Detection of Viral Proteins in Cytopathic Structures in Cowpea Protoplasts Infected with Cowpea Mosaic Virus

Infection of cowpea (Vigna unguiculata) cells or protoplasts with cowpea mosaic virus is accompanied by the appearance of characteristic cytopathic structures. A major constituent of these cytopathic structures, represented in thin sections by electrondense material, was shown to contain viral non-structural proteins by its reaction with antisera to non-structural proteins and their detection with colloidal gold-labelled Protein A. With this same technique virus particles were found to accumulate mainly in the cytoplasm.