Effect of Cadmium on γ-Glutamylcysteine Synthesis in Maize Seedlings

Rüegsegger, Adrian; Brunold, Christian (1992). Effect of Cadmium on γ-Glutamylcysteine Synthesis in Maize Seedlings. Plant Physiology, 99(2), pp. 428-433. American Society of Plant Physiologists 10.1104/pp.99.2.428

Text 1992_PlantPhysiol_99_428.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (1MB)

Cysteine, γ-glutamylcysteine, and glutathione and the extractable activity of the enzymes of glutathione biosynthesis, γ-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots and leaves of maize seedlings (Zea mays L. cv LG 9) exposed to CdCl2 concentrations up to 200 micromolar. At 50 micromolar Cd2+, γ-glutamylcysteine contents increased continuously during 4 days up to 21-fold and eightfold of the control in roots and leaves, respectively. Even at 0.5 micromolar Cd2+, the concentration of γ-glutamylcysteine in the roots was significantly higher than in the control. At 5 micromolar and higher Cd2+ concentrations, a significant increase in γ-glutamylcysteine synthetase activity was measured in the roots, whereas in the leaves this enzyme activity was enhanced only at 200 micromolar Cd2+. Labeling of isolated roots with [35S]sulfate showed that both sulfate assimilation and glutathione synthesis were increased by Cd. The accumulation of γ-glutamylcysteine in the roots did not affect the root exudation rate of this compound. Our results indicate that maize roots are at least in part autonomous in providing the additional thiols required for phytochelatin synthesis induced by Cd.

Interest & Impact

Downloads

2 since deposited on 31 Jan 2018
0 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item