Transport channels enabling uptake, translocation and detoxification of arsenic in plants

Arsenic (As), a toxic metalloid and global environmental contaminant, poses serious threats to living organisms through groundwater and dietary exposure. Both acute and chronic exposures of As result in severe physiological and biochemical disturbances in organisms. In plants, As uptake occurs through transporters for essential metal ions, which often lack selectivity due to structural similarities between As species and essential ions. Nodulin 26-like intrinsic proteins (NIPs) facilitate the transport of As(III), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA), while phosphate transporters (PHTs) mediate As(V) uptake due to its similarity to phosphate. Internalized As is detoxified through sulfur (S)-rich molecules like glutathione (GSH) and phytochelatins (PCs), forming thiol-As complexes. These complexes are either transported to shoots for sequestration or stored in vacuoles, reducing toxicity. Detoxification relies on sulfate transporters (SULTRs) for S uptake and ATP-binding cassette (ABCC) transporters for vacuolar sequestration of thiol-As complexes. Understanding these molecular mechanisms is crucial for mitigating As toxicity. This review outlines the roles of transporters and their regulation controlling As detoxification. These transporters are promising targets for genome-editing and molecular breeding to develop crops with reduced As levels in edible tissues, addressing food safety and environmental remediation.