Cadmium accumulation and subcellular distribution in populations of Hylotelephium spectabile (Boreau) H. Ohba.

A pot experiment was conducted among six populations of Hylotelephium spectabile (Boreau) H. Ohba: four from Jiangsu province, one from Shandong province, and one from Shanxi province, China, to investigate the variation of Cd accumulation and subcellular distribution of this species (a newly reported Cd high accumulator). Under five different real Cd-contaminated soils (Cd: 0.93-97.97 mg/kg), results showed considerable differences in Cd concentration in (a) leaf (1.09-50.7 mg/kg), (b) stem (0.61-13.0 mg/kg), and (c) root (1.55-24.5 mg/kg) among the populations. Analysis of subcellular Cd distribution indicated that Cd accumulated in the leaves of H. spectabile was mainly in the cellular debris (44.1 to 53.5%), followed by heat-stable protein (HSP, 20.9 to 29.0%), Cd-rich granules (MRG, 9.9 to 19.5%), heat-denatured protein (6.0 to 8.5%), and organelle fractions (3.1 to 7.4%). The populations of H. spectabile with more Cd partitioned to cellular debris and biological detoxified metal (HSP + MRG) fractions have greater capacity to accumulate Cd, indicating the probable intrinsic mechanism to accumulate Cd. Therefore, H. spectabile has the considerable potential of phytoremediation for Cd-contaminated soils, but screening suitable populations according to soil Cd concentrations is necessary before used for phytoremediation of Cd-contaminated soils.