Subcellular Distribution of Cadmium in Mining Ecotype Sedum alfredii

The mining ecotype Sedum alfredii Hance could tolerate and grow normally in a nutritive solution containing cadmium (Cd) as high as 400 μmol/L Under such a high Cd concentration, the subcel-lular accumulation of Cd in root, stem and leaf of this plant was found to be the highest in the cell wall, less in the soluble fraction and lowest in the cell organs. The mode of subcellular distribution of Cd in the mining ecotype S. alfredii was similar to other hyper accumulators of heavy metals, in which Cd was distributed more in the aerial part of plant. The results suggest that the mining ecotype S. alfredii is a new species of Cd hyperaccumulator.