Circadian-regulated transcription of the psbD light-responsive promoter in wheat chloroplasts.
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.
Nakahira
Y
Y
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
Baba
K
K
Yoneda
A
A
Shiina
T
T
Toyoshima
Y
Y
D001483:Base Sequence; D002736:Chloroplasts / Q000378:metabolism; D002940:Circadian Rhythm; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D018087:Plastids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014908:Triticum / Q000235:genetics* / Q000378:metabolism
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D012333:RNA, Messenger