Molecular evidence supporting the classification of Hosta virus X as a distinct species of the genus

Summary.

 A potexvirus, Hosta virus X (HVX-Kr), causing mosaic and mottle symptoms was isolated from hosta plants (Hosta spp.) in Korea. The 3′-terminal 2,711 nucleotides excluding the poly (A) tail were determined and shown to include the partial viral replicase, triple gene block (TGB) 1 (26 kDa), TGB2 (13 kDa), TGB3 (8 kDa), and 23 kDa coat protein (CP) and the 3′-nontranslated region (NTR), typical of potexviruses. The CP gene of the type isolate of HVX (HVX-U) was amplified by RT-PCR and its nucleotide sequence was determined. The CPs of HVX-Kr and HVX-U had 100% and 98.9% identical amino acids and nucleotides, respectively. Most of the regions of the genome HVX had over 50% nucleotide identical to other sequenced potexviruses. This is the first report of sequence information of HVX and molecular evidence supporting the virus as a distinct species of the genus Potexvirus.