Photoreceptor signaling networks in plant responses to shade

Annu Rev Plant Biol. 2013:64:403-27. doi: 10.1146/annurev-arplant-050312-120221. Epub 2013 Jan 25.

Abstract

The dynamic light environment of vegetation canopies is perceived by phytochromes, cryptochromes, phototropins, and UV RESISTANCE LOCUS 8 (UVR8). These receptors control avoidance responses to preclude exposure to limiting or excessive light and acclimation responses to cope with conditions that cannot be avoided. The low red/far-red ratios of shade light reduce phytochrome B activity, which allows PHYTOCHROME INTERACTING FACTORS (PIFs) to directly activate the transcription of auxin-synthesis genes, leading to shade-avoidance responses. Direct PIF interaction with DELLA proteins links gibberellin and brassinosteroid signaling to shade avoidance. Shade avoidance also requires CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1), a target of cryptochromes, phytochromes, and UVR8. Multiple regulatory loops and the input of the circadian clock create a complex network able to respond even to subtle threats of competition with neighbors while still compensating for major environmental fluctuations such as the day-night cycles.

Publication types

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

MeSH terms

  • Ecosystem*
  • Gibberellins / metabolism
  • Light
  • Photoreceptors, Plant / metabolism*
  • Phytochrome / metabolism
  • Plant Growth Regulators / metabolism
  • Plants / metabolism*
  • Signal Transduction*

Substances

  • Gibberellins
  • Photoreceptors, Plant
  • Plant Growth Regulators
  • Phytochrome