Removal of high lead concentration by hydroponic cultures of normal and transformed plants of Scirpus americanus Pers

Abstract

Abstract Lead is a very toxic metal which affects human health. An alternative to remove it from contaminated water is the use of macrophytes, as Scirpus americanus. This species is tolerant to salt and metals, and has high biomass. The present research analyzed the capacity of hydroponic cultures of normal and transgenic plants (line T12) from S. americanus to remove high concentrations of lead (100, 250 and 400 mg kg-1 Pb). The MINTEQ3.1 program was used to define the media composition in order to have the metal available to the plants. The presence of metal did not affect the growth of roots and stems at all concentration tested. The normal and T12 plants accumulated 69389 and 45297 mg lead kg-1, respectively, and could be considered as hyperaccumulators. The bioconcentration factor indicated that plant bioconcentrated between 192-300 times the metal. The activation of the antioxidant mechanisms seems to participate in lead tolerance. Then, S. americanus could be used for phytoremediation of water contaminated with high concentration of lead.