Synergistic effect of Salt and cadmium stresses on phytoremediation potential of Lepidium sativum

Abstract

In this study Lepidium sativum ability to accumulate cadmium (1M Cd) under increasing doses of NaCl was investigated. Results revealed L. sativum reduced Cd accumulation by simultaneously application of high NaCl dose. Combined stress (Cd+NaCl) induced reduction of dry matter production and photosynthetic pigments contents. Nevertheless, foliar tissues contained important Cd amounts independently of presence or not of NaCl. Lipid peroxidation parameter as an indicator of internal damage induced was markedly accumulated in leaves of treated plants. Furthermore, Cd enhanced antioxidant enzymes such superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (GPX) and glutathione reductase (GR) activities in order to minimize the harmful effects of reactive oxygen species (ROS) generated by Cd. In fact, addition of Cd in nutrient solution containing increasing salt doses of NaCl (100, 200, 300mM), showed an inhibition of antioxidant system efficiency. Our results suggest that L. sativum has the ability to maintain effectively phytoremidiation under salt and Cd stresses.