title: Root-level exposure reveals multiple physiological toxicity of triazine xenobiotics in Arabidopsis thaliana.
abstract: Herbicides are pollutants of great concern due to environmental ubiquity resulting from extensive use in modern agriculture and persistence in soil and water. Studies at various spatial scales have also highlighted frequent occurrences of major herbicide breakdown products in the environment. Analysis of plant behavior toward such molecules and their metabolites under conditions of transient or persistent soil pollution is important for toxicity evaluation in the context of environmental risk assessment. In order to understand the mechanisms underlying the action of such environmental contaminants, the model plant Arabidopsis thaliana, which has been shown to be highly responsive to pesticides and other xenobiotics, was confronted with varying levels of the widely-used herbicide atrazine and of two of its metabolites, desethylatrazine and hydroxyatrazine, which are both frequently detected in water streams of agriculturally-intensive areas. After 24h of exposure to varying concentrations covering the range of triazine concentrations detected in the environment, root-level contaminations of atrazine, desethylatrazine and hydroxyatrazine were found to affect early growth and development in various dose-dependent and differential manners. Moreover, these differential effects of atrazine, desethylatrazine and hydroxyatrazine pointed to the involvement of distinct mechanisms directly affecting respiration and root development. The consequences of the identification of additional targets, in addition to the canonical photosystem II target, are discussed in relation with the ecotoxicological assessment of environmental xenobiotic contamination.
authors.affiliation: Université de Rennes 1, Centre National de la Recherche Scientifique, UMR CNRS 6553 ECOBIO, Campus de Beaulieu, bâtiment 14A, 263 avenue du Général Leclerc, F-35042 Rennes Cedex, France.
authors.forename: Diana
authors.initials: D
authors.lastname: Alberto
authors.affiliation: Université de Rennes 1, Centre National de la Recherche Scientifique, UMR CNRS 6553 ECOBIO, Campus de Beaulieu, bâtiment 14A, 263 avenue du Général Leclerc, F-35042 Rennes Cedex, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Couée
authors.affiliation: Université de Rennes 1, Centre National de la Recherche Scientifique, UMR CNRS 6553 ECOBIO, Campus de Beaulieu, bâtiment 14A, 263 avenue du Général Leclerc, F-35042 Rennes Cedex, France. Electronic address: cecile.sulmon-maisonneuve@univ-rennes1.fr.
authors.forename: Cécile
authors.initials: C
authors.lastname: Sulmon
authors.affiliation: Université de Rennes 1, Centre National de la Recherche Scientifique, UMR CNRS 6553 ECOBIO, Campus de Beaulieu, bâtiment 14A, 263 avenue du Général Leclerc, F-35042 Rennes Cedex, France.
authors.forename: Gwenola
authors.initials: G
authors.lastname: Gouesbet
mesh_terms: D000383:Agriculture; D017360:Arabidopsis / Q000187:drug effects* / Q000254:growth & development*; D001280:Atrazine / Q000633:toxicity; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism; D002734:Chlorophyll; D017753:Ecosystem; D004785:Environmental Pollutants / Q000633:toxicity; D006540:Herbicides / Q000737:chemistry / Q000633:toxicity; D008954:Models, Biological; D010788:Photosynthesis / Q000187:drug effects; D045332:Photosystem II Protein Complex / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D012639:Seeds / Q000254:growth & development; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D013312:Stress, Physiological / Q000187:drug effects*; D014227:Triazines / Q000633:toxicity*; D014876:Water Pollution; D015262:Xenobiotics / Q000633:toxicity*
chemical_list: D004785:Environmental Pollutants; D006540:Herbicides; D045332:Photosystem II Protein Complex; D012987:Soil; D012989:Soil Pollutants; D014227:Triazines; D015262:Xenobiotics; C405102:desethylatrazine; D002734:Chlorophyll; D002245:Carbon Dioxide; D001280:Atrazine
keywords: Atrazine/desethylatrazine/hydroxyatrazine; Chemical injury; Chemical priming; Herbicide pollution; Photosystem II; Xenobiotic stress