Lead tolerance and accumulation in Hirschfeldia incana, a Mediterranean Brassicaceae from metalliferous mine spoils.

Florence Auguy (1) , Mouna Fahr (2, 3, 4) , Patricia Moulin (5) , Anaïs Brugel (6) , Laurent Laplaze (6, 7) , Mohamed El Mzibri (2, 3) , Abdelkarim Filali-Maltouf (3, 8) , Patrick Doumas (6, 2, 3, 9) , Abdelaziz Smouni (2, 4)

1 UMR DIADE - Diversité, adaptation, développement des plantes
2 CNESTN - Centre National de l'Energie, des Sciences et des Techniques Nucléaires
3 Laboratoire Mixte International
4 Laboratoire de Physiologie et Biotechnologie Végétale
5 IRD Hann Maristes - Institut de recherche pour le développement [Dakar, Sénégal]
6 UMR IPME - UMR - Interactions Plantes Microorganismes Environnement
7 LAPSE - LMI Adaptation des Plantes et microorganismes associés aux Stress Environnementaux [Dakar]
8 Laboratoire de Microbiologie et Biologie Moléculaire
9 BPMP - Biochimie et Physiologie Moléculaire des Plantes

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.

Mots clés: HYPERACCUMULATOR THLASPI-CAERULESCENS; HEAVY-METAL RESISTANCE; ARABIDOPSIS METALLOTHIONEINS; CONTAMINATED SOILS; P-1B-TYPE ATPASE; GENE-EXPRESSION; TRACE-ELEMENTS; PLANTS; CADMIUM; ZINC

Domaines: Sciences du Vivant [q-bio]

Florence Auguy, Mouna Fahr, Patricia Moulin, Anaïs Brugel, Laurent Laplaze, et al.. Lead tolerance and accumulation in Hirschfeldia incana, a Mediterranean Brassicaceae from metalliferous mine spoils.. PLoS ONE, 2013, 8 (5), pp.e61932. ⟨10.1371/journal.pone.0061932⟩. ⟨hal-00860145⟩