Cadmium is a toxic heavy metal that may be detected in soils and plants. Wheat, as a food consumed by 60% of the world's population, may uptake a high quantity of Cd through its roots and translocate Cd to the shoots and grains thus posing risks to human health. Therefore, we tried to explore the journey of Cd in wheat via a review of several papers. Cadmium may reach the root cells by some transporters (such as zinc-regulated transporter/iron-regulated transporter-like protein, low-affinity calcium transporters, and natural resistance-associated macrophages), and some cation channels or Cd chelates via yellow stripe 1-like proteins. In addition, some of the effective factors regarding Cd uptake into wheat, such as pH, organic matter, cation exchange capacity (CEC), Fe and Mn oxide content, and soil texture (clay content), were investigated in this paper. Increasing Fe and Mn oxide content and clay minerals may decrease the Cd uptake by plants, whereas reducing pH and CEC may increase it. In addition, the feasibility of methods to diminish Cd accumulation in wheat was studied. Amongst agronomic approaches for decreasing the uptake of Cd by wheat, using organic amendments is most effective. Using biochar might reduce the Cd accumulation in wheat grains by up to 97.8%.
Keywords: biochar; cadmium; silicon; uptake; wheat.