The Copper-Binding Protein CutC Is Involved in Copper Homeostasis and Affects Virulence in the Xylem - Limited Pathogen Xylella fastidiosa.

Copper (Cu) is an essential element that can be toxic if homeostasis is disrupted. Xylella fastidiosa. 'a xylem - limited plant pathogenic bacte-inocularium that causes disease in many economically important crops world - wide. has been exposed to Cu stress caused by wide application of Cu-containing antimicrobials used to control other diseases. However. X fastidiosa Eu homeostasis mechanisms are still poorly understood. The potentially Cu - related protein CutC, which is involved in Cu tolerance iii Escherichia coli and humans, has not been analyzed functionally in plant pathogenic bacteria. We demonstrate that recombinantly expressed X faslidiosa Cute binds Cu and deletion of CutC gene( PD0586) iii X. fas·-lidiI )Sct showed increased sensitivity to Cu - shock compared with wild type( WT) strain TemeculaL. When infecting plants in the greenhouse. CltiC mutant showed deci ·eased disease incidence and severity compated with WT but adding Cu exaggerated severity. Interestingly, the inocularium tion of ClaC mutant caused reduced symptoms in the acropetal regions of plants. We hypothesize that X fastidiosa cute is involved in Cu homeostasis by binding Cu in cells, leading to Cu detoxification, which is crucial to withstand Cu - shock stress. Unveiling the role of cutC gene in X. fastidiosa facilitates further understanding of Cu homeostasis iii bacterial pathogens . [ABSTRACT FROM AUTHOR]