A new type of mutation in the plant photoreceptor phytochrome B causes loss of photoreversibility and an extremely enhanced light sensitivity

Plant J. 2000 May;22(3):177-86. doi: 10.1046/j.1365-313x.2000.00715.x.


Photoreversibility, reversion of the inductive effect of a brief red light pulse by a subsequent far-red light pulse, is a property of photoresponses regulated by the plant photoreceptor phytochrome B (phyB). We screened for mutants with impaired photoreversibility to gain better insight into the phyB-specific signalling cascade. The phenotype of the mutant described is caused by a single amino acid exchange in a phyB subdomain that is highly conserved in all phytochromes but whose functional significance was unknown. The mutated phyB showed a slower dark reversion but no major alterations in its spectral properties. In addition to its loss of photoreversibility, the mutant also exhibited a hypersensitivity towards continuous red-light irradiation and an altered phenotype of adult plants under short-day conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • DNA Primers
  • Light*
  • Molecular Sequence Data
  • Mutation*
  • Phenotype
  • Photoreceptor Cells*
  • Phytochrome / chemistry
  • Phytochrome / genetics*
  • Phytochrome / metabolism
  • Phytochrome B
  • Radiation Tolerance
  • Sequence Homology, Amino Acid
  • Transcription Factors*


  • DNA Primers
  • Transcription Factors
  • Phytochrome
  • Phytochrome B