Abstract
Yeast PCA1, which is assigned a member of the heavy-metal-transporting P-type ATPase, is localized in plasma membrane and export copper. Yeast CAD2 that is identified as mutated PCA1 acquires the ability to transport cadmium as well as copper, conferring copper and cadmium resistance by exporting these metals. In this study, we analyzed the heavy metal resistance of transgenic Arabidopsis overexpressing yeast the PCA1 or CAD2 gene.
On MS medium, each transgenic plant carrying PCA1 orCAD2 showed retarded growth of roots, as compared with the wild type plants. Furthermore, we observed that on MS medium containing high concentration of each metal, the PCA1 transgenic plants showed resistance to copper and the CAD2 transgenic plants showed resistance both copper and cadmium. These results indicate that Yeast PCA1 or CAD2 protein function as efflux pump of heavy metal in plant cells and controlled intracellular heavy metal homeostasis and resistance.
