|BARRETO-SANDOVAL, YANETH - Fresno State University|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2019
Publication Date: 8/3/2019
Citation: Burbank, L.P., Barreto-Sandoval, Y. 2019. Role of Xylella fastidiosa PNPase in RNA metabolism during cold stress and virulence in grapevine. American Phytopathological Society Abstracts.
Technical Abstract: Xylella fastidiosa (Xf) is a xylem-obligate plant pathogenic bacterium that causes diseases in diverse crop plants. In grapevines the infection known as Pierce’s disease is limited to regions with warmer climates. In previous research, it was observed that grapevines infected with Xf can lose the infection during the winter season (“cold curing”), but this phenomenon is not completely understood. Compared with other bacterial pathogens, Xf lacks certain aspects of cold response, including expression of cold-inducible cold shock proteins. Due to the importance of cold shock proteins in RNA stabilization, this study investigates the role of RNA metabolism in Xf in response to cold temperatures, specifically a polynucleotide phosphorylase homolog (PNPase). PNPase has been characterized in other bacterial systems for RNA exonuclease and polymerase activity essential to survival at low temperatures. Xf PNPase is differentially expressed at the transcriptional level in a cold shock protein mutant (Xf 'csp1) as determined by RNAseq analysis, and purified Xf PNPase shows functional activity in an RNA synthesis assay. An Xf PNPase knockout mutant ('pnp) is currently being evaluated for cold survival, in planta virulence, and cold-inducible gene expression. The results will provide important information regarding Xf cold response which is relevant to understanding the mechanism of cold curing of Xf in grapevine.