Molecular Properties of Bari 1, a Mild Strain of Cauliflower Mosaic Virus

Abstract
We studied aspects of the structure and expression of the genome of Bari 1, a mild strain of cauliflower mosaic virus. Differences were observed between gene products of Bari 1 detected in inclusion body preparations and those of the more typically severe strain, Cabb B-J1. The most striking difference was the gel mobility of the Bari 1 gene VI polypeptide (apparent Mr 70K) which contrasted with that of Cabb B-JI(Mr 62K). This difference was also observed between products of in vitro translation of viral mRNA suggesting that it was not due to post-translational modification. The open reading frame in the nucleotide sequence of the Bari 1 gene VI region was very similar in size to that of other CaMV strains but corresponded to an amino acid sequence with a much lower overall homology and diverged greatly in a 40 base pair sequence in the 3'' region compared to gene VI sequences of other strains. The level of the Bari 1 aphid transmission polypeptide P18, the product of gene II, was much lower than that of Cabb B-JI. Some of the possible subcellular consequences resulting from the molecular properties of Bari 1 were examined by electron microscopy. Differences were observed in the composition and intactness of Bari 1 cytoplasmic inclusion bodies compared with those of a severe strain, and the presence of nuclear inclusions.

This publication has 30 references indexed in Scilit: