Effects of Growth Stage and Cd Chemical Form on Cd and Zn Accumulation in Arabidopsis halleri ssp. gemmifera

Abstract

Cadmium is a hazardous heavy metal and causes contamination globally. Phytoremediation can potentially become a low-cost and eco-friendly technique for mitigating Cd contamination. Arabidopsis halleri ssp. gemmifera hyper-accumulates Cd and Zn, and may be used to remediate Cd-contaminated sites. However, few studies have focused on Cd accumulation by A. halleri ssp. gemmifera. Herein, we demonstrate the accumulation of Cd by A. halleri ssp. gemmifera. The biomass, Cd, and Zn concentration of the plant increased in the 103 days of experimentation. Cd concentration of soil significantly decreased compared to its initial concentration (≈10%). The material balance of Cd uptake by plant and Cd decrement from soil ranged from 63.3% to 83.7% in each growth stage. Analysis indicated that the water-eluted and exchangeable forms of Cd were stable during the experiment. However, Cd concentration extracted with 0.1 M HCl decreased (25% of initial), and this fraction was not bioavailable. The study exhibits the mass balance of Cd between plant uptake and decrement from the soil and the changes in the chemical form of Cd during stages of A. halleri ssp. gemmifera cultivation.