The Level of Oxidative Stress in Poplars due to Heavy Metal Pollution in Soil

Poplar trees are commonly used in phytoremediation thanks to its specific characteristics such as large leaf surface, the conductivity of water and minerals throughout the section of the tree (diffuse porous species) and easy vegetative propagation through cuttings. The use of poplars in detoxification of soil and water contaminated with heavy metals has been demonstrated for various species. The effect of different concentrations of three heavy metals ions, Cu2+, Ni3+ and Cd2+, on oxidative stress in three poplar clones from two different species (PE 19/66 and B229), belonging to Populus deltoides (Marshall) and to (M1 clone) Populus euramericana (Dode-Guinier) were analysed. Biochemical parameters which were applied for identifying the level of oxidative stress in these three clones were the following: soluble protein content, lipid peroxidation, ferric reducing antioxidative power assay and superoxide dismutase activity. Possible antioxidant capacity of these clones in the response to different concentrations of heavy metals ions in substrate was measured in order to find which clone is most appropriate for phytoremediation processes. Results showed variable responses within poplar leaves and roots in response to oxidative stress induced by heavy metals and the most promising clone for phytoremediation of contaminated soils is B229 clone, while M1 and PE 19/66 showed variable antioxidant response.