Genome insights into the plant growth-promoting bacterium Saccharibacillus brassicae ATSA2 T

• Published in: AMB Express Vol. 13; no. 1; p. 9
• Main Authors: Jiang, Lingmin, Seo, Jiyoon, Peng, Yuxin, Jeon, Doeun, Park, Soon Ju, Kim, Cha Young, Kim, Pyoung Il, Kim, Chul Hong, Lee, Ju Huck, Lee, Jiyoung
• Format: Journal Article
• Language: English
• Published: Germany 21.01.2023
• Subjects: Plant growth-promotion; Endophyte; Whole-genome; antiSMASH; Saccharibacillus brassicae
• ISSN: 2191-0855; 2191-0855

Endophytes can facilitate the improvement of plant growth and health in agriculturally important crops, yet their genomes and secondary metabolites remain largely unexplored. We previously isolated Saccharibacillus brassicae strain ATSA2 from surface-sterilized seeds of kimchi cabbage and represented a novel species of the genus Saccharibacillus. In this study, we evaluated the plant growth-promoting (PGP) effect of strain ATSA2 in kimchi cabbage, bok choy, and pepper plants grown in soils. We found a significant effect on the shoot and root biomass, and chlorophyll contents following strain ATSA2 treatment. Strain ATSA2 displayed PGP traits such as indole acetic acid (IAA, 62.9 μg/mL) and siderophore production, and phosphate solubilization activity. Furthermore, genome analysis of this strain suggested the presence of gene clusters involved in iron acquisition (fhuABD, afuABC, fbpABC, and fepCDG) and phosphate solubilization (pstABCHS, phoABHLU, and phnCDEP) and other phytohormone biosynthesis genes, including indole-3-acetic acid (trpABCDEFG), in the genome. Interestingly, the secondary metabolites cerecidin, carotenoid, siderophore (staphylobactin), and bacillaene underlying plant growth promotion were found in the whole genome via antiSMASH analysis. Overall, physiological testing and genome analysis data provide comprehensive insights into plant growth-promoting mechanisms, suggesting the relevance of strain ATSA2 in agricultural biotechnology.