Arabidopsis circadian clock and photoperiodism: time to think about location

Curr Opin Plant Biol. 2010 Feb;13(1):83-9. doi: 10.1016/j.pbi.2009.09.007. Epub 2009 Oct 14.


Plants possess a circadian clock that enables them to coordinate internal biological events with external daily changes. Recent studies in Arabidopsis revealed that tissue-specific clock components exist and that the clock network architecture also varies within different organs. These findings indicate that the makeup of circadian clock(s) within a plant is quite variable. Plants utilize the circadian clock to measure day-length changes for regulating seasonal responses, such as flowering. To ensure that flowering occurs under optimum conditions, the clock regulates diurnal CONSTANS (CO) expression. Subsequently, CO protein induces FLOWERING LOCUS T (FT) expression which leads to flowering. It is emerging that both CO and FT expression are intricately controlled by groups of transcription factors with overlapping functions.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Circadian Rhythm*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Flowers / growth & development
  • Gene Expression Regulation, Plant
  • Photoperiod*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Arabidopsis Proteins
  • CCA1 protein, Arabidopsis
  • CONSTANS protein, Arabidopsis
  • DNA-Binding Proteins
  • FT protein, Arabidopsis
  • TOC1 protein, Arabidopsis
  • Transcription Factors