title: Phytotoxic effects of a natural bloom extract containing microcystins on Lycopersicon esculentum.
abstract: The cyanobacterial toxins microcystins (MC) are known to affect many processes in plants. Their presence in the water used for irrigation may have considerable impact on the survivorship, growth and development of plants. In this study, a crude extract of a toxic cyanobacterial bloom from "Lalla Takerkoust" reservoir (Morocco) was used to study the effects of extract containing MC on tomato plants (Lycopersicon esculentum). Five MC variants: MC-LR, MC-FR, MC-LY, MC-(H4)-YR and DMC-LR were identified by HPLC in the cyanobacterial extract. Exposure of the seeds to the crude extract (containing 22.24 μg MC mL(-1)) caused a reduction of germination up to 85%. Experiments showed that 30 days exposure of plant to the cyanobacterial extract containing MC caused inhibition of L. esculentum growth and productivity, as well as harmful effects on photosystem II activity, measured by Fv/Fm fluorescence. An accumulation of nutrients Na(+), K(+) and Ca(2+) was also registered. The activity of peroxidase and phenolic content indicated that the extract caused an oxidative stress. The tissue necrosis of leaves was also a consequence of MC exposure indicating a disorder in the exposed plant metabolism.
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakesh, Morocco.
authors.forename: Fatima
authors.initials: F
authors.lastname: El Khalloufi
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakesh, Morocco.
authors.forename: Issam
authors.initials: I
authors.lastname: El Ghazali
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakesh, Morocco.
authors.forename: Sana
authors.initials: S
authors.lastname: Saqrane
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakesh, Morocco.
authors.forename: Khalid
authors.initials: K
authors.lastname: Oufdou
authors.affiliation: Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal; CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal. Electronic address: vmvascon@fc.up.pt.
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
authors.affiliation: Laboratory of Biology and Biotechnology of Microorganisms, Environmental Microbiology and Toxicology Unit, Cadi Ayyad University, Faculty of Sciences Semlalia, P.O. Box 2390, Marrakesh, Morocco.
authors.forename: Brahim
authors.initials: B
authors.lastname: Oudra
mesh_terms: D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000254:growth & development; D018525:Germination / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000502:physiology; D008387:Marine Toxins; D052998:Microcystins / Q000633:toxicity*; D009018:Morocco; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects; D012639:Seeds / Q000187:drug effects / Q000502:physiology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D014874:Water Pollutants, Chemical; C084459:microcystin LY; D009195:Peroxidase; C057862:cyanoginosin LR