Inhibition of Donor and Acceptor Side of Photosystem II by Cadmium Ions

2021 ◽  
pp. 187-196
Author(s):  
Roberto Barbato
Keyword(s):  
Photosystem Ii ◽  
Cadmium Ions ◽  
Acceptor Side ◽  
Donor And Acceptor

scholarly journals Alteration of photosystem II properties with non-photochemical excitation quenching

2000 ◽  
Vol 355 (1402) ◽  
pp. 1405-1418 ◽  
Author(s):  
A. Laisk ◽  
V. Oja
Keyword(s):  
Photosystem Ii ◽  
Turnover Rate ◽  
Photochemical Quenching ◽  
Ps Ii ◽  
Single Turnover ◽  
Acceptor Side ◽  
Donor And Acceptor ◽  
Inhibitory Type ◽  
Non Photochemical Quenching ◽  
Oxygen Yield

Oxygen yield from single turnover flashes and multiple turnover pulses was measured in sunflower leaves differently pre–illuminated to induce either ‘energy–dependent type’ non–photochemical excitation quenching ( q E ) or reversible, inhibitory type non–photochemical quenching ( q I ). A zirconium O 2 analyser, combined with a flexible gas system, was used for these measurements. Oxygen yield from saturating single turnover flashes was the equivalent of 1.3–2.0 μmol e − m −2 in leaves pre–adapted to low light. It did not decrease when q E quenching was induced by a 1 min exposure to saturating light, but it decreased when pre–illumination was extended to 30–60 min. Oxygen evolution from saturating multiple turnover pulses behaved similarly: it did not decrease with the rapidly induced q E but decreased considerably when exposure to saturating light was extended or O 2 concentration was decreased to 0.4%. Parallel recording of chlorophyll fluorescence and O 2 evolution during multiple turnover pulses, interpreted with the help of a mathematical model of photosystem II (PS II) electron transport, revealed PS II donor and acceptor side resistances. These experiments showed that PS II properties depend on the type of non–photochemical quenching present. The rapidly induced and rapidly reversible q E type (photoprotective) quenching does not induce changes in the number of active PS II or in the PS II maximum turnover rate, thus confirming the antenna mechanism of q E. The more slowly induced but still reversible q I type quenching (photoinactivation) induced a decrease in the number of active PS II and in the maximum PS II turnover rate. Modelling showed that, mainly, the acceptor side resistance of PS II increased in parallel with the reversible q I. Oxygen yield from single turnover flashes and multiple turnover pulses was measured in sunflower leaves differently pre–illuminated to induce either ‘energy–dependent type’ non–photochemical excitation quenching ( q E ) or reversible, inhibitory type non–photochemical quenching ( q I ). A zirconium O 2 analyser, combined with a flexible gas system, was used for these measurements. Oxygen yield from saturating single turnover flashes was the equivalent of 1.3–2.0 μmol e − m −2 in leaves pre–adapted to low light. It did not decrease when q E quenching was induced by a 1 min exposure to saturating light, but it decreased when pre–illumination was extended to 30–60 min. Oxygen evolution from saturating multiple turnover pulses behaved similarly: it did not decrease with the rapidly induced q E but decreased considerably when exposure to saturating light was extended or O 2 concentration was decreased to 0.4%. Parallel recording of chlorophyll fluorescence and O 2 evolution during multiple turnover pulses, interpreted with the help of a mathematical model of photosystem II (PS II) electron transport, revealed PS II donor and acceptor side resistances. These experiments showed that PS II properties depend on the type of non–photochemical quenching present. The rapidly induced and rapidly reversible q E type (photoprotective) quenching does not induce changes in the number of active PS II or in the PS II maximum turnover rate, thus confirming the antenna mechanism of q E. The more slowly induced but still reversible q I type quenching (photoinactivation) induced a decrease in the number of active PS II and in the maximum PS II turnover rate. Modelling showed that, mainly, the acceptor side resistance of PS II increased in parallel with the reversible q I.

UV-B Radiation-Induced Donor- and Acceptor-Side Modifications of Photosystem II in the CyanobacteriumSynechocystissp. PCC 6803†

Biochemistry ◽  
1999 ◽  
Vol 38 (39) ◽  
pp. 12786-12794 ◽  
Author(s):  
Imre Vass ◽  
Diana Kirilovsky ◽  
Anne-Lise Etienne
Keyword(s):  
Photosystem Ii ◽  
Acceptor Side ◽  
Donor And Acceptor ◽  
Radiation Induced ◽  
Pcc 6803

UV-B-Induced Inhibition of Photosystem II Electron Transport Studied by EPR and Chlorophyll Fluorescence. Impairment of Donor and Acceptor Side Components†

Biochemistry ◽  
1996 ◽  
Vol 35 (27) ◽  
pp. 8964-8973 ◽  
Author(s):  
Imre Vass ◽  
László Sass ◽  
Cornelia Spetea ◽  
Alexandra Bakou ◽  
Demetrios F. Ghanotakis ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Photosystem Ii ◽  
Acceptor Side ◽  
Donor And Acceptor

