Unfortunately, the plants which naturally extract such poisons are slow growing and small, whereas the bacteria that can detoxify pollutants are generally less robust than the plants. Now Scott Bizily at the University of Georgia, Athens, Georgia, USA and colleagues get round these problems by putting a couple of bacterial genes into a plant.
Mercury occurs naturally at relatively safe levels.
But industrial activities have produced vast quantities of a toxic, 'ionic' form of mercury that water-borne bacteria can easily convert into the even more deadly methylmercury. Previous research has shown that plants engineered to contain the bacterial gene merB transform methylmercury to ionic mercury. Another bacterial gene, merA , when inserted into plants, causes plants to convert ionic mercury to elemental mercury that dissipates into the atmosphere. These genes cause plants to produce a protein that acts as a catalyst, converting one form of mercury to another. Bizily's team developed a new variant of thale cress with both genes.