Youngia erythrocarpa, a newly discovered cadmium hyperaccumulator plant.

The farmland weed Youngia erythrocarpa has been found to have the basic characteristics of a cadmium (Cd) hyperaccumulator. This study carried out preliminary and further Cd concentration gradient experiments and field experiment using Y. erythrocarpa to confirm this fact. The results showed that the biomass and resistance coefficient of Y. erythrocarpa decreased, but the root/shoot ratio and the Cd content in roots and shoots increased with the increase in soil Cd concentration. The Cd content in shoots of Y. erythrocarpa exceeded 100 mg/kg when the soil Cd concentration was 25 mg/kg in the two concentration gradient experiments, up to the maxima of 293.25 and 317.87 mg/kg at 100 mg/kg soil Cd. Both the bioconcentration factor of the shoots and the translocation factor exceeded 1 in all Cd treatments. In the field experiment, the total Cd extraction by shoots was 0.934-0.996 mg/m(2) at soil Cd levels of 2.04-2.89 mg/kg. Therefore, Y. erythrocarpa is a Cd hyperaccumulator that could be used to remediate Cd-contaminated farmland soil efficiently.