ABSTRACT
Cauliflower mosaic virus (CaMV) is the prototype member of the caulimoviruses, a group of double-stranded DNA viruses that infect higher plants. Artificial recombinants between different phenotypic strains of CaMV in addition to insertional mutants have allowed the association of biological functions with particular segments of the CaMV genome. The minichromosome is active in transcription and contains DNA associated with histones in a nucleosomal structure. Gene V of CaMV specifies the reverse transcriptase, which participates in replication of viral DNA. Comparisons of the amino acid sequence (inferred from the nucleotide sequence of gene V) with that of known reverse transcriptases show a high degree of homology. The understanding of the genetic organization of CaMV is based largely on the DNA sequences of three strains of the virus. The caulimoviruses are dependent on insects for movement from infected plants to healthy ones, except in cases where the infected host is vegetatively propagated.
