VIEW ARTICLE

Vector Relations

Role of Virion and Helper Component in Regulating Aphid Transmission of Tobacco Etch Virus. Thomas P. Pirone, Department of Plant Pathology, University of Kentucky, Lexington 40546; David W. Thornbury, Department of Plant Pathology, University of Kentucky, Lexington 40546. Phytopathology 73:872-875. Accepted for publication 27 December 1982. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-872.

Three isolates of tobacco etch virus (TEV) were either highly, poorly, or nontransmissible by aphids (HAT, PAT, or NAT, respectively) from infected plants. Purified virus of these isolates acquired through membranes was transmitted with high, intermediate, and low efficiency, respectively, in the presence of helper component (HC). Thus, intrinsic differences in properties of the virions, most likely differences in the coat proteins, appear to be responsible for differences in transmissibility. Helper component could be extracted from plants infected with each of the three isolates, and HC activity was highest from PAT-infected plants, suggesting that absence or deficiency of HC was not responsibile for differences in transmissibility. However, since aphids given access first to HC and then to infected plants were able to transmit the NAT isolate, and transmitted the PAT isolate with increased frequency, a role for HC in regulating the efficiency of aphid transmission from plants cannot be ruled out.