title: Quorum-sensing regulation in rhizobia and its role in symbiotic interactions with legumes.
abstract: Legume-nodulating bacteria (rhizobia) usually produce N-acyl homoserine lactones, which regulate the induction of gene expression in a quorum-sensing (or population-density)-dependent manner. There is significant diversity in the types of quorum-sensing regulatory systems that are present in different rhizobia and no two independent isolates worked on in detail have the same complement of quorum-sensing genes. The genes regulated by quorum sensing appear to be rather diverse and many are associated with adaptive aspects of physiology that are probably important in the rhizosphere. It is evident that some aspects of rhizobial physiology related to the interaction between rhizobia and legumes are influenced by quorum sensing. However, it also appears that the legumes play an active role, both in terms of interfering with the rhizobial quorum-sensing systems and responding to the signalling molecules made by the bacteria. In this article, we review the diversity of quorum-sensing regulation in rhizobia and the potential role of legumes in influencing and responding to this signalling system.
authors.affiliation: John Innes Centre, Colney Lane, Norwich NR4 7UH, UK. allan.downie@bbsrc.ac.uk
authors.forename: Maria
authors.initials: M
authors.lastname: Sanchez-Contreras
authors.forename: Wolfgang D
authors.initials: WD
authors.lastname: Bauer
authors.forename: Mengsheng
authors.initials: M
authors.lastname: Gao
authors.forename: Jayne B
authors.initials: JB
authors.lastname: Robinson
authors.forename: J
authors.initials: J
authors.lastname: Allan Downie
mesh_terms: D007887:Fabaceae / Q000382:microbiology*; D006714:Homoserine / Q000502:physiology; D053038:Quorum Sensing / Q000235:genetics / Q000502:physiology*; D012231:Rhizobium / Q000235:genetics / Q000502:physiology*; D013559:Symbiosis / Q000235:genetics / Q000502:physiology
chemical_list: D006714:Homoserine