Differential effects of Zn concentrations on Cr(VI) uptake by two Salvinia species: involvement of thiol compounds

PRADO, CAROLINA; CHOCOBAR-PONCE, SILVANA; PAGANO, EDUARDO; PRADO, FERNANDO; ROSA, MARIANA

INTERNATIONAL JOURNAL OF PHYTOREMEDIATION

TAYLOR & FRANCIS INC

Año: 2020 p. 1 - 8

1522-6514

Floating ferns of the genus Salvinia have great potential for phytoremediation of heavy metals. Todate, the effect of essential metals on the accumulation and transport of toxic metals by aquaticferns has not been suitably established. The aim of this study was to compare the ability offloating leaves of Salvinia minima and Salvinia rotundifolia species to accumulate Cr from Cr(VI solutionscontaining very low (0.02mg L1) and low (5mg L1) Zn concentrations. After 7-day metalexposureperiod, results showed that Zn increased Cr accumulation in S. minima leaves whereas inS. rotundifolia decreased significantly. Contrarily Zn accumulation did not show great differencesbetween species. This fact may indicate that Zn interfere Cr(VI) uptake by S. rotundifolia.Bioconcentration factor (BCF) and translocation factor (TF) were affected differently by Zn in bothSalvinia species. Membrane stability index (MSI) of both Salvinia species was decreased significantlyby 5mg L1 Zn concentration. Zn ions also increased hydrogen peroxide accumulation infronds of Salvinia species. Total thiols (TT), non-protein thiols (NPT) and protein-bound thiols (PBT)were differentially affected by Cr(VI) and Zn ions. This study provides evidences on the involvementof different mechanisms against Cr(VI)/Zn toxicity in S. minima and S rotundifolia species.