AUTHOR=Li Kaihuai , Liao Jinxing , Wei Ming , Qiu Shanxu , Wu Weiyin , Zhao Yancun , Wang Haihong , Liu Qiongguang , Liu Fengquan , Chang Changqing 

TITLE=The Xanthomonas citri Reverse Fitness Deficiency by Activating a Novel β-Glucosidase Under Low Osmostress

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.887967

DOI=10.3389/fmicb.2022.887967

ISSN=1664-302X

ABSTRACT=<p>Bacteria can withstand various types of environmental osmostress. A sudden rise in osmostress affects bacterial cell growth that is countered by activating special genes. The change of osmostress is generally a slow process under the natural environment. However, the collective response of bacteria to low osmostress remains unknown. This study revealed that the deletion of <italic>phoP</italic> (Δ<italic>phoP</italic>) from <italic>X. citri</italic> significantly compromised the growth and virulence as compared to the wild-type strain. Interestingly, low osmostress reversed physiological deficiencies of <italic>X. citri phoP</italic> mutant related to bacterial growth and virulence. The results also provided biochemical and genetic evidence that the physiological deficiency of <italic>phoP</italic> mutant can be reversed by low osmostress induced β-glucosidase (BglS) expression. Based on the data, this study proposes a novel regulatory mechanism of a novel β-glucosidase activation in <italic>X. citri</italic> through low osmostress to reverse the fitness deficiency.</p>