Comparison of susceptibility of leaves on short-term UV-B irradiation

2012 ◽  
Vol 26 (4) ◽  
pp. 395-400
Author(s):  
E. Skórska ◽  
A. Murkowski
Keyword(s):  
Photosystem Ii ◽  
Ultraviolet B ◽  
Oxygen Evolving Complex ◽  
Short Term ◽  
Chlorophyll Fluorescence Parameters ◽  
Acceptor Side ◽  
Donor And Acceptor ◽  
Ultraviolet B Irradiation ◽  
Oxygen Evolving ◽  
Short Time

Abstract The effects of short-time ultraviolet-B irradiation (0.74 kJ m-2 d-1) at light on cucumber and peppermint leaves were studied.Aconsiderable decrease of the most important chlorophyll fluorescence parameters values mainly in the cucumber leaves, compared to the control, was observed. It indicates damages as well as at a donor and acceptor side of photosystem II, specially in the oxygen evolving complex, electron transport and connected with the dark reactions. In the peppermint leaves these values were unchanged or slight decreased. After 24 h from disappearing of the applied UV-B stress, adverse changes became established, especially in the cucumber leaves show irreversible damages of photosystem II. Coefficient of nonphotochemical quenching increased by 50% in the peppermint leaves, while in cucumber remained unchanged. Chlorophyll delayed luminescence coefficient was decreased by 36% in the UV-B irradiated cucumber leaves and by 25% in the peppermint leaves. Content of ultraviolet-absorbing compounds was higher in peppermint leaves by 78% than in the cucumber. Generally, peppermint seemed to be more tolerant to the applied UV-B radiation compared to cucumber.

Coupled Activation of the Donor and the Acceptor Side of Photosystem II during Photoactivation of the Oxygen Evolving Cluster†

Biochemistry ◽  
1998 ◽  
Vol 37 (31) ◽  
pp. 11039-11045 ◽  
Author(s):  
Maria Rova ◽  
Fikret Mamedov ◽  
Ann Magnuson ◽  
Per-Olof Fredriksson ◽  
Stenbjörn Styring
Keyword(s):  
Photosystem Ii ◽  
Acceptor Side ◽  
Oxygen Evolving

scholarly journals How to build a water-splitting machine: structural insights into photosystem II assembly

2020 ◽  
Author(s):  
Jure Zabret ◽  
Stefan Bohn ◽  
Sandra Schuller ◽  
Oliver Arnolds ◽  
Madeline Möller ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Water Splitting ◽  
Conformational Changes ◽  
Binding Pocket ◽  
Heme Iron ◽  
Structural Motif ◽  
Acceptor Side ◽  
Non Heme Iron ◽  
Assembly Intermediate ◽  
Stepwise Assembly

Abstract Biogenesis of photosystem II (PSII), nature’s water splitting catalyst, is assisted by auxiliary proteins that form transient complexes with PSII components to facilitate stepwise assembly events. Using cryo-electron microscopy, we solved the structure of such a PSII assembly intermediate with 2.94 Å resolution. It contains three assembly factors (Psb27, Psb28, Psb34) and provides detailed insights into their molecular function. Binding of Psb28 induces large conformational changes at the PSII acceptor side, which distort the binding pocket of the mobile quinone (QB) and replace bicarbonate with glutamate as a ligand of the non-heme iron, a structural motif found in reaction centers of non-oxygenic photosynthetic bacteria. These results reveal novel mechanisms that protect PSII from damage during biogenesis until water splitting is activated. Our structure further demonstrates how the PSII active site is prepared for the incorporation of the Mn4CaO5 cluster, which performs the unique water splitting reaction.

Studies about the Mechanism of Herbicidal Interaction with Photosystem II in Isolated Chloroplasts

1979 ◽  
Vol 34 (11) ◽  
pp. 1010-1014 ◽  
Author(s):  
Gernot Renger
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
Electron Acceptor ◽  
Functional Organization ◽  
Regulatory Element ◽  
Release Kinetics ◽  
Acceptor Side ◽  
Receptor Sites ◽  
Isolated Chloroplasts

Abstract Based on the functional organization scheme of system-II-electron transport and its modification by different procedures a proteinaceous component enwrapping the redox components (plastoquinone molecules) of the acceptor side (thereby acting as regulatory element) is inferred to be the unique target for herbicidal interaction with system II. This proteinaceous component, which is attacked by trypsin, provides the receptor sites for the herbicides. Studies of the release kinetics in trypsinated chloroplasts of the inhibition of oxygen evolution with K3 [Fe (CN)6] as electron acceptor indicates, that there exists a binding area with different specific subreceptor sites rather than a unique binding site for the various types of inhibitors. Furthermore, trypsination of the proteinaceous component enhances the efficiency of the plastoquinone pool to act as a non-photochemical quencher for excitation energy.

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