Complete nucleotide sequence of a nonvector-transmissible strain of abutilon mosaic geminivirus in Hawaii

The complete nucleotide sequence of a geminivirus infecting lantern 'ilima (Abutilon hybridum) in Hawaii was determined. Sequence analysis showed that this geminivirus was a strain of Abutilon mosaic geminivirus (AbMV-HI). The genome of AbMV-HI consisted of two circular, single-stranded DNA molecules of 2,634 bases (DNA-A) and 2,571 bases (DNA-B). AbMV-HI shared 95 and 91% nucleotide sequence identity with the DNA-A and DNA-B components, respectively, of a West Indian strain of AbMV (AbMV-WI). AbMV-HI also shared 90% identity with the deduced amino acid sequences of the coat proteins of tomato mottle virus, bean dwarf mosaic virus, and potato yellow mosaic virus. Results of transmission experiments showed that AbMV-HI was not transmissible by the sweet potato whitefly Bemisia tabaci. The derived amino acid sequences of the coat proteins of two nonwhitefly-transmissible strains of AbMV were compared with those of 19 whitefly-transmissible geminiviruses. Five amino acids in the N-terminal region of the coat proteins were identical for two strains of AbMV, but were different from vector-transmissible geminiviruses. These results suggested that some or all of the five amino acids at the N-terminal end of the coat protein may have been involved in whitefly transmission of bipartite geminiviruses.