title: Stable isotope tracing: a powerful tool for selenium speciation and metabolic studies in non-hyperaccumulator plants (ryegrass Lolium perenne L.).
abstract: Selenium is both essential and toxic for mammals; the range between the two roles is narrow and not only dose-dependent but also related to the chemical species present in foodstuff. Unraveling the metabolism of Se in plants as a function of Se source may thus lead to ways to increase efficiency of fertilization procedures in selenium deficient regions. In this study, stable-isotope tracing was applied for the first time in plants to simultaneously monitor the bio-incorporation of two inorganic Se species commonly used as foodstuff enrichment sources. Occurrence and speciation of Se coming from different Se sources were investigated in root and leaf extracts of ryegrass (Lolium perenne L.), which had been co-exposed to two labeled Se species ((77)SeIV and (82)SeVI). Although the plant absorbed similar amounts of Se when supplied in the form of selenite or selenate, the results evidenced marked differences in speciation and tissues allocation. Selenite was converted into organic forms incorporated mostly into high molecular weight compounds with limited translocation to leaves, whereas selenate was highly mobile being little assimilated into organic forms. Double-spike isotopic tracer methodology makes it possible to compare the metabolism of two species-specific Se sources simultaneously in a single experiment and to analyze Se behavior in not-hyperaccumulator plants, the ICP-MS sensitivity being improved by the use of enriched isotopes.
authors.affiliation: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053, Pau Cedex 9, France.|Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298, Châtenay-Malabry Cedex, France.
authors.forename: Pamela
authors.initials: P
authors.lastname: Di Tullo
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR7619 METIS, 4 place Jussieu, 75005, Paris, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Versini
authors.affiliation: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053, Pau Cedex 9, France.
authors.forename: Maïté
authors.initials: M
authors.lastname: Bueno
authors.affiliation: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053, Pau Cedex 9, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Le Hécho
authors.affiliation: Andra, Research and Development Division, Parc de la Croix Blanche, 1-7 rue Jean Monnet, 92298, Châtenay-Malabry Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Thiry
authors.affiliation: UPMC Univ Paris 06, CNRS-iEES, Campus Inra-AgroParisTech, 78550, Thiverval-Grignon, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Biron
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR7619 METIS, 4 place Jussieu, 75005, Paris, France.
authors.forename: Maryse
authors.initials: M
authors.lastname: Castrec-Rouelle
authors.affiliation: Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour/CNRS, UMR 5254, IPREM, Hélioparc, 2 Avenue du Président Angot, 64053, Pau Cedex 9, France. florence.pannier@univ-pau.fr.
authors.forename: Florence
authors.initials: F
authors.lastname: Pannier
mesh_terms: D001692:Biological Transport; D007553:Isotope Labeling / Q000379:methods*; D007554:Isotopes / Q000032:analysis / Q000378:metabolism*; D008129:Lolium / Q000737:chemistry / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D012643:Selenium / Q000032:analysis / Q000378:metabolism*
chemical_list: D007554:Isotopes; D012643:Selenium
keywords: HPLC-ICP-MS; Metabolism; Plants; Selenium; Speciation; Stable isotope tracer