Maya Abboud, University of Guelph

Dr. Baozhong Meng

Expressing & Multiplying

Grapevine rupestris stem-pitting associated virus (GRSPaV) is one of the most prevalent viruses infecting grapevines worldwide. It belongs to the Betaflexiviridae plant virus family and is further organized into the Foveavirus genus, home to many detrimental viruses that infect agriculturally significant crops. The Foveavirus genus impacts global agriculture not by catastrophic outbreaks, but through slow chronic reduction in plant vigor and yield, making them difficult to contain. Despite the prevalence of GRSPaV, little is known about its replication within the host. It has been hypothesized that GRSPaV uses strategies like that of Potato Virus X (PVX), arguably the most well understood plant virus, based on the undeniable similarities in genome organization. Nonetheless, this correlation has yet to be experimentally determined. This study aims to understand how GRSPaV expresses all encoded proteins. This is currently being investigated through northern blotting to identify the number of sub-genomic RNAs the viral polymerase transcribes and their relative size. Stable positive controls have been established, and testing of total RNA samples isolated from model plants infected with GRSPaV is underway. Once this has been established, the transcription start sites of each sgRNA will be identified through 5' Rapid Amplification of cDNA Ends (5'RACE). This will help establish how GRSPaV replicates within its host and identify promoter elements suitable therapeutic targets for anti-viral development. This study is important for the management of GRSPaV and will also shed light on viruses belonging to the entire Foveavirus genus and even the Betaflexiviridae family.