Purification and Protein Characterization of Sorghum Stunt Mosaic Rhabdovirus. R. Creamer, Department of Plant Pathology, University of California, Riverside 92521; Phytopathology 82:1473-1476. Accepted for publication 11 September 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-1473.
Sorghum stunt mosaic rhabdovirus (SSMV) was purified from infected sweet corn by Celite filtration and sucrose density centrifugation. Bacilliform particles measuring 71 × 218 nm were observed in preparations by electron microscopy. Transmission of membrane-acquired purified virus to sweet corn by Graminella sonora indicated that the purified virus was infectious. Polyacrylamide gel electrophoresis of dissociated virions revealed four major proteins with calculated molecular mass of 91, 59, 36, and 30 kDa. After treating the virus with 2% Triton X-100 and 0.4 M NaCl, centrifugation resulted in a pellet containing the 59-kDa protein (and traces of the 36-kDa protein), indicating the presence in the viral core particle of the 59-kDa protein. The 91-kDa protein stained positive with Schiff’s reagent, indicative of a glycoprotein. The SSMV viral RNA was estimated to be 4.2 × 106 Da mol. wt., migrating identically to ssRNA of beet yellows virus in a 0.8% agarose gel. Antisera to a variety of other plant rhabdoviruses did not react with SSMV virions by indirect ELISA, and polyclonal rabbit antisera produced against SSMV did not react with any of the other plant rhabdovirus proteins assayed by western blotting.