Phototropin and light-signaling in phototropism

Curr Opin Plant Biol. 2006 Oct;9(5):503-8. doi: 10.1016/j.pbi.2006.07.003. Epub 2006 Jul 25.


Blue-light-induced phototropism in higher plants is regulated by phototropin, which is a photoreceptor kinase that contains a flavin mononucleotide (FMN). Recently, it was found that this kinase is inhibited by the binding of the LOV2 (light-oxygen-voltage2) domain in the dark but that its activity is increased in the light by the release of the LOV2 domain. Phototropin-associated proteins have been identified, although the proteins that are phosphorylated by phototropin are still unknown. The asymmetrical auxin distribution caused by unilateral irradiation suggests that differential growth is induced by a difference in auxin-regulated gene expression between the shaded and illuminated sides of plant organs. Transcription-related factors, such as NPH4/ARF7, MSG2/IAA19 and SCF(TIR1), play key roles in this process.

Publication types

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

MeSH terms

  • Cryptochromes
  • Flavoproteins / physiology*
  • Gene Expression Regulation, Plant
  • Indoleacetic Acids / metabolism
  • Light*
  • Photoreceptor Cells / physiology
  • Phototropism / physiology*
  • Plant Proteins / metabolism
  • Signal Transduction* / physiology


  • Cryptochromes
  • Flavoproteins
  • Indoleacetic Acids
  • Plant Proteins