title: Pb low doses induced genotoxicity in Lactuca sativa plants.
abstract: Soil and water contamination by lead (Pb) remains a topic of great concern, particularly regarding crop production. The admissible Pb values in irrigation water in several countries range from ≈0.1 to ≈5 mg L-1. In order to evaluate putative effects of Pb within legal doses on crops growth, we exposed Lactuca sativa seeds and seedlings to increasing doses of Pb(NO3)2up to 20 mg L-1. The OECD parameter seed germination and seedling/plant growth were not affected by any of the Pb-concentrations used. However, for doses higher than 5 mg L-1significant DNA damage was detected: Comet assay detected DNA fragmentation at ≥ 5 mg L-1and presence of micronuclei (MN) were detected for 20 mg L-1. Also, cell cycle impairment was observed for doses as low as 0.05 mg L-1and 0.5 mg L-1(mostly G2arrest). Our data show that for the low doses of Pb used, the OECD endpoints were not able to detect toxicity, while more sensitive endpoints (related with DNA damage and mitotic/interphase disorders) identified genotoxic and cytostatic effects. Furthermore, the nature of the genotoxic effect was dependent on the concentration. Finally, we recommend that MN test and the comet assay should be included as sensitive endpoints in (eco)toxicological assays.
authors.affiliation: Department of Chemistry, QOPNA and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: soniasilva@ua.pt.
authors.forename: S
authors.initials: S
authors.lastname: Silva
authors.affiliation: Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Silva
authors.affiliation: Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: H
authors.initials: H
authors.lastname: Oliveira
authors.affiliation: Animal and Veterinary Research Centre (CECAV) and Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Gaivão
authors.affiliation: Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Matos
authors.affiliation: Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB) & Department of Biology and Environment, University of Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real, Portugal.
authors.forename: O
authors.initials: O
authors.lastname: Pinto-Carnide
authors.affiliation: Department of Biology & GreenUP-CitabUP, Faculty of Sciences, University of Porto, Rua Campo Alegre s/n, 4169-007 Porto, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Santos
mesh_terms: D018533:Biomass; D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects; D004249:DNA Damage; D018744:DNA, Plant / Q000378:metabolism; D018525:Germination / Q000187:drug effects; D007854:Lead / Q000633:toxicity*; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D015162:Micronucleus Tests; D008940:Mitotic Index; D009153:Mutagens / Q000633:toxicity*; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects; D018520:Plant Shoots / Q000033:anatomy & histology / Q000187:drug effects; D014867:Water
chemical_list: D018744:DNA, Plant; D009153:Mutagens; D014867:Water; D007854:Lead
keywords: Cell cycle; Comet assay; Metal toxicity; Micronucleus; Phytotoxicity