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Etiology

Citrus Tristeza Virus: Characterization of Coat Proteins. R. F. Lee, University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850; L. A. Calvert(2), J. Nagel(3), and J. D. Hubbard(4). (2)University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850; (3)University of Florida, Institute of Food and Agricultural Sciences, Department of Plant Pathology, Gainesville 32611; (4)U.S. Grain Marketing Research Lab, USDA, SEA-ARS, Manhattan, KS 66502. Phytopathology 78:1221-1226. Accepted for publication 18 April 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/Phyto-78-1221.

The coat proteins of several aphid-transmitted Florida isolates of citrus tristeza virus (CTV) were characterized by polyacrylamide gel electrophoresis, western blotting followed by serological probing, and polypeptide mapping on sodium dodecyl sulfate polyacrylamide gels following treatment with proteolytic enzymes. All isolates had a major coat protein (CP1) of about M_r 23,000 and a minor coat protein (CP2) of about M_r 21,000, both of which reacted with CTV-specific antisera when using western blot and enzyme-linked immunosorbent assays. The amino acid composition of CP1 was similar to that reported for the coat proteins of other closteroviruses. Polypeptide maps of CP1 and CP2 were similar. In vitro translation of RNA extracted from purified virions produced proteins of various sizes, but only one peptide of about M_r 26,000 was immunoprecipitated with CTV-specific antiserum.