Phytoremediation Potential and Antioxidative Stress Response of Ensete ventricosum (Welw.) Cheesman under Long-Term Exposure to Cadmium

Objective: Global food security and ecosystem stability are under constant threat due to agricultural soil contamination driven by cadmium (Cd) and other heavy metals. Therefore, identification of tolerant and high-biomass-producing plant species is critical for sustainable phytoremediation.Materials and Methods: Ensete ventricosum (Welw.) Cheesman (wild banana) plants were grown in soil culture pots under controlled phytotron conditions and treated with different Cd concentrations (0, 10, 20 and 40 µM) for 270 days. The accumulation of Cd, long-term morphological changes, physiological stress responses, and phytoremediation potential of E. ventricosum were evaluated.Results: Inductively coupled plasma optical emission spectroscopy (ICP-OES) revealed that Cd accumulation in plant organs was found in the order of root > corm > stem > leaf. Decreased Cd accumulation in corms with increased soil Cd shows a physiological barrier limiting metal translocation into storage organs. Plants exhibited a hormetic growth response when exposed to low Cd concentrations (10-20 µM). E. ventricosum employed a tissue-specific and dose-dependent antioxidant defence strategy through the upregulation of catalase, guaiacol peroxidase, and ascorbate peroxidase activities to scavenge reactive oxygen species. In addition, the increased level of total soluble proteins in roots also reflects the synthesis of stress response proteins.Conclusion: E. ventricosum tolerates extended Cd exposure through coordinated enzymatic detoxification and morphological plasticity. E. ventricosum is a promising candidate for phytostabilization given its high plant biomass and high root Cd accumulation in Cd-contaminated soils.