Efficiency of Bacillus subtilis and Bacillus cereus to Abate Salinity Stress and Augment Plant Growth

PGPR are potential tools to alleviate plant growth and augment tolerance to abiotic stress tolerance, with reduced level of agro-chemical application, as excessive use of fertilizers poses threat to soil fertility, soil ecology and fertilizer run-off leads to water contamination, water eutrophication. PGPR also elicit 'induced systemic tolerance' to salt and drought. The present study indicated that soil inoculation with rhizobacterial strains of Bacillus subtilis and Bacillus cereus (NCBI accession numbers: LC480918 and LC481470 respectively) promotes growth of Capsicum annu um under both non-saline and saline conditions by directly or indirectly regulating plant chlorophyll content, leaf osmotic potential. The potential of the two rhizobacterial strain to produce exopolysaccharide, indole acetic acid, gibberelic acid production confirmed its ability as plant growth promoting isolates. Present study recorded maximum root length of 22.9 cm and total chlorophyll content of 182 mu g/g in B.subtilis inoculated plants compared to root length of 22.6 cm and total chlorophyll content of 160 mu g/g in control plants, under non saline condition. B. subtilis inoculated plants under salt stress showed root length of 17.2 cm total chlorophyll content of 69 mu g/g compared to root length of 16.0 cm total chlorophyll content of 64 mu g/g in control plants at 200mM salt concentration. Different paradigms of applicability of the PGPR have been displayed comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insight into the role of PGPRs inoculum as biofertilizers for sustainable agriculture productivity and reclaiming soil fertility unlike chemical fertilizers.