The plastoquinone pool outside the thylakoid membrane serves in plant photoprotection as a reservoir of singlet oxygen scavengers.

Autor: Ksas B; CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France., Légeret B; CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, 13108, Saint-Paul-lez-Durance, France., Ferretti U; Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic., Chevalier A; CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France., Pospíšil P; Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic., Alric J; CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France., Havaux M; CEA Cadarache, CNRS UMR 7265 Biologie Végétale et Microbiologie Environnementales, Aix Marseille Université, Laboratoire d'Ecophysiologie Moléculaire des Plantes, 13108, Saint-Paul-lez-Durance, France.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2018 Oct; Vol. 41 (10), pp. 2277-2287. Date of Electronic Publication: 2018 Jun 29.
DOI: 10.1111/pce.13202
Abstrakt: The Arabidopsis vte1 mutant is devoid of tocopherol and plastochromanol (PC-8). When exposed to excess light energy, vte1 produced more singlet oxygen ( 1 O 2 ) and suffered from extensive oxidative damage compared with the wild type. Here, we show that overexpressing the solanesyl diphosphate synthase 1 (SPS1) gene in vte1 induced a marked accumulation of total plastoquinone (PQ-9) and rendered the vte1 SPS1oex plants tolerant to photooxidative stress, indicating that PQ-9 can replace tocopherol and PC-8 in photoprotection. High total PQ-9 levels were associated with a noticeable decrease in 1 O 2 production and higher levels of Hydroxyplastoquinone (PQ-C), a 1 O 2 -specific PQ-9 oxidation product. The extra PQ-9 molecules in the vte1 SPS1oex plants were stored in the plastoglobules and the chloroplast envelopes, rather than in the thylakoid membranes, whereas PQ-C was found almost exclusively in the thylakoid membranes. Upon exposure of wild-type plants to high light, the thylakoid PQ-9 pool decreased, whereas the extrathylakoid pool remained unchanged. In vte1 and vte1 SPS1oex plants, the PQ-9 losses in high light were strongly amplified, affecting also the extrathylakoid pool, and PQ-C was found in high amounts in the thylakoids. We conclude that the thylakoid PQ-9 pool acts as a 1 O 2 scavenger and is replenished from the extrathylakoid stock.
(© 2018 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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