Mercury induced stress in wheat (Triticum aestivum L.) plants

Worldwide, wheat is a staple food of man kind. To evaluate the phytotoxicity of different concentrations (0.0, 2.5, 5.0, 10 and 25 µM) of mercury (Hg) parameters like growth, biomass, total protein and chlorophyll content were determined. Hg induced oxidative damage was analysed by the measurement of electrolytic leakage, H2O2 and MDA content. Further, to investigate antioxidative defense mechanism induced by Hg, the level of non enzymatic antioxidants such as CAR, ASC and the activity of enzymatic antioxidants CAT, POX, APX, and SOD have been measured. Wheat plants exposed to lower concentrations of Hg (2.5 and 5 µM) did not experience any oxidative stress. However, treatment with 10 µM of Hg, the roots and leaves of wheat plants responded differently. Both the leaves and roots of plants treated with higher concentration of Hg (25 µM) were subjected to comparatively greater oxidative damage demonstrating that the antioxidant components were not able to remove the Hg stress at higher concentration in Triticum aestivum.