Deepening the knowledge on the removal of Cr(VI) by L. minuta Kunth: removal efficiency and mechanisms, lipid signaling pathways, antioxidant response, and toxic effects

FERNÁNDEZ, MARÍA I.; PEROTTI, ROMINA; PAISIO, CINTIA E.; VILLASUSO, ANA LAURA; GONZÁLEZ, PAOLA S.; AGOSTINI, ELIZABETH

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Año: 2020 vol. 27 p. 14567 - 14580

0944-1344

Lemna minuta Kunth was used to remove Cr(VI) from aqueous solutions, and some of the mechanisms involved in this processwere analyzed. In addition, the cellular signaling mediated by phospholipase D activity as well as antioxidant responses was alsoevaluated during the process. Cr(VI) removal efficiencies were 40% for 0.5 mg/L, after 24 h, and up to 18% at metal concentrations as high as 5 mg/L. Removal mechanisms displayed by these macrophytes include bioadsorption to cell surfaces and, to agreater extent, Cr internalization and bioaccumulation within cells. Inside of them, Cr(VI) was reduced to Cr(III), a less toxicform of this metal. At the first hours of Cr(VI) exposure, plants were able to sense chromium, activating membrane signaltransduction pathways mediated by phospholipase D and phosphatidic acid. Moreover, an increase in the activity of antioxidantenzymes such as superoxide dismutases and peroxidases was observed in the same time. These and other components of theantioxidant defense system would help to reduce the stress generated by the metal. The toxicity of the products formed during theremoval process was assessed through Lactuca sativa L. and AMPHIAGU test. It was evidenced that Cr(VI) phytoremediationprocess by L. minuta plants did not generate acute toxicity neither for L. sativa seeds nor for embryos of Rhinella arenarum(Hensel, 1876). Thus, L. minuta plants could be considered as valuable species for the treatment of waters contaminated withCr(VI).