title: Are ineffective defence reactions potential target for induced resistance during the compatible wheat-powdery mildew interaction?
abstract: Powdery mildew caused by Blumeria graminis f.sp. tritici, an obligate aerial biotrophic fungus, would be one of the most damaging wheat (Triticum aestivum) diseases without the extensive use of conventional fungicides. In our study, the expression levels of some basal defence-related genes were investigated during a compatible interaction in order to evaluate wheat reactions to infection, along with the different stages of the infectious process in planta. As fungal conidia initiated their germination and developed appressorial germ tube (AGT), early defence reactions involved the expression of a lipoxygenase (LOX)- and an oxalate oxidase (OXO)-encoding genes, followed by activations of corresponding LOX (EC 1.13.11.12) and OXO (EC 1.2.3.4) activities, respectively. When penetration of AGT took place, up-regulation of chitinases (CHI) and PR1-encoding genes expression occurred along with an increase of CHI (EC 3.2.1.14) activity. Meanwhile, expression of a phenylalanine ammonia-lyase-encoding gene also took place. Up-regulation of a phospholipase C- and lipid transfer proteins-encoding genes expression occurred during the latest stages of infection. Neither the phi glutathione S-transferase (GST)-encoding gene expression nor the GST (EC 2.5.1.13) activity was modified upon wheat infection by powdery mildew. Whether these defence reactions during such a compatible interaction are markers of immunity or susceptibility, and whether they have the ability to contribute to protection upon modulation of their timing and their intensity by resistance inducers are discussed.
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France. Electronic address: christine.tayeh@anses.fr.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Tayeh
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Randoux
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France.
authors.forename: B
authors.initials: B
authors.lastname: Tisserant
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Khong
authors.affiliation: Université de Lille, Institut Régional de Recherche en Agroalimentaire et Biotechnologie Charles Viollette, Cité Scientifique, F-59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Ph
authors.initials: P
authors.lastname: Jacques
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV-EA4492), Univ. Lille-Nord de France, GIS PhyNoPi, B.P.699, F-62229 Calais Cedex, France. Electronic address: philippe.reignault@univ-littoral.fr.
authors.forename: Ph
authors.initials: P
authors.lastname: Reignault
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D015870:Gene Expression; D017343:Genes, Plant; D054884:Host-Pathogen Interactions; D014908:Triticum / Q000235:genetics / Q000382:microbiology*; D015854:Up-Regulation
keywords: Blumeria graminis f. sp. tritici; Compatible interaction; Defence reaction; Triticum aestivum; qRT-PCR