Fitoextração, fitoestabilização e análise ultraestrutural de Gomphrena claussenii Moq. exposta a Cu e Pb

Abstract

Environmental issues have increased concern throughout the years and part of this can be related to heavy metals contamination. Mining activities are, and will always be, important for the outcome of the country and for the community. However, these activities can create huge amounts of soil contaminants and it has been debated worldwide recently. Phytoremediation techniques, which use plants with high capacities of uptaking and tolerate trace metals, are important, low costs tools that can be used to remedy a contaminated area. In the vicinities of mining areas it can be found some plant species that are appropriate for remediation. This study aims at investigating the phytoextracting potential of Cu and Pb, as well as its accumulation, the total contents, the translocation indexes and Cu and Pb tolerance capacity in Gomphrena claussenii. Cellular changes were investigated using transmission electron microscopy (TEM). The study was conducted in the greenhouse at the Federal University of Lavas, MG, Brazil. The plants were cultivated in buckets with Clark solution with Cu concentrations ranging from 0,5; 2,5; 5,0;10; 25; 50; 75 to 100 µmol L-1 and Pb from 50; 100; 200; 400; 600 to 800 µmol L-1. After 35 days of cultivation, roots and shoots system were collected and dried and the contents of Cu and Pb were evaluated. The plants of Gomphrena claussenii were sensitive to increasing doses of Cu and Pb in nutrient solution, showing phytotoxicity symptoms and reduction in dry matter production. Even at high concentrations of Cu and Pb doses, the plants survived and can be used for phytoremediation programs, because with the first trace element characteristics presented fitoextratora plant, and the second fitoesbilização.