Specific mechanisms of tolerance to copper and cadmium are compromised by a limited concentration of glutathione in alfalfa plants
| Autor: | Luis E. Hernández, Sarra Hattab, Sabrine Hattab, Hamadi Boussetta, María Laura Flores-Cáceres, Mohammed Banni |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Antioxidant
medicine.medical_treatment Glutathione reductase chemistry.chemical_element Plant Science Biology medicine.disease_cause Antioxidants chemistry.chemical_compound Botany Genetics medicine Soil Pollutants Buthionine sulfoximine Cadmium food and beverages General Medicine Glutathione APX Oxidative Stress chemistry Biochemistry Shoot Agronomy and Crop Science Oxidative stress Copper Medicago sativa |
| Zdroj: | Plant science : an international journal of experimental plant biology. 233 |
| ISSN: | 1873-2259 |
| Popis: | The induction of oxidative stress is a characteristic symptom of metal phytotoxicity and is counteracted by antioxidants such as glutathione (GSH) or homoglutathione (hGSH). The depletion of GSH│hGSH in fifteen-day-old alfalfa (Medicago sativa) plants pre-incubated with 1mM buthionine sulfoximine (BSO) affected antioxidant responses in a metal-specific manner under exposure to copper (Cu; 0, 6, 30 and 100μM) or cadmium (Cd; 0, 6 and 30μM) for 7 days. The phytotoxic symptoms observed with excess Cu were accompanied by an inhibition of root glutathione reductase (GR) activity, a response that was augmented in Cd-treated plants but reverted when combined with BSO. The synthesis of phytochelatins (PCs) was induced by Cd, whereas the biothiol concentration decreased in Cu-treated plants, which did not accumulate PCs. The depletion of GSH│hGSH by BSO also produced a strong induction of oxidative stress under excess Cu stress, primarily due to impaired GSH│hGSH-dependent redox homeostasis. In addition, the synthesis of PCs was required for Cd detoxification, apparently also determining the distribution of Cd in plants, as less metal was translocated to the shoots in BSO-incubated plants. Therefore, specific GSH│hGSH-associated mechanisms of tolerance were triggered by stress due to each metal. |
| Databáze: | OpenAIRE |
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