Cyanide acclimation in willow (Salix babylonica L.), a prospect for the phytoremediation of cyanide

Phytoremediation counts as a major method for future which essentially needs resistance to contaminating agents. We pretreated the plants (Salix babylonica, as a model plant in phytoremediation of polluted waters) by sodium cyanide (0, 3 and 5 mg CN- L-1) to induce resistance with regard to acclimation and then examined their resistance to higher concentrations of cyanide. Accordingly, some of the resistance- related physiological parameters were measured. The results showed that the pretreatment increased the resistance up to 3 folds more than toxicity threshold. It induced the superoxide dismutase activity and ion leakage from roots. Dehydrogenase activity, reducing capacity of the roots and chlorophyll was decreased in pretreated plants. Results also showed that no difference was seen between the control and pretreated plants in the uptake of cyanide from media. The induced resistance via cyanide acclimation could be attributed to physiological responses such as higher activities of antioxidants and not to prevention of cyanide uptake into the cells.