The ELF4-ELF3-LUX complex links the circadian clock to diurnal control of hypocotyl growth

Nature. 2011 Jul 13;475(7356):398-402. doi: 10.1038/nature10182.


The circadian clock is required for adaptive responses to daily and seasonal changes in environmental conditions. Light and the circadian clock interact to consolidate the phase of hypocotyl cell elongation to peak at dawn under diurnal cycles in Arabidopsis thaliana. Here we identify a protein complex (called the evening complex)--composed of the proteins encoded by EARLY FLOWERING 3 (ELF3), ELF4 and the transcription-factor-encoding gene LUX ARRHYTHMO (LUX; also known as PHYTOCLOCK 1)--that directly regulates plant growth. ELF3 is both necessary and sufficient to form a complex between ELF4 and LUX, and the complex is diurnally regulated, peaking at dusk. ELF3, ELF4 and LUX are required for the proper expression of the growth-promoting transcription factors encoded by PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and PIF5 (also known as PHYTOCHROME INTERACTING FACTOR 3-LIKE 6) under diurnal conditions. LUX targets the complex to the promoters of PIF4 and PIF5 in vivo. Mutations in PIF4 and/or PIF5 are epistatic to the loss of the ELF4-ELF3-LUX complex, suggesting that regulation of PIF4 and PIF5 is a crucial function of the complex. Therefore, the evening complex underlies the molecular basis for circadian gating of hypocotyl growth in the early evening.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / growth & development
  • Arabidopsis / physiology*
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Basic Helix-Loop-Helix Transcription Factors / deficiency
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Circadian Clocks / physiology*
  • Circadian Clocks / radiation effects
  • Circadian Rhythm / physiology*
  • Circadian Rhythm / radiation effects
  • Gene Expression Regulation, Plant
  • Hypocotyl / cytology
  • Hypocotyl / growth & development*
  • Hypocotyl / radiation effects
  • Light
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / metabolism
  • Mutation
  • Protein Binding
  • Transcription Factors / metabolism*
  • Two-Hybrid System Techniques


  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • ELF3 protein, Arabidopsis
  • ELF4 protein, Arabidopsis
  • Lux Arrhythmo protein, Arabidopsis
  • Multiprotein Complexes
  • PIF4 protein, Arabidopsis
  • PIF5 protein, Arabidopsis
  • Transcription Factors