title: Beneficial contribution of the arbuscular mycorrhizal fungus, Rhizophagus irregularis, in the protection of Medicago truncatula roots against benzo[a]pyrene toxicity.
abstract: Arbuscular mycorrhizal fungi are able to improve plant establishment in polluted soils but little is known about the genes involved in the plant protection against pollutant toxicity by mycorrhization, in particular in the presence of polycyclic aromatic hydrocarbons (PAH). The present work aims at studying in both symbiotic partners, Medicago truncatula and Rhizophagus irregularis: (i) expression of genes putatively involved in PAH tolerance (MtSOD, MtPOX, MtAPX, MtGST, MtTFIIS, and MtTdp1α), (ii) activities of antioxidant (SOD, POX) and detoxification (GST) enzymes, and (iii) H2O2and the heavy PAH, benzo[a]pyrene (B[a]P) accumulation. In the presence of B[a]P, whereas induction of the enzymatic activities was detected in R. irregularis and non-mycorrhizal roots as well as upregulation of the gene expressions in the non-mycorrhizal roots, downregulation of the gene expressions and decrease of enzyme activities were observed in mycorrhizal roots. Moreover, B[a]P increased H2O2production in non-mycorrhizal roots and in R. irregularis but not in mycorrhizal roots. In addition, a lower B[a]P bioaccumulation in mycorrhizal roots was measured in comparison with non-mycorrhizal roots. Being less affected by pollutant toxicity, mycorrhizal roots did not activate any defense mechanism either at the gene expression regulation level or at the enzymatic level.
authors.affiliation: Univ Littoral Côte d'Opale, EA 4492 - UCEIV - Unité de Chimie Environnementale et Interactions sur le Vivant, F-62228 Calais cedex, France., SFR Condorcet FR CNRS 3417, 50, rue Ferdinand Buisson, F-62228, Calais cedex, France.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Lenoir
authors.affiliation: Univ Littoral Côte d'Opale, EA 4492 - UCEIV - Unité de Chimie Environnementale et Interactions sur le Vivant, F-62228 Calais cedex, France., SFR Condorcet FR CNRS 3417, 50, rue Ferdinand Buisson, F-62228, Calais cedex, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Fontaine
authors.affiliation: Univ Littoral Côte d'Opale, EA 4492 - UCEIV - Unité de Chimie Environnementale et Interactions sur le Vivant, F-62228 Calais cedex, France., SFR Condorcet FR CNRS 3417, 50, rue Ferdinand Buisson, F-62228, Calais cedex, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Tisserant
authors.affiliation: Univ Littoral Côte d'Opale, EA 4492 - UCEIV - Unité de Chimie Environnementale et Interactions sur le Vivant, F-62228 Calais cedex, France., SFR Condorcet FR CNRS 3417, 50, rue Ferdinand Buisson, F-62228, Calais cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Laruelle
authors.affiliation: Univ Littoral Côte d'Opale, EA 4492 - UCEIV - Unité de Chimie Environnementale et Interactions sur le Vivant, F-62228 Calais cedex, France., SFR Condorcet FR CNRS 3417, 50, rue Ferdinand Buisson, F-62228, Calais cedex, France. lounes@univ-littoral.fr.
authors.forename: Anissa
authors.identifier: http://orcid.org/0000-0001-8478-0128
authors.initials: A
authors.lastname: Lounès-Hadj Sahraoui
mesh_terms: D001564:Benzo(a)pyrene / Q000633:toxicity*; D055137:Glomeromycota / Q000502:physiology; D046913:Medicago truncatula / Q000187:drug effects* / Q000382:microbiology; D038821:Mycorrhizae / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects* / Q000382:microbiology; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D001564:Benzo(a)pyrene
keywords: Arbuscular mycorrhizal fungi; Benzo[a]pyrene; Gene expression; Oxidative stress; Polycyclic aromatic hydrocarbons