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

Chlorophyll antenna size adjustments by irradiance in Dunaliella salina involve coordinate... 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. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Molecular Biology Springer Journals

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

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References (77)

Publisher
Springer Journals
Copyright
Copyright © 2003 by Kluwer Academic Publishers
Subject
Life Sciences; Biochemistry, general; Plant Sciences; Plant Pathology
ISSN
0167-4412
eISSN
1573-5028
DOI
10.1023/A:1022545118212
Publisher site
See Article on Publisher Site

Abstract

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.

Journal

Plant Molecular BiologySpringer Journals

Published: Oct 7, 2004

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