Abstract

In the present study, the cadmium’s effect on anti-oxidative enzymes in tomato (Lycopersicon esculentum) plants was evaluated. Plants treated with increasingly CdCl₂concentrations (0, 20, 40, 80, 100 and 200 μM respectively) were grown in a basic nutrient solution for 7 days. APX (Ascorbate Peroxidase) and GPX (Guaïgol Peroxidase) activities showed to increase below 100 μM concentration after treatment. In excessive concentration however, more than determined level, a significant decrease in the enzymes activities was determined. The increase in enzymatic activity can be associated with induction of oxidative stress by cadmium treatment. Excessive calcium displayed also low APX and GPX activities, which were virtually the same activity levels of control plants. However, it should be note that concentration more than 80 μm of Cd resulted in decreasing of APX and GPX activity. The enzymatic activity of GSH followed in the presence of Cd showed a significant increase by 80 μM of Cd then the activity showed decreasing. Calcium treatment resulted in impairing of GSH stimulation in the presence of Cd conditions. Eventually, Cd treatment resulted in decline in GST activity that was significantly increased in the presence of calcium, suggesting stimulation of antioxidant enzymatic activities. Therefore, accumulation of Cd can be associated with oxidative stress, which may be inhibited and reduced its adverse effects by calcium treatment in the cell culture.

Keywords: Cadmium, Calcium, APX, GPX, GSH, GST, Lycopersicon esculentum,enzymatic activity.