Structure-Function studies on three complementary ORFs of grapevine red blotch virus to elucidate disease etiology

Red blotch disease is one of the major threats faced by the grapevine industry in the United States and caused by Grapevine red blotch virus (GRBV), a newly identified ssDNA virus within the family Geminiviridae. Since its initial identification in 2011, the disease has rapidly spread in the major US grape-growing regions of the Pacific Northwest, causing major economic impacts. Geminiviruses, the largest family of plant viruses can induce, and be targets of, host post-transcriptional gene-silencing (PTGS) anti-viral mechanisms. As a counter defense mechanism, viruses have evolved to possess viral silencing suppressor proteins to evade PTGS mechanisms and establish a successful infection in host plants. Towards the understanding the mechanism of red blotch disease through which GRBV causes disease symptoms in infected plants, I aimed at characterization of GRBV complementary strand encoded ORFs for their potential to act as host small RNA silencing suppressors. C2 ORF was identified as the candidate suppressor of PTGS. Through several molecular studies, I gained insights into the candidate interactions between GRBV C2 and host targets and investigated differential expression of host sRNA and mRNA targets in response to GRBV. The project goal, driven by this new knowledge, is to generate transgenic grapevine rootstocks expressing hairpin constructs targeting GRBV C2 suppressor. Such a disease resistance strategy could benefit the wine and table grape industry upon commercial deployment in transgenic rootstocks since the scions could be considered ‘non genetically modified organisms’ (non-GMO).

Embargo status: Restricted until 09/2027. To request the author grant access, click on the PDF link to the left.