title: Nicotianamine over-accumulation confers resistance to nickel in Arabidopsis thaliana.
abstract: Nicotianamine is a methionine derivative involved in iron homeostasis, able to bind various other metals in vitro. To investigate its role in vivo, we expressed a nicotianamine synthase cDNA (TcNAS1) isolated from the polymetallic hyperaccumulator Thlaspi caerulescens in Arabidopsis thaliana. Transgenic plants expressing TcNAS1 over-accumulated NA, up to 100-fold more than wild type plants. Furthermore, increased NA levels in different transgenic lines were quantitatively correlated with increased nickel tolerance. The tolerance to nickel is expressed at the cellular level in protoplast experiments and is associated with an increased NA content. We have also shown that the most NA-over accumulating line showed a high tolerance to nickel and a significant Ni accumulation in the leaves when grown on nickel-contaminated soil. Our results highlight a new potential role for nicotianamine in heavy metal tolerance at the cellular but also at the whole plant level, easily transposable to a non-tolerant non-hyperaccumulator species. These results open new perspectives for the modulation of nicotianamine content in plants for phytoremediation.
authors.affiliation: UMR5004, Centre National de la Recherche Scientifique, Institut National pour la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie et Université Montpellier 2, cedex 5, F-34095, cc002 Montpellier, France.
authors.forename: Katia
authors.initials: K
authors.lastname: Pianelli
authors.forename: Stéphane
authors.initials: S
authors.lastname: Mari
authors.forename: Laurence
authors.initials: L
authors.lastname: Marquès
authors.forename: Michel
authors.initials: M
authors.lastname: Lebrun
authors.forename: Pierre
authors.initials: P
authors.lastname: Czernic
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001483:Base Sequence; D001673:Biodegradation, Environmental; D004274:DNA, Recombinant / Q000235:genetics; D004351:Drug Resistance; D017343:Genes, Plant; D009532:Nickel / Q000633:toxicity*; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity; D031227:Thlaspi / Q000201:enzymology / Q000235:genetics; D014170:Transformation, Genetic
chemical_list: D004274:DNA, Recombinant; D011994:Recombinant Proteins; D012989:Soil Pollutants; C082893:nicotianamine; D001383:Azetidinecarboxylic Acid; D009532:Nickel; D019883:Alkyl and Aryl Transferases; C118230:nicotianamine synthase