Accumulation kinetics of viral gene products in cauliflower mosaic virus-infected turnip protoplasts.

The expression of cauliflower mosaic virus (CaMV) genes was studied in a turnip protoplast system. Six CaMV-encoded gene products were detected in infected turnip protoplasts by means of Western blotting. The infected turnip protoplasts showed different patterns of protein accumulation; e.g. an open reading frame (ORF) I-encoded movement protein, an ORF V-encoded reverse transcriptase and an ORF VI-encoded posttranscriptional transactivator representing the early accumulated proteins, an ORF II-encoded aphid transmission factor and an ORF IV-encoded coat protein the late accumulated proteins and an ORF III-encoded DNA binding protein the intermediate protein. The results suggest that the expression of CaMV genes is differentially regulated.