Contaminated soils and residues can be remediated by various methods, such as removal, isolation, incineration, solidification/stabilization, vitrification, thermal treatment, solvent extraction, chemical oxidation, etc. These methods have the disadvantage of being very expensive and in some cases, they involve the movement of contaminated materials to treatment sites thus, adding risks of secondary contamination [ -]. Therefore, currently preference is being given to in situ methods that are

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... ss environmentally disruptive and more economical. In this context, biotechnology offers phytoremediation techniques as a suitable alternative. Phytoremediation can be understood as the use of plants trees, shrubs, grasses and aquatic plants and their associated microorganisms in order to remove, degrade or isolate toxic substances from the environment [ -]. The word phytoremediation derives from the Greek «phyton», meaning plant , and Latin «remedium», which means to remedy or to correct . Substances that may be subjected to phytoremediation include metals Pb, Zn, Cd, Cu, Ni, Hg , metalloids "s, Sb , inorganic compounds NO -NH + , PO -, radioactive chemical elements U, Cs, Sr , petroleum hydrocarbons "TEX , pesticides and herbicides atrazine, bentazone, chlorinated and nitroaromatic compounds , explosives TNT, DNT , chlorinated solvents TCE, PCE and industrial organic wastes PCPs, P"Hs , and others [ ].