INSECT-SYMBIOTIC BACTERIA INHIBITORY TO XYLELLA FASTIDIOSA IN SHARPSHOOTERS: PRESSURE BOMB EXTRACTION OF XYLEM FLUID TO IMPROVE BACTERIAL DETECTION OF XYLELLA IN PLANTS

• Author(s): Bextine, Blake; Miller, Thomas; Cooksey, Donald; Lampe, David; Lauzon, Carol;
• Abstract: The glassy-winged sharpshooter (GWSS) is the principal vector of the xylem-limited bacterium Xylella fastidiosa (Xf), which causes Pierces disease (PD) in grapes and oleander leaf scorch. Limiting the spread of this pathogen by rendering GWSS incapable of pathogen transmission is a promising method of pathogen control. Paratransgenic approaches to pathogen control are currently being developed to deliver single-stranded antibodies to disrupt Triatomid transmission of Trypanosoma cruzi (Beard et al. 2002), and to prevent colitis in mammals (Beninati 2000; Steidler, 2002). Candidate paratransgenic bacterial agents must thrive in the cibarial/foregut area where they will be in close proximity to the pathogen, Xf for a paratransgenic strategy to be applicable to the Xf/GWSS system. Alcaligenes xylosoxidans denitrificans (Ax) was cultured and identified from the cibarium and foregut regions of GWSSs alimentary canal several times throughout the growing season indicating that it is a consistent symbiotic organism (Lauzon, in preparation). Ax has been described as a non-pathogenic plant endophyte and a non-pathogenic soil-borne microbe (Meade et al. 2001, Yang et al. 1999). This bacterium was genetically transformed with exogenous DNA being incorporated into the chromosome to express fluorescent markers (Lampe, in preparation). My project was to set up a disease cycle, which would offer evaluation of paratransgenic delivery. To do this it was important to improve detection of Xf.
• Publication Date: Dec 2002
• Journal: 2002 Pierce's Disease Research Symposium