Biomarkers of oxidative stress in Bidens laevis for analyzing pollution by current use pesticides in La Brava lagoon (Argentina).

LOMBARDERO, LR; ITURBURU, F. G.; MEDICI, SANDRA; MENDIETA, JULIETA; CRUPKIN, A; VILLAGRAN, D; PÉREZ DJ.,; MENONE, ML

Valdivia

Congreso; SETAC Latin America 14th Biennial Meeting.; 2021

La Brava lake is a protected landscape by the Provincial Agency forSustainable Development of Buenos Aires Province (OPDS), Argentina.Despite this status, the lake is surrounded by important agriculturalactivities. The aim of the present study was to evaluate the pollution bycurrent use pesticides (CUPs) in surface water of La Brava basin usingbiomarkers of oxidative stress in the aquatic macrophyte Bidens laevis.Two samplings per year were performed in Tajamar creek, one in springand the other in summer when peak pesticides concentrations wereexpected. Samplings were performed for two consecutive years. Eachtime, macrophyte samples (n=10) for biomarkers analysis and surfacewater (n=3) for pesticides quantification using UPLC- MS/MS, werecollected. Catalase (CAT), glutathione reductase (GR), and guaiacolperoxidase (POD) activity, as well as levels of hydrogen peroxide(H2O2) and malondialdehyde (MDA) in roots and leaves werespectrophotometrically analyzed. In the first year, in spring the herbicideglyphosate (3.5 µg/L) and the insecticide chlorpyrifos (0.7 µg/L) weredetected while in summer glyphosate (2.0 µg/L), its metabolite AMPA(2.7 µg/L) and chlorpyrifos (2.4 µg/L) were detected. Leaf tissuespresented higher levels of H2O2 and MDA as well as higher activitiesof GR but lower activity of POD in summer than in spring. Roots tissuesshowed higher levels of H2O2 and MDA and lower activities of CATand POD in summer, in comparison to spring. In the second year, onlychlorpyrifos in spring (3.1 µg/L) and summer (1.5 µg/L) was found. In both analyzed tissues, higher activity of POD, lower levels of H2O2 buthigher levels of MDA in summer than in spring were detected. Theseresults show that the oxidative stress biomarkers in summer increasedrespect the spring, mainly the oxidative damage, according to thehighest levels of CUPs detected in La Brava lake. More studies will becarried out to elucidate the direct relationship between the CUPs and theadverse effects in B. laevis.