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 today’s 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.

II International Symposium on Saffron Biology and Technology

M. Hadizadeh, E. Keyhani

antioxidant enzyme, heavy metals, root elongation, ROS, saffron

https://doi.org/10.17660/ActaHortic.2007.739.58