TIME FOR COFFEE is an essential component in the maintenance of metabolic homeostasis in Arabidopsis thaliana

Plant J. 2013 Oct;76(2):188-200. doi: 10.1111/tpj.12292. Epub 2013 Aug 23.


Plants often respond to environmental changes by reprogramming metabolic and stress-associated pathways. Homeostatic integration of signaling is a central requirement for ensuring metabolic stability in living organisms. Under diurnal conditions, properly timed rhythmic metabolism provides fitness benefits to plants. TIME FOR COFFEE (TIC) is a circadian regulator known to be involved in clock resetting at dawn. Here we explored the mechanism of influence of TIC in plant growth and development, as initiated by a microarray analysis. This global profiling showed that a loss of TIC function causes a major reprogramming of gene expression that predicts numerous developmental, metabolic, and stress-related phenotypes. This led us to demonstrate that this mutant exhibits late flowering, a plastochron defect, and diverse anatomical phenotypes. We further observed a starch-excess phenotype and altered soluble carbohydrate levels. tic exhibited hypersensitivity to oxidative stress and abscisic acid, and this was associated with a striking resistance to drought. These phenotypes were connected to an increase in total glutathione levels that correlated with a readjustment of amino acids and polyamine pools. By comparatively analyzing our transcriptomic and metabolomic data, we concluded that TIC is a central element in plant homeostasis that integrates and coordinates developmental, metabolic, and environmental signals.

Keywords: Arabidopsis thaliana; TIME FOR COFFEE; circadian clock; metabolism; stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / physiology*
  • Carbohydrate Metabolism
  • Circadian Rhythm / genetics
  • Gene Expression Regulation, Plant*
  • Glutathione / metabolism
  • Homeostasis
  • Metabolome
  • Nuclear Proteins / genetics
  • Nuclear Proteins / physiology*
  • Oxidative Stress
  • Phenotype
  • Stress, Physiological
  • Transcriptome


  • Arabidopsis Proteins
  • Nuclear Proteins
  • TIC protein, Arabidopsis
  • Abscisic Acid
  • Glutathione