An engineered plant that safely sucks up arsenic could restore toxic soils and provide insight into producing biological tools for absorbing chemical pollutants.

By inserting two genes from the bacteria escherichia coli into the plant thale cress (arabidopsis thaliana), scientists at the University of Georgia in Athens created an arsenic-tolerant plant that stores the toxin in its leaves. The inserted genes make enzymes that digest arsenic compounds, allowing the plant to absorb them.

The plant could prove important to phytoremediation — the technique of using plants to clean toxic sites. Metal toxins such as arsenic, cadmium, mercury, copper and zinc don’t break down into non-toxic forms and must be removed from industrial and mining sites, where they’re concentrated. Typically this involves excavation and burial, which is messy and expensive. With phytoremediation, plants can be grown and then incinerated when they’ve sucked up toxins.

The problem is finding the plants. Few naturally-occurring plants are capable of tolerating the extreme conditions of industrial waste sites. Selective breeding has created better strains, but using biotechnology could prove a better approach: Researchers who engineered the arsenic-eater believe their technique can help convert many large plants — such as cottonwood, rice, willow, sweet gums, wetland grasses and water lilies — into cleaning machines capable of cleansing a toxic site in just two or three years. by Better Humans staff


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