title: N-hexanoyl-L-homoserine lactone, a mediator of bacterial quorum-sensing regulation, exhibits plant-dependent stability and may be inactivated by germinating Lotus corniculatus seedlings.
abstract: The half-life of N-hexanoyl-l-homoserine lactone (C6-HSL) was determined under various pH and temperature conditions, and in several plant environments. C6-HSL was sensitive to alkaline pH, a process that was also temperature-dependent. In addition, C6-HSL disappeared from plant environments, i.e. axenic monocot and dicot plants cultivated under gnotobiotic, hydroponic conditions, albeit with variable kinetics. The disappearance was rapid at the root system of legume plants such as clover or Lotus, and slow or non-existent at the root system of monocots such as wheat or corn. These variable kinetics were not dependent upon pH changes that may have affected the growth media of the plants. Furthermore, C6-HSL did not accumulate in the plant, and the plant did not produce inhibitors of the C6-HSL signal. HPLC analyses revealed that C6-HSL disappeared from the media, and hence, Lotus exhibited a natural C6-HSL inactivating ability. This ability was not specific for C6-HSL and allowed the degradation of other N-acyl-homoserine lactones such as 3-oxo-C6-HSL, 3-oxo-octanoyl-HSL and 3-oxo-decanoyl-HSL. Preliminary investigation revealed that the inactivating ability is temperature-dependant and possibly of enzymatic origin.
authors.affiliation: Institut des Sciences du Végétal, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX, France.
authors.forename: Laurie
authors.initials: L
authors.lastname: Delalande
authors.forename: Denis
authors.initials: D
authors.lastname: Faure
authors.forename: Aurélie
authors.initials: A
authors.lastname: Raffoux
authors.forename: Stéphane
authors.initials: S
authors.lastname: Uroz
authors.forename: Cathy
authors.initials: C
authors.lastname: D'Angelo-Picard
authors.forename: Miena
authors.initials: M
authors.lastname: Elasri
authors.forename: Aurélien
authors.initials: A
authors.lastname: Carlier
authors.forename: Romain
authors.initials: R
authors.lastname: Berruyer
authors.forename: Annik
authors.initials: A
authors.lastname: Petit
authors.forename: Paul
authors.initials: P
authors.lastname: Williams
authors.forename: Yves
authors.initials: Y
authors.lastname: Dessaux
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002861:Chromobacterium / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D000070116:Lotus / Q000378:metabolism* / Q000382:microbiology; D012231:Rhizobