Blue light regulates the accumulation of two psbD-psbC transcripts in barley chloroplasts

EMBO J. 1989 Oct;8(10):2785-94.


Synthesis of D2, a Photosystem II reaction center protein encoded by psbD, is differentially maintained during light-induced chloroplast maturation. The continued synthesis of D2 is paralleled by selective light-induced accumulation of two psbD-psbC transcripts which share a common 5' terminus. In the present study, we examine the nature of the photoreceptor and the fluence requirement for psbD-psbC transcript induction. The light-induced change in psbD-psbC RNA population can be detected between 1 and 2 h after 4.5 day old dark-grown barley seedlings are transferred to the light. Light-induced transcript accumulation occurs normally in the chlorophyll-deficient barley mutant, xan-f10, indicating that light-activated chlorophyll formation and photosynthesis are not required for RNA induction. High fluence blue light fully induces psbD-psbC transcript accumulation; low or high fluence red or far-red light do not. However, psbD-psbC transcript accumulation elicited by blue light pulses can be partially attenuated if far-red light is given immediately following the blue light treatment. Thus, although blue light is needed to initiate transcript accumulation, phytochrome modulates the amplitude of the response. Pretreatment of dark-grown plants with cycloheximide blocks light-induced psbD-psbC transcript accumulation. This could implicate a blue-light responsive nuclear gene in the light-induced accumulation of the two psbD-psbC transcripts.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 4-Aminobutyrate Transaminase / antagonists & inhibitors
  • Amino Acids / pharmacology
  • Chloramphenicol / pharmacology
  • Chlorophyll / genetics*
  • Chloroplasts / metabolism*
  • Cycloheximide / pharmacology
  • Dose-Response Relationship, Radiation
  • Edible Grain / genetics*
  • Gene Expression Regulation
  • Genes
  • Hordeum / genetics*
  • Light*
  • Light-Harvesting Protein Complexes
  • Mutation
  • Photosynthetic Reaction Center Complex Proteins
  • Photosystem II Protein Complex
  • Phytochrome / pharmacology
  • Plant Proteins / genetics*
  • Protein Biosynthesis
  • RNA / analysis
  • Time Factors
  • Transcription, Genetic* / drug effects


  • Amino Acids
  • Light-Harvesting Protein Complexes
  • Photosynthetic Reaction Center Complex Proteins
  • Photosystem II Protein Complex
  • Plant Proteins
  • Phytochrome
  • Chlorophyll
  • RNA
  • Chloramphenicol
  • 4-amino-5-fluoropent-2-enoic acid
  • Cycloheximide
  • 4-Aminobutyrate Transaminase