Impacts of toxic metals on responses morphological and biochemical some of barley and wheat varieties

Heavy metals (HM) effect on the health of animals and humans via food chains. Either directly or indirectly, HM cause oxidative damage in plants through reactive oxygen species (ROS) formation. However, cells can detoxify the harmful effects of ROS with the help of enzymatic or nonenzymatic antioxidant defense mechanisms. Of those, glutathione S-transferases (GST) are a diverse group of enzymes catalyzing the conjugation of electrophilic xenobiotic substrates with the tripeptide glutathione (GSH). On the other hand, GSH is considered as one of the most important metabolite for intracellular defense against ROS induced oxidative damage. In this study, toxic effects of lead chloride (PbCl2) and cadmium chloride (CdCl2) on germination, lenght of hypocotyl and radicle, water content, GSH contents, GST activities of wheat (Triticum aestivum L. cv. İzgi-2001 and Triticum aestivum L. cv. Alpu-2001) and barley genotypes (Hordeum vulgare L. Kalaycı-97 and Hordeum vulgare L. Bilgi-91) were investigated. The application of HMs to plants caused differences in GSH contents as compared to their control groups. As a result of GST activity measurements, the highest activities were observed in Bilgi-91 and Kalaycı-97 shoots with 3 mM Pb treatment (502 and 308% of control for Bilgi-91 and Kalayci-97, respectively) and in roots with 1,5 mM Cd treatment (558 and 478% of control, respectively). In conclusion heavy metals affects physiological and biochemical mechanisms of wheat and barley genotypes Alpu-2001 and Bilgi-91 have more tolerated to heavy metals.