Arsenic, a class-1 carcinogenic, is a ubiquitous metalloid found in the atmosphere, soils, natural waters, and organisms. The World Health Organization (WHO) estimates that hundred million people worldwide might be chronically exposed to arsenic in drinking water at concentrations above the safety standard. Conventionally applied techniques to remove arsenic species show low removal efficiency, high operational costs, and high-energy requirements. The biological methods, especially phytoremediation, could be cost-effective for protecting human health and the environment from toxic metal contamination. Plants, as sessile organisms, have developed an extraordinary capacity to tolerate arsenic through three main strategies: uptake repression, sequestration into the vacuole, or extrusion. Therefore, arsenic perception and tolerance require a coordinated response that involves arsenic transporters, extrusion pumps, vacuole transporters, and the activation of the phytochelatin biosynthetic pathway. For phytoremediation to become a feasible strategy for arsenic removal from contaminated sites, it is essential to completely understand the molecular mechanisms of arsenic uptake, extrusion, and sequestration, as well as how this response is coordinated. The new genome-wide technologies provide a unique opportunity to understand the molecular mechanisms underlying arsenic perception and accumulation in plants that will open up new possibilities for phytoremediation of arsenic-contaminated waters and soils.
Part of the book: Environmental Chemistry and Recent Pollution Control Approaches