The surroundings of the lead mine and smelter in Žerjav represents one of the most polluted areas in Mežica valley. The metal pollution negatively affects the vegetation and health of the people living in the surroundings. In this master 's thesis, common and Tartary buckwheat containing higher amounts of secondary metabolites that alleviate oxidative stress, were planted in the soil collected in the vicinity of the lead mine and smelter. A half of the buckwheat plants was foliarly sprayed with selenium in the form of potassium selenate (K2SeO4). Zinc, Pb and Cd translocation from the soil to the plant and further to the selected model animal organism – Spanish slug was tested. In addition, toxicity effects in common and Tartary buckwheat and slugs fed with Se biofortified common and Tartary buckwheat were compared. The results show that selenium affects Zn, Pb and Cd toxicity as monitored by different physiological parameters of individual buckwheat species. The majority of metals was accumulated in the roots, while only a small portion was transferred to the shoots. The presumably higher contents of antioxidants in Tartary buckwheat did not have a positive effect on the physiological parameters of Tartary buckwheat compared to the common buckwheat, since Tartary buckwheat accumulated higher concentrations of metals. Selenium in most cases increased metal concentrations in individual plant organs and reduced the growth rate of slugs fed with common and Tartary buckwheat Selenium reduced the MDA equivalent concentrations in common and Tartary buckwheat leaves. Metals (Zn, Pb and Cd) were mainly accumulated in the slug hepatopancreas, and only Zn was transferred to the slug’s muscle tissue. Selenium reduced the bioaccumulation and bioavailability of Zn from common and Tartary buckwheat to the slug. Selenium increased concentrations and contents of Pb in hepatopankreas of slugs fed with common buckwheat. Selenium increased concentrations and contents of Cd in hepatopancreas and faeces of slugs fed with common and Tartary buckwheat. In snails fed with Tartary buckwheat, the bioaccumulation and bioavailability of Cd were lower than those fed with common buckwheat. Snails fed with Tartary buckwheat had higher amounts of metals (Zn, Pb and Cd) in their faeces. Selenium increased the amounts of Pb and Cd in the faeces in both groups of snails. The influence of selenium on Pb and Zn in the organs and faeces of slugs was buckwheat species dependent. This research brings new knowledge on Se biofortification of crops grown in metal polluted soils.
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