Plant Molecular Biology

, Volume 51, Issue 5, pp 757–771

Chlorophyll antenna size adjustments by irradiance in Dunaliella salina involve coordinate regulation of chlorophyll a oxygenase (CAO) and Lhcb gene expression

  • Tatsuru Masuda
  • Ayumi Tanaka
  • Anastasios Melis

DOI: 10.1023/A:1022545118212

Cite this article as:
Masuda, T., Tanaka, A. & Melis, A. Plant Mol Biol (2003) 51: 757. doi:10.1023/A:1022545118212


To elucidate the mechanism of irradiance-dependent adjustments in the chlorophyll antenna size of photosynthesis, we addressed the regulation of expression of genes encoding a variety of chlorophyll biosynthesis enzymes and that of the Lhcb genes in the model organism Dunaliella salina. Among the chlorophyll biosynthesis enzymes tested, only the chlorophyll a oxygenase (CAO) gene responded to changes in the level of irradiance with substantial mRNA level and kinetics of change that were similar to those of the Lhcb genes. Evidence is presented for the operation of a cytosolic signal transduction pathway for the rapid (order of minutes) regulation of both CAO and Lhcb gene expression by irradiance. Inhibitor studies and transient activation of Ca2+-dependent kinase suggested phopholipase-C activation to Ca2+ release, and activation of a specific Ca2+/CaM-dependent protein kinase in this cytosolic signal transduction pathway. The redox state of the plastoquinone pool also serves to regulate CAO and Lhcb gene expression on a slower time scale (hours) and probably serves as a plastidic-origin signal that acts coordinately with the cytosolic signal transduction pathway. It is proposed that irradiance-dependent adjustments in the chlorophyll antenna size occur by coordinate regulation of CAO and Lhcb gene expression via two distinct signal transduction pathways in photosynthetic organisms.

CAO chlorophyll antenna size gene expression green algae Lhcb signal transduction 

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Tatsuru Masuda
    • 1
  • Ayumi Tanaka
    • 2
  • Anastasios Melis
    • 3
  1. 1.Department of Biological Sciences, Graduate School of Bioscience and BiotechnologyTokyo Institute of TechnologyYokohamaJapan
  2. 2.Institute of Low Temperature SciencesHokkaido UniversitySapporoJapan
  3. 3.Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyUSA e-mail

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