Exploring cadmium uptake pathways in the roots of Coptis chinensis Franch.

Abstract

To investigate the cadmium (Cd) uptake mechanism in the roots of Coptis chinensis Franch., we utilized non-invasive micro-test technology (NMT) to analyze Cd²⁺ and H⁺ fluxes, alongside ICP-MS to assess Cd content and fluxes under various inhibitors and ion channel blockers. Results revealed that Cd²⁺ uptake primarily occurs in the root meristematic zone. Cd²⁺ addition significantly inhibited H⁺ influx. The P-type ATPase inhibitor Na₃VO₄ and the metabolism inhibitor CCCP both reduced Cd²⁺ fluxes and Cd content in roots of C. chinensis Ca²⁺ channel blocker LaCl₃ exhibited more pronounced inhibition on Cd²⁺ flux than K⁺ channel blocker TEA, indicating Cd²⁺ uptake mainly via Ca²⁺ channels. Therefore, active transport and Ca²⁺ channels may play an important role in Cd uptake in C. chinensis roots.