Rice breaks ground for cadmium-free cereals.

It is important to reduce the risk of long-term cadmium (Cd) exposure through ingestion. Cd in plant-derived foods (especially rice grain in Japan) is a major source of human Cd intake. In rice, Cd uptake and xylem loading in roots, remobilization from leaf blades and intervascular transfer in nodes to redirect Cd transport are crucial for grain Cd accumulation. Different metal transporters mediate these processes with cell-type specific expressions. In this review, we summarize and discuss the recent rapid advance in molecular understanding of Cd transport in rice. The achievements and perspectives in developing 'low-Cd rice' by the use of various alleles of Cd transporter genes are also discussed.