Redox state of the photosynthetic electron transport chain in wild-type and mutant leaves of Arabidopsis thaliana: Impact on photosystem II fluorescence

2010 ◽  
Vol 98 (3) ◽  
pp. 180-187 ◽  
Author(s):  
David Joly ◽  
Essemine Jemâa ◽  
Robert Carpentier
Keyword(s):  
Arabidopsis Thaliana ◽  
Electron Transport ◽  
Photosystem Ii ◽  
Electron Transport Chain ◽  
Redox State ◽  
Photosynthetic Electron Transport ◽  
Wild Type ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

Exposure of high-light-grown cultures of Chlorella vulgaris to darkness inhibits the relaxation of excitation pressure: uncoupling of the redox state of the photosynthetic electron transport chain and phenotypic plasticity

Botany ◽  
2017 ◽  
Vol 95 (12) ◽  
pp. 1125-1140 ◽  
Author(s):  
Lauren Hollis ◽  
Norman P.A. Hüner
Keyword(s):  
Electron Transport ◽  
Chlorella Vulgaris ◽  
Electron Transport Chain ◽  
Redox State ◽  
Light Harvesting ◽  
Photosynthetic Electron Transport ◽  
High Light ◽  
Photon Flux ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain

Chlorella vulgaris acclimated to high light (HL) conditions exhibited a pale-green phenotype characterized by reduced chlorophyll and light harvesting polypeptide abundance compared with the dark green phenotype of the control, low-light-grown (LL) cultures. We hypothesized that if chloroplast redox status was the sole regulator of phenotype, exposure to darkness should cause reversion of the HL to LL phenotype. Surprisingly, HL cells transferred to darkness or dim light failed to green. Thus, phenotypic reversion is light-dependent with an optimal photon flux density (PFD) of 110 μmol photons·m−2·s−1. HL cells shifted to this PFD exhibited increased chlorophyll and light harvesting polypeptide abundance, which were inhibited by 2,5-dibromo-3-methyl-6-isopropyl-benzoquinone but not by 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea. We conclude that photoacclimation of HL-grown cells to LL is governed by the redox state of the intersystem photosynthetic electron transport chain (PETC) at this PFD. At lower light levels, cells maintained the HL phenotype, despite an oxidized status of the PETC. Because 110 μmol photons·m−2·s−1 was the optimal PFD for protochlorophyllide oxidoreductase accumulation, we suggest that stabilization of light-harvesting polypeptides by chlorophyll binding may also govern photoacclimation in C. vulgaris. The possible role of the metabolic balance between respiration and photosynthesis is also discussed.

scholarly journals Expression of Glutamate Dehydrogenase Genes In Arabidopsis Thaliana Depends on The Redox State of Chloroplast Electron Transport Chain

2021 ◽  
Author(s):  
Elena Yu. Garnik ◽  
Vadim I. Belkov ◽  
Vladislav I. Tarasenko ◽  
Yury M. Konstantinov
Keyword(s):  
Arabidopsis Thaliana ◽  
Electron Transport ◽  
Glutamate Dehydrogenase ◽  
Electron Transport Chain ◽  
Redox State ◽  
Photosynthetic Electron Transport ◽  
Glucose Content ◽  
Tetrapyrrole Synthesis ◽  
Transport Chain ◽  
Significant Difference

