title: Involvement of N-acylhomoserine lactones throughout plant infection by Erwinia carotovora subsp. atroseptica (Pectobacterium atrosepticum).
abstract: Erwinia carotovora subsp. atroseptica is responsible for potato blackleg disease in the field and tuber soft rot during crop storage. The process leading to the disease occurs in two phases: a primary invasion step followed by a maceration step. Bacteria-to-bacteria communication is associated with a quorum-sensing (QS) process based on the production of N-acylhomoserine lactones (HSL). The role of HSL throughout plant infection was analyzed. To this purpose, HSL produced by a specific E. carotovora subsp. atroseptica wild-type strain, which was particularly virulent on potato, were identified. A derivative of this strain that expressed an HSL lactonase gene and produced low amounts of HSL was generated. The comparison of these strains allowed the evaluation of the role of HSL and QS in disease establishment and development. Bacterial growth and motility; activity of proteins secreted by type I, II, and III systems; and hypersensitive and maceration reactions were evaluated. Results indicated that HSL production and QS regulate only those traits involved in the second stage of the host plant infection (i.e., tissue maceration) and hypersensitive response in nonhost tobacco plants. Therefore, the use of QS quenching strategies for biological control in E. carotovora subsp. atroseptica cannot prevent initial infection and multiplication of this pathogen.
authors.affiliation: Laboratoire de Microbiologie du Froid--UPRES 2123, Université de Rouen, 55 rue Saint-Germain, 27000 Evreux, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Smadja
authors.forename: Xavier
authors.initials: X
authors.lastname: Latour
authors.forename: Denis
authors.initials: D
authors.lastname: Faure
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chevalier
authors.forename: Yves
authors.initials: Y
authors.lastname: Dessaux
authors.forename: Nicole
authors.initials: N
authors.lastname: Orange
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016973:Pectobacterium carotovorum / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D011198:Solanum tuberosum / Q000382:microbiology; D014026:Nicotiana / Q000382:microbiology; D014774:Virulence
chemical_list: C088386:homoserine lactone; D015107:4-Butyrolactone