title: Induction of resistance in wheat against powdery mildew by bacterial cyclic lipopeptides.
abstract: In conventional agricultural practices, fungicides are extensively used to control the development of many fungal plant pathogens. However, the reduction of pesticide applications in the field, which is recommended by authorities and approved by public opinion, may lead to a re-emergence of diseases. Alternative strategies have therefore to be developed in order to control fungal infection; one of them is based on plants natural resistance reinforcement caused by elicitors. Our project aims at characterizing mycosubtilin, surfactin and fengycin, three bacterial cyclic non-ribosomal lipopeptides produced by the rhizobacterium Bacillus subtilis, for their ability to induce resistance in wheat against powdery mildew (Blumeria graminis f.sp. tritici). RT-qPCR approach was used to investigate effect of lipopeptides on expression pattern of defence-related genes, such as PR protein-encoding genes or genes involved in plant defence pathways (reactive oxygen species (ROS) metabolism, lipid peroxidation, phenylpropanoid and octadecanoid pathways) in response to fungus and revealed that expression of LOX and PR1 was strongly induced by surfactin at 24h and 18h after inoculation, respectively. Mycosubtilin seemed to be more efficace to induce expression of OXO and Ltp. Surfactin could also induce expression of chitinase encoding genes but neither surfactin nor mycosubtilin could induce the expression of GSTphi and PAL genes in response to the fungus.
authors.affiliation: Université du Littoral Côte d'Opale, Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), GIS PhyNoPi, B.P. 699, FR-62228, Calais cedex, France.
authors.forename: N G
authors.initials: NG
authors.lastname: Khong
authors.forename: B
authors.initials: B
authors.lastname: Randoux
authors.forename: Ch
authors.initials: Ch
authors.lastname: Tayeh
authors.forename: F
authors.initials: F
authors.lastname: Coutte
authors.forename: N
authors.initials: N
authors.lastname: Bourdon
authors.forename: B
authors.initials: B
authors.lastname: Tisserant
authors.forename: F
authors.initials: F
authors.lastname: Laruelle
authors.forename: Ph
authors.initials: P
authors.lastname: Jacques
authors.forename: Ph
authors.initials: P
authors.lastname: Reignault
mesh_terms: D001203:Ascomycota / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D055666:Lipopeptides / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014908:Triticum / Q000382:microbiology*
chemical_list: D055666:Lipopeptides