ANALYSIS OF THE NUCLEOTIDE-SEQUENCE OF THE TREEHOPPER-TRANSMITTED GEMINIVIRUS, TOMATO PSEUDO-CURLY TOP VIRUS, SUGGESTS A RECOMBINANT ORIGIN

The genome of tomato pseudo-curly top virus (TPCTV), originating from Florida, has been cloned and sequenced. TPCTV is the only geminivirus identified with a vector specificity which falls outside the Cicadelli dae (leafhoppers) and Aleyrodidae (whiteflies). Infectivity of the clo ned viral genome was demonstrated by Agrobacterium-mediated inoculatio n of several host species. Progeny virus was transmissible by the tree hopper vector of TPCTV, Micrutalis malleifera (Fowler). The genome of TPCTV shows features typical of both subgroups I and III genera of the family Geminiviridae. The coat protein of TPCTV, although distinct fr om all previously characterized geminiviruses, exhibits features more akin to the leafhopper-transmitted geminiviruses than those transmissi ble by the whitefly Bemisia tabaci Genn. The relationship of TPCTV to other geminiviruses, particularly beet curly top virus, is discussed i n relation to the possible evolutionary origins of this virus. (C) 199 6 Academic Press, Inc.