Selenium (Se) is an essential element for living organisms that play an important role in reducing adverse effects ofenvironmental stresses in plants .To evaluate the effects of selenium on garlic (Allium sativun L.) seedlings exposed to various concentrations of cadmium (Cd), a factorial experiment was conducted in a completely randomized design with three replications. Cd in four concentrations (0, loa, l0-3 and l0-2 M of Cadmium chloride), and Se in two levels (0 and 5 mg& of Sodium selenite) were used. The results showed that the accumulation of Na, K, Ca and Mg in the shoot and root tissues of garlic plants changed under different Cd concentrations and Se treatment significantly' Uptake ofNa increased by the supply of 10{ to l0-2 M Cd and shoot tissues contained higher Na than th€ roots in all treatments. While K, Ca and Mg concentrations decreased under Cd stress conditions. Selenium supply suppressed the negative effects ofCd on the nutrient uptake. The application of Se increased K, Ca and Mg contents by 25.40,28.12 and n.23o/o io th" ioots and 8.10, 22.27 and 20.960/o in the shoot, respectively at the l0-3 M Cd concentration. Also, Cd toxicity reduced Zn, Cu and Mn contents of garlic plants, while increased Fe concentration in the root and shoot tissues. With Se supply the concentrations ofFe, Zn, and Cu in the shoot and Mn in the root back to control levels. The presence of 10-2 M Cd in media led to dramatic decreases in the activity of the antioiidant enzymes (SOD, APX and CAT). The activity of SOD and APX under I 0{ M Cd concentration by 48.2 and 42.1%o, and under l0-3 M Cd concentration by 100 and 94.7%owerc more than the control, respectively. In contrast, CAT activity was decreased after exposure to 10-4 and 10-3 M Cd concentrations. Plant treated by Se resulted in a significant increase in SOD and APX activities at both I 04 and I 0i M Cd concentrations, while it did not alleviate the inhibitory effects ofCd on CAT activity. The results ofthis study
