In recent decades, there has been an increase in anthropogenic activities such as industrialization, urbanization, energy generation, agricultural practices, and the burning of fossil fuels, which has resulted in an increase of heavy metals (HM) concentrations in soils and waters to amounts that are harmful to plants, animals, and humans. An alternative is the use of plants with ability to produce large amounts of biomass and with active mechanisms for the phytoextraction of pollutants, that is, the application of green technologies such as phytoremediation. However, there are plants with great capacity to remove pollutants, but they produce little biomass. In that sense, the genetic transformation of plants is an alternative. This chapter summarizes the work that has been carried out so far where plant engineering is used to improve tolerance and removal of HM in contaminated areas. The information here described will be useful for to design strategies of phytoremediation of contaminated sites.
