Alleviative mechanisms of silicon solubilizing Bacillus amyloliquefaciens mediated diminution of arsenic toxicity in rice

Silicon (Si) has gained considerable attention for its utility in improved plant health under biotic and abiotic stresses through alteration of physiological and metabolic processes. Its interaction with arsenic (As) has been the compelling area of research amidst heavy metal toxicity. However, microbe mediated Si solubilization and their role for reduced As uptake is still an unexplored domain. Foremost role of Bacillus amyloliquefaciens (NBRISN13) in impediment of arsenite (AsIII) translocation signifies our work. Reduced grain As content (52-72%) during SN13 inoculation under feldspar supplementation (Si+SN+As) highlight the novel outcome of our study. Upregulation of Lsi1, Lsi2 and Lsi3genes in Si+SN+As treated rice plants associated with restricted As translocation, frames new propositions for future research on microbemediated reduced As uptake through increased Si transport. In addition to low As accumulation, alleviation of oxidative stress markers by modulation of defense enzyme activities and differential accumulation of plant hormones was found to be associated with improved growth and yield. Thus, our findings confer the potential role of microbe mediated Si solubilization in mitigation of As stress to restore plant growth and yield.