title: Lead tolerance and accumulation in Hirschfeldia incana, a Mediterranean Brassicaceae from metalliferous mine spoils.
abstract: Lead is a heavy metal of particular concern with respect to environmental quality and health. The lack of plant species that accumulate and tolerate Pb is a limiting factor to understand the molecular mechanisms involved in Pb tolerance. In this study we identified Hirschfeldia incana, a Brassicaceae collected from metalliferous mine spoils in Morocco, as a Pb accumulator plant. H. incana exhibited high Pb accumulation in mine soils and in hydroponic cultures. Major Pb accumulation occurred in the roots and a part of Pb translocated from the roots to the shoots, even to the siliques. These findings demonstrated that H. incana is a Pb accumulator species. The expression of several candidate genes after Pb-exposure was measured by quantitative PCR and two of them, HiHMA4 and HiMT2a, coding respectively for a P1B-type ATPase and a metallothionein, were particularly induced by Pb-exposure in both roots and leaves. The functional characterization of HiHMA4 and HiMT2a was achieved using Arabidopsis T-DNA insertional mutants. Pb content and primary root growth analysis confirmed the role of these two genes in Pb tolerance and accumulation. H. incana could be considered as a good experimental model to identify genes involved in lead tolerance and accumulation in plants.
authors.affiliation: Institut de Recherche pour le Développement, Unité Mixte de Recherche Diversité Adaptation et Développement des Plantes, Montpellier, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Auguy
authors.forename: Mouna
authors.initials: M
authors.lastname: Fahr
authors.forename: Patricia
authors.initials: P
authors.lastname: Moulin
authors.forename: Anaïs
authors.initials: A
authors.lastname: Brugel
authors.forename: Laurent
authors.initials: L
authors.lastname: Laplaze
authors.forename: Mohamed El
authors.initials: ME
authors.lastname: Mzibri
authors.forename: Abdelkarim
authors.initials: A
authors.lastname: Filali-Maltouf
authors.forename: Patrick
authors.initials: P
authors.lastname: Doumas
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Smouni
mesh_terms: D019607:Brassicaceae / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity; D007220:Industrial Waste; D007854:Lead / Q000378:metabolism* / Q000633:toxicity*; D008906:Mining; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D007220:Industrial Waste; D007854:Lead