title: Toxicity assessment of two soils from Jales mine (Portugal) using plants: growth and biochemical parameters.
abstract: Contaminants in soils can enter food chains through primary producers. Bioavailable contaminants can induce growth, and reproductive or biochemical changes in plants. To evaluate the bioavailability of heavy metals in two soils from Jales mine surroundings, bioassays with the plants Brassica rapa (RCBr) and Avena sativa were performed. Biochemical parameters (protein and malondialdehyde [MDA] content, and catalase and peroxidase activities) were also measured. The soils had different heavy metal contents: JNC soil contained low heavy metal concentrations, whereas JC soil had high heavy metal contents. Results stressed the difference between species sensitivity, with A. sativa showing no toxicity effects when exposed to both soils. On the other hand, B. rapa presented a decrease in growth parameters when exposed to JNC soil and no changes when exposed to JC soil. A Life Cycle Bioassay confirmed this trend for B. rapa exposed to JNC soil, but also evidenced that JC soil was affecting B. rapa in terms of flower and seed pod production. Biochemical assays showed that plants affected by heavy metals also displayed oxidative stress, with an increase in MDA production, reduction of protein content, and reduction of catalase and peroxidase activities. All bioassays revealed that JNC soil, although with a lower heavy metal content, had a higher bioavailable fraction when compared to JC soil, which consequently increased its toxicity to plants.
authors.affiliation: Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal. sloureiro@bio.ua.pt
authors.forename: Susana
authors.initials: S
authors.lastname: Loureiro
authors.forename: Conceição
authors.initials: C
authors.lastname: Santos
authors.forename: Glória
authors.initials: G
authors.lastname: Pinto
authors.forename: Armando
authors.initials: A
authors.lastname: Costa
authors.forename: Marta
authors.initials: M
authors.lastname: Monteiro
authors.forename: António J A
authors.initials: AJ
authors.lastname: Nogueira
authors.forename: Amadeu M V M
authors.initials: AM
authors.lastname: Soares
mesh_terms: D001151:Arsenic / Q000032:analysis / Q000633:toxicity; D018554:Avena / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D001937:Brassica / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D002374:Catalase / Q000378:metabolism; D018525:Germination / Q000187:drug effects; D007220:Industrial Waste; D008315:Malondialdehyde / Q000378:metabolism; D008670:Metals / Q000032:analysis / Q000633:toxicity; D008906:Mining; D009195:Peroxidase / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis; D011174:Portugal; D036226:Seedlings / Q000187:drug effects / Q000502:physiology; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*
chemical_list: D007220:Industrial Waste; D008670:Metals; D010940:Plant Proteins; D012989:Soil Pollutants; D008315:Malondialdehyde; D002374:Catalase; D009195:Peroxidase; D001151:Arsenic