title: The glutathione antioxidant system as a biomarker suite for the assessment of heavy metal exposure and effect in the grey mangrove, Avicennia marina (Forsk.) Vierh.
abstract: Alterations in the glutathione antioxidant system and lipid peroxidation in Avicennia marina were studied under laboratory and field conditions. The activity of glutathione peroxidase (GPx) was found to respond to Zn exposure, and a significant positive relationship between leaf Zn concentration and GPx activity was observed after 96 h and 8 weeks. Lipid hydroperoxides increased proportionally with increasing leaf Zn concentration after 2 and 8 weeks, while no changes in total glutathione were observed. Induction of GPx at 96 h predicted effects at the individual level at a later time interval (reduced biomass at 8 weeks). Results from the field revealed that increasing leaf metal concentration (Zn, Cu or Pb) produced a proportional increase in GPx activity whereas lipid hydroperoxides and total glutathione were not affected. The utility of GPx as an early warning biomarker is suggested, since GPx activity increases in a dose-dependant fashion in response to accumulated leaf metals, and is predictive of later effects on growth.
authors.affiliation: Centro de Estudos de Estresse Oxidativo, Departamento de Bioquímica (ICBS - UFRGS), Rua Ramiro Barcelos, 2600 anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
authors.forename: Fernanda F
authors.initials: FF
authors.lastname: Caregnato
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Koller
authors.forename: Geoff R
authors.initials: GR
authors.lastname: MacFarlane
authors.forename: José C F
authors.initials: JC
authors.lastname: Moreira
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001315:Australia; D032407:Avicennia / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D015415:Biomarkers; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D005978:Glutathione / Q000378:metabolism*; D019216:Metals, Heavy / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D005978:Glutathione; D015032:Zinc