The Effect of Use of the Biologically Active Substances in Alleviating the Stress Caused by Lead in Barley Seedling on the Basis of Biochemical and Physiological Parameters

Plants are constantly exposed to a variety of stressors during their lives. One of such stressors is contamination of the environment with heavy metals. Lead is one of highly toxic metals and it significantly inhibits normal plant growth. The study aimed at assessing the degree of relieving the stress caused by 1 mM Pb(NO3)2 via different biologically active substances (AsA, GSH, PP, α-Toc, SA) on the basis of the measurement of morphological (root length, coleoptile length, fresh weight), biochemical (Pro, MDA, CAT, POX) and physiological (Chl a+b, Car) traits in 10-day leaves of spring barley of the cultivar Eunova under laboratory conditions. Pb-stress reduced the fresh weight, root length and coleoptiles of the barley tested. Lead increased lipid peroxidation and Pro content, enhanced CAT and POX activity, and significantly suppressed the photosynthetic pigments content. Among the substances used in the experiment, PP, α-Toc and GSH generally relieved the toxic effect of lead to the barley seedlings to the greatest degree.