Application of transgenic technology to phytoremediation of soils contaminated by heavy metals: a review of studies in China and abroad

Soil pollution by heavy metals has become a global problem that urgently needs to be solved. Compared with traditional technologies for recovery of polluted soil by heavy metals, phytoremediation technology exhibits advantages, such as low cost, envi-ronment protection and easy acceptance to public, thus attracting much attention from scientific community. But finding hyperaccu-mulative plants from wild habitats has proven to be difficult and is limited by low biomass, short growth season and geographical distribution of the plants. So there are difficulties in extension of this technique. Improvement of plants by genetic engineering opens up new possibilities for phytoremediation. Evidences have shown that high-level expression of transgenes in plants stimulates ab-sorption, translocation and degradation of contaminated substances, thus increasing the remediation efficiency. The paper reviews the recent developments in phytoremediation of soil contaminated with heavy metals in China and abroad and describes in detail the mechanisms and applications of the transgenic, such as PCs, MTs, MerA, MerB, ArsC, γ-ECS and so on, in phytoremediation for soil contaminated by heavy metals. Finally it may be suggested that application of gene technology is an important aspect of phy-toremediation because it not only accelerates the research of various subjects and enriches the research field of environmental science, but also overcomes some inextricable problems of the traditional technologies for recovery of polluted soil by heavy metals. It is also very important to realize that the transgenic plants would damage the health of people.