Mechanistic insights into cadmium uptake and tolerance in Ligusticum chuanxiong: Implications for sustainable cultivation

Ligusticum chuanxiong Hort., a key medicinal herb, is vulnerable to cadmium (Cd) contamination in soil, which affects its growth and quality. This study investigates the physiological responses of L. chuanxiong to Cd stress using six Cd concentrations (0, 0.05, 0.1, 0.25, 0.5, and 2.00 mM). Our results show that soil Cd predominantly exists in the acid-soluble state, enhancing bioavailability. Plant growth followed a dose-dependent pattern: low concentrations (0.05 and 0.1 mM) promoted growth, while higher concentrations inhibited it. For example, ferulic acid content increased by 40 % under Cd2 at T1, and enzyme activities (CAT, POD, SOD) were elevated under low stress but inhibited at high concentrations. Cd accumulation was highest in roots (0.61 mg/kg at T4), followed by rhizomes. Notably, L. chuanxiong detoxified Cd by redistributing it from the soluble fraction to the cell wall. The bioconcentration factor (BCF) for rhizomes at T4 under Cd0.1 was 3.25, confirming it as a Cd-hyperaccumulator. Our findings provide insights into the Cd uptake, translocation, and detoxification mechanisms of L. chuanxiong , offering a theoretical basis for reducing Cd absorption in medicinal plants and ensuring safe cultivation. • Cadmium exposure alters soil Cd forms, increasing bioavailability to L. chuanxiong . • Low Cd levels stimulate growth and antioxidant activity, while high Cd inhibits both. • Cd is detoxified by redistribution to cell walls, with rhizomes showing highest accumulation.