Inhibitory Effect of Cadmium on the Growth of Mung Bean (Vigna radiata (L.) R. Wilczek) and the Removal by Chelating Agent

Abstract

This research studied the effect of cadmium (Cd) on the growth of mung bean (Vigna radiata (L.) R. Wilczek). The mung bean was cultured in a Hoagland solution containing different concentrations of Cd (0, 0.1, 0.3 and 0.5 mg/L) for 5 days. The result showed a significant decrease in the lengths of the roots and shoots of mung bean that was grown in cadmium solution. This effect was proportional to the concentrations of Cd. To assess cell death in the root of mung bean, Evan’ s blue staining technique was used in this study. The results showed that the concentrations of Evan's blue dye taken up by Cd-exposed mung beans at 0.1, 0.3, and 0.5 mg/L were 1.5612 ± 0.5417, 6.8641 ± 1.7447, and 8.0850 ± 2.6336 mg/L, respectively. A concentration-dependent increase of dead cellswas found in the Cd-treated group, mostly at the root cap zone. With respect to this result, the level of dead cells that was stained with Evan’s blue dye could be used as a biomarker to indicate cadmium contamination in water. Furthermore, the effects of chelating agents (EDTA) on cadmium removal were also studied. The results showed the possibility of using EDTA as a cadmium treatment agent and promoted plant growth in cadmium contamination areas.