Proteome and Metabolite Changes in Various Cultivars of Grape Berry Provide Insights into Central Metabolism

Grape berries (Vitis sps.) are well known for variety of nutraceutical characteristics, with potential anticancer activity. Florida hybrid bunch grape (FH) are unique as they also show tolerance to Pierce’s disease (PD). This study integrates proteome and metabolite analysis to gain insight of changes in metabolic activities during berry development. Total, 2602 proteins were identified in cv. Blanc Du Bois (BDB) on an LTQ XL mass spectrometer and 163 were differentially expressed (p value <0.05) spread in 6 clusters across the developmental stages. GO terms revealed 32 proteins, known to be antioxidant activity. Comparative proteome studies on mature berries of different cultivars (cv. BDB, Suwanee, Blue Lake) showed 67 differentially expressed proteins suggesting the genetic diversity for disease and stress tolerance. Cultivar, Blue lake showed high expression level of active energy and secondary metabolism that enhanced the synthesis of active compounds. Semi-quantitative RT-PCR analysis of selected genes followed similar expression pattern as in proteins. Protein-protein interaction studies using pull down assay reveal that, differentially expressed proteins are associated with transcriptional regulation, scavenging ROS and the biosynthesis of nutraceutical compounds. Our findings suggest the tolerant characteristics of cv. Blue lake by increased expression of resistant genes, and morphological plasticity due to epigenetic modifications. Supported by NSF Awards 0741876/1156900.