Biotech Updates

Arabidopsis Resistant to Zinc and Cadmium

May 9, 2008

Plants have the potential to remove toxic heavy metals from the environment (phytoremediation) or extract useful metals from the soil (phytomining). For these applications to be realized however, it will be necessary to elucidate the genetic basis of metal hyperaccumulation in plant cells. Scientists from the University of Heidelberg and Max Planck Institute in Germany found out that expression of a gene that encodes for a metal transporter (HMA4) confers heavy metal tolerance to Arabidopsis halleri.

A. halleri,  a sister species of the model plant A. thaliana that can thrive on extreme non-habitable conditions is a powerful model for research on adaptation. The plant accumulates and tolerates leaf concentration as high as 2.2% zinc and 0.3% cadmium in dry biomass. Using RNA interference, the researchers were able to show that zinc hyperaccumulation and cadmium tolerance depend on HMA4 expression. The researchers found three copies of HMA4 in the genome. Transfer of the gene to A. thaliana resulted to plants with increased zinc tolerance.

The full article is available at