THE CONTRIBUTION OF THE PECTIN-DEGRADING ENZYME POLYGALACTURONASE (PG) IN TRANSMISSION OF XYLELLA FASTIDIOSA TO GRAPE AND THE USE OF PG-INHIBITING PROTEINS FOR TRANSGENIC RESISTANCE TO PIERCES DISEASE

• Author(s): Backus, Elaine; Labavitch, John; Morgan, David; Dandekar, Abhaya; Greve, Carl; Kirkpatrick, Bruce; Matthews, Mark; Perez, Alonso; Roper, Caroline; Rost, Thomas; Shackel, Ken;
• Abstract: Work this year has shown that the Xylella fastidiosa (Xf) polygalacturonase (PG) is an endo-acting enzyme. This provides us a reference that we can now use to biochemically characterize the interaction between the pathogens PG and PG inhibiting proteins (IPs) that is implied by the fact that transgenic expression of PGIPs protects vines against PD. We also report that PG, in combination with a bacterial -1,4-glucanase enzyme (BGase) that has also been discussed in previous reports can act to cause tears in the pit membranes that are likely to be barriers slowing the systemic spread of the Xf population. We also report on a few set-backs that have slowed our examination of the roles of insect plant cell wall-degrading enzymes in PD development. Fortunately, the set-backs are now being corrected so that important questions can be addressed in work supported by a no-cost extension.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium