Expression rate of the Zonula Occludens Toxin (zot) gene in two growth states and two media types of Xylella fastidiosa

Xylella fastidiosa is the causal agent of many plant diseases, inclduing Pierce's Disease of grapevines, citrus variegated chlorosis in orange trees, and leaf scorch in almonds, alfalfa, oleander, and coffee. A detailed pathogenic mechanism has not been described, though a combination of factor...

Full description

Saved in:
Bibliographic Details
Published in:Phytopathology 2010-06, Vol.100 (6), p.S116-S116
Main Authors: Schreiber, H L, Skipper, CE, Repshare, J M, Morano, L D, Bextine, B R
Format: Article
Language:English
Subjects:
Citrus
Nerium oleander
Prunus dulcis
Ralstonia solanacearum
Vitaceae
Vitis vinifera
Xanthomonas campestris
Xylella fastidiosa
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Xylella fastidiosa is the causal agent of many plant diseases, inclduing Pierce's Disease of grapevines, citrus variegated chlorosis in orange trees, and leaf scorch in almonds, alfalfa, oleander, and coffee. A detailed pathogenic mechanism has not been described, though a combination of factors leading to xylem occlusion seems likely. Recently the Zonula Occludens Toxin (Zot) was noted as a possible virulence factor in X. fastidiosa. Zot is an exotoxin produced by the prophage gene zot which is homologous to the zot gene found in other phytopathogens, such as Xanthomonas campestris and Ralstonia solanacearum. Many pathogenic bacteria, including X. fastidiosa, lose virulency after serial passages through axenic media as the expression of virulence genes is downregulated. Using quantitative, real-time polymerase chain reactions (qRT-PCR), this study quantified the expression rate of the zot gene relative to a conserved housekeeping gene gyrase B (gyrB) in newly harvested (NH) and serially passed (SP) cultures of X. fastidiosa grown in axenic media or media augmented with extracted xylem sap from Vitis vinifera. This comparison revealed significant differences in zot expression rate between NH and SP cultures of X. fastidiosa as well as differences between rates zot expression in X. fastidiosa grown in axenic media and X. fastidiosa cultured in augmented media. These results support the hypothesis that the Zot exotoxin is a virulence factor in X. fastidiosa.
ISSN:0031-949X