Redox Regulation of Light-Harvesting Complex II and cab mRNA Abundance in Dunaliella salina

Maxwell, Denis P.; Laudenbach, David E.; Hüner, Norman P. A.

doi:10.1104/pp.109.3.787

Cited by 211 publications

(136 citation statements)

References 38 publications

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“…There are two major hypotheses concerning this mechanism. One hypothesis is that the expression of LHCII apoprotein controls the size (Escobas et al, 1995;Maxwell et al, 1995). This hypothesis is based on observations that transcription of Lhcb1 gene or its related genes encoding the major LHCII apoproteins is strongly correlated to changes in antenna size or the Chl a: b ratio.…”

Section: Introductionmentioning

confidence: 99%

Overexpression of chlorophyllide a oxygenase (CAO) enlarges the antenna size of photosystem II in Arabidopsis thaliana

et al. 2001

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SummaryThe light-harvesting ef®ciency of a photosystem is thought to be largely dependent on its photosynthetic antenna size. It has been suggested that antenna size is controlled by the biosynthesis of chlorophyll b. To verify this hypothesis, we overexpressed the enzyme for chlorophyll b biosynthesis, chlorophyllide a oxygenase (CAO), in Arabidopsis thaliana by transforming the plant with cDNA for CAO under the control of the 35S cauli¯ower mosaic virus promoter. In the early de-etiolation phase, when the intrinsic CAO expression is very low, the chlorophyll a : b ratio was drastically decreased from 28 to 7.3, indicating that enhancement of chlorophyll b biosynthesis had been successfully achieved. We made the following observations in full-green rosette leaves of transgenic plants.(1) The chlorophyll a : b ratio was reduced from 2.85 to 2.65. (2) The ratio of the peripheral light-harvesting complexes (LHCII) to the core antenna complex (CPa) resolved with the green-gel system increased by 20%. (3) The ratio of the light-harvesting complex II apoproteins (LHCP) to 47-kDa chlorophyll a protein (CP47), which was estimated by the results of immunoblotting, increased by 40%. These results indicated that the antenna size increased by at least 10±20% in transgenic plants, suggesting that chlorophyll b biosynthesis controls antenna size. To the best of our knowledge, this is the ®rst report on enlargement of the antenna size by genetic manipulations.

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Section: Introductionmentioning

confidence: 99%

Overexpression of chlorophyllide a oxygenase (CAO) enlarges the antenna size of photosystem II in Arabidopsis thaliana

et al. 2001

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“…One proposal is that the redox state of the photosynthetic electron transport carrier(s) between the two PS in green algae monitors the energy balance because such carriers will be over-reduced if the energy input exceeds the requirement for the dark reaction. The abundance of LHCII protein and/or mRNA decreases with the increase of the reduced Q A population probed by chlorophyll a fluorescence in Chlorella vulgaris (Maxwell et al, 1995a) and Dunaliella salina (Maxwell et al, 1995b). Expression of the LHCII gene in Dunaliella tertiolecta is enhanced by interrupting electron transfer from Q A to Q B with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), and it is repressed by inhibiting the oxidation of plastoquinol with 2,5-dibromo-3-methyl-6-isopropyl-1 This research was supported by a grant for the Frontier Research System at The Institute of Physical and Chemical Research and by the Ministry of Education, Culture, Sports, Science and Technology of Japan (grant no.…”

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Light-Intensity-Dependent Expression of Lhc Gene Family Encoding Light-Harvesting Chlorophyll-a/b Proteins of Photosystem II in Chlamydomonas reinhardtii

