Bioaccumulation in Miscanthus sacchariflorus grown on cadmium-contaminated sediments: a comparative study between submerged and non-submerged environments

Abstract

Bioaccumulation of heavy metals in aquatic plants is significantly affected by hydrological regime and therefore the accumulation and translocation of cadmium in five organs—panicle, leaf, stem, root, and bud—of an emergent plant (Miscanthus sacchariflorus) were compared between the submerged environment and non-submerged environment. In the submerged condition, the cadmium concentration was higher in the panicle and leaf than in the stem, root, and bud. Cadmium concentration in the root exhibited a positive regression with cadmium concentration in the sediment. However, cadmium concentration in the panicle, leaf, stem, and bud exhibited no significant regression with cadmium concentration in the sediment. In the non-submerged environment, the cadmium concentration was higher in the below-ground organs than in the aboveground organs. The mean bioaccumulation coefficient in the 24 investigated plots in the submerged environment was higher than that in the 20 and 40 mg kg⁻¹ cadmium treatments in the non-submerged environment. The mean translocation factor in the submerged environment was nine times higher than that in non-submerged environment. These results indicate that submergence enhanced cadmium bioaccumulation in the aboveground organs and that this plant can be used to remove heavy metals from polluted rivers and lakes.

Keywords:

• Aboveground organ
• below-ground organ
• bioaccumulation coefficient
• translocation factor

Acknowledgments

The authors greatly appreciate the five anonymous reviewers for the constructive suggestions on an earlier version of this manuscript.

Additional information

Funding

This study was financially supported by the Scientific Research Fund of Hunan Provincial Education Department (16B121); Key Research and Development Program of Hunan Province (2017WK2082; 2017SK2300); and Foundation for Advanced Talents in Hunan Agricultural University.