Sedum alfredii Hance: A cadmium and zinc hyperaccumulating plant

The hyperaccumulating ecotype Sedum alfredii Hance is one of few Cd hyperaccumulators with Cd contents in leaves and stems up to 9000 mg/kg (dry weight, DW) and 6500 mg/kg (DW) respectively without displaying significant toxicity symptoms as reported in 2004. Numerous studies have been conducted to uncover the mystery of its hypertolerance and hyperaccumulation using high-throughput sequencing, biochemical and molecular techniques, mainly pointing to the root-microorganism interaction, restrained Cd storage in roots, efficient root-shoot translocation, effective cellular detoxification, and phloem-mediated metal remobilization. This also encourages studies on functional genes involved in metal transport, antioxidant, transcription regulation and stress response, providing candidates for genetic modification. Moreover, researchers have focused on the practical application and optimal managements in phytoremediation. Sedum alfredii Hance is of scientific significance as a model plant elucidating hypertolerance and hyperaccumulation traits or decontaminating heavy metals. More efforts are required to deepen the knowledge of Sedum alfredii Hance and provide theoretical guidance for practical phytoremediation.