the interaction between plants and microorganisms under nutrient deficiency, further explained the critical role of rhizosphere microorganisms in the process of plant nutrient stress, and provided a theoretical basis for the use of microorganisms to improve plant resistance.