Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Neda Nguyen - Florida A&M University
Pierce’s disease (PD) is a significant threat to grape cultivation and industry. The disease caused by the bacterium Xylella clogs xylem vessels by the formation of biofilm and results in the wilting of plant. Xylem sap is known to contain signal transduction proteins, stress-related proteins and pathogenrelated proteins. However information regarding the total protein composition of Vitis xylem sap is limited. Hence, the study was carried out to investigate xylem sap proteome of different Vitis species to understand the genetic diversity and various metabolic pathways associated with PD tolerance. In this study, we include V. vinifera (bunch), Florida Hybrid bunch grape (FH) and V. rotundifolia (muscadine) cultivars to characterize differentially expressed and unique proteins. A total of 402 xylem sap proteins were identified using LC MS/MS, of which 185 proteins were common to all species. Bunch, FH, and muscadine sap showed 52, 53, and 30 unique proteins respectively. The cluster dendrogram analysis the proteome showed that all of the Vitis species are bifolious. Florida hybrid bunch and muscadines are more closely related to each other than the bunch grape. Functional analysis revealed that carbohydrate proteins are abundant in bunch grape, while defense related proteins are more abundant in FH and muscadine grape. Proteins such as beta-1, 3-glucanase, WD repeat-containing protein, peroxidase, and receptor-like protein kinase feronia-like are involved in defense responses and contribute to the plant defense mechanism against bacterium and oxygen generation are uniquely found in the muscadine xylem sap. Proteins involved in the defense and peroxidase activity, are present in abundant levels in FH and muscadine xylem sap and in reduced levels in bunch xylem sap indicate possible role conferring the PD tolerance to Florida hybrid and muscadine cultivars.
Funder Acknowledgement(s): National Science Foundation
Faculty Advisor: Ramesh Katam,