title: Influence of Se concentrations and species in hydroponic cultures on Se uptake, translocation and assimilation in non-accumulator ryegrass.
abstract: The success of biofortification and phytoremediation practices, addressing Se deficiency and Se pollution issues, hinges crucially on the fate of selenium in the plant media in response to uptake, translocation and assimilation processes. We investigate the fate of selenium in root and shoot compartments after 3 and 6 weeks of experiment using a total of 128 plants grown in hydroponic solution supplied with 0.2, 2, 5, 20 and 100 mg L-1of selenium in the form of selenite, selenate and a mixture of both species. Selenate-treated plants exhibited higher root-to-shoot Se translocation and total Se uptake than selenite-treated plants. Plants took advantage of the selenate mobility and presumably of the storage capacity of leaf vacuoles to circumvent selenium toxicity within the plant. Surprisingly, 28% of selenate was found in shoots of selenite-treated plants, questioning the ability of plants to oxidize selenite into selenate. Selenomethionine and methylated organo-selenium amounted to 30% and 8% respectively in shoots and 35% and 9% in roots of the identified Se, suggesting that selenium metabolization occurred concomitantly in root and shoot plant compartments and demonstrating that non-accumulator plants can synthesize notable quantities of precursor compound for volatilization. The present study demonstrated that non-accumulator plants can develop the same strategies as hyper-accumulator plants to limit selenium toxicity. When both selenate and selenite were supplied together, plants used selenate in a storage pathway and selenite in an assimilation pathway. Plants might thereby benefit from mixed supplies of selenite and selenate by saving enzymes and energy required for selenate reduction.
authors: CIRAD, UPR Recyclage et risque, Station de la Bretagne, 40 Chemin de Grand Canal, CS 12014, 97743 Saint-Denis Cedex 9, La Réunion, France. Electronic address: antoine.versini@cirad.fr.
authors: Antoine
authors: A
authors: Versini
authors: 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; French Agency for Radioactive Waste Management (Andra), Research and Development Division, Parc de la Croix Blanche, 1-7 Rue Jean Monnet, 92298 Châtenay-Malabry, France.
authors: Pamela
authors: P
authors: Di Tullo
authors: Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR7619 METIS, 4 Place Jussieu, 75005 Paris, France.
authors: Emmanuel
authors: E
authors: Aubry
authors: 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: Maïté
authors: M
authors: Bueno
authors: French Agency for Radioactive Waste Management (Andra), Research and Development Division, Parc de la Croix Blanche, 1-7 Rue Jean Monnet, 92298 Châtenay-Malabry, France.
authors: Yves
authors: Y
authors: Thiry
authors: 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: Florence
authors: F
authors: Pannier
authors: Sorbonne Universités, UPMC Univ Paris 06, CNRS, EPHE, UMR7619 METIS, 4 Place Jussieu, 75005 Paris, France.
authors: Maryse
authors: M
authors: Castrec-Rouelle
mesh_terms: D001692:Biological Transport; D018527:Hydroponics / Q000379:methods*; D008129:Lolium / Q000187:drug effects* / Q000378:metabolism*; D064586:Selenic Acid / Q000493:pharmacokinetics; D020887:Selenious Acid / Q000493:pharmacokinetics; D012643:Selenium / Q000378:metabolism / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D020887:Selenious Acid; D012643:Selenium; D064586:Selenic Acid