Response of fenugreek (Trigonella foenum-graecum L.) seedlings under moisture and heavy metal stress with special reference to antioxidant system

In the present investigation, the impact of drought and heavy metal in fenugreek was critically monitored. Fenugreek seedlings were exposed to 1- bar polyethylene glycol (PEG) solution (osmotic stress) and 10 ppm solution of HgCl 2 (heavy metal). Within 3 days of seedling growth, mercury exposure induced relatively high level of adverse impact of root growth and biomass production where cell division was significantly reduced measured by mitotic index and development of root vascular bundle was affected indicating negative impact on nutrient transport chain. Mercury stress showed a five-fold increase in malonaldehyde (MAD) production along with antioxidant enzyme peroxidase (POD) activity and mercury stress showed simultaneous and lower antioxidant activity compared to osmotic stress increased activity in super oxide dismutase (SOD) and catalase (CAT) indicates that mercury pollution leads to serious damage in cell membrane through accumulation of lipid peroxides and POD activity to quench it whereas osmotic stress is not so serious and adopt the mechanism to quench the superoxides by SOD and followed by the detoxification of H 2 O 2 by catalase and formation of lower level of MAD. Keywords: Fenugreek, antioxidant, heavy metal, osmotic stress African Journal of Biotechnology , Vol. 13(3), pp. 434-440, 15 January, 2014