EFFECT OF EDTA ON ACCUMULATION OF HEAVY METALS FROM MINING TAILINGS AND ITS RELATIONSHIP WITH ON GROWTH, PHYSIOLOGICAL RESPONSE AND ANTIOXIDANT ACTIVITY OF GRINDELIA TARAPACANA PHIL.

Wild plants that grow in areas contaminated with heavy metals can be used in phytoremediation due to the adaptation processes they use. In this work, the phytoremediation capabilities of Grindelia tarapacana in the presence of the chelating agent Ethylenediamine tetraacetic acid (EDTA) was evaluated. The effect of EDTA (50, 100, and 150 mg/kg) on the accumulation of heavy metals from mining tailings and its relationship with the physiological response and metabolism of greenhouse plants were tested. It was found that the biomass was increased in the treatment with 50 mg / Kg of EDTA. But the growth was decreased by up to 10% in treatments with higher concentrations. The photosynthetic pigments did not vary significantly in content. In the treatments with higher EDTA content, soluble carbohydrates were decreased significantly (p <0.05), and soluble protein content changed significantly (p <0.05). However, an opposite effect is observed for the antioxidant activity which increases with higher concentrations of EDTA in the substrate; consequently, lipid peroxidation also was decreased. The application of EDTA favored the accumulation of heavy metals in this species, in the order of roots> leaves> stems. Finally, it is concluded that Grindelia is a stabilizer and phytoextractor plant.