MAGNETIC RESONANCE IMAGING: A NON-DESTRUCTIVE APPROACH FOR DETECTION OF XYLEM BLOCKAGES IN XYLELLA.FASTIDIOSA-INFECTED GRAPEVINES

• Author(s): Labavitch, John; Shackel, Ken; Greve, Carl; Matthews, Mark; Perez, Alonso; Walton, Jeffrey;
• Abstract: Our report in the 2005 Pierces Disease Research Symposium (Shackel and Labavitch, 2005) demonstrated the value of using MRI to follow the development of cavitations in grapevine xylem following introduction of Xylella fastidiosa (Xf) via needle inoculation. Strong correlations between increasing proportions of stem xylem conduits that were cavitated, visualized using MRI, and decreased water conductance. Similar observations were made on stems after treatment of vines with ethylene, supporting, but not proving, the suggestion of our Pierces disease (PD) development model (Labavitch et al., 2005) that vine ethylene production was an important factor in the development of Xf infection. This years effort has been devoted primarily to the replication of the observations of the first two years of this project. In addition, we have continued with the development of conventional, destructive anatomical approaches that we will use to define the nature of the more permanent xylem obstructions, gels and tyloses, whose presence in the water conduits of infected vines may be associated with the occurrence of cavitations. Finally, after considerable delay, we can report that our collaboration with colleagues in the University of California, Davis (UCD) NMR Facility to develop an NMR probe designed for ease of use in grapevine imaging and greater resolution appears to be on course.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium