ELF3 encodes a circadian clock-regulated nuclear protein that functions in an Arabidopsis PHYB signal transduction pathway

Plant Cell. 2001 Jun;13(6):1293-304. doi: 10.1105/tpc.13.6.1293.


Many aspects of plant development are regulated by photoreceptor function and the circadian clock. Loss-of-function mutations in the Arabidopsis EARLY FLOWERING 3 (ELF3) and PHYTOCHROME B (PHYB) genes cause early flowering and influence the activity of circadian clock-regulated processes. We demonstrate here that the relative abundance of the ELF3 protein, which is a novel nucleus-localized protein, displays circadian regulation that follows the pattern of circadian accumulation of ELF3 transcript. Furthermore, the ELF3 protein interacts with PHYB in the yeast two-hybrid assay and in vitro. Genetic analyses show that ELF3 requires PHYB function in early morphogenesis but not for the regulation of flowering time. This suggests that ELF3 is a component of a PHYB signaling complex that controls early events in plant development but that ELF3 and PHYB control flowering via independent signal transduction pathways.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins*
  • Circadian Rhythm / genetics*
  • Cloning, Molecular
  • Genes, Plant
  • Light
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / physiology
  • Photoreceptor Cells*
  • Phytochrome / physiology
  • Phytochrome B
  • Plant Proteins / genetics*
  • Plant Proteins / physiology
  • Protein Binding
  • Signal Transduction* / physiology
  • Signal Transduction* / radiation effects
  • Transcription Factors / genetics*
  • Transcription Factors / physiology


  • Arabidopsis Proteins
  • ELF3 protein, Arabidopsis
  • Nuclear Proteins
  • PHYB protein, Arabidopsis
  • Plant Proteins
  • Transcription Factors
  • Phytochrome
  • Phytochrome B