Impact of Cadmium and Lead Heavy Metal Stress on Plant Growth and Physiology of Rocket (Eruca sativa L.)

This study was conducted to evaluate the influence of cadmium (Cd) (0, 100, 150 and 200 mg kg(-1)) and lead (Pb) (0, 1000, 1500 and 2000 mg kg(-1)) on morphological, physiological and biochemical responses of rocket (Eruca sativa L.) in greenhouse conditions. Plant growth, some physiological (membrane permeability, relative water content, stomal conductance, etc.) and biochemical (antioxidant enzyme activity, proline and sucrose content) parameters of rocket plants were altered with Cd and Pb levels. The Cd and Pb content in rocket increased with elevated concentration. Both Cd and Pb stress conditions negatively affected plant growth, photosynthetic activity and chlorophyll content. The negative effect of heavy metals elevated with increased doses of Cd and Pb. The treatment of Cd and Pb significantly elevated antioxidant enzyme activities. Furthermore, the heavy metal stressed plants had more malondialdehyde (MDA), hydrogen peroxide (H2O2), proline and sucrose as compared to control plants. This study indicated that rocket plants developed defense mechanisms by regulating enzyme activity and osmolyte accumulation against heavy metal stress.