title: Phytotoxicity and genotoxicity assessment of imazethapyr herbicide using a battery of bioassays.
abstract: The imazethapyr herbicide (formulation Verosil(®)) was evaluated for phytotoxicity and genotoxicity using a battery of bioassays: (1) the growth inhibition of the green alga Pseudokirchneriella subcapitata, (2) the root growth and germination of the higher plant Lactuca sativa, (3) the genetic damage using the Salmonella/microsome test, and (4) the aneugenic and clastogenic effects on Allium cepa. The Verosil(®) formulation was highly toxic to the non-target green alga (median effective concentration (EC50) = 1.05 ± 0.05 mg active ingredient (a.i.) L(-1)), and concentrations above 10 mg a.i. L(-1) inhibited root elongation in lettuce: relative growth index (RGI) between 0.28 ± 0.01 and 0.66 ± 0.10. No genotoxic effect was observed in S almonella typhimurium at 100 mg a.i. L(-1), either with or without the microsomal fraction. However, significant differences in the frequency of chromosomal aberrations in anaphases and telophases (bridges, chromosome fragments, and vagrants) were observed in A. cepa at concentrations between 0.01 and 1 mg a.i. L(-1) with respect to the control. The frequencies of micronuclei showed significant differences with respect to the control at concentrations between 0.001 and 0.1 mg a.i. L(-1). A very high mitotic index (MI = 93.8 ± 5.8) was observed associated with a high number of cells in the prophase stage at 100 mg a.i. L(-1), indicating cytotoxicity. These results showed that imazethapyr is toxic to the non-target populations in both aquatic and terrestrial ecosystems. This herbicide might also exert clastogenic and aneugenic mitotic damage in higher plants. Therefore, the imazethapyr formulation may constitute an environmental risk to plants.
authors.affiliation: Cátedra de Salud Pública e Higiene Ambiental, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junin 956, 4° Piso, C1113AAC, Buenos Aires, Argentina. amagda65@yahoo.com.ar.
authors.forename: Anahí
authors.initials: A
authors.lastname: Magdaleno
authors.affiliation: Cátedra de Salud Pública e Higiene Ambiental, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junin 956, 4° Piso, C1113AAC, Buenos Aires, Argentina.
authors.forename: Marina
authors.initials: M
authors.lastname: Peralta Gavensky
authors.affiliation: Departamento de Química Biológica, IQUIBICEN UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Anabella V
authors.initials: AV
authors.lastname: Fassiano
authors.affiliation: Departamento de Química Biológica, IQUIBICEN UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Ríos de Molina
authors.affiliation: Instituto Nacional de Tecnología Industrial (INTI), San Martín, Buenos Aires, Argentina.
authors.forename: Marina
authors.initials: M
authors.lastname: Santos
authors.affiliation: Agrofina S.A., Vicente López, Buenos Aires, Argentina.
authors.forename: Hugo
authors.initials: H
authors.lastname: March
authors.affiliation: Cátedra de Salud Pública e Higiene Ambiental, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junin 956, 4° Piso, C1113AAC, Buenos Aires, Argentina.
authors.forename: Juan
authors.initials: J
authors.lastname: Moretton
authors.affiliation: Departamento de Química Biológica, IQUIBICEN UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.|Departamento de Biodiversidad y Biología Experimental, IBBEA UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Ángela B
authors.initials: ÁB
authors.lastname: Juárez
mesh_terms: D001681:Biological Assay; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development; D002869:Chromosome Aberrations; D004249:DNA Damage; D006540:Herbicides / Q000633:toxicity*; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D015162:Micronucleus Tests; D008938:Mitosis; D008940:Mitotic Index; D009153:Mutagens / Q000633:toxicity*; D009539:Nicotinic Acids / Q000633:toxicity*; D019697:Onions / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D006540:Herbicides; D009153:Mutagens; D009539:Nicotinic Acids; D014874:Water Pollutants, Chemical; C093630:imazethapyr
keywords: Allium cepa; Ames test; Genotoxicity; Imazethapyr; Lactuca sativa; Pseudokirchneriella subcapitata; Toxicity