ARS | Publication request: CHARACTERIZATION OF XYLEM ANATOMICAL STRUCTURES AND THE EFFECT OF XYLEM SAP FROM VITIS TO PIERCE'S DISEASE

Submitted to: American Society of Enology and Viticulture Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 2005
Publication Date: June 20, 2005
Citation: Lin, H., Fritschi, F.B., Walker, A., Barros, S. 2005. Characterization of xylem anatomical structures and the effect of xylem sap from vitis to pierce's disease. [Abstract]. American Society of Enology and Viticulture Annual Meeting. p.48

Technical Abstract: This study tests the hypothesis that Pierce's disease (PD) resistance is due to the presence of chemical factors, e.g. anti-microbial 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 Xf's mobility in xylem. A wide range of PD resistance from various genetic backgrounds of Vitis species was selected for this study. To evaluate if PD resistance is associated with xylem structure, a PD resistant stem was bridged with PD susceptible grape. This inter-grafting method allows examining how the pathogen moves cross resistant xylem tissue. ELISA assay was carried out for quantitative measurement. SEM was used to characterize xylem structure. To test if the effect of xylem sap collected from PD resistant grape presents any antimicrobial activity which affects biofilm formation or suppress Xf growth, an in vitro bioassay method was developed. The preliminary bioassay results suggest that xylem saps from some PD resistant grapes may have effect on bacterium biofilm formation and growth when the test was compared with the sap from V. vinifera cv. Chardonnay.