Molecular characterization of stress tolerance genes associated with D. indicus strain under extreme environment conditions.

Abstract

Deinococcus indicus is a novel bacteria isolated from West Bengal, India known for its UV radiation and heavy metal tolerance. Since, this organism is reported from a region known for heavy metal contamination and earlier investigations demonstrated its radiation resistance, our study focused on the multiple stress responsive and DNA repair mechanisms. Though, most of the members of the genus Deinococcus are Gram positive cocci, D. indicus postures Gram negative rod shaped cells. Hence, the objectives were framed precisely to understand DNA repair pathway and stress responsive genes expression with a broader perspective. Based on available whole genome sequence of D. indicus, quantitative real time PCR (qPCR) was done to determine the expression pattern of multiple stress responsive genes upon various environmental extremities. Among them, UV responsive genes like UvrD and UvsE showed elevated expression when subjected to UV-C radiation at different time intervals. Similarly, when supplemented with arsenic and chromium, ArsR and ArsB exhibited considerably higher level of expression. While all the genes were subsequently analyzed in-silico, depicted that most of them were with N-glycosylation site, GPI anchor sites, N-terminal trans-membrane helix region besides putative signal peptides. Overall, this study opined the functional information onstress tolerance genes that aid to understand the DNA damage recovery mechanism towards elucidation of DNA repair pathways.