Copper uptake and translocation in a submerged aquatic plant Hydrilla verticillata (L.f.) Royle

A comprehensive understanding of the uptake, tolerance and transport of heavy metals in the wetland system through aquatic plants will be essential for the development of phytoremediation technologies. Copper accumulation and translocation of a submersed macrophyte Hydrilla verticillata (L.f.) Royle were investigated. Plant shoots showed a significant accumulation of Cu with a maximum of 30 830 mg Cu kg(-1) dry weight after exposed to 4000 mu g L-1 Cu for 4 d. Both roots and shoots can directly take up Cu from solution and Cu mainly accumulated in cell wall fractions. Moreover, H. verticillata predominantly accumulated Cu through shoots from the aqueous solutions because of the higher weights and bioaccumulation factors of shoots than those of roots. Acropetal translocation of Cu in the plant is higher than the basipetal translocation, which implies that upward translocation of Cu is mainly via the xylem and downward translocation is mainly through the phloem. These findings contribute to the application of submerged aquatic plants to copper removal from moderately contaminated waters. (C) 2010 Elsevier Ltd. All rights reserved.