Identification and characterization of a tombusvirus isolated from Japanese gentian.

The DECS (dsRNA isolation, exhaustive amplification, cloning and sequencing) analysis technique for viral diagnosis detected a tombusvirus in Japanese gentian not displaying severe symptoms. We tentatively named this virus "gentian virus A" (GeVA). GeVA systemically but inefficiently infected Japanese gentian without causing visible symptoms, while it led to severe symptoms in some other plants. The complete genome sequence of GeVA indicated a typical tombusvirus-like structure. Phylogenetic analysis of the deduced amino acid sequences of four tombusvirus-encoded proteins did not reveal other known tombusviruses that were closely-related to GeVA, suggesting that it is a novel tombusvirus.