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TECHNICAL SESSION: From virus biology to management strategies

Characterization of novel thrips vector proteins that bind to tomato spotted wilt virus
Yuting Chen - North Carolina State University. Kathleen Martin- North Carolina State University, Ismael Badillo-Vargas- Texas A&M AgriLife Research, Anna Whitfield- North Carolina State University, Dorith Rotenberg- North Carolina State University

Tomato spotted wilt virus (TSWV) is transmitted by thrips species in a persistent, propagative manner. Frankliniella occidentalis is the most efficient vector, but at least six other thrips species are competent vectors. The TSWV structural glycoprotein (GN) plays an important role in viral attachment and possibly entry into insect host cells. However, the insect molecules that interact with GN during infection and dissemination in thrips vector are still largely unknown. The goals of this study were to characterize TSWV-interacting proteins (TIPs) that interact directly with TSWV GN and to localize expression of these proteins in thrips tissues of importance along the route of virus dissemination. We identified six novel TIPs from first instar larvae (L1) that share homology to proteins associated with the infection cycle of other vector-borne viruses. Two of the thrips proteins, endocuticular structural glycoprotein (endoCP-GN) and cyclophilin, were validated to be consistent interactors with GN in membrane-bound yeast two-hybrid and insect cell co-localization assays. Immunolocalization of these TIPs in L1s revealed robust expression in the midgut and salivary glands of F. occidentalis, the key tissues during viral infection, replication and plant-inoculation. In addition, the homologous endoCP-GN from another thrips vector F. fusca was cloned and validated to interact with TSWV GN. Our findings suggest that the TIPs-GN interaction occurs in vivo and the TSWV GN-endoCP-GN interaction may be conserved among Frankliniella vector species of TSWV.