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Response of antioxidative enzymes to nickel and cadmium stress in hyperaccumulator plants of the genus Alyssum
Author(s) -
Schickler Hedva,
Caspi Hadar
Publication year - 1999
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.1999.105107.x
Subject(s) - hyperaccumulator , apx , glutathione reductase , phytoremediation , shoot , biology , peroxidase , cadmium , botany , superoxide dismutase , enzyme assay , enzyme , horticulture , chemistry , biochemistry , glutathione peroxidase , soil water , ecology , organic chemistry
The term ‘phytoremediation’ is used to describe the clean‐up of heavy metals from contaminated soils by plants. In this study, we examined Alyssum argenteum and Alyssum maritimum for their ability to accumulate Cd 2+ . We also exemined Ni 2+ accumulation by A. maritimum with comparison with the known Ni‐hyperaccumulator A. argenteum , in a hydroponic system. Both species were tolerant to low levels of Cd 2+ , and accumulated high quantities under the experimental conditions. Only very low levels of Ni 2+ were found in the shoot of A. maritimum , defining it as a non‐hyperaccumulator. The role of the antioxidative enzyme system was investigated in relation to Ni 2+ and Cd 2+ stress. In both species, superoxide dismutase (SOD) activity was elevated at high Cd 2+ concentrations, while ascorbate peroxidase (APX) activity remained unchanged and glutathione reductase (GR) activity was reduced. In the presence of Ni 2+ , A. maritimum exhibited a typical antioxidative defense mechanism, as evidenced by the elevated activities of all three enzymes tested. A. argenteum exhibited a different enzyme response pattern, with a significant reduction in SOD activity, and elevated APX and GR activities only at the highest Ni 2+ concentration.