Effect of glyphosate on the growth, morphology, ultrastructure and metabolism of Scenedesmus vacuolatus

IUMMATO M.M.; FASSIANO ANABELLA; GRAZIANO MARTÍN; DOS SANTOS AFONSO M; DEL CARMEN RÍOS DE MOLINA, MARÍA; JUAREZ AB

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2019 vol. 172 p. 471 - 479

0147-6513

The effects of a commercial glyphosate formulation on theoxidative stress parameters, and morphology and ultrastructure of thephytoplanktonic green microalga Scenedesmus vacuolatus were evaluated.After 96 h of exposure to the herbicide (0, 4, 6, 8 mg L-1 activeprinciple) plus alkyl aryl polyglycol ether surfactant, the growth of thecultures decreased with the increasing concentrations (IC50-96 h 4.90 mgL-1) and metabolic and morphology alterations were observed. Significantincreases in cellular volume (103 - 353%) and dry weight (105%) and asignificant decrease in pigment content (41 - 48%) were detected.Oxidative stress parameters were significantly affected, showing anincrease in the reactive oxygen species (ROS) and reduced glutathione(GSH) contents, oxidative damage to lipids and proteins and a decrease inthe activities of the antioxidant enzymes superoxide dismutase (SOD) andcatalase (CAT) and the detoxifying enzyme glutathione-S-transferase(GST). Cells exposed to glyphosate formulation were larger and showed anincrease in vacuole size, bleaching, cell wall thickening and alterationof the stacking pattern of thylakoids. The results of this study showedthe participation of oxidative stress in the mechanism of action of thecommercial glyphosate formulation on S. vacuolatus and the correlationbetween the biochemical, morphological and ultrastructure alterations.