ANATOMICAL PECULIARITIES IN WHEAT (TRITICUM AESTIVUM L.) VARIETIES UNDER COPPER STRESS

The effect of different concentrations (0.25 mM, 0.5 mM) of Cu2+ on anatomical parameters of leaves and roots was investigated in hydroponically grown five wheat (Triticum aestivum L.) varieties (Kazakhstanskaya rannaya, Kazakhstanskaya-3, Meltum, Kaiyr and Shagala). The results showed that wheat varieties exposed to 0.5 mM Cu2+ exhibited significant alterations in anatomical structure of leaves and roots. The thickness of the upper and lower epidermis, diameter of vascular bundles of leaves of almost all varieties showed a tendency to decrease under copper stress. Our experiments showed an activation of defense responses in the root anatomical structure like exodermis thickening in some varieties in the presence of copper in growth medium as compared to the control. This indicates that copper ions increase the thickness of exodermis, which reduce the absorption of toxic elements by root cells. Copper stress caused a decrease in the thickness of the lower and upper epidermis to varying degrees and reduction in the diameter of vascular bundles of wheat leaves. Copper stress caused a reduction in endodermis thickness thereby decreasing the diameter of the central cylinder of wheat roots.