Circadian-Regulated Transcription of the psbD Light-Responsive Promoter in Wheat Chloroplasts1

AUTOR(ES)

Nakahira, Yoichi

FONTE

American Society of Plant Physiologists

RESUMO

The level of mRNAs derived from the plastid-encoded psbD light-responsive promoter (LRP) is controlled by a circadian clock(s) in wheat (Triticum aestivum). The circadian oscillations in the psbD LRP mRNA level persisted for at least three cycles in continuous light and for one cycle in continuous dark, with maxima in subjective morning and minima in subjective early night. In vitro transcription in chloroplast extracts revealed that the circadian cycles in the psbD LRP mRNA level were dominantly attributed to the circadian-regulated transcription of the psbD LRP. The effects of various mutations introduced into the promoter region on the psbD LRP activity in vitro suggest the existence of two positive elements located between −54 and −36, which generally enhance the transcription activity, and an anomalous core promoter structure lacking the functional “−35” element, which plays a crucial role in the circadian fluctuation and light dependency of psbD LRP transcription activity.

Documentos Relacionados

• Light-responsive and transcription-enhancing elements regulate the plastid psbD core promoter.
• Cryptochrome 1, Cryptochrome 2, and Phytochrome A Co-Activate the Chloroplast psbD Blue Light–Responsive Promoter
• Involvement of a Nuclear-Encoded Basic Helix-Loop-Helix Protein in Transcription of the Light-Responsive Promoter of psbD1
• Involvement of protein kinase and extraplastidic serine/threonine protein phosphatases in signaling pathways regulating plastid transcription and the psbD blue light-responsive promoter in barley.
• Synthesis and degradation of dinoflagellate plastid-encoded psbA proteins are light-regulated, not circadian-regulated