Cadmium phytoextraction by Sedum alfredii and Sedum plumbizincicola : mechanisms, challenges and prospects

Phytoextraction using natural cadmium (Cd) hyperaccumulators, notably Sedum alfredii and Sedum plumbizincicola, represents an economical and efficient approach for soil Cd purification. However, achieving high phytoremediation efficiency necessitates a comprehensive understanding of the mechanisms underlying Cd tolerance and accumulation in these plants. This review summarizes key mechanisms, encompassing Cd activation in the rhizosphere, uptake and transport in the roots, translocation via the xylem, and Cd tolerance. Additionally, physical, chemical, and biological strategies for enhancing phytoremediation efficiency are overviewed and compared. Despite advancements, disparities persist between field and laboratory research, posing certain limitations to the application of natural hyperaccumulators for large-scale phytoextraction or specific soil types. To address these challenges, we propose combining novel hyperaccumulating-like biomaterials with intelligent agriculture to achieve large-scale precision phytoremediation. Furthermore, we aim to draw attention to strategies for enhancing the phytoextraction potential of non-hyperaccumulator plants with high biomass production and stimulate further research into phytoextraction-inducing substances.