a satellite rna was found to be naturally associated with bamboo mosaic virus isolated from infected bambusa vulgaris mcclure . nucleotide sequence revealed that this satellite rna genome contains 836 nucleotides and encodes a 20 kda protein . infectious transcripts have been generated from full length cdna downstream t7 rna polymerase promoter . precise replacement of open reading frame of cdna of satellite rna with sequence encoding bacterial cat resulted in high level expression of cat in infected dicotyledon plants , chenopodium quinoa and tobacco in the presence of bamv genomic rna . thus , this satellite system is potentially useful as a satellite - based plant expression vector .