Assistant Professor of Plant Pathology

The long-range goal of my research is to decipher virus/host interactions involved in induction and suppression of host defense mechanisms including RNA silencing. Our work utilizes Geminiviruses, which are eukaryotic DNA plant viruses that cause significant diseases of crops worldwide, increasing public health problems such as malnutrition and starvation. Initiation and development of viral disease depends on key interactions between the virus and host, including suppression and/or modulation of host defense responses. Geminiviruses code for a multifunctional protein, AL2, that modulates metabolism, regulates transcription and suppresses RNA silencing. Identification of cellular components involved in RNA silencing is significant because this is an ancient mechanism conserved across kingdoms that targets aberrant RNA, both genomic and viral, for degradation. Both animal and plant viruses have evolved to code for proteins to suppress this innate defense response. Most viral-encoded suppressors of RNA silencing function in both animal and plant cells, regardless of viral origin, and so it is logical to assume these suppressors target conserved components of the silencing pathway. Identification of cellular factors involved in RNA silencing in plants, could therefore facilitate the identification, cloning and functional annotation of mammalian homologues. Virus infections are useful model systems for understanding this defense mechanism, and will be beneficial towards improving the practical application of RNA silencing technology as an antiviral therapy. Viral silencing suppressors also represent potent targets for the development of antiviral vaccines. Moreover, elucidating molecular mechanisms by which viruses interact with components of the RNA silencing pathway to both induce, and suppress silencing, will likely have a significant impact on our understanding of innate immunity in animals and humans. RNA silencing also plays a key role in regulating differentiation and development in animals and plants, and identifying genes in this pathway will contribute to our understanding of this eukaryotic transcriptional regulatory mechanism. This has the potential to provide insight into the consequences of defects in this pathway in human disease. Understanding defense responses in plants will also significantly benefit both human and environmental health through enhanced food production, and development of alternate strategies for reducing pesticide use in plant disease control.