Abstract
Disc electrophoresis of the soluble proteins in leaf extracts failed to reveal any change induced by infection with raspberry ringspot virus either in inoculated or in systemically infected symptom-bearing or recovered leaves of Nicotiana benthamiana. Evidence is given that three of the four proteins previously thought to occur only in virus-infected or polyacrylic acid-injected Nicotiana tabacum leaves are probably normal constituents. Environmental conditions were critical for the change in protein pattern induced by alfalfa mosaic virus in tobacco leaves.