Study Progress on the Root Uptake Pathway of As, Cd and Pb and Its Influence Factors

Toxic elements in the environment taken up by plants, not only damage plant growth, but also harm the health of human beings through the food chain. Toxic elements are taken up by plants commonly through root, stem and foliar, of which the foliar is the most important way. Knowing the ways of toxic elements entering the root cell and its influence factors would lower the uptake of toxic elements by plants and lower the edible danger. In recent years, uptake kinetic process, transport protein identification and action mechanism of external factors are carried out internationally in the field of root system uptake pathway of toxic elements. In this paper, we focus on the root uptake pathway of As, Cd and Pb and its influence factors. Transport processes by transport protein and ion channel of transmembrane protein, rhizosphere environment and the effects of coexisting elements are reviewed. It is concluded that the dynamic process of cellular uptake of As, Cd and Pb at the molecular scale, the cell response mechanism, and rhizosphere effect mechanism of many factors are the main research orientation in the future. Moreover, it is possible that the efflux mechanism of As(Ⅲ) is similar to P and Pb²⁺ is transported to xylem by Ca²⁺ channels.