Cytopathic Structures Associated with Tonoplasts of Plant Cells Infected with Cucumber Mosaic and Tomato Aspermy Viruses

Electron microscopic examination of cucumber mosaic and tomato aspermy virus-infected leaf cells has revealed the presence of membrane-bound vesicles associated with the tonoplasts. The vesicles measured between 50 and 90 nm in diam. and the membranes of some were seen to be continuous with the tonoplast. Although the significance and function of the virus-specific vesicles is not clear, evidence is presented that they may be the sites of viral RNA synthesis.