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.; PAISIO, CINTIA E.; GONZÁLEZ, PAOLA S.; PEROTTI, ROMINA; MERINGER, VERÓNICA; VILLASUSO, ANA LAURA; AGOSTINI, ELIZABETH

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Año: 2020 vol. 27 p. 14567 - 14580

0944-1344

Lemnaminuta Kunth was used to remove Cr(VI) from aqueous solutions, and some of the mechanisms involved in this process wereanalyzed.Inaddition,thecellularsignalingmediatedbyphospholipaseDactivityaswellasantioxidantresponseswasalso evaluated during the process. Cr(VI) removal efficiencies were 40% for 0.5 mg/L, after 24 h, and up to 18% at metal concentrationsashighas5mg/L.Removalmechanismsdisplayedbythesemacrophytesincludebioadsorptiontocellsurfacesand,toa greater extent, Cr internalization and bioaccumulation within cells. Inside of them, Cr(VI) was reduced to Cr(III), a less toxic form of this metal. At the first hours of Cr(VI) exposure, plants were able to sense chromium, activating membrane signal transduction pathways mediated by phospholipase D and phosphatidic acid. Moreover, an increase in the activity of antioxidant enzymes such as superoxide dismutases and peroxidases was observed in the same time. These and other components of the antioxidantdefensesystemwouldhelptoreducethestressgeneratedbythemetal.Thetoxicityoftheproductsformedduringthe removal process was assessed through Lactuca sativa L. and AMPHIAGU test. It was evidenced that Cr(VI) phytoremediation process 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 with Cr(VI).