Changes in Antioxidant Enzyme Activities and Elemental Profiling of Abutilon indicum L. Subjected to Copper Stress

Abstract

The effects of Cu stress on the alterations in the activities of antioxidant enzymes from both leaf and root samples of Abutilon indicum L. were studied under controlled climatic conditions. Plants were treated with different concentrations of Cu (0, 25, 50, 100 and 200 mg/kg of soil) for 15 days. In most plants supplemented with 50 and 100 mg of Cu, a rapid increase in antioxidant activities such as catalase (CAT), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) were detected but at higher concentration (200 mg/kg of soil), the activities were declined. Isoforms of CAT, GPX and SOD were separated using native-polyacrylamide gel electrophoresis and their activities were analyzed. Major reshuffling in isoenzyme pattern of CAT, GPX and SOD were detected in response to Cu treatment. Elemental contents were analyzed by energy dispersive X-ray fluorescence spectrometer from both leaf and root samples of control and treated plants. The increasing concentrations of Cu have a great impact on the alternation in concentration of other elements namely Mg, P, S, K, Ca, Mn, Fe and Zn. The trace elements which act as cofactors for antioxidant enzymes like Mn, Fe and Zn significantly decreased depending on Cu concentration.