title: Effects of microcystin-LR, cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture on growth, oxidative stress and mineral content in lettuce plants (Lactuca sativa L.).
abstract: Toxic cyanobacterial blooms are documented worldwide as an emerging environmental concern. Recent studies support the hypothesis that microcystin-LR (MC-LR) and cylindrospermopsin (CYN) produce toxic effects in crop plants. Lettuce (Lactuca sativa L.) is an important commercial leafy vegetable that supplies essential elements for human nutrition; thus, the study of its sensitivity to MC-LR, CYN and a MC-LR/CYN mixture is of major relevance. This study aimed to assess the effects of environmentally relevant concentrations (1, 10 and 100 µg/L) of MC-LR, CYN and a MC-LR/CYN mixture on growth, antioxidant defense system and mineral content in lettuce plants. In almost all treatments, an increase in root fresh weight was obtained; however, the fresh weight of leaves was significantly decreased in plants exposed to 100 µg/L concentrations of each toxin and the toxin mixture. Overall, GST activity was significantly increased in roots, contrary to GPx activity, which decreased in roots and leaves. The mineral content in lettuce leaves changed due to its exposure to cyanotoxins; in general, the mineral content decreased with MC-LR and increased with CYN, and apparently these effects are time and concentration-dependent. The effects of the MC-LR/CYN mixture were almost always similar to the single cyanotoxins, although MC-LR seems to be more toxic than CYN. Our results suggest that lettuce plants in non-early stages of development are able to cope with lower concentrations of MC-LR, CYN and the MC-LR/CYN mixture; however, higher concentrations (100 µg/L) can affect both lettuce yield and nutritional quality.
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal; Faculty of Sciences, Porto University, Rua do Campo Alegre, 4169-007 Porto, Portugal; Polytechnic Institute of Porto, Environmental Health Department, Escola Superior de Tecnologia da Saúde do Porto, CISA/Research Center in Environment and Health, Rua de Valente Perfeito, 322, 4400-330 Gaia, Portugal.
authors.forename: Marisa
authors.initials: M
authors.lastname: Freitas
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Azevedo
authors.affiliation: REQUIMTE/ Departamento de Ciências Químicas, Laboratório de Bromatologia e Hidrologia da Faculdade de Farmácia da Universidade do Porto, Portugal.
authors.forename: Edgar
authors.initials: E
authors.lastname: Pinto
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Neves
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Campos
authors.affiliation: CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, P 4050-123 Porto, Portugal; Faculty of Sciences, Porto University, Rua do Campo Alegre, 4169-007 Porto, Portugal.
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
mesh_terms: D000470:Alkaloids; D000975:Antioxidants / Q000494:pharmacology; D001427:Bacterial Toxins / Q000633:toxicity*; D000087522:Cyanobacteria Toxins; D018545:Lactuca / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development; D008387:Marine Toxins; D052998:Microcystins / Q000633:toxicity*; D008903:Minerals / Q000032:analysis*; D018384:Oxidative Stress / Q000187:drug effects*; D018515:Plant Leaves / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects; D014498:Uracil / Q000031:analogs & derivatives* / Q000633:toxicity
chemical_list: D000470:Alkaloids; D000975:Antioxidants; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D008903:Minerals; C089595:cylindrospermopsin; D014498:Uracil; C057862:cyanoginosin LR
keywords: Cylindrospermopsin; GPx; GST; Lactuca sativa; Microcystin-LR; Minerals