The role of subcellular distribution of cadmium and phytochelatins in the generation of distinct phenotypes of AtPCS1- and CePCS3-expressing tobacco
Copyright 2010 Elsevier GmbH. All rights reserved.
| Veröffentlicht in: | Journal of plant physiology. - 1979. - 167(2010), 12 vom: 15. Aug., Seite 981-8 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2010
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| Zugriff auf das übergeordnete Werk: | Journal of plant physiology |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis Proteins Caenorhabditis elegans Proteins Dipeptides Cadmium 00BH33GNGH Phytochelatins 98726-08-0 Aminoacyltransferases mehr... |
| Zusammenfassung: | Copyright 2010 Elsevier GmbH. All rights reserved. Exposure to Cd2+ leads to activation of phytochelatin synthase (PCS) and the formation of phytochelatins (PCs) in the cytosol. Binding of Cd by PCs and the subsequent transport of PC-Cd complexes to the vacuole are essential for Cd tolerance. Attempts to improve Cd detoxification by PCS overexpression have resulted in contrasting plant phenotypes, ranging from enhanced Cd tolerance to Cd hypersensitivity. In the present paper, changes in the subcellular phytochelatin, glutathione, gamma-glutamylcysteine and cadmium vacuolar and cytosolic distribution underlying these phenotypes were examined. Cadmium and PCs levels were determined in protoplasts and vacuoles isolated from leaves of Nicotiana tabacum expressing either of two phytochelatin synthase genes, AtPCS1 and CePCS (differing in their level of Cd tolerance; being Cd hypersensitive or more Cd-tolerant as compared to wild-type plants, respectively). We showed that Cd hypersensitivity of AtPCS1-expressing tobacco results from a significant decrease in both the cytosolic and vacuolar pool of PCs, indicating a decreased cadmium detoxification capacity. By contrast, enhanced Cd tolerance of CePCS plants was accompanied by an increased cytosolic and vacuolar SH of PC/Cd ratio, suggesting more efficient Cd detoxification. Surprisingly, the substantially reduced level of PCs did not influence Cd accumulation in vacuoles of AtPCS1-transformed tobacco (relative to the wild-type), which suggests the important role of mechanisms other than PC-Cd transport in Cd translocation to the vacuole. Our data suggest that the key role of the PCs in Cd tolerance is temporary binding of Cd2+ in the cytosol, and contrary to the current view, their contribution to cadmium sequestration seems to be less important |
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| Beschreibung: | Date Completed 22.11.2010 Date Revised 13.12.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2010.02.010 |