BINDING OF TOMATO SPOTTED WILT VIRUS TO A 94-KDA THRIPS PROTEIN

Using protein blot assays, a 94-kDa thrips protein was identified that exhibited specific binding to tomato spotted wilt virus (TSWV) partic les. Renaturation of the 94-kDa protein, which is conserved among the two major vector species of TSWV, Frankliniella occidentalis and Thrip s tabaci, was crucial for its virus-binding properties, whereas under the same conditions no specific binding was observed with aphid (Myzus persicae) proteins. The 94-kDa protein species was present in all dev elopmental stages of both vectoring thrips, whereas it was present mai nly in the adult stage of a nonvectoring thrips species, Parthenothrip s dracenae. Using antibodies against the different TSWV structural pro teins, the G2 envelope glycoprotein was identified as the viral determ inant involved. Because the virus-binding protein is present throughou t the thrips body, but not in the gut, it may represent a receptor pro tein involved during circulation of the virus through its vector but p robably not during viral uptake in the midgut.