Changes in growth, biochemical components, and antioxidant activity in aquatic plant Wolffia arrhiza (Lemnaceae) exposed to cadmium and lead.
The present study investigated the biochemical response of aquatic plant Wolffia arrhiza (Lemnaceae) treated with lead (Pb) and cadmium (Cd) at a range of concentrations from 1 to 1000 microM. W. arrhiza has been identified as good scavenger of heavy metals from aqueous solution. Pb and Cd accumulation was found to be increased in a concentration- and duration-dependent manner. However, the highest biosorption of heavy metals was found in plants exposed to low levels (10 microM) of Cd and Pb in the nutrient medium. In observing the response to heavy-metal stress, we noted inhibited plant growth and decreased photosynthetic pigments, monosaccharides, and proteins. In addition, Cd was found to be more toxic to plants than Pb. Heavy metals also induced oxidative damage as evidenced by increased lipid peroxidation and hydrogen peroxide levels. In contrast, the deleterious effects resulting from the cellular oxidative state can be alleviated by enzymatic (catalase, ascorbate peroxidase, nicotinamide dinucleotide [NADH] peroxidase) and nonenzymatic (ascorbate, glutathione) antioxidant mechanisms activated in W. arrhiza plants exposed to Cd and Pb, especially at 10 microM. These results suggest that W. arrhiza is a promising bioindicator of heavy-metal toxicity.
Piotrowska
Alicja
A
Department of Plant Biochemistry and Toxicology, Institute of Biology, University of Bialystok, Swierkowa 20 B, 15-950, Bialystok, Poland. alicjap@uwb.edu.pl
Bajguz
Andrzej
A
Godlewska-Zyłkiewicz
Beata
B
Zambrzycka
Elzbieta
E
D000975:Antioxidants / Q000378:metabolism*; D029064:Araceae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D004784:Environmental Monitoring; D007854:Lead / Q000378:metabolism / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects
D000975:Antioxidants; D002104:Cadmium; D007854:Lead