Light signals and flowering

J Exp Bot. 2006;57(13):3387-93. doi: 10.1093/jxb/erl071. Epub 2006 Sep 15.

Abstract

Physiological studies over a long period have shown that light acts to regulate flowering through the three main variables of quality, quantity, and duration. Intensive molecular genetic and genomic studies with the model plant Arabidopsis have given considerable insight into the mechanisms involved, particularly with regard to quality and photoperiod. For photoperiodism light, acting through phytochromes and cryptochromes, the main photomorphogenetic photoreceptors, acts to entrain and interact with a circadian rhythm of CONSTANS (CO) expression leading to transcription of the mobile floral integrator, FLOWERING LOCUS T (FT). The action of phytochromes and cryptochromes in photoperiodism is augmented by ZEITLUPE (ZTL) and FLAVIN-BINDING, KELCH REPEAT, F-BOX (FKF1) acting as accessory photoreceptors on entrainment and interaction, respectively. Light quality acts independently of the circadian system through Phytochromes B, D, and E to regulate FT. Light quantity effects, on the other hand, are still incompletely understood but are likely to be linked either directly or indirectly to patterns of assimilate partitioning and resource utilization within the plant.

Publication types

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

MeSH terms

  • Arabidopsis / growth & development*
  • Arabidopsis / metabolism
  • Arabidopsis / physiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Circadian Rhythm
  • Cryptochromes
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Flavoproteins / metabolism
  • Flavoproteins / physiology
  • Flowers / growth & development*
  • Flowers / metabolism
  • Flowers / physiology
  • Light*
  • Models, Biological
  • Photoperiod
  • Phytochrome / metabolism
  • Phytochrome / physiology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Arabidopsis Proteins
  • CONSTANS protein, Arabidopsis
  • CRY1 protein, Arabidopsis
  • Cryptochromes
  • DNA-Binding Proteins
  • FKF1 protein, Arabidopsis
  • FT protein, Arabidopsis
  • Flavoproteins
  • Transcription Factors
  • ZTL protein, Arabidopsis
  • Phytochrome