PHYTOREMEDIATION OF SOIL METALS

The phytoremediation of metal-contaminated soils offers a low-cost met hod for soil remediation and some extracted metals may be recycled for value. Both the phytoextraction of metals and the phytovolatilization of Se or Hg by plants offer great promise for commercial development. Natural metal hyperaccumulator phenotype is much more important than high-yield ability when using plants to remove metals from contaminate d soils. The hypertolerance of metals is the key plant characteristic required for hyperaccumulation; vacuolar compartmentalization appears to be the source of hypertolerance of natural hyperaccumulator plants. Alternatively, soil Pb and Cr6+ may be inactivated in the soil by pla nts and soil amendments (phytostabilization). Little molecular underst anding of plant activities critical to phytoremediation has been achie ved, but recent progress in characterizing Fe, Cd and Zn uptake by Ara bidopsis and yeast mutants indicates strategies for developing transge nic improved phytoremediation cultivars for commercial use. (C) Curren t Biology Ltd.