Antioxidative response in variegated Pelargonium zonale leaves and generation of extracellular H2O2 in (peri)vascular tissue induced by sunlight and paraquat
Copyright © 2016 Elsevier GmbH. All rights reserved.
| Veröffentlicht in: | Journal of plant physiology. - 1979. - 206(2016) vom: 01. Nov., Seite 25-39 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2016
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| Zugriff auf das übergeordnete Werk: | Journal of plant physiology |
| Schlagworte: | Journal Article Abscisic acid Ascorbate-glutathione cycle Hydrogen peroxide Paraquat Strong light Variegated plants Antioxidants Hydrogen Peroxide BBX060AN9V mehr... |
| Zusammenfassung: | Copyright © 2016 Elsevier GmbH. All rights reserved. In this study we exposed variegated leaves of Pelargonium zonale to strong sunlight (>1100μmolm-2s-1 of photosynthetically active radiation) with and without paraquat (Pq), with the aim to elucidate the mechanisms of H2O2 regulation in green and white tissues with respect to the photosynthetically-dependent generation of reactive oxygen species (ROS). Sunlight induced marked accumulation of H2O2 in the apoplast of vascular and (peri)vascular tissues only in green sectors. This effect was enhanced by the addition of Pq. In the presence of diphenyl iodide, an NADPH oxidase inhibitor, H2O2 accumulation was abolished. Distinct light-induced responses were observed: in photosynthetic cells, sunlight rapidly provoked ascorbate (Asc) biosynthesis and an increase of glutathione reductase (GR) and catalase activities, while in non-photosynthetic cells, early up-regulation of soluble ascorbate peroxidase, dehydroascorbate reductase (DHAR) and GR activities was observed. Paraquat addition stimulated DHAR and GR activities in green sectors, while in white sectors activities of monodehydroascorbate reductase, DHAR and class III peroxidases, as well as Asc content rapidly increased. Differential antioxidative responses in the two tissues in the frame of their contrasting metabolisms, and the possible role of (peri)vascular H2O2 in signaling were discussed |
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| Beschreibung: | Date Completed 11.04.2017 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2016.07.017 |