The Pea rbcS-3A Promoter Mediates Light Responsiveness but not Organ Specificity.

The expression of the pea rbcS-3A gene is responsive to light and restricted to chloroplast-containing cells. Previously, we identified transcriptional elements between -410 and -50 relative to the transcription start site as being sufficient for this regulated expression. Here we investigate the role of the promoter region (-50 to +15) in rbcS-3A expression. We demonstrate an interaction between the promoter and upstream sequences located between -189 and -166, which is important for high level expression. In addition we show that, when the rbcS promoter is driven by a weak test enhancer, it can confer light-responsive but not organ-specific expression upon a bacterial reporter gene.