Unravelling rhizosphere competent plant growth promoting bacteria for mainstreaming finger millet to climate smart agriculture.

Climate change induced abiotic stresses pose a major challenge to global food security, particularly in crops grown in marginal environments such as finger millet. The use of plant growth-promoting bacteria has emerged as a promising strategy to alleviate the detrimental impacts of stress and enhance plant development. In the present study, we investigated 30 bacterial isolates from finger millet rhizosphere and prioritized them based on their plant growth-promoting attributes using Bonitur Scale. Sixteen isolates were further evaluated for key competence traits, including tolerance to salinity, temperature and drought, antibiotic resistance, amylase production, biofilm and exopolysaccharide (EPS) formation, and root colonization ability. Three EPS-producing and drought-tolerant isolates (A11, P1a and B16a) were selected for pot experiments to assess their role in mitigating drought stress in finger millet. Inoculated plants showed significantly improved growth under water stress compared to uninoculated controls. Enhanced total sugars, proteins, phenolics, catalase activity, delayed wilting and better chlorophyll retention contributed to the improved drought tolerance of bacterized seedlings. Field evaluation of eight isolates further demonstrated reduced blast incidence and improved crop performance. Based on 16 S rRNA gene sequence analysis, four potent strains (A10, A11, P1a and B16a) were identified as belonging to the genus Bacillus. These isolates exhibit strong PGP and stress-alleviating capacities, highlighting their potential as effective bioinoculants for improving finger millet productivity under climate-induced stress conditions and supporting sustainable agriculture.