The phytotoxicity of Se(IV) was determined through root and shoot growth inhibition, biomass (dry (DM), fresh (FM)) production, water content, photosynthetic pigment (chlorophyll a, chlorophyll b and carotenoids) levels and Se accumulation in the roots and shoots. The sensitivities of monocotyledonae (Hordeum vulgare, Triticum aestivum) and dicotyledonae plants (Sinapis alba, Brassica napus) were also compared. Except for H. vulgare, Se(IV) inhibited root growth more than shoot growth. As for biomass production, Se reduced both FM and DM of all studied plants' roots. Although in shoots FM was decreased with increased Se concentration, DM was reduced only in monocotyledonae plants (H, vulgare, T aestivum). No significant differences between roots and shoots were confirmed for the DM/FM relationship, except for S. alba seedlings. In all of the tested plants, except for B. napus, chlorophyll b was the strongest reduced pigment. Accumulation of Se was higher in the roots than in the shoots of all studied plants. Selenium concentration in the roots was at least 3-times higher than that in controls. Se(IV) accumulation in the shoots was not significantly different from that in controls. The exception was confirmed only for B. napus (87 mg Se(IV) l(-1)) and T aestivum (36 mg Se(IV) l(-1)). (C) 2009 Elsevier B.V. All rights reserved.