Chloroplasts require glutathione reductase to balance reactive oxygen species and maintain efficient photosynthesis.

Autor: Müller-Schüssele SJ; Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, Bonn, 53113, Germany., Wang R; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany., Gütle DD; Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany., Romer J; Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, 53115, Germany., Rodriguez-Franco M; Cell Biology, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, 79104, Germany., Scholz M; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany., Buchert F; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany., Lüth VM; Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany., Kopriva S; Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, 50674, Germany., Dörmann P; Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Bonn, 53115, Germany., Schwarzländer M; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany., Reski R; Plant Biotechnology, Faculty of Biology, University of Freiburg, Schänzlestrasse1, Freiburg, 79104, Germany.; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestrasse18, Freiburg, 79104, Germany., Hippler M; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster, 48143, Germany.; Institute of Plant Science and Resources, Okayama University, Kurashiki, 710-0046, Japan., Meyer AJ; Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, Bonn, 53113, Germany.
Jazyk: angličtina
Zdroj: The Plant journal : for cell and molecular biology [Plant J] 2020 Aug; Vol. 103 (3), pp. 1140-1154. Date of Electronic Publication: 2020 May 23.
DOI: 10.1111/tpj.14791
Abstrakt: Thiol-based redox-regulation is vital for coordinating chloroplast functions depending on illumination and has been throroughly investigated for thioredoxin-dependent processes. In parallel, glutathione reductase (GR) maintains a highly reduced glutathione pool, enabling glutathione-mediated redox buffering. Yet, how the redox cascades of the thioredoxin and glutathione redox machineries integrate metabolic regulation and detoxification of reactive oxygen species remains largely unresolved because null mutants of plastid/mitochondrial GR are embryo-lethal in Arabidopsis thaliana. To investigate whether maintaining a highly reducing stromal glutathione redox potential (E GSH ) via GR is necessary for functional photosynthesis and plant growth, we created knockout lines of the homologous enzyme in the model moss Physcomitrella patens. In these viable mutant lines, we found decreasing photosynthetic performance and plant growth with increasing light intensities, whereas ascorbate and zeaxanthin/antheraxanthin levels were elevated. By in vivo monitoring stromal E GSH dynamics, we show that stromal E GSH is highly reducing in wild-type and clearly responsive to light, whereas an absence of GR leads to a partial glutathione oxidation, which is not rescued by light. By metabolic labelling, we reveal changing protein abundances in the GR knockout plants, pinpointing the adjustment of chloroplast proteostasis and the induction of plastid protein repair and degradation machineries. Our results indicate that the plastid thioredoxin system is not a functional backup for the plastid glutathione redox systems, whereas GR plays a critical role in maintaining efficient photosynthesis.
(© 2020 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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