Complete genome sequence analysis Hosta virus X and comparison to other potexviruses

A potexvirus, Hosta virus X (HVX-Kr), causing mosaic and mottle symptoms was isolated from hosta plants (Hosta spp.), and its entire genome RNA sequence was determined. in Korea using cDNA library and RACE methods. The genome of HVX encodes five open reading frames coding for viral replicase, triple gene block (TGB), and viral coat protein (CP) from the 5'to 3' ends, which is a typical genome structure of potexviruses. The 3-terminal region of the virus includes the TGBI (26 kDa), TGB2 (13 kDa), TGB3 (8 kDa), and 23 kDa coat protein (CP) and the 3-nontranslated region (NTR). 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 complete genome sequence information of HVX and molecular evidence supporting the virus as a distinct species of the genus Potexvirus.