Our long-term objective is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic organic and heavy metal pollutants (Meagher, 2000) applying scientific strategies and technologies from a rapidly developing field called phytoremediation. The phytoremediation of toxic elemental and organic pollutants requires the use relatively different approaches (Meagher, 2000). Our current specific objectives are to use transgenic plants to control the chemical species, electrochemical state, and aboveground binding of mercury to (1) prevent methylmercury from entering the food-chain, (2) remove mercury from polluted sites, and (3) hyperaccumulate mercury in aboveground tissues for later harvest. Various parts of this strategy are being critically tested by examining different genes in model plants and field species and comparing the results to control plants as recently reviewed (Meagher et al., 2000; Rugh et al., 2000).