et al. 2002

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Excessive light conditions repressed the levels of mRNAs accumulation of multiple Lhc genes encoding light-harvesting chlorophyll-a/b (LHC) proteins of photosystem (PS)II in the unicellular green alga, Chlamydomonas reinhardtii. The light intensity required for the repression tended to decrease with lowering temperature or CO 2 concentration. The responses of six LhcII genes encoding the major LHC (LHCII) proteins and two genes (Lhcb4 and Lhcb5) encoding the minor LHC proteins of PSII (CP29 and CP26) were similar. The results indicate that the expression of these Lhc genes is coordinately repressed when the energy input through the antenna systems exceeds the requirement for CO 2 assimilation. The Lhc mRNA level repressed under high-light conditions was partially recovered by adding the electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, suggesting that redox signaling via photosynthetic electron carriers is involved in the gene regulation. However, the mRNA level was still considerably lower under high-light than under low-light conditions even in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Repression of the Lhc genes by high light was prominent even in the mutants deficient in the reaction center(s) of PSII or both PSI and PSII. The results indicate that two alternative processes are involved in the repression of Lhc genes under high-light conditions, one of which is independent of the photosynthetic reaction centers and electron transport events.Photosynthesis is regulated at various levels in response to fluctuating light intensity under various ambient temperature and nutrient conditions. The proper responses to the various environmental cues are necessary for photosynthetic plants to use light energy efficiently and to protect themselves from photoinhibitory damage caused by excessive irradiance (Aro et al., 1993;Long et al., 1994;Osmond, 1994). Excessive light energy absorbed by chlorophyll is dissipated by non-radiative processes (Crofts and Yerkes, 1994;Horton et al., 1996;Gilmore, 1997) and is properly distributed between two photosystems (PS) by state transition (Allen, 1995;Gal et al., 1997), whereas the energy input is regulated by changes in the size of the light-harvesting antenna systems to modulate the optical cross section.Light-harvesting chlorophyll a/b (LHC)II proteins, which are major components of light-harvesting antennae of PSII in higher plants and green algae, typically change their abundance in response to the intensity of irradiance (Anderson et al., 1988(Anderson et al., , 1995. Under stress and intense light, enhanced amounts of reactive oxygen species will react with proteins and lipids, not only in chloroplasts but also in the cytosol, and will induce various types of photodamage. Therefore, the quality and quantity control of the LHC protein complex is required to avoid photodamage by alleviating excitation energy pressure. Although the LHC protein complex could be controlled by various mechanisms including pigment synthesis, the repression of the...

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“…Although significant progress has been made in dissecting the regulation in developing seedlings of gene expression by phytochrome and blue-light photoreceptors, our recent work indicates that the regulation of acclimation is largely independent of such photoreceptor-mediated light signals . There is growing evidence that acclimation depends instead on signals from photosynthetic metabolism, most notably the redox state of one or more electron carriers (Escoubas et al, 1995;Maxwell et al, 1995;Pfannschmidt et al, 1999Pfannschmidt et al, , 2001. However, there is little understanding of these signals or of the mechanisms by which they are transduced.…”

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confidence: 99%

Identification of Mutants of Arabidopsis Defective in Acclimation of Photosynthesis to the Light Environment

Walters¹,

Shephard²,

Rogers³

et al. 2003

Plant Physiology

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In common with many other higher plant species, Arabidopsis undergoes photosynthetic acclimation, altering the composition of the photosynthetic apparatus in response to fluctuations in its growth environment. The changes in photosynthetic function that result from acclimation can be detected in a noninvasive manner by monitoring chlorophyll (Chl) fluorescence. This technique has been used to develop a screen that enables the rapid identification of plants defective atACCLIMATION OF PHOTOSYNTHESIS TO THE ENVIRONMENT(APE) loci. The application of this screen to a population of T-DNA-transformed Arabidopsis has successfully led to the identification of a number of mutant lines with altered Chl fluorescence characteristics. Analysis of photosynthesis and pigment composition in leaves from three such mutants showed that they had altered acclimation responses to the growth light environment, each having a distinct acclimation-defective phenotype, demonstrating that screening for mutants using Chl fluorescence is a viable strategy for the investigation of acclimation. Sequencing of the genomic DNA flanking the T-DNA elements showed that in the ape1mutant, a gene was disrupted that encodes a protein of unknown function but that appears to be specific to photosynthetic organisms, whereas the ape2 mutant carries an insertion in the region of the TPT gene encoding the chloroplast inner envelope triose phosphate/phosphate translocator.

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Redox Regulation of Light-Harvesting Complex II and cab mRNA Abundance in Dunaliella salina

Cited by 211 publications

References 38 publications

Overexpression of chlorophyllide a oxygenase (CAO) enlarges the antenna size of photosystem II in Arabidopsis thaliana

Overexpression of chlorophyllide a oxygenase (CAO) enlarges the antenna size of photosystem II in Arabidopsis thaliana

Light-Intensity-Dependent Expression of Lhc Gene Family Encoding Light-Harvesting Chlorophyll-a/b Proteins of Photosystem II in Chlamydomonas reinhardtii

Identification of Mutants of Arabidopsis Defective in Acclimation of Photosynthesis to the Light Environment

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