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United States Department of Agriculture

Agricultural Research Service

Title: Linking the Model of the Development of Pd Grapevines to An Understanding of the Dynamics of Glassy-Winged Sharpshooter Transmission of Xylella Fastidiosa to Grapevines and Grapevine Gene Expression Markers of Pd

Authors
item Labavitch, John - UNIV OF CA-DAVIS
item Backus, Elaine
item Matthews, Mark - UNIV OF CA-DAVIS
item Shackel, Ken - UNIV OF CA-DAVIS

Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: October 13, 2004
Publication Date: December 7, 2004
Citation: Labavitch, J., Backus, E.A., Matthews, M., Shackel, K. 2004. Linking the model of the development of pd grapevines to an understanding of the dynamics of glassy-winged sharpshooter transmission of xylella fastidiosa to grapevines and grapevine gene expression markers of PD. Proceedings of CDFA Pierce's Disease Control Program Research Symposium. p. 22-24.

Interpretive Summary: Previous research has shown that xylem vessel obstruction are early consequences of infection with Xylella fastidiosa (Xf), before bacterial populations are substantial and have spread far from the inoculation point. This new project will study the role of Xf enzymes in cell wall breakdown, especially of pit cell membranes. Preliminary results imply greater porosity of pit cell membranes between xylem vessel elements in infected vs. healthy stems. Thus, pit membranes probably are being opened up in infected veines, perhaps to permit the systemic movement of Xf.

Technical Abstract: Previous research has shown that xylem vessel obstruction (tyloses, plant cell wall component-derived gels and bacterial extracellular polysaccharides) are early consequences of infection with Xylella fastidiosa (Xf), before bacterial populations are substantial and have spread far from the inoculation point. Also, ethylene treatment of vines also triggers vessel obstruction development and reduced water movement. This new project will study the role of Xf enzymes in cell wall breakdown, especially of pit cell membranes. Preliminary results show that colloidal gold particles of 20 nm diameter cannot move through healthy stem segments, but can through PD-symptomatic stems, implying loss of polymer integrity in pit cell membranes between xylem vessel elements, hence greater porosity. Thus, pit membranes probably are being opened up in infected veines, perhaps to permit the systemic movement of Xf.

Last Modified: 11/27/2014
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