Enhanced Selenium Tolerance and Accumulation in Transgenic Arabidopsis Expressing a Mouse Selenocysteine Lyase
| Autor: | Elizabeth A. H. Pilon-Smits, Marinus Pilon, Gulnara F. Garifullina, Jennifer D. Owen, Hisaaki Mihara, Tatsuo Kurihara, Nobuyoshi Esaki |
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| Rok vydání: | 2003 |
| Předmět: |
Physiology
Arabidopsis Lyases Plant Science Gene Expression Regulation Enzymologic Mice Selenium chemistry.chemical_compound Selenocysteine lyase Genetics Animals Arabidopsis thaliana Alanine biology Selenocysteine Wild type food and beverages Plants Genetically Modified biology.organism_classification Lyase Adaptation Physiological Chloroplast Cytosol Biochemistry chemistry Research Article |
| Zdroj: | Plant Physiology. 131:1250-1257 |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1104/pp.102.014639 |
| Popis: | Selenium (Se) toxicity is thought to be due to nonspecific incorporation of selenocysteine (Se-Cys) into proteins, replacing Cys. In an attempt to direct Se flow away from incorporation into proteins, a mouse (Mus musculus) Se-Cys lyase (SL) was expressed in the cytosol or chloroplasts of Arabidopsis. This enzyme specifically catalyzes the decomposition of Se-Cys into elemental Se and alanine. The resulting SL transgenics were shown to express the mouse enzyme in the expected intracellular location, and to have SL activities up to 2-fold (cytosolic lines) or 6-fold (chloroplastic lines) higher than wild-type plants. Se incorporation into proteins was reduced 2-fold in both types of SL transgenics, indicating that the approach successfully redirected Se flow in the plant. Both the cytosolic and chloroplastic SL plants showed enhanced shoot Se concentrations, up to 1.5-fold compared with wild type. The cytosolic SL plants showed enhanced tolerance to Se, presumably because of their reduced protein Se levels. Surprisingly, the chloroplastic SL transgenics were less tolerant to Se, indicating that (over) production of elemental Se in the chloroplast is toxic. Expression of SL in the cytosol may be a useful approach for the creation of plants with enhanced Se phytoremediation capacity. |
| Databáze: | OpenAIRE |
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