AUTHOR=Fan Xiaojing , Guo Jing , Zhou Yinghui , Zhuo Tao , Hu Xun , Zou Huasong 

TITLE=The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01171

DOI=10.3389/fmicb.2018.01171

ISSN=1664-302X

ABSTRACT=<p><italic>Xanthomonas citri</italic> subsp. <italic>citri</italic> (<italic>Xcc</italic>) is the major causal agent of citrus canker disease. The <italic>XAC1347</italic> gene, which encodes a conserved membrane protein in <italic>Xcc</italic>, is required for virulence during infection. However, the molecular events mediated by <italic>XAC1347</italic> remain unclear. In this study, we reported that <italic>XAC1347</italic> gene is positively regulated by two component regulatory system <italic>ColRS</italic> and required for type III secretion system function. A non-polar deletion mutant of the <italic>XAC1347</italic> gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that <italic>XAC1347</italic> gene is induced by copper ions. The expression levels of representative genes from four <italic>hrp</italic> operons, including <italic>hrpB1, hrcV, hrpF</italic>, and <italic>hrpD6</italic>, were reduced in <italic>XAC1347</italic> mutant, indicating that <italic>XAC1347</italic> is involved <italic>hrp</italic> gene expression.</p>