Mapping the Core of the Arabidopsis Circadian Clock Defines the Network Structure of the Oscillator

W. Huang, P. Perez-Garcia, A. Pokhilko, A. J. Millar, I. Antoshechkin, J. L. Riechmann, P. Mas

Research output: Contribution to journalArticle

267 Citations (Scopus)

Abstract

In many organisms, the circadian clock is composed of functionally coupled morning and evening oscillators. In Arabidopsis, oscillator coupling relies on a core loop in which the evening oscillator component TIMING OF CAB EXPRESSION 1 (TOC1) was proposed to activate a subset of morning-expressed oscillator genes. Here, we show that TOC1 does not function as an activator but rather as a general repressor of oscillator gene expression. Repression occurs through TOC1 rhythmic association to the promoters of the oscillator genes. Hormone-dependent induction of TOC1 and analysis of RNA interference plants show that TOC1 prevents the activation of morning-expressed genes at night. Our study overturns the prevailing model of the Arabidopsis circadian clock, showing that the morning and evening oscillator loops are connected through the repressing activity of TOC1.

Original languageEnglish
Pages (from-to)75-79
Number of pages5
JournalScience
Volume336
Issue number6077
DOIs
Publication statusPublished - 6 Apr 2012

Keywords

  • pseudo-response regulators
  • rhythms
  • TOC1
  • thaliana
  • gene
  • time
  • expression
  • gigantea
  • growth

Cite this

Huang, W., Perez-Garcia, P., Pokhilko, A., Millar, A. J., Antoshechkin, I., Riechmann, J. L., & Mas, P. (2012). Mapping the Core of the Arabidopsis Circadian Clock Defines the Network Structure of the Oscillator. Science, 336(6077), 75-79. https://doi.org/10.1126/science.1219075