Effect of cadmium toxicity on gene expression and enzyme activity of superoxide dismutase and ascorbate peroxidas in chickpea (Cicer arietinum L.) seedlings

When plants are exposed to stressful environmental conditions, the production of reactive oxygen species (ROS) increases and can cause significant damage to the cells. Antioxidant defense systems, which can detoxify ROS, are present in plants. In this study, the changes in expression profile and enzyme activity of superoxide dismutase and ascorbate peroxidase were analyzed in chickpea seedlings in response to different concentrations (0, 0.5, 2.5, 7.5, 12.5, 25 and 50 mM) of cadmium chloride. The results showed that in Chickpea plants, the SOD and APX were induced both at mRNA and enzyme activity levels in leaves of seedlings in response to cadmium overload. The enzyme activity of SOD and APX and mRNA transcript levels of Cu/ZnSOD and APX increased significantly at low and medium cadmium levels but decreased gradually throughout on increasing cadmium concentration from 12.5 to 50 mM. It was concluded that the enzymatic antioxidant defense system in chickpea played a major role in its response to cadmium tixicity.