Blue Light- and Low Temperature-Regulated COR27 and COR28 Play Roles in the Arabidopsis Circadian Clock. Issue 11 (11th November 2016)

• Record Type: Journal Article
• Authors: Li, Xu; Ma, Dingbang; Lu, Sheen X.; Hu, Xinyi; Huang, Rongfeng; Liang, Tong; Xu, Tongda; Tobin, Elaine M.; Liu, Hongtao
• Is Part Of: The Plant Cell. Volume 28:Issue 11(2016)
• Page Start: 2755
• Page End: 2769
• Publication Date: 2016-11-11
• DOI: 10.1105/tpc.16.00354
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : COR27 and COR28 are regulated by light and low temperature and, in turn, regulate the circadian clock, freezing tolerance, and flowering time. Abstract: Light and temperature are two key environmental signals that profoundly affect plant growth and development, but underlying molecular mechanisms of how light and temperature signals affect the circadian clock are largely unknown. Here, we report that COR27 and COR28 are regulated not only by low temperatures but also by light signals. COR27 and COR28 are negative regulators of freezing tolerance but positive regulators of flowering, possibly representing a trade-off between freezing tolerance and flowering. Furthermore, loss-of-function mutations in COR27 and COR28 result in period lengthening of various circadian output rhythms and affect central clock gene expression. Also, the cor27 cor28 double mutation affects the pace of the circadian clock. Additionally, COR27 and COR28 are direct targets of CCA1, which represses their transcription via chromatin binding. Finally, we report that COR27 and COR28 bind to the chromatin of TOC1 and PRR5 to repress their transcription, suggesting that their effects on rhythms are in part due to their regulation of TOC1 and PRR5 . These data demonstrate that blue light and low temperature-regulated COR27 and COR28 regulate the circadian clock as well as freezing tolerance and flowering time.