Dr Jonathan Griffiths

Plant viruses are serious pathogens that can be difficult to study. In my lab, we are using multiple different approaches towards understanding and combating plant viral pathogens. Plum pox virus has been a major issue for stone fruit crops in Ontario for years. We are currently evaluating novel approaches to reduce the impact of this virus including a non-transgenic, topical RNAi approach to either downregulate host genes required for viral replication, or directly targeting this virus to reduce replication and viral load. We are also heavily involved in investigating the role of viruses in Sudden Apple Decline and Tree fruit decline, two disorders that have recently been plaguing tree fruit producers across Canada. We are using traditional surveying and pathology approaches to understand the distribution of major plant viruses in tree fruits. In grapes, we are employing an omics-based approach to understand the distribution and variation of major grape viruses in Ontario, which will be followed up with a reverse genetics approach to understand the function of major viral proteins. We are developing a novel survey approach using commercial pollination services to obtain quicker and cheaper images of plant virus distribution. We are evaluating how to sample honey bees used to pollinate fruit trees to detect plant viruses using an RNAseq approach. Finally, we are actively studying Tomato brown rugose fruit virus and Pepino mosaic virus, two similarly transmitted, yet distantly related tomato pathogens. We are also using a genetic mapping/positional cloning approach to identify sources of resistance to Tomato brown rugose fruit virus.