title: Removal of azinphos methyl by alfalfa plants (Medicago sativa L.) in a soil-free system.
abstract: The objective of this study was to investigate the removal of azinphos methyl assisted by alfalfa plants, with special emphasis on the effects of this compound on some plant's physiological parameters. Hydroponic cultures of alfalfa (Medicago sativa L., var Romagnola) were employed as a model system. These cultures were exposed to a nutrient medium containing 10 mg/l of azinphos methyl. A first-order kinetic approach was used to describe the removal of azinphos methyl from the solution. After 20 days of culture, the initial amount of azinphos methyl was reduced to non-detectable levels in the presence of plants. In the absence of plants, 20% of azinphos methyl remained in the solution after 30 days of treatment. The half-life of the pesticide was reduced from 10.8 to 3.4 days in the presence of plants. The growth index of alfalfa plants exposed to azinphos methyl was negatively affected. Chlorophyll contents were reduced after 24 h of treatment and thereafter the levels were comparable to that of control plants. The peroxidase activity of alfalfa roots was not affected by the presence of azinphos methyl. In conclusion, alfalfa plants were able to survive when exposed to an effective concentration of 10 mg/l of azinphos methyl in the root zone, with some alterations on their physiological parameters.
authors.affiliation: Cátedra de Microbiología Industrial y Biotecnología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 6th Floor, C1113AAD Buenos Aires, Argentina. flocco@ffyb.uba.ar
authors.forename: C G
authors.initials: CG
authors.lastname: Flocco
authors.forename: M P
authors.initials: MP
authors.lastname: Carranza
authors.forename: L G
authors.initials: LG
authors.lastname: Carvajal
authors.forename: R M
authors.initials: RM
authors.lastname: Loewy
authors.forename: A M
authors.initials: AM
authors.lastname: Pechén de D'Angelo
authors.forename: A M
authors.initials: AM
authors.lastname: Giulietti
mesh_terms: D001387:Azinphosmethyl / Q000737:chemistry / Q000493:pharmacokinetics* / Q000633:toxicity*; D002734:Chlorophyll / Q000378:metabolism; D006207:Half-Life; D018527:Hydroponics; D000455:Medicago sativa / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology
chemical_list: D002734:Chlorophyll; D001387:Azinphosmethyl