CHARACTERIZATION AND IDENTIFICATION OF PIERCES DISEASE RESISTANCE MECHANISMS: ANALYSIS OF XYLEM ANATOMICAL STRUCTURES AND OF NATURAL PRODUCTS IN XYLEM SAP AMONG VITIS

• Author(s): Lin, Hong; Walker, Andrew;
• Abstract: This research tests the hypothesis that Pierces disease (PD) resistance is due to the presence of chemical factors, e.g. antimicrobial compounds expressed in the xylem sap that suppress Xylella fastidiosa (Xf) and /or are due to anatomical features of the xylem, e.g. pit membrane that restrict Xfs mobility in xylem. A wide range of PD resistance from various genetic backgrounds of Vitis species was selected for this study. To determine if pathogen movement in xylem is related to anatomic structure, an inter-grafting method was used to evaluate the movement of Xf across between PD susceptible and resistant stems. SEM and quantitative PCR were used for this study. To test the effect of xylem sap, an in vitro bioassay method was developed. The preliminary bioassay results suggest that xylem saps from PD resistant grapes may have effect when the test was compared with the sap from V. vinifera cv. Chardonnay.
• Publication Date: Dec 2004
• Journal: 2004 Pierce's Disease Research Symposium