Abstract Plant glutamate dehydrogenase is an enzyme interconverting L-glutamate and 2-oxoglutarate and providing a link between carbon and nitrogen metabolism. In Arabidopsis thaliana, this enzyme is encoded by three genes. Two of them, GDH1 and GDH2, provide most of the enzyme activity in plant leaves and roots. Expression of GDH1 and GDH2 genes is very low in the light and high in the dark. The molecular signals and mechanisms that provide the light-dependent GDH genes regulation remain unknown. Using photosynthetic electron transport inhibitors 3-(3.4-dichlorophenyl)-1.1-dimethylurea (DCMU) and 2.5-dibromo-3-methyl-6-isopropyl benzoquinone (DBMIB) we demonstrate that transcript levels of the GDH1 and GDH2 genes in Arabidopsis leaves change in accordance with a redox state of chloroplast electron transport chain: they are low when it is highly reduced and high when it is oxidized. Hydrogen peroxide or high light treatment did not result in decreasing of GDH1 or GDH2 expression, so reactive oxygen species cannot be the signals that reduce expression of these genes during dark-to-light shifts. There was no significant difference between the glucose content in the leaves of plants treated with DCMU and the plants treated with DBMIB, so glucose is not the only or the main factor that regulates expression of the studied genes. We presume that expression of Arabidopsis GDH1 and GDH2 genes depends on the chloroplast electron transport chain redox state. This regulatory mechanism could arise because of a need to avoid a competition for substrate between tetrapyrrole synthesis, glutathione synthesis and using of L-glutamate as an energy source during prolonged darkness.

scholarly journals Polymer-Modified Single-Walled Carbon Nanotubes Affect Photosystem II Photochemistry, Intersystem Electron Transport Carriers and Photosystem I End Acceptors in Pea Plants

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5958
Author(s):  
Nia Petrova ◽  
Momchil Paunov ◽  
Petar Petrov ◽  
Violeta Velikova ◽  
Vasilij Goltsev ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Electron Transport Chain ◽  
Photosynthetic Electron Transport ◽  
Single Walled Carbon Nanotubes ◽  
Donor Side ◽  
Photosynthetic Electron Transport Chain ◽  
Transport Chain ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWCNT) have recently been attracting the attention of plant biologists as a prospective tool for modulation of photosynthesis in higher plants. However, the exact mode of action of SWCNT on the photosynthetic electron transport chain remains unknown. In this work, we examined the effect of foliar application of polymer-grafted SWCNT on the donor side of photosystem II, the intersystem electron transfer chain and the acceptor side of photosystem I. Analysis of the induction curves of chlorophyll fluorescence via JIP test and construction of differential curves revealed that SWCNT concentrations up to 100 mg/L did not affect the photosynthetic electron transport chain. SWCNT concentration of 300 mg/L had no effect on the photosystem II donor side but provoked inactivation of photosystem II reaction centres and slowed down the reduction of the plastoquinone pool and the photosystem I end acceptors. Changes in the modulated reflection at 820 nm, too, indicated slower re-reduction of photosystem I reaction centres in SWCNT-treated leaves. We conclude that SWCNT are likely to be able to divert electrons from the photosynthetic electron transport chain at the level of photosystem I end acceptors and plastoquinone pool in vivo. Further research is needed to unequivocally prove if the observed effects are due to specific interaction between SWCNT and the photosynthetic apparatus.

scholarly journals DNA Microarray Analysis of Redox-Responsive Genes in the Genome of the Cyanobacterium Synechocystis sp. Strain PCC 6803

2003 ◽  
Vol 185 (5) ◽  
pp. 1719-1725 ◽  
Author(s):  
Yukako Hihara ◽  
Kintake Sonoike ◽  
Minoru Kanehisa ◽  
Masahiko Ikeuchi
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Dna Microarrays ◽  
Redox State ◽  
Photosynthetic Electron Transport ◽  
Photosynthetic Electron Transport Chain ◽  
Photosynthetic Genes ◽  
Transport Chain ◽  
Redox Responsive ◽  
Pcc 6803

ABSTRACT Whole-genome DNA microarrays were used to evaluate the effect of the redox state of the photosynthetic electron transport chain on gene expression in Synechocystis sp. strain PCC 6803. Two specific inhibitors of electron transport, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), were added to the cultures, and changes in accumulation of transcripts were examined. About 140 genes were highlighted as reproducibly affected by the change in the redox state of the photosynthetic electron transport chain. It was shown that some stress-responsive genes but not photosynthetic genes were under the control of the redox state of the plastoquinone pool in Synechocystis sp. strain PCC 6803.

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