title: The impact of Ni on the physiology of a Mediterranean Ni-hyperaccumulating plant.
abstract: High nickel (Ni) levels exert toxic effects on plant growth and plant water content, thus affecting photosynthesis. In a pot experiment, we investigated the effect of the Ni concentration on the physiological characteristics of the Ni hyperaccumulator Alyssoides utriculata when grown on a vermiculite substrate in the presence of different external Ni concentrations (0-500 mg Ni L(-1)). The results showed that the Ni concentration was higher in leaves than in roots, as evidenced by a translocation factor = 3 and a bioconcentration factor = 10. At the highest concentration tested (500 mg Ni L(-1)), A. utriculata accumulated 1100 mg Ni per kilogram in its leaves, without an effects on its biomass. Plant water content increased significantly with Ni accumulation. Ni treatment did not, or only slightly, affected chlorophyll fluorescence parameters. The photosynthetic efficiency (FV/FM) of A. utriculata was stable between Ni treatments (always ≥ 0.8) and the photosynthetic performance of the plant under Ni stress remained high (performance index = 1.5). These findings support that A. utriculata has several mechanisms to avoid severe damage to its photosynthetic apparatus, confirming the tolerance of this species to Ni under hyperaccumulation.
authors.affiliation: DISTAV Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Laboratorio di Biologia Vegetale, Università degli Studi di Genova, Viale Benedetto XV, 5, I 16132, Genoa, Italy. enrica.roccotiello@unige.it.
authors.forename: Enrica
authors.initials: E
authors.lastname: Roccotiello
authors.affiliation: Centro de Ecologia, Evolução e Alterações Ambientais (cE3c) Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2 Piso 5, 1749-016, Lisbon, Portugal.
authors.forename: Helena Cristina
authors.initials: HC
authors.lastname: Serrano
authors.affiliation: DISTAV Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Laboratorio di Biologia Vegetale, Università degli Studi di Genova, Viale Benedetto XV, 5, I 16132, Genoa, Italy.
authors.forename: Mauro Giorgio
authors.initials: MG
authors.lastname: Mariotti
authors.affiliation: Centro de Ecologia, Evolução e Alterações Ambientais (cE3c) Faculdade de Ciências, Universidade de Lisboa, Campo Grande, C2 Piso 5, 1749-016, Lisbon, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Branquinho
mesh_terms: D018533:Biomass; D019607:Brassicaceae / Q000187:drug effects* / Q000378:metabolism; D009532:Nickel / Q000378:metabolism / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D009532:Nickel
keywords: Bioconcentration factor; Biomass; Brassicaceae; Hyperaccumulation; Metal; Photosynthesis