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Response of antioxidant enzymes in coontail ( Ceratophyllum demersum L.) plants under cadmium stress
Author(s) -
Mishra Seema,
Srivastava Sudhakar,
Tripathi R. D.,
Dwivedi Sanjay,
Shukla M. K.
Publication year - 2008
Publication title -
environmental toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.813
H-Index - 77
eISSN - 1522-7278
pISSN - 1520-4081
DOI - 10.1002/tox.20340
Subject(s) - ceratophyllum demersum , catalase , glutathione reductase , antioxidant , superoxide dismutase , cadmium , lipid peroxidation , toxicity , chemistry , peroxidase , glutathione , proline , glutathione peroxidase , biochemistry , botany , food science , biology , enzyme , aquatic plant , ecology , macrophyte , organic chemistry , amino acid
Cadmium (Cd) contamination of aquatic systems is of major concern since it is a nonessential element and hampers plant growth upon accumulation. The aim of this study was to investigate the Cd accumulation behavior of coontail plant, Ceratophyllum demersum L., toxicity induced and response of the antioxidant system. Plants were exposed to various concentrations of Cd (0–10 μM) for a period of 1–7 days. Accumulation of Cd was found to be a concentration duration dependent phenomenon. The maximum accumulation of Cd, 1293 μg g −1 dw, was observed after 7 days at 10 μM. Plants showed significant stimulation of the activities of various antioxidant enzymes viz., superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), and glutathione reductase (EC 1.6.4.2) and tolerated toxicity of Cd up to moderate concentration of 5 μM. At 10 μM exposure, enzyme activities declined and plants experienced toxicity, which was evident by the significant decrease in the photosynthetic pigments and by increase in the levels of H 2 O 2 , lipid peroxidation and ion leakage. In conclusion, modulation of antioxidant system in a coordinated manner in response to Cd accumulation appears to help plants tolerate toxicity of Cd up to 5 μM. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.