Phytochromes control photomorphogenesis by differentially regulated, interacting signaling pathways in higher plants

Annu Rev Plant Biol. 2002;53:329-55. doi: 10.1146/annurev.arplant.53.100301.135302.


In this review the kinetic properties of both phytochrome A and B measured by in vivo spectroscopy in Arabidopsis are described. Inactivation of phyA is mediated by destruction and that of phyB by fast dark reversion. Recent observations, describing a complex interaction network of various phytochromes and cryptochromes, are also discussed. The review describes recent analysis of light-dependent nuclear translocation of phytochromes and genetic and molecular dissection of phyA- and phyB-mediated signal transduction. After nuclear transport, both phyA- and phyB-mediated signal transduction probably include the formation of light-dependent transcriptional complexes. Although this hypothesis is quite attractive and probably true for some responses, it cannot account for the complex network of phyA-mediated signaling and the interaction with the circadian clock. In addition, the biological function of phytochromes localized in the cytosol remains to be elucidated.

Publication types

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

MeSH terms

  • Morphogenesis
  • Phytochrome / metabolism
  • Phytochrome / physiology*
  • Plant Development*
  • Plants / genetics
  • Plants / metabolism
  • Signal Transduction*
  • Subcellular Fractions / metabolism


  • Phytochrome