Integrated transcriptomic and metabolomic analyses reveal root-centered regulatory networks conferring cadmium tolerance in Salix

Cadmium (Cd) pollution is a major environmental threat, and the mechanisms of Cd tolerance in remediation-suitable Salix species are poorly understood. We analyzed two willow ecotypes with distinct Cd responses: the tolerant ecotype maintained growth and efficiently transported Cd to shoots, while the sensitive ecotype had stunted growth and retained Cd in roots. Multi-omics revealed that coordinated metabolic and transporter pathways form a systemic defense network for Cd tolerance. Our results provide targets for breeding high-efficiency phytoremediation plants.