Different kinetics of photoinactivation of photosystem I-mediated electron transport and P700 in isolated thylakoid membranes

Highly characteristic responses of thylakoid membranes were observed in function and composition when fully developed plants of Amaranthus hypochondriacus L. grown under light sufficient (2000 μmol m-2 s-1) conditions were transferred to light limited conditions (650 μmol m-2 s-1 and 200 μmol m-2 s-1). The whole-chain, photosystem I and photosystem II electron transport rates were depressed in both bundle sheath and mesophyll thylakoids with remarkable differences between them in variation of rates under limiting light. The reduction in PSI electron transport in the mesophyll could be attributed to reduced PSI centres, while in the bundle sheath, a modulation of cytochrome b6/f complex regulated the rates of PSI electron transport. The requirement for an unaltered number of PSI centres under limiting light in the bundle sheath is ascribed to operation of an energy-consuming C4 pump.

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Identification of Ferredoxin-Dependent Cyclic Electron Transport around Photosystem I Using the Kinetics of Dark P700+ Reduction

Russian Journal of Plant Physiology ◽

10.1007/s11183-005-0042-5 ◽

2005 ◽

Vol 52 (3) ◽

pp. 283-287 ◽

Cited By ~ 2

Author(s):

N. G. Bukhov ◽

E. A. Egorova

Keyword(s):

Electron Transport ◽

Photosystem I ◽

Cyclic Electron Transport ◽

Kinetics Of

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Ferredoxin–NADP+ reductase is the site of oxygen reduction in pseudocyclic electron transport

Canadian Journal of Botany ◽

10.1139/b94-034 ◽

1994 ◽

Vol 72 (2) ◽

pp. 256-260 ◽

Cited By ~ 11

Author(s):

D. Christoper Goetze ◽

Robert Carpentier

Keyword(s):

Electron Transport ◽

Oxygen Reduction ◽

Photosystem I ◽

Spinacia Oleracea ◽

Thylakoid Membranes ◽

Photoelectrochemical Cell ◽

Reaction Products ◽

Additional Increase ◽

Ps I

The effects of ferredoxin (Fd) and Fd–NADP+ reductase (FNR) on the oxygen photoreduction by photosystem I (PS I) in spinach (Spinacia oleracea L.) thylakoid membranes were investigated using a unique photoelectrochemical cell. This cell was previously shown to monitor the Mehler reaction products of photosynthetic oxygen reduction and represents an excellent tool for studying pseudocyclic electron transport. The magnitude of the photocurrent produced by the thylakoids was increased by as much as 40% in the presence of 60 μM Fd. If thylakoids were supplemented by both Fd and FNR, an additional increase of photocurrent was observed. All these reactions were inhibited by catalase, an enzyme that degrades H2O2, to demonstrate that O2 reduction was involved in all the photoreactions studied. The fact that more O2 was consumed in the presence of FNR was interpreted as evidence that the most effective site of oxygen reduction on the acceptor side of PS I is on FNR and not on Fd. The in vivo implication is that during pseudocyclic electron transport, NADP+ and oxygen directly compete for PS I electrons, with the former having significantly faster reaction kinetics. The advantageous physiological consequences of such a competition are (i) pseudocyclic electron transport would represent a true attenuating mechanism of the redox state of the NADP+–NADPH pool, (ii) oxygen would be a contingent acceptor under high illumination stress, helping to cope with the resultant elevated electron transport rates, and (iii) this mechanism is indisputably a faster response to stress than cyclic electron transport. Key words: Spinacia oleracea, photosystem I, thylakoid membranes, ferredoxin–NADP+ reductase, pseudocyclic electron transport, photoelectrochemistry.

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Stimulatory Effects of an Ammonium Salt Biocide on Photosynthetic Electron Transport Reactions

Zeitschrift für Naturforschung C ◽

10.1515/znc-1994-1-214 ◽

1994 ◽

Vol 49 (1-2) ◽

pp. 87-94 ◽

Cited By ~ 2

Author(s):

Klaus P. Bader ◽

Susanne Höper

Keyword(s):

