GENOME PROPERTIES OF BAMBOO MOSAIC-VIRUS

Bamboo mosaic virus (BaMV), isolated from infected green bamboo (Bambusa oldhamii) in Taiwan, is a flexuous, rod-shaped virus. The genome of BaMV is a single-stranded plus-sense RNA, Mr 2.1 x 10(6), encapsidated with capsid protein subunits of M(r) 28K. Sodium dodecyl sulfate-immunodiffusion and western blot analysis showed that BaMV is serologically unrelated to the tested potexviruses and other viruses. BaMV RNA, fractionated or unfractionated, directed the synthesis of one prominent high molecular weight product, M(r) 160K, together with several polypeptides of smaller sizes when translated in rabbit reticulocyte lysate. Immunoprecipitation of the in vitro translation products failed to reveal the synthesis of viral capsid protein. No encapsidated subgenomic RNA could be detected by northern hybridization with cDNA transcribed from genomic RNA. However, northern blots of RNAs extracted from infected barley protoplasts detected two major subgenomic RNAs of 2.0 and 1.0 kb in size. All of these properties suggest that BaMV is indeed a member of the potexvirus group.