Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2008
Publication Date: 5/2/2008
Citation: Li, W., Hilf, M.E., Webb, S.E., Baker, C.A., Adkins, S.T. 2008. Presence of P1b and absence of HC-Pro in Squash vein yellowing virus suggests a general feature of the genus Ipomovirus in the family Potyviridae. Virus Research. 135:213-219. Interpretive Summary: This report presents the complete sequence and analysis of the Squash vein yellowing virus (SqVYV) genome. SqVYV is the causal agent of a viral watermelon vine decline recently detected in Florida. This research offers insight into the nature of SqVYV and the taxonomy of the virus group to which it belongs.
Technical Abstract: The genus Ipomovirus is one of six currently recognized genera in the family Potyviridae. The complete nucleotide sequence of Squash vein yellowing virus (SqVYV), a putative ipomovirus recently described in Florida, has been determined. The SqVYV genomic RNA has one large open reading frame encoding a single polyprotein, typical of the genome organization for most members in the family Potyviridae. The ten mature proteins predicted to be derived from the SqVYV polyprotein include a duplicated P1 protein (P1a and P1b) but lack HC-Pro, similar to Cucumber vein yellowing virus (CVYV) but different from Sweet potato mild mottle virus (SPMMV), both recognized members of the genus Ipomovirus. Phylogenetic analysis of these proteins supports classification of SqVYV as a novel species within the genus Ipomovirus. The similar genome organization strategy of SqVYV and CVYV, which differs from that of SPMMV, indicates that the taxonomy of the genus Ipomovirus needs to be re-examined and a new genus created within the family Potyviridae to accommodate the observed discrepancies in ipomovirus genome organization.