Localization of [gamma]-Glutamylcysteine Synthetase and Glutathione Synthetase Activity in Maize Seedlings
| Autor: | Adrian Rüegsegger, Christian Brunold |
|---|---|
| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Plant Physiology. 101:561-566 |
| ISSN: | 1532-2548 0032-0889 |
| Popis: | Fresh weight, protein, cysteine, [gamma]-glutamylcysteine, glutathione, and the extractable activity of the enzymes of glutathione biosynthesis, [gamma]-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots, scutella, endosperms, and shoots of 3-, 7-, and 11-d-old maize (Zea mays L. cv LG 9) seedlings. In 3-d-old seedlings, the scutella represented 14% of the seedling fresh weight, containing 43% of total protein and 63 and 55% of the activity of [gamma]-glutamylcysteine synthetase and glutathione synthetase, respectively; in 11-d-old seedlings, the corresponding values were 4.5% for fresh weight, 8.0% for protein content, and 14 and 20% for the enzyme activities. The highest concentrations of thiols were found for cysteine (0.27 mM) in the roots, for glutathione (4.4 mM) in the shoots, and for [gamma]-glutamylcysteine (13 [mu]M) in the scutella of 3-d-old seedlings. The enzyme activities of roots were localized in subcellular fractions after sucrose density gradient centrifugation. Nearly half of the [gamma]-glutamylcysteine synthetase activity was detected in the root proplastids of 4-d-old seedlings, whereas |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|