FATTY ACIDS AND PHYSIOLOGICAL RESPONSES OF CORN LEAVES EXPOSED TO HEAVY METALS

Heavy metals affect biochemical pathway by changing the fatty acid composition in plant cells. The high concentration of heavy metals impresses biochemical pathway and changes fatty acid compositions of plant cells. Fatty acids participate in various biological processes and have the functional role in regulating membrane functions in plants. In the present study, heavy metal content was analyzed with ICP-MS, fatty acid composition was investigated with GC and physiological parameters were determined with spectrophotometrically in the leaves of tomato subjected to increasing doses of heavy metals. In this study, the treatment of heavy metals on the growth medium changed the fatty acid contents of corn. The application of Cu significantly increased the level of palmitic acid and oleic acid. The treatment of Pb raised the content of oleic acid, whereas it significantly decreased the content of alpha-linolenic acid and erucic acid at 20 and 50 mg kg(-1), respectively. The addition of Cd significantly increased the level of oleic acid and linoleic acid; however, it significantly decreased the content of alpha-linolenic acid and erucic acid. Cu and Pb significantly raised the proline content. The application of Cu and Cd showed similar effect on hydrogen peroxide and the higher doses of them increased the content of H2O2. The level of lipid peroxidation significantly increased in response to all applied concentration of Cu. The results obtained in this study show that the aapplication of heavy metals changed the content of fatty acids, particularly that of oleic acid significantly increased in response to them. The levels of proline and lipid peroxidation generally increased together with oleic acid and palmitic acid in the leaves in reply to copper.