Arsenic metabolism in plants: an inside story

From murder plots to environmental disasters, arsenic (As) has always been in the headlines. As-contaminated soils, sediments and water supplies are major sources of food chain contamination and thereby endanger human health; this is a global problem, but the situation is nowhere worse than in India and Bangladesh, where more than 400 million people are affected by As poisoning in drinking water (Chakraborti et al., 2003). Inorganic species of As, arsenate (AsO4−3, referred to as AsV) and arsenite (AsO4−3, referred to as AsIII), are carcinogenic and have been shown to cause cancer of the lung, liver and kidney and to cause skin pigmentation. Plants too are affected by As; it is a nonessential element and, in general, inorganic As species…