Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2012
Publication Date: 8/4/2012
Citation: Rogers, E.E. 2012. Characterization of novel secreted proteins from Xylella fastidiosa. Phytopathology. 102:S4.102.
Technical Abstract: Xylella fastidiosa is a bacterium that causes disease of agriculturally important crops, including Pierce’s disease of grapevine. Little is known about virulence factors that are necessary for X. fastidiosa to grow and cause disease in the xylem vessels of a plant host. Any protein secreted by the bacterium has the potential to interact with the plant host and affect pathogen virulence and/or recognition. A number of novel X. fastidiosa proteins with predicted signal sequences for secretion were investigated. An E. coli model system and/or X. fastidiosa itself was used to confirm secretion for the majority of tested proteins. A tobacco rattle virus (TRV) vector was used to express these proteins and examine effect on pathogenicity of TRV in Nicotiana benthamiana. Of 58 proteins assayed, 8 were shown to reproducibly and significantly increase the virulence of TRV, implying they function as pathogenicity factors in X. fastidiosa. Currently, mutations are being constructed in each of the 8 candidate pathogenicity factors in X. fastidiosa; once knock-out strains are available, disease assays in grapevine will be performed.