title: Changes in chlorophyll a fluorescence of glyphosate-tolerant soybean plants induced by glyphosate: in vivo analysis by laser-induced fluorescence spectroscopy.
abstract: A significant increase in the use of the herbicide glyphosate has generated many questions about its residual accumulation in the environment and possible damage to crops. In this study, changes in chlorophyll a (chl-a) fluorescence induced by glyphosate in three varieties of glyphosate-resistant soybean plants were determined with an in vivo analysis based on a portable laser-induced fluorescence system. Strong suppression of chl-a fluorescence was observed for all plants treated with the herbicide. Moreover, the ratio of the emission bands in the red and far-red regions (685 nm/735 nm) indicates that the application of glyphosate led to chlorophyll degradation. The results also indicated that the use of glyphosate, even at concentrations recommended by the manufacturer, suppressed chl-a fluorescence. In summary, this study shows that fluorescence spectroscopy can detect, in vivo, very early changes in the photosynthetic status of transgenic soybeans treated with this herbicide.
authors.affiliation: Grupo de Óptica Aplicada, Universidade Federal da Grande Dourados, Dourados, CP 364, Mato Grosso Do Sul CEP 79804-970, Brazil.
authors.forename: Joelson
authors.initials: J
authors.lastname: Fernandes
authors.forename: William Ferreira
authors.initials: WF
authors.lastname: Falco
authors.forename: Samuel Leite
authors.initials: SL
authors.lastname: Oliveira
authors.forename: Anderson Rodrigues Lima
authors.initials: AR
authors.lastname: Caires
mesh_terms: D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D004361:Drug Tolerance; D005504:Food Analysis / Q000379:methods*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006540:Herbicides / Q000494:pharmacology / Q000600:supply & distribution; D007834:Lasers; D013025:Glycine max / Q000187:drug effects* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods; D000097797:Glyphosate
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A; D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate