VIEW ARTICLE

Cytology and Histology

Association of Virions and Coat Protein of Tobacco Vein Mottling Potyvirus with Cylindrical Inclusions in Tobacco Cells. E. D. Ammar, Department of Plant Pathology, University of Kentucky, Lexington 40546; E. Rodríguez-Cerezo(2), J. G. Shaw(3), and T. P. Pirone(4). (2)(3)(4)Department of Plant Pathology, University of Kentucky, Lexington 40546; (2)Current address: Centro Nacional de Biotechnologia-CSIC, Campus Universidad Autónoma, 28049 Madrid, Spain. Phytopathology 84:520-524. Accepted for publication 24 February 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/Phyto-84-520.

The course of infection with tobacco vein mottling potyvirus (TVMV) in tobacco protoplasts and leaves was studied by electron microscopy with immunogold labeling. In sections of protoplasts inoculated with TVMV RNA 10, 21, or 45 h prior to fixation, antibodies to TVMV coat protein (CP) were bound to cylindrical inclusions and individual virions usually associated with these inclusions. Also, in sections of leaves from plants inoculated with TVMV 5, 14, or 21 days prior to fixation, antibodies to TVMV CP were bound to cylindrical inclusions and aggregates of virions in the cytoplasm. In protoplasts and leaves, the specific labeling of CP on the cylindrical inclusions increased significantly with time postinoculation, and in most cases, these inclusions were associated with the rough endoplasmic reticulum. Association of TVMV virions and CP with cylindrical inclusions at early stages of infection suggests that these inclusions may be involved in potyviral protein synthesis and virion assembly in addition to their possible role in viral RNA replication.