Evidence for type II phytochrome-induced rapid signalling leading to cab::luciferase gene expression in tobacco cotyledons

Planta. 2001 Apr;212(5-6):759-64. doi: 10.1007/s004250000462.


We studied the activation of cab gene expression by phytochrome-induced intercellular signalling and report insights into the mechanism of induction and outspread of a plant internal signal. By micro-beam irradiation techniques and use of a photon-imaging charge-coupled device (CCD) camera system we monitored cab::luciferase reporter gene expression in cotyledons of transgenic tobacco (Nicotiana tabacum L. cv. Xanthi) plants. We found that (i) the photoreceptor triggering intercellular signalling and reporter-gene expression is type II but not type I phytochrome, (ii) phytochrome in its far-red-absorbing (Pfr) form is necessary for the induction but not for the outspread of the signalling, (iii) red/far-red reversibility is restricted to the red-irradiated cells, and (iv) the phytochrome-induced signal spreads rapidly throughout the cotyledon and reaches its target cells within minutes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins*
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cotyledon / physiology
  • Cotyledon / radiation effects
  • Gene Expression Regulation, Plant* / radiation effects
  • Genes, Reporter
  • Infrared Rays
  • Kinetics
  • Light
  • Light-Harvesting Protein Complexes
  • Luciferases / genetics
  • Photoreceptor Cells
  • Phytochrome / genetics
  • Phytochrome / metabolism*
  • Phytochrome / radiation effects
  • Plants, Genetically Modified
  • Plants, Toxic*
  • Recombinant Fusion Proteins / genetics
  • Signal Transduction*
  • Tobacco / genetics
  • Tobacco / physiology*
  • Tobacco / radiation effects


  • Arabidopsis Proteins
  • CAB2 protein, Arabidopsis
  • Carrier Proteins
  • Light-Harvesting Protein Complexes
  • Recombinant Fusion Proteins
  • Phytochrome
  • Luciferases