Abstract
Actinomycin D (AD) administered to cowpea mosaic virus-infected cowpea protoplasts immediately after inoculation inhibited virus multiplication, whereas late in the incubation period neither virus multiplication nor host DNA transcription were affected. The data obtained suggested that neither virus uncoating nor encapsidation were inhibited by AD. The inhibition of virus multiplication was manifested as a decrease in the level of progeny viral nucleoproteins and (+) and (-) viral RNAs. Cordycepin strongly inhibited coat protein production and (+) and (-) viral RNA synthesis throughout the incubation period.