Evaluation of Some Defense Mechanisms in Crop Varieties Under Heavy Metal Stress - Abstract
Today, heavy metal (HM) pollution is one of the most important ecological problems worldwide. Higher concentrations of HMs can lead to toxic effects in all organisms. Some HMs, such as Cd and Pb, although being non-essential and without physiological function, are very toxic even at very low concentrations, which cause some serious disruption in plant growth and productivity with a heavy losses in agricultural yield and crop production. Beside their negative impacts on plants, transfer of toxic elements to the food chain leads to several diseases which human beings faced. Therefore, to reduce the risk of contamination in human beings, HM tolerant varieties should be selected and use for phytoremediation purposes where necessary.In this study, the effects of HM stress onsome of those enzymatic and non-enzymatic antioxidant defense mechanisms, together with protein contents were investigated in two different crop varieties. The selected concentrations (0,150,300 µM) of single PbCl2, CdCl2 and their combinations (PbCl2 + CdCl2 ) were applied in hydrophonic solution to examine the changes of glutathione (GSH), protein and glutathione S-transferase (GST) activities in the roots and shoots of Hordeum vulgare cv. Erginel and Triticum aestivum cv. Bezostaya varieties.Results indicates that, both single and combined treatments cause a difference at some extend depending on the plant, plant parts and concentrations of HMs. Observation of high levels in examined parameters according to control values indicatesa general adaptability to stress conditions.In line with our results, barley variety were found to be more tolerant to HM stress by comparing to wheat andcan be used for remediation purposes at contaminated sites as a plant agent.