Environmental Adaptations of an Extremely Plant Beneficial Bacillus subtilis Dcl1 Identified Through the Genomic and Metabolomic Analysis

• Published in: Microbial ecology 2021-04, Vol.81 (3), p.687-702
• Main Authors: Jayakumar, Aswathy, Nair, Indu C., Radhakrishnan, E. K.
• Format: Article
• Language: English
• Subjects: Acetoin; Adaptation; Agricultural production; Annotations; Aquatic plants; Bacillus subtilis; Biofertilizers; Biofilms; Biological control; Biomedical and Life Sciences; Butanediol; Catalase; Chitinase; Chitosanase; Drought; Drought resistance; Ecology; Endophytes; Flagella; Gene sequencing; Genes; Genomes; Geoecology/Natural Processes; Glutathione; Glycine; Glycine (amino acid); Glycine betaine; Glycosidases; Glycoside hydrolase; Glycosides; Hydrogen sulfide; Hydrolase; Identification; Life Sciences; Metabolomics; Microbial Ecology; Microbiology; Nature Conservation; Oxidative stress; Phosphates; Plant growth; Plant Microbe Interactions; Plant tissues; Probiotics; Properties; Rhizomes; Solubilization; Superoxide dismutase; Surfactin; Trehalose; Water Quality/Water Pollution; Whole genome sequencing
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-020-01605-7

Bacterial endophytes ubiquitously colonize the internal tissues of plants and promote the plant growth through diverse mechanisms. The current study describes the mechanistic basis of plant-specific adaptations present in an extremely beneficial endophytic bacterium. Here, the endophytic Bacillus subtilis Dcl1 isolated from the dried rhizome of Curcuma longa was found to have the drought tolerance, IAA and ACC deaminase production and phosphate solubilization properties. The whole genome sequencing and annotation further showed the genome of B. subtilis Dcl1 to have the size of 4,321,654 bp. This also showed the presence of genes for IAA, H 2 S, acetoin, butanediol, flagella and siderophore production along with phosphate solubilization and biofilm formation for the B. subtilis Dcl1. In addition, the genes responsible for the synthesis of surfactin, iturin, fengycin, bacillibactin, bacillaene, bacilysin, chitinase, chitosanase, protease and glycoside hydrolase could also be annotated from the genome of B. subtilis Dcl1. Identification of genes for the glycine betaine, glutamate and trehalose further indicated the drought stress tolerance features of B. subtilis Dcl1. The presence of the genetic basis to produce the catalase, superoxide dismutase, peroxidases, gamma-glutamyltranspeptidase, glutathione and glycolate oxidase also indicated the plant oxidative stress protective effect of B. subtilis Dcl1. Identification of these properties and the demonstration of its plant probiotic effect in Vigna unguiculata confirmed the applicability of B. subtilis Dcl1 as a biofertilizer, biocontrol and bioremediator agent to enhance the agricultural productivity.