Photo-oxidative damage of photosystem I by repetitive flashes and chilling stress in cucumber leaves.

Autor: Shimakawa G; Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, 91198 Gif-sur-Yvette, France; Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan., Müller P; Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, 91198 Gif-sur-Yvette, France., Miyake C; Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan., Krieger-Liszkay A; Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, 91198 Gif-sur-Yvette, France. Electronic address: anja.liszkay@i2bc.paris-saclay.fr., Sétif P; Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, 91198 Gif-sur-Yvette, France.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Bioenergetics [Biochim Biophys Acta Bioenerg] 2024 Nov 01; Vol. 1865 (4), pp. 149490. Date of Electronic Publication: 2024 Jul 02.
DOI: 10.1016/j.bbabio.2024.149490
Abstrakt: Photosystem I (PSI) is an essential protein complex for oxygenic photosynthesis and is also known to be an important source of reactive oxygen species (ROS) in the light. When ROS are generated within PSI, the photosystem can be damaged. The so-called PSI photoinhibition is a lethal event for oxygenic phototrophs, and it is prevented by keeping the reaction center chlorophyll (P700) oxidized in excess light conditions. Whereas regulatory mechanisms for controlling P700 oxidation have been discovered already, the molecular mechanism of PSI photoinhibition is still unclear. Here, we characterized the damage mechanism of PSI photoinhibition by in vitro transient absorption and electron paramagnetic resonance (EPR) spectroscopy in isolated PSI from cucumber leaves that had been subjected to photoinhibition treatment. Photodamage to PSI was induced by two different light treatments: 1. continuous illumination with high light at low (chilling) temperature (C/LT) and 2. repetitive flashes at room temperature (F/RT). These samples were compared to samples that had been illuminated with high light at room temperature (C/RT). The [FeS] clusters F X and (F A F B ) were destructed in C/LT but not in F/RT. Transient absorption spectroscopy indicated that half of the charge separation was impaired in F/RT, however, low-temperature EPR revealed the light-induced F X signal at a similar size as in the case of C/RT. This indicates that the two branches of electron transfer in PSI were affected differently. Electron transfer at the A-branch was inhibited in F/RT and also partially in C/LT, while the B-branch remained active.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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