Exploring the metabolome network and phytoremediation potential of wild plant species thriving in a heavy metal-contaminated abandoned mine in Korea

Abstract

Heavy metal contamination poses considerable ecological and health risks, particularly in regions affected by abandoned mining operations. This study addresses the limited understanding of the metabolic responses of different wild plant species to heavy metal stress in natural ecosystems and abandoned mine sites. In this study, we aimed to investigate the resilience and metabolic adaptations of plant species thriving in heavy metal-contaminated soils at abandoned mine sites in South Korea. Seventeen plant species were identified, with Plantago asiatica and Ambrosia artemisiifolia displaying high translocation factors (TFs) for arsenic and zinc, respectively, highlighting their phytoremediation potential. Conversely, Ailanthus altissima exhibited a low TF and confined heavy metals to its roots, supporting its suitability for phytostabilization. Metabolome analysis revealed distinct metabolic profiles between plants from contaminated and control sites, with key metabolites, such as malic acid, tartaric acid, and sucrose, playing critical roles in detoxification. Species-specific metabolic responses were observed, highlighting distinct biochemical strategies to manage heavy metal stress. Association network analysis revealed that malic acid, a key metabolite in the tricarboxylic acid cycle, was linked to stress-related pathways involving γ-aminobutyric acid, alanine, and maltose, supporting heavy metal chelation and enhanced stress resilience. These findings highlight the role of wild plant species in mitigating contamination and reveal key metabolic mechanisms. Our study provides novel field-based insights into species-specific and shared biochemical responses, offering a foundation for more effective and sustainable phytoremediation strategies.