The plastid gene rpoB encodes a plastid-specific, DNA-dependent RNA polymerase. A study of a barley mutant, albostrians, indicated that rpoB itself is transcribed by a nuclear-encoded RNA polymerase. However, the molecular nature of the nuclear-encoded RNA polymerase and mechanisms of the transcriptional regulation of rpoB expression have not been elucidated. Using an in vivo transient assay system for gene expression in plastids, the 5'-flanking region of rpoB from Arabidopsis thaliana in plastids of cultured BY-2 tobacco cells was analyzed. A series of deletion analyses of the 5'-flanking region indicated that there were two positive and one negative regulatory regions for rpoB expression. Comparison of the 5'-flanking sequences of rpoB among several plant species revealed the existence of three conserved motifs in these regions.
|Number of pages||8|
|Publication status||Published - 1997 Apr|
ASJC Scopus subject areas
- Plant Science
- Cell Biology