Phytochrome Interacting Factors: central players in phytochrome-mediated light signaling networks

Trends Plant Sci. 2007 Nov;12(11):514-21. doi: 10.1016/j.tplants.2007.10.001. Epub 2007 Oct 22.


To adapt to the surrounding environment, plants constantly monitor and respond to changes in the red and far-red regions of the light spectrum through the phytochrome family of photoreceptors. Extensive efforts using genetic, molecular and photobiological techniques have led to the identification of a group of basic helix-loop-helix transcription factors called the Phytochrome Interacting Factors, PIFs, which directly bind to the photoactivated phytochromes. Members of the PIF family have been shown to control light-regulated gene expression directly and indirectly. PIF1, PIF3, PIF4 and PIF5 are degraded in response to light signals, and physical interaction of PIF3 with phytochromes is necessary for the light-induced phosphorylation and degradation of PIF3. PIFs constitute an excellent model for the investigation of the biochemical mechanisms of signal transfer from photoactivated phytochromes and the light-regulation of gene expression that controls photomorphogenesis in plants.

Publication types

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

MeSH terms

  • Arabidopsis Proteins / physiology
  • Arabidopsis Proteins / radiation effects
  • Basic Helix-Loop-Helix Transcription Factors / physiology
  • Basic Helix-Loop-Helix Transcription Factors / radiation effects
  • Helix-Loop-Helix Motifs / physiology
  • Helix-Loop-Helix Motifs / radiation effects
  • Light*
  • Phytochrome / physiology*
  • Phytochrome / radiation effects
  • Plant Physiological Phenomena / radiation effects*
  • Plant Proteins / physiology
  • Plant Proteins / radiation effects
  • Plant Structures / physiology
  • Plant Structures / radiation effects


  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • Plant Proteins
  • Phytochrome