| Title | Roles of RpoS in Yersinia pseudotuberculosis stress survival, motility, biofilm formation and type VI secretion system expression |
|---|---|
| Author | Jingyuan Guan1,2, Xiao Xiao3, Shengjuan Xu1,2, Fen Gao1,3, Jianbo Wang1,2, Tietao Wang3, Yunhong Song3, Junfeng Pan1,2, Xihui Shen1,3*, and Yao Wang1,2* |
| Address | 1State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China, 2Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China, 3Department of Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, P. R. China |
| Bibliography | Journal of Microbiology, 53(9),633-642, 2015, |
| DOI | 10.1007/s12275-015-0099-6 |
| Key Words | Yersinia pseudotuberculosis, RpoS, T6SS, stress resistance, motility, biofilm |
| Abstract | RpoS (σS), the stationary phase/stress σ factor, controls the expression of a large number of genes involved in cellular responses to a variety of stresses. However, the role of RpoS appears to differ in different bacteria. While RpoS is an important regulator of flagellum biosynthesis, it is associated with biofilm development in Edwardsiella tarda. Biofilms are dense communities formed by bacteria and are important for microbe survival under unfavorable conditions. The type VI secretion system (T6SS) discovered recently is reportedly associated with several phenotypes, ranging from biofilm formation to stress sensing. For example, Vibrio anguillarum T6SS was proposed to serve as a sensor for extracytoplasmic signals and modulates RpoS expression and stress response. In this study, we investigated the physiological roles of RpoS in Yersinia pseudotuberculosis, including bacterial survival under stress conditions, flagella formation, biofilm development and T6SS expression. We found that RpoS is important in resistance to multiple stressors–including H2O2, acid, osmotic and heat shock–in Y. pseudotuberculosis. In addition, our study showed that RpoS not only modulates the expression of T6SS but also regulates flagellum formation by positively controlling the flagellar master regulatory gene flhDC, and affects the formation of biofilm on Caenorhabditis elegans by regulating the synthesis of exopolysaccharides. Taken together, these results show that RpoS plays a central role in cell fitness under several adverse conditions in Y. pseudotuberculosis. |