Oxidative stress in duckweed (Lemna minor L.) caused by short-term cadmium exposure.
The mechanisms of plant defence against cadmium toxicity have been studied by short-term exposure of Lemna minor L. (common duckweed) to concentrations of CdCl2 ranging from 0 to 500microM. High accumulation of cadmium was observed (12,320+/-2155microgg(-1) at 500microM CdCl2), which caused a gradual decrease of plant growth, increased lipid peroxidation, and weakened the entire antioxidative defence. Total glutathione concentration decreased significantly; however, the concentration of oxidized glutathione remained stable. The responses of four antioxidant enzymes showed that catalase was the most inhibited after CdCl2 exposure, ascorbate peroxidase and guaiacol peroxidase moderately, and glutathione reductase least. The total antioxidative potential revealed an induced antioxidative network at 0.1microM CdCl2 (137+/-13.2% of the control) and its reduction to only 47.4+/-4.0% of the control at higher cadmium concentrations. The possible application of the examined biomarkers in ecotoxicological research is discussed.
Razinger
Jaka
J
Department for Environmental Technologies and Biomonitoring, Institute of Physical Biology, Veliko Mlacevo 59, SI-1290 Grosuplje, Slovenia. jaka@ifb.si
Dermastia
Marina
M
Koce
Jasna Dolenc
JD
Zrimec
Alexis
A
D000975:Antioxidants / Q000032:analysis; D029064:Araceae / Q000187:drug effects / Q000378:metabolism*; D060387:Ascorbate Peroxidases; D015415:Biomarkers / Q000032:analysis; D002104:Cadmium / Q000633:toxicity*; D002374:Catalase / Q000032:analysis; D004785:Environmental Pollutants / Q000633:toxicity*; D005978:Glutathione / Q000032:analysis; D019803:Glutathione Disulfide / Q000032:analysis; D005980:Glutathione Reductase / Q000032:analysis; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D009195:Peroxidase / Q000032:analysis; D010544:Peroxidases / Q000032:analysis; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D023382:Toxicity Tests, Acute
D000975:Antioxidants; D015415:Biomarkers; D004785:Environmental Pollutants; D002104:Cadmium; D010544:Peroxidases; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione; D019803:Glutathione Disulfide