title: Intraspecific variability of cadmium tolerance and accumulation, and cadmium-induced cell wall modifications in the metal hyperaccumulator Arabidopsis halleri.
abstract: Certain molecular mechanisms of Cd tolerance and accumulation have been identified in the model species Arabidopsis halleri, while intraspecific variability of these traits and the mechanisms of shoot detoxification were little addressed. The Cd tolerance and accumulation of metallicolous and non-metallicolous A. halleri populations from different genetic units were tested in controlled conditions. In addition, changes in shoot cell wall composition were investigated using Fourier transform infrared spectroscopy. Indeed, recent works on A. halleri suggest Cd sequestration both inside cells and in the cell wall/apoplast. All A. halleri populations tested were hypertolerant to Cd, and the metallicolous populations were on average the most tolerant. Accumulation was highly variable between and within populations, and populations that were non-accumulators of Cd were identified. The effect of Cd on the cell wall composition was quite similar in the sensitive species A. lyrata and in A. halleri individuals; the pectin/polysaccharide content of cell walls seems to increase after Cd treatment. Nevertheless, the changes induced by Cd were more pronounced in the less tolerant individuals, leading to a correlation between the level of tolerance and the extent of modifications. This work demonstrated that Cd tolerance and accumulation are highly variable traits in A. halleri, suggesting adaptation at the local scale and involvement of various molecular mechanisms. While in non-metallicolous populations drastic modifications of the cell wall occur due to higher Cd toxicity and/or Cd immobilization in this compartment, the increased tolerance of metallicolous populations probably involves other mechanisms such as vacuolar sequestration.
authors: Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors: Claire-Lise
authors: CL
authors: Meyer
authors: Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors: Michal
authors: M
authors: Juraniec
authors: Laboratoire de Chimie Analytique Bio Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM, UMR 5254), Université de Pau et des Pays de l'Adour, 64053 Pau cedex 9, France.
authors: Stéphanie
authors: S
authors: Huguet
authors: Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors: Elena
authors: E
authors: Chaves-Rodriguez
authors: Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors: Pietro
authors: P
authors: Salis
authors: Laboratoire de Chimie Analytique Bio Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux (IPREM, UMR 5254), Université de Pau et des Pays de l'Adour, 64053 Pau cedex 9, France.
authors: Marie-Pierre
authors: MP
authors: Isaure
authors: Laboratory for the Structure and Function of Biological Membranes, Center for Structural Biology and Bioinformatics, Université Libre de Bruxelles, 1050 Brussels, Belgium.
authors: Erik
authors: E
authors: Goormaghtigh
authors: Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050 Brussels, Belgium nverbru@ulb.ac.be.
authors: Nathalie
authors: N
authors: Verbruggen
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D018533:Biomass; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D002473:Cell Wall / Q000187:drug effects* / Q000378:metabolism; D014644:Genetic Variation; D006824:Hybridization, Genetic; D018527:Hydroponics; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D025341:Principal Component Analysis; D013045:Species Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D013312:Stress, Physiological
chemical_list: D002104:Cadmium
keywords: Accumulation; Arabidopsis halleri; FT-IR; cadmium; cell wall; tolerance.