Grant: Discovery Grants Program - Individual

Plant viruses are obligate intracellular parasites that infect many major crops and cause yearly losses over multibillion dollars in the world. Potyviruses constitute the largest group of plant viruses, including approximately 30% of all known plant viruses. Some of the most agriculturally important potyviruses include Turnip mosaic virus (TuMV), Clover yellow vein virus (ClYVV), Plum pox virus (PPV), Soybean mosaic virus (SMV), Potato virus Y (PVY), and Tobacco etch virus (TEV). One of the common properties shared by plant potyviruses and other plant viruses is their relatively small genome with a very limited protein-coding capacity. Thus, these viral pathogens must interact with host cells to recruit an array of host proteins (host factors) and metabolites to fulfill their life cycles. Recent studies on virus-plant interactions have identified several host factors. It has been shown that some of them can be manipulated to generate genetic resistance against target viruses. Thus, a better understanding of molecular potyvirus-host interactions may result in new strategies to control plant potyviruses as well as other plant viruses. In search for host factors, in the previous funding cycle, we have screened out approximately 4000 host factor gene candidates using diverse tools such as microarray, yeast two-hybrid system, and expressed sequence tags. These candidate genes include genes coding for translation initiation factors that may be required for viral genome translation, RNA helicase proteins that may participate in viral RNA replication, assembly and transport, and vesicular transport proteins that may be essential for the intracellular trafficking of virus replication complexes. This proposal will enable the identification of genes in these three important gene groups required in potyviral infection, and further characterization of their roles in the formation, function and trafficking of the virus replication complex. Therefore, this proposal will advance our knowledge of the virus replication mechanism. It is anticipated that the new knowledge generated in this study will contribute to the development of novel antiviral strategies.