Endophytic bacterial community of rice (Oryza sativa L.) from coastal saline zone of West Bengal: 16S rRNA gene based metagenomics approach

Rice is one of the most important cereal crops and a staple food for more than half of the world's population and West Bengal is its leading producer in India. But several abiotic conditions, like draught, soil salinity affect rice productivity. A novel approach using endophytic bacteria to ameliorate various stress conditions is gaining popularity for the betterment of agriculture. However, work on endophytic bacteria isolated from rice has not been properly evaluated in India. In this study we wanted to explore the diversity of bacterial endophytes inhabiting roots of rice plants growing in the Coastal saline zone of Sundarbans, West Bengal. This has been achieved through amplicon metagenomics of bacterial 16S rRNA gene in the IlluminaMiSeq platform. In our investigation endophytic bacterial community was exclusively dominated by the order Rickettsiales followed by Enterobacteriales. Our result identified the genera, some of whom have potential plant growth promotion (PGP) abilities as well as role in defense mechanisms of plants (viz. Pantoea, Enterobacter, Paenibacillus, etc.). Few genera (viz. Aerinimonas, Arcobacter, Chitinophaga, Hydrogenispora, Sulfospirillum, etc.) identified in our study have not been reported previously as endophytes and most probably are unique endophytes of this region. This study has enumerated the diversity of endophytic bacteria from rice grown in the saline zone of West Bengal that would help us to design a better strategy for cultivation under abiotic stress condition.