Biological and molecular properties of a begomovirus from Dicliptera sexangularis

Sixangle foldwing, Dicliptera sexangularis (Acanthaceae), showing severe ye llow mottle and leaf distortion symptoms was collected from the shoreline o f Calusa Island (Lee County, FL). The putative virus was transmitted from i nfected D. sexangularis to healthy seedlings by mechanical, whitefly (Bemis ia tabaci biotype B), and graft-inoculations. Different forms of geminiviru s-like DNAs were detected in total DNA extracted from infected plants by So uthern blot hybridization analyses using DNA-A and -B of Bean golden mosaic virus (BGMV) from Guatemala as probes. Preliminary polymerase chain reacti on experiments and sequence comparisons indicated that the virus was a dist inct bipartite begomovirus. The virus was designated Dicliptera yellow mott le virus (DiYMV). Replicative dsDNAs of DiYMV were extracted, digested with selected restriction enzymes, and cloned into a plasmid vector. Both DNA-A and -B were sequenced and compared with those of other begomoviruses. Phyl ogenetic analyses using AV1, AC1, and BV1 nucleotide sequences indicated th at DiYMV has a close relationship with the New World begomoviruses, especia lly those distributed in the nearby geographic areas of the Florida coast a nd the Caribbean Basin. However, different percent nucleotide sequence iden tities and phylogenetic relationships were detected when different open rea ding frames (ORFs) of DiYMV were compared with their counterparts from bego moviruses from the Caribbean Basin. Based on phylogenetic analyses of the A C1 and BV1 ORFs, DiYMV was closely related to BGMV type ii isolates, wherea s sequence comparisons of the common region and the AC4-derived amino acid sequences indicated its close relationship with Potato yellow mosaic virus from Venezuela.