Subcellular localization of cadmium in hyperaccumulator Populus × canescens
In this study, subcellular localization of cadmium in hyperaccumulator grey poplar (Populus × canescens) was investigated by the transmission electron microscopy (TEM) method. Young Populus × canescens were grown and hydroponic experiments were conducted under four Cd2+ concentrations (10, 30, 50, and 70 μM) in contrast to the control (non-Cd) for 28 day(s). Results indicate that Cd stress could induce serious damage in root cells of grey poplar. Cd induced plasmolysis, concentrated cytoplasm, disappearance of the cristae in mitochondria, ambiguity of framework and destruction of mitochondria envelope in root tip, stem and leaves cells. The hollowing cells were also found in Cd treatment, and there existed some different granule in these hollowing cells. Plasmolysis was found in all treatments in cells of stem, but no damage was detected in cells of leaves. The degree of damage to organs of grey poplar was as follows: root > stem> leaves. It was suggested that the Populus × canescens as a renewable resource has the potential to decontaminate cadmium stress development, accumulation and distribution.
Key words: Cadmium, phytoremediation, hyperaccumulator, grey poplar, organ.