The study investigates the mechanisms of cadmium (Cd) mobility and accumulation in Indian mustard (Brassica juncea L.), a high-biomass crop plant. Indian mustard accumulated significant amounts of Cd, with bioaccumulation coefficients of up to 1100 in shoots and 6700 in roots at nonphytotoxic concentrations of Cd (0.1 μg/ml). Cd accumulation was associated with the rapid production of phytochelatins in the roots, where most of the Cd was coordinated with sulfur ligands, likely forming a Cd-S₃ complex, as evidenced by x-ray absorption spectroscopy. In contrast, Cd in the xylem sap was predominantly coordinated with oxygen or nitrogen ligands. The rate of Cd accumulation in the leaves followed saturation kinetics, suggesting that Cd transport from the root to the xylem is mediated by a saturable transport system. However, Cd translocation to the shoot appeared to be driven by transpiration, as indicated by the dramatic reduction in Cd accumulation in leaves when exposed to abscisic acid (ABA). Within leaves, Cd preferentially accumulated in trichomes, which may serve as a detoxification mechanism. The study highlights the potential of Indian mustard for phytoremediation of Cd-contaminated soils and provides insights into the mechanisms of Cd accumulation and transport in plants.The study investigates the mechanisms of cadmium (Cd) mobility and accumulation in Indian mustard (Brassica juncea L.), a high-biomass crop plant. Indian mustard accumulated significant amounts of Cd, with bioaccumulation coefficients of up to 1100 in shoots and 6700 in roots at nonphytotoxic concentrations of Cd (0.1 μg/ml). Cd accumulation was associated with the rapid production of phytochelatins in the roots, where most of the Cd was coordinated with sulfur ligands, likely forming a Cd-S₃ complex, as evidenced by x-ray absorption spectroscopy. In contrast, Cd in the xylem sap was predominantly coordinated with oxygen or nitrogen ligands. The rate of Cd accumulation in the leaves followed saturation kinetics, suggesting that Cd transport from the root to the xylem is mediated by a saturable transport system. However, Cd translocation to the shoot appeared to be driven by transpiration, as indicated by the dramatic reduction in Cd accumulation in leaves when exposed to abscisic acid (ABA). Within leaves, Cd preferentially accumulated in trichomes, which may serve as a detoxification mechanism. The study highlights the potential of Indian mustard for phytoremediation of Cd-contaminated soils and provides insights into the mechanisms of Cd accumulation and transport in plants.