Identification and molecular characterization of Panax notoginseng virus A, which may represent an undescribed novel species of the genus Totivirus, family Totiviridae

A double-stranded RNA (dsRNA), PN-S, isolated from Panax notoginseng was sequenced and characterized. dsRNA PN-S was determined to be 5003 base pairs (bp) in length and to have a genome organization similar to that of totiviruses. The two deduced proteins encoded by dsRNA PN-S have the highest amino acid (aa) sequence identity to CP and RNA-dependent RNA polymerase (RdRp) of black raspberry virus F (BrVF), a tentative member of the genus Totivirus, family Totiviridae, at 39 % and 54 %, respectively. In a phylogenetic tree based on an alignment of the RdRp amino acid sequences of dsRNA PN-S and selected totiviruses, dsRNA PN-S formed a monophyletic clade with dsRNA viruses belonging to the genus Totivirus. These data suggest that dsRNA PN-S may represent the genome of a member of a novel species of the genus Totivirus, family Totiviridae, for which we propose the name Panax notoginseng virus A (PnVA).