Cadmium and nickel uptake by Alyssum murale L. in hydroponic conditions

Today، soil pollution by heavy metals is considered as a major environmental problem، which is cause health risks and diseases for human. Phytoremediation is an emerging technology which is quite a novel technique of cleaning polluted sites through the use of plants. In this study، the accumulation of heavy metals in different parts of Alyssum murale was treated by toxic concentrations of cadmium and nickel (0، 40، 70، 100 μM) were estimated in hydroponic system. Also some physiological parameters of treated plants were analyzed. The results show that the roots are able to absorb more metal than aerial parts that indicate metal connection to the cell wall in the roots. The low transfer of metals from root to shoot indicates exclusion mechanism. Cadmium uptake more than nickel by plants، may indicate that A. murale is accumulator species for cadmium. The results show that this species can be used to reduce contamination of contaminated soils with cadmium. Chlorophyll content decreased in elevated concentrations of Cd and Ni. Also the proline content in plant was increased under heavy metal stress، Also SOD activity in Alyssum murale showed a decrease and with increasing concentrations of heavy metal showed a increase. Furthermore، substantial increases were observed in antioxidant enzymes، such as catalase (CAT)، ascorbate peroxidase (APX)، in Cd and Ni-stressed plants in comparison with control.