Author(s): NISHISAKA, C. S.; VENTURA, J. P.; BAIS, H. P.; MENDES, R.

Summary: Abstract: Background: Bacillus subtilis is well known for promoting plant growth and reducing abiotic and biotic stresses. Mutant gene-defective models can be created to understand important traits associated with rhizosphere fitness. This study aimed to analyze the role of exopolymeric genes in modulating tomato rhizosphere microbiome assembly under a gradient of soil microbiome diversities using the B. subtilis wild-type strain UD1022 and its corresponding mutant strain UD1022eps?TasA, which is defective in exopolysaccharide (EPS) and TasA protein production. Results: qPCR revealed that the B. subtilis UD1022eps?TasA? strain has a diminished capacity to colonize tomato roots in soils with diluted microbial diversity. The analysis of bacterial ?-diversity revealed significant differences in bacterial and fungal community structures following inoculation with either the wild-type or mutant B. subtilis strains. The Verrucomicrobiota, Patescibacteria, and Nitrospirota phyla were more enriched with the wild-type strain inoculation than with the mutant inoculation. Co-occurrence analysis revealed that when the mutant was inoculated in tomato, the rhizosphere microbial community exhibited a lower level of modularity, fewer nodes, and fewer communities compared to communities inoculated with wild-type B. subtilis.

Publication year: 2024

Types of publication: Journal article

Unit: Embrapa Environment

Keywords: Bacillus subtilis, Bactéria, Bactéria não Patogênica, Dilution to extinction, EPS, Exopolysaccharides, Microbiome, PGPR, Rhizosphere bacteria, Rizosfera, TasA, Tomate, Tomatoes