Umwelt- und analytische Toxikologie

Selenium Treatment Mitigates the Effect of Lead Exposure in Coleus Blumei Benth

Abstract

Juhong Yuan, Mianhao Hu and Zaohong Zhou

We examined the effects of selenium (Se) on coleus (Coleus blumei Benth.) under lead (Pb) stress, to determine possible mitigating mechanisms of Se. Coleus plants were exposed to 1.0 mM Pb(NO3)2 and varying concentrations of Na2SeO3 for 21 d. Application of 1.0 mM Se enhanced biomass allocation and Pb distribution in different organs, decreased superoxide dismutase (SOD) and peroxidase (POD) activity in the roots, and acted as an antioxidant by inhibiting lipid peroxidation via increasing glutathione levels. Root catalase (CAT) and glutathione peroxidase (GSH-Px) activities increased with Se concentration, and changes to root and leaf particles were observed by scanning electron microscopy and X-ray diffraction. Our results indicate Pb is tolerated by coleus plants through allocation plasticity, activation of antioxidant systems, and improvements in particle size and mineralogical effects. C. blumei can be useful in phytoremediation of aquatic systems contaminated with Pb, especially with addition of low concentrations of Se.