title: Impact of phosphate on glyphosate uptake and toxicity in willow.
abstract: Phosphate (PO4(3-)) has been shown to increase glyphosate uptake by willow, a plant species known for its phytoremediation potential. However, it remains unclear if this stimulation of glyphosate uptake can result in an elevated glyphosate toxicity to plants (which could prevent the use of willows in glyphosate-remediation programs). Consequently, we studied the effects of PO4(3-) on glyphosate uptake and toxicity in a fast growing willow cultivar (Salix miyabeana SX64). Plants were grown in hydroponic solution with a combination of glyphosate (0, 0.001, 0.065 and 1 mg l(-1)) and PO4(3-) (0, 200 and 400 mg l(-1)). We demonstrated that PO4(3-) fertilization greatly increased glyphosate uptake by roots and its translocation to leaves, which resulted in increased shikimate concentration in leaves. In addition to its deleterious effects in photosynthesis, glyphosate induced oxidative stress through hydrogen peroxide accumulation. Although it has increased glyphosate accumulation, PO4(3-) fertilization attenuated the herbicide's deleterious effects by increasing the activity of antioxidant systems and alleviating glyphosate-induced oxidative stress. Our results indicate that in addition to the glyphosate uptake, PO4(3-) is involved in glyphosate toxicity in willow by preventing glyphosate induced oxidative stress.
authors.affiliation: Université du Québec à Montréal, Department of Biological Sciences, TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Succ. Centre-Ville, H3C 3P8 Montréal, Québec, Canada; Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Marcelo Pedrosa
authors.initials: MP
authors.lastname: Gomes
authors.affiliation: Université du Québec à Montréal, Department of Biological Sciences, TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Succ. Centre-Ville, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Sarah Gingras
authors.initials: SG
authors.lastname: Le Manac'h
authors.affiliation: Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Moingt
authors.affiliation: Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Elise
authors.initials: E
authors.lastname: Smedbol
authors.affiliation: Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Serge
authors.initials: S
authors.lastname: Paquet
authors.affiliation: Institut de Recherche en Biologie Végétale, Montreal Botanical Garden, 4101 Sherbrooke East, H1X 2B2, Montréal, Québec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Labrecque
authors.affiliation: Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Lucotte
authors.affiliation: Université du Québec à Montréal, Department of Biological Sciences, TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Succ. Centre-Ville, H3C 3P8 Montréal, Québec, Canada; Université du Québec à Montréal, Institut des Sciences de l'Environnement, Succ. Centre-Ville, C.P. 8888, H3C 3P8 Montréal, Québec, Canada. Electronic address: juneau.philippe@uqam.ca.
authors.forename: Philippe
authors.initials: P
authors.lastname: Juneau
mesh_terms: D005308:Fertilizers; D005998:Glycine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000633:toxicity; D006540:Herbicides / Q000493:pharmacokinetics / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010710:Phosphates / Q000494:pharmacology*; D010758:Phosphorus / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D032108:Salix / Q000187:drug effects* / Q000378:metabolism; D000097797:Glyphosate
chemical_list: D005308:Fertilizers; D005998:Glycine; D006540:Herbicides; D010710:Phosphates; D010758:Phosphorus; D017382:Reactive Oxygen Species; D000097797:Glyphosate
keywords: Antioxidant enzymes; Fertilization; Herbicide; Phosphorus; Photosynthesis