Whole-genome sequencing uncovers the plant growth-promoting potential of Bacillus licheniformis G41, isolated from the rhizosphere soil of Gannan navel orange

Abstract Background Gannan navel orange orchards currently rely heavily on inorganic fertilizers, which have significantly degraded soil quality. Therefore, developing sustainable methods aligned with modern green agriculture is crucial. Plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms that can promote plant growth and contribute to soil ecological balance. In-depth research and application of PGPR can support both agricultural productivity and environmental sustainability. Results In this study, Bacillus licheniformis G41 was isolated from the rhizosphere soil of navel orange in southern Jiangxi Province. It was found that this strain possesses the ability to produce indole-3-acetic acid (IAA), synthesize siderophores, and solubilize phosphate. To further validate its PGP effects, strain G41 was inoculated into navel orange seedlings. After the inoculation experiment, plant height, biomass accumulation, chlorophyll content, and antioxidant enzyme activities increased in the inoculated group compared to the control group. Whole-genome sequencing revealed a genome size of 4,610,067 bp, with a total of 21 scaffolds, an average GC content of 46.17%, 4,700 predicted genes, 82 tRNAs, and 3 rRNAs. By comparing the predicted genes with the KEGG database, key functional genes related to IAA biosynthesis, siderophore biosynthesis and transport, and phosphorus cycle were identified. Conclusion Overall, genomic analyses and PGP experiments suggest that B. licheniformis G41, which possesses multiple plant growth-promoting traits, can effectively promote the growth of navel orange seedlings and exhibits potential as an efficient and environmentally friendly microbial fertilizer.