Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2007
Publication Date: N/A
Technical Abstract: Early development of grape berries is marked by several biological changes, including cell division and expansion, as berries initiate double sigmoid growth. In most genotypes, a significant gain of ontogenic resistance (OR) to some pathogens, including powdery mildew (PM) (Uncinula necator), also occurs within the first 3-weeks following bloom. The prior identification of a genotype that remains susceptible to PM provided genetic variation for exploring hypotheses for mechanisms of OR while characterizing conserved aspects berry development in diverse Vitis spp. Wax extractions from several time points of 6 genotypes were analyzed using GC-FID. Profile changes related to development were identified, in accordance with previous studies, and are being evaluated for the correlation to OR. Aspects of the physical development of the cuticle were investigated using SEM, but no significant patterns were shown to correlate to OR. Comparative proteomic analysis using computational bulking of samples based on phenotype with DiGE technology was used to compare protein expression of developing berry peels. Identification of the approximately 10% of the total pool of proteins that are differentially expressed in the first weeks of development is being conducted. In this study, genetic diversity is supporting the identification of candidate mechanisms for OR while distinguishing conserved hallmarks of early berry development.