Abstract
We will present the transgenic plants expressing an yeast zinc transporter, ZRC1. The ZRC1 transports excessive zinc from cytoplasm into vacuole and functions to maintain intracellular zinc homeostasis. The zrc1-overexpressing yeast has been shown to tolerate not only zinc but also cadmium. Therefore, we tried to introduce the zrc1 gene into tobacco and analyzed their heavy metal accumulation. Although the level of expression of the ZRC1 in tobacco was low, some transformants showed higher amounts of cadmium accumulation compared with those of wild type tobacco. Moreover, the dry weight of some transformants increased significantly and consequently total accumulation of cadmium increased. These results indicate that ZRC1 reduces the cadmium concentration in the cytoplasm by pumping up the cadmium into the vacuole, resulting with normal plant growth. The zrc1 gene is one of the good candidates for producing hyper-accumulator used for phytoremediation.
