Dynamic flexibility in the light reactions of photosynthesis governed by both electron and proton transfer reactions

Kramer, David; Avenson, Thomas J.; Edwards, Gerald E.

doi:10.1016/j.tplants.2004.05.001

Cited by 347 publications

(308 citation statements)

References 66 publications

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“…ECS measurements under continuous illumination can also be used to study alternative electron flow processes (reviewed in Eberhardt et al 2008, section II.3) and to assess the relative extents of the light-induced ΔΨ and pH in plants (Kramer et al 2004;Cruz et al 2005;Takizawa et al 2007) and unicellular algae (Finazzi et al 2006;Cardol et al 2008, section II.4). In the following, we provide a more detailed description of the different applications of the ECS in vivo in the case of some unicellular algae.…”

Section: Ecs and Photosynthesismentioning

confidence: 99%

Electrochromism: a useful probe to study algal photosynthesis

et al. 2010

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In photosynthesis, electron transfer along the photosynthetic chain results in a vectorial transfer of protons from the stroma to the lumen space of the thylakoids.This promotes the generation of an electrochemical proton gradient (Δμ H + ), which comprises a gradient of electric potential (ΔΨ) and of proton concentration (ΔpH).The Δμ H + has a central role in the photosynthetic process, providing the energy source for ATP synthesis, and being involved in many regulatory mechanisms. The pH modulates the rate of electron transfer and triggers de excitation of excess light within the light harvesting complexes. The ΔΨ is required for metabolites and protein transport across the membranes. Its presence also induces a shift in the absorption spectra of some photosynthetic pigments, resulting in the so called Electro Chromic Shift (ECS). In this review, we discuss the characteristics features of the ECS, and illustrate possible applications of it for the study of photosynthetic processes in vivo.

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Section: Ecs and Photosynthesismentioning

confidence: 99%

Electrochromism: a useful probe to study algal photosynthesis

et al. 2010

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“…However, caution must be observed in assigning a role for heme x in cyclic electron flow, since the observed rate heme b n (red) + heme x(ox) f heme b n (ox) + heme x(red) (1) heme x(red) + PQ (or PQ •-+ 2H + ) f heme x(ox) + PQ •-or PQH 2 (2) of cytochrome b reduction by NADPH-ferredoxin shows a kinetic limitation (12,35,36), which implies regulation and control of this pathway that is not understood at present (37). Moreover, work on C3 plants suggests that electron transport is apparently inhibited by mutation of a Fd:PQ oxidoreductase and a NADPH:PQ oxidoreductase (38).…”

Section: Accessibility Of Heme X To Exogenousmentioning

confidence: 99%

Characterization of the High-Spin Heme x in the Cytochrome b₆f Complex of Oxygenic Photosynthesis

et al. 2004

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“…Autotrophic O 2 evolution and C i assimilation are governed by the rate of electron turnover by the photochemical 'light' reactions (Allen, 2002;Behrenfeld et al, 2004;Kramer et al, 2004). Absorbed light energy promotes the splitting of water to release O 2 , protons and electrons.…”

Section: Introductionmentioning

confidence: 99%

“…A gradient of protons across the thylakoid membranes drives synthesis of ATP via ATP synthase. ATP is then used to fix C i but is also consumed by additional energy-demanding processes that are crucial for the maintenance and regulation of photochemical pathways, in particular uptake and assimilation of nutrients including C i (Falkowski and Raven, 1997;Allen, 2002;Kramer et al, 2004). ATP also can be provided by respiration (Badger et al, 2000;Geider and MacIntyre, 2002) but at the expense of previously fixed carbon.…”

Section: Introductionmentioning

confidence: 99%

Photosynthetic electron turnover in the tropical and subtropical Atlantic Ocean

Suggett

Moore

Marañón

et al. 2006

Deep Sea Research Part II: Topical Studies in Oceanography

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Photosynthetic electron transport directly generates the energy required for carbon fixation and thus underlies the aerobic metabolism of aquatic systems. We determined photosynthetic electron turnover rates, ETRs, from ca. 100 FRR fluorescence water-column profiles throughout the subtropical and tropical Atlantic during six Atlantic Meridional Transect cruises (AMT 6, May-June 1998, to AMT 11, September-October 2000. Each FRR fluorescence profile yielded a water-column ETR-light response from which the maximum electron turnover rate ðETR max RCII Þ, effective absorption (s PSII ) and light saturation parameter (E k ) specific to the concentration of photosystem II reaction centres (RCIIs) were calculated. ETR max RCII and E k increased whilst s PSII decreased with mixed-layer depth and the daily integrated photosynthetically active photon flux when all provinces were considered together. These trends suggested that variability in maximum ETR can be partly attributed to changes in effective absorption. Independent bio-optical measurements taken during AMT 11 demonstrated that s PSII variability reflects taxonomic and physiological differences in the phytoplankton communities. ETR max RCII and E k , but not s PSII , remained correlated with mixed-layer depth and daily integrated photosynthetically active photon flux when data from each oceanic province were considered separately, indicating a decoupling of electron turnover and carbon fixation rates within each province. Comparison of maximum ETRs with 14 C-based measurements of P max further suggests that light absorption and C fixation are coupled to differing extents for the various oligotrophic Atlantic provinces. We explore the importance of quantifying RCII concentration for determination of ETRs and interpretation of ETR-C fixation coupling. r

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Dynamic flexibility in the light reactions of photosynthesis governed by both electron and proton transfer reactions

Cited by 347 publications

References 66 publications

Electrochromism: a useful probe to study algal photosynthesis

Electrochromism: a useful probe to study algal photosynthesis

Characterization of the High-Spin Heme x in the Cytochrome b₆f Complex of Oxygenic Photosynthesis

Photosynthetic electron turnover in the tropical and subtropical Atlantic Ocean

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Dynamic flexibility in the light reactions of photosynthesis governed by both electron and proton transfer reactions

Cited by 347 publications

References 66 publications

Electrochromism: a useful probe to study algal photosynthesis

Electrochromism: a useful probe to study algal photosynthesis

Characterization of the High-Spin Heme x in the Cytochrome b6f Complex of Oxygenic Photosynthesis

Photosynthetic electron turnover in the tropical and subtropical Atlantic Ocean

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Characterization of the High-Spin Heme x in the Cytochrome b₆f Complex of Oxygenic Photosynthesis