Electron Transport ◽

Photosystem Ii ◽

Ammonium Salt ◽

Photosystem I ◽

Reaction Rates ◽

Filamentous Cyanobacterium ◽

Relaxation Kinetics ◽

Photosynthetic Membranes ◽

Oscillatoria Chalybea ◽

Kinetics Of

Alkylbenzyldimethylammonium chloride (ABDAC, zephirol) has been shown to improve the functioning of the photosynthetic apparatus of the filamentous cyanobacterium Oscillatoria chalybea (Bader, K. P. (1989) Biochim. Biophys. Acta 975, 399-402). This biocide exerts stimulatory effects on various electron transport reactions in Oscillatoria chalybea and chloroplasts from higher plants. By means of oxygen evolution measurements and of repetitive flash-induced absorption spectroscopy we were able to demonstrate an impact of the drug on the major complexes of photosynthetic membranes, i.e. the water splitting complex, photosystem II and photosystem I. Both, P820- and X320-absorption change signals were enhanced by the addition of ABDAC. Along with the quantitative analysis we investigated the relaxation kinetics of the signals and observed a substantial stabilization of the oxidized states of the respective redox components in the presence of the ammonium salt. Under appropriate conditions the relaxation kinetics of the absorption signals were significantly slowed down. ABDAC also affects photosystem I in Oscillatoria chalybea, but only under conditions, where a donor/acceptor system i.e. an isolated photosystem I reaction with photosystem II being disconnected was measured. Electron transport through the whole chain i.e. with water as the electron donor yielded no effect of the quaternary ammonium salt. It is suggested that this is due to an extremely bad linkage between the two photosystem, each of which, however, shows good reaction rates, when separately measured. The described interactions of the biocide with photosynthetic membranes are not restricted to Oscillatoria chalybea but are also observed with higher plant chloroplasts. In these systems, ABDAC enhances X320- and P700-signals to a comparable extent. In this case the P700-signal is stimulated in assays with electrons which are furnished from water which hints at good coupling between the two photosystems in our tobacco chloroplast preparations.

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Respiration Interacts With Photosynthesis Through the Acceptor Side of Photosystem I, Reflected in the Dark-to-Light Induction Kinetics of Chlorophyll Fluorescence in the Cyanobacterium Synechocystis sp. PCC 6803

Frontiers in Plant Science ◽

10.3389/fpls.2021.717968 ◽

2021 ◽

Vol 12 ◽

Author(s):

Takako Ogawa ◽

Kenta Suzuki ◽

Kintake Sonoike

Keyword(s):

Chlorophyll Fluorescence ◽

Electron Transport ◽

Photosystem I ◽

Fluorescence Induction ◽

Chlorophyll Fluorescence Induction ◽

Light Induction ◽

Acceptor Side ◽

Induction Kinetics ◽

Electron Transport Chains ◽

Kinetics Of

In cyanobacteria, the photosynthetic prokaryotes, direct interaction between photosynthesis and respiration exists at plastoquinone (PQ) pool, which is shared by the two electron transport chains. Another possible point of intersection of the two electron transport chains is NADPH, which is the major electron donor to the respiratory chain as well as the final product of the photosynthetic chain. Here, we showed that the redox state of NADPH in the dark affected chlorophyll fluorescence induction in the cyanobacterium Synechocystis sp. PCC 6803 in a quantitative manner. Accumulation of the reduced NADPH in the dark due to the defect in type 1 NAD(P)H dehydrogenase complex in the respiratory chain resulted in the faster rise to the peak in the dark-to-light induction of chlorophyll fluorescence, while depletion of NADPH due to the defect in pentose phosphate pathway resulted in the delayed appearance of the initial peak in the induction kinetics. There was a strong correlation between the dark level of NADPH determined by its fluorescence and the peak position of the induction kinetics of chlorophyll fluorescence. These results indicate that photosynthesis interacts with respiration through NADPH, which enable us to monitor the redox condition of the acceptor side of photosystem I by simple measurements of chlorophyll fluorescence induction in cyanobacteria.

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Superoxide-and Ethane-Formation in Subchloroplast Particles: Catalysis by Pyridinium Derivatives

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-9-1019 ◽

1980 ◽

Vol 35 (9-10) ◽

pp. 770-775 ◽

Cited By ~ 11

Author(s):

E. F. Elstner ◽

H. P. Fischer ◽

W. Osswald ◽

G. Kwiatkowski

Keyword(s):

Electron Transport ◽

Photosystem I ◽

Photosynthetic Electron Transport ◽

Redox Potentials ◽

Light Reaction ◽

Pyridinium Bromide ◽

Superoxide Formation ◽

Fatty Acid Peroxidation ◽

Chlorophyll Bleaching ◽

Ethane Formation

Abstract Oxygen reduction by chloroplast lamellae is catalyzed by low potential redox dyes with E′0 values between -0 .3 8 V and -0 .6 V. Compounds of E′0 values of -0 .6 7 V and lower are inactive. In subchloroplast particles with an active photosystem I but devoid of photosynthetic electron transport between the two photosystems, the active redox compounds enhance chlorophyll bleaching, superoxide formation and ethane production independent on exogenous substrates or electron donors. The activities of these compounds decrease with decreasing redox potential, with one exception: 1-methyl-4,4′-bipyridini urn bromide with an E′0 value of lower -1 V (and thus no electron acceptor of photosystem I in chloroplast lamellae with intact electron transport) stimulates light dependent superoxide formation and unsaturated fatty acid peroxidation in sub chloroplast particles, maximal rates appearing after almost complete chlorophyll bleaching. Since this activity is not visible with compounds with redox potentials below -0 .6 V lacking the nitrogen atom at the 1-position of the pyridinium substituent, we assume that 1 -methyl-4,4′-bi-pyridinium bromide is “activated” by a yet unknown light reaction.

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Photosystem II Inhibition by Pyran-enamine Derivatives

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-3-409 ◽

1993 ◽

Vol 48 (3-4) ◽

pp. 163-167

Author(s):

Koichi Yoneyama ◽

Yoshihiro Nakajima ◽

Masaru Ogasawara ◽

Hitoshi Kuramochi ◽

Makoto Konnai ◽

...

Keyword(s):

Electron Transport ◽

Photosystem Ii ◽

Thylakoid Membranes ◽

Major Determinant ◽

Ps Ii ◽

Structure Activity Relationships ◽

Structure Activity

Abstract Through the studies on structure-activity relationships of 5-acyl-3-(1-aminoalkylidene)-4-hydroxy-2 H-pyran-2,6(3 H)-dione derivatives in photosystem II (PS II) inhibition, overall lipophilicity of the molecule was found to be a major determinant for the activity. In the substituted N -benzyl derivatives, not only the lipophilicity but also the electronic and steric characters of the substituents greatly affected the activity. Their mode of PS II inhibition seemed to be similar to that of DCMU , whereas pyran-enamine derivatives needed to be highly lipophilic to block the electron transport in thylakoid membranes, which in turn diminished the permeability through biomembranes.

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Probing the biogenesis pathway and dynamics of thylakoid membranes

Nature Communications ◽

10.1038/s41467-021-23680-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Tuomas Huokko ◽

Tao Ni ◽

Gregory F. Dykes ◽

Deborah M. Simpson ◽

Philip Brownridge ◽

...

Keyword(s):

Plasma Membrane ◽

Photosystem I ◽

Spatial Organization ◽

Electron Flux ◽

Protein Complexes ◽

Thylakoid Membranes ◽

Thylakoid Biogenesis ◽

Photosynthetic Complexes ◽

Photosynthetic Machinery ◽

Pcc 7942

AbstractHow thylakoid membranes are generated to form a metabolically active membrane network and how thylakoid membranes orchestrate the insertion and localization of protein complexes for efficient electron flux remain elusive. Here, we develop a method to modulate thylakoid biogenesis in the rod-shaped cyanobacterium Synechococcus elongatus PCC 7942 by modulating light intensity during cell growth, and probe the spatial-temporal stepwise biogenesis process of thylakoid membranes in cells. Our results reveal that the plasma membrane and regularly arranged concentric thylakoid layers have no physical connections. The newly synthesized thylakoid membrane fragments emerge between the plasma membrane and pre-existing thylakoids. Photosystem I monomers appear in the thylakoid membranes earlier than other mature photosystem assemblies, followed by generation of Photosystem I trimers and Photosystem II complexes. Redistribution of photosynthetic complexes during thylakoid biogenesis ensures establishment of the spatial organization of the functional thylakoid network. This study provides insights into the dynamic biogenesis process and maturation of the functional photosynthetic machinery.

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Photoinhibition of Electron Transport Activity of Photosystem II in Isolated Thylakoids Studied by Thermoluminescence and Delayed Luminescence

Zeitschrift für Naturforschung C ◽

10.1515/znc-1988-11-1213 ◽

1988 ◽

Vol 43 (11-12) ◽

pp. 871-876 ◽

Cited By ~ 35

Author(s):

Imre Vass ◽

Narendranath Mohanty ◽

Sándor Demeter

Keyword(s):

Electron Transport ◽

Photosystem Ii ◽

Photosystem I ◽

Half Life ◽

Delayed Luminescence ◽

Transport Activity ◽

Primary Target ◽

Electron Transport Activity ◽

The Stability ◽

Spinach Thylakoids

Abstract The effect of photoinhibition on the primary (QA) and secondary (QB) quinone acceptors of photosystem I I was investigated in isolated spinach thylakoids by the methods of thermoluminescence and delayed luminescence. The amplitudes of the Q (at about 2 °C) and B (at about 30 °C) thermoluminescence bands which are associated with the recombination of the S2QA- and S2QB charge pairs, respectively, exhibited parallel decay courses during photoinhibitory treatment. Similarly, the amplitudes of the flash-induced delayed luminescence components ascribed to the recombination of S20A and S2OB charge pairs and having half life-times of about 3 s and 30 s, respectively, declined in parallel with the amplitudes of the corresponding Q and B thermoluminescence bands. The course of inhibition of thermoluminescence and delayed luminescence intensity was parallel with that of the rate of oxygen evolution. The peak positions of the B and Q thermoluminescence bands as well as the half life-times of the corresponding delayed luminescence components were not affected by photoinhibition. These results indicate that in isolated thylakoids neither the amount nor the stability of the reduced OB acceptor is preferentially decreased by photoinhibition. We conclude that either the primary target of photodamage is located before the O b binding site in the reaction center of photosystem II or QA and OB undergo simultaneous damage.

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