Book ChapterDOI
Photoinhibition of Photosystem II
TLDR
In this chapter, it is shown that the evidence behind the chemistry-based models and the photophysically oriented models can be brought together to build a mechanism that confirms with all types of experimental data.Abstract:
Photoinhibition of Photosystem II (PSII) is the light-induced loss of PSII electron-transfer activity. Although photoinhibition has been studied for a long time, there is no consensus about its mechanism. On one hand, production of singlet oxygen ((1)O(2)) by PSII has promoted models in which this reactive oxygen species (ROS) is considered to act as the agent of photoinhibitory damage. These chemistry-based models have often not taken into account the photophysical features of photoinhibition-like light response and action spectrum. On the other hand, models that reproduce these basic photophysical features of the reaction have not considered the importance of data about ROS. In this chapter, it is shown that the evidence behind the chemistry-based models and the photophysically oriented models can be brought together to build a mechanism that confirms with all types of experimental data. A working hypothesis is proposed, starting with inhibition of the manganese complex by light. Inability of the manganese complex to reduce the primary donor promotes recombination between the oxidized primary donor and Q(A), the first stable quinone acceptor of PSII. (1)O(2) production due to this recombination may inhibit protein synthesis or spread the photoinhibitory damage to another PSII center. The production of (1)O(2) is transient because loss of activity of the oxygen-evolving complex induces an increase in the redox potential of Q(A), which lowers (1)O(2) production.read more
Citations
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Journal ArticleDOI
Meeting the Global Food Demand of the Future by Engineering Crop Photosynthesis and Yield Potential
TL;DR: There is a timely need to accelerate the understanding of the photosynthetic process in crops to allow informed and guided improvements via in-silico-assisted genetic engineering.
Journal ArticleDOI
Linking chlorophyll a fluorescence to photosynthesis for remote sensing applications: mechanisms and challenges
Albert Porcar-Castell,Esa Tyystjärvi,Jon Atherton,Christiaan van der Tol,Jaume Flexas,Erhard Pfündel,Jose Moreno,Christian Frankenberg,Joseph A. Berry +8 more
TL;DR: The basis of photosynthetic acclimation and its optical signals is presented, the physical and physiological basis of ChlF is introduced from the molecular to the leaf level and beyond, and PAM and SIF methodology are introduced.
Journal ArticleDOI
Reactive oxygen species, oxidative signaling and the regulation of photosynthesis.
TL;DR: Reactive oxygen species (ROS) are produced in abundance by photosynthesis and function in redox signal transduction that is important in chloroplast to nucleus communication.
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In Posidonia oceanica cadmium induces changes in DNA methylation and chromatin patterning
TL;DR: The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase, linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin.
Journal ArticleDOI
PROTON GRADIENT REGULATION5 Is Essential for Proper Acclimation of Arabidopsis Photosystem I to Naturally and Artificially Fluctuating Light Conditions
Marjaana Suorsa,Sari Järvi,Michele Grieco,Markus Nurmi,Malgorzata Pietrzykowska,Marjaana Rantala,Saijaliisa Kangasjärvi,Virpi Paakkarinen,Mikko Tikkanen,Stefan Jansson,Eva-Mari Aro +10 more
TL;DR: It is shown that PROTON GRADIENT REGULATION5 (PGR5)–dependent regulation of electron transfer and proton motive force is crucial for protection of PSI against photodamage, which occurred particularly during the high light phases of fluctuating light cycles.
References
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Journal ArticleDOI
The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence
TL;DR: In this article, the quantum yield of non-cyclic electron transport was found to be directly proportional to the product of the photochemical fluorescence quenching (qQ) and the efficiency of excitation capture by open Photosystem II (PS II) reaction centres (Fv/Fm).
Journal ArticleDOI
ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under Control
Graham Noctor,Christine H. Foyer +1 more
TL;DR: A detailed account of current knowledge of the biosynthesis, compartmentation, and transport of these two important antioxidants, with emphasis on the unique insights and advances gained by molecular exploration are provided.
Journal ArticleDOI
Chlorophyll Fluorescence and Photosynthesis: The Basics
G. H. Krause,E. Weis +1 more
TL;DR: Fluorescence as a Reaction Competing in the Deactivation of Excited Chlorophyll and the Origin of Fluorescence Emission.
Journal ArticleDOI
Chlorophyll fluorescence: a probe of photosynthesis in vivo
TL;DR: This review examines how fluorescence parameters can be used to evaluate changes in photosystem II (PSII) photochemistry, linear electron flux, and CO(2) assimilation in vivo, and outlines the theoretical bases for the use of specificfluorescence parameters.
Journal ArticleDOI
Architecture of the Photosynthetic Oxygen-Evolving Center
TL;DR: The data strongly suggest that the OEC contains a cubane-like Mn3CaO4 cluster linked to a fourth Mn by a mono-μ-oxo bridge, and the details of the surrounding coordination sphere of the metal cluster and the implications for a possible oxygen-evolving mechanism are discussed.