TOXIC EFFECT OF CADMIUM AND CATALASE ACTIVITY IN THE CORMS OF CROCUS SATIVUS L.
Cadmium is a highly carcinogenic heavy metal and a known contaminant of todays industrial world. In this research, we report its effect on rooting and on the activity of catalase, a major antioxidant enzyme, in Crocus sativus L. corms cultivated for 3, 6 and 9 days in distilled water and in water supplemented with 0, 0.5, 2, 5, 20, 50 mg/L cadmium (Cd2+). Over 9 days cultivation, root elongation was unaffected in 0.1 mg/L Cd2+, moderately inhibited in 0.5 and 2 mg/L Cd2+ and drastically inhibited in 5-20 mg/L Cd2+; no root elongation was observed after one day cultivation in 50 mg/L Cd2+. However, exposure to Cd2+ triggered an increase in catalase activity after 3 days cultivation. In corms grown for 3 days in distilled water a 60% increase in catalase activity compared to dormant corms was observed. This increase was brought to 130% in corms cultivated in 0.1 mg/L Cd2+and to 110%, 90% and 65% in corms cultivated in 0.5, 2-20 and 50 mg/L Cd2+, respectively. Thus, in up to 0.5 mg/L Cd2+, the increase in catalase activity doubled compared to the control in response to metal-induced oxidative stress; in higher Cd2+ concentrations, the catalase activity would itself be hampered by the metal, resulting in a more moderate increase. In contrast to corms grown for 3 days in the presence of increasing Cd2+ concentrations, in corms exposed for 6 days to Cd2+ catalase activity remained close to that found in corms grown in distilled water for 6 days. After 9 days cultivation, an increase in catalase activity compared to the control was again observed in the presence of Cd2+, but the activity remained lower than in dormant corms. Our investigation showed the importance of catalase in controlling Cd2+ toxicity in Crocus sativus L. corm.
Hadizadeh, M. and Keyhani, E. (2007). TOXIC EFFECT OF CADMIUM AND CATALASE ACTIVITY IN THE CORMS OF CROCUS SATIVUS L.. Acta Hortic. 739, 443-449
antioxidant enzyme, heavy metals, root elongation, ROS, saffron