RICE TUNGRO BACILLIFORM VIRUS - TRANSCRIPTION AND TRANSLATION IN PROTOPLASTS

Protoplasts from cell suspension cultures of Oryza sativa (monocot) an d Orychophragmus violaceus (dicot) support transcription from the rice tungro bacilliform virus (RTBV) promoter and translation of the resul ting mRNA despite the presence of a long leader sequence with strong s econdary structure and 12 short open reading frames. Transcriptional e lements,located both upstream and downstream of the transcription init iation site are defined by deletion analysis and the functional TATA m otif is determined. Expression of an open reading frame downstream of the entire leader is more efficient than that downstream of truncated derivatives. For optimal expression sequences in the 5' and 3' parts o f the leader are required. (C) 1994 Academic Press, Inc.