Seasonal variation of metal accumulation and translocation in yellow pond-lily (Nuphar lutea)

Heavy metal bioaccumulation and translocation properties of aquatic plants are interesting because of their potential use in phytoextraction. However, there is not enough knowledge about the seasonal changes of the metal distribution properties of aquatic plants. Our study focused on seasonal variation of some heavy metals in relation to their bioaccumulation and translocation in Nuphar lutea, a floating leaved, widespread plant that is important to wildlife. In this study, N. lutea, corresponding sediment and water samples were collected at different seasons from Lake Abant (Turkey) and analysed for their heavy metal content (Pb, Cr, Cu, Mn, Ni, Zn and Cd). Accumulation and translocation of heavy metal ratios were calculated seasonally. It was found that Cr and Zn were actively transported from sediment to the root, where they accumulated especially in summer; it was also shown that Cu, Mn and Zn were not only taken up from the sediment but also from the surrounding water. The investigations suggested that translocation ratios for leaf/root of Pb, Cr, Mn and Zn reached their highest levels in spring. It was found that the bioaccumulation and translocation of heavy metals at different parts of N. lutea changes with respect to season and the type of heavy metal.