Department of Plant Sciences

We analyzed the real-time translocation of 107Cd from root to shoot among 6 rice cultivars using a positron-emitting tracer imaging system (PETIS). 107Cd first accumulated at the basal region of the shoot within 2 h after the exposure and the signals were much stronger in high-Cd-accumulating cultivars (indica) than in low-Cd-accumulating ones (japonica). 107Cd accumulated increasingly at the upper portion of the shoot with time, and the signals were obviously strong in high-Cd-accumulating cultivars. These results suggest that the different ability of root-to-shoot translocation of Cd is closely related to the genotypic variation in shoot Cd accumulation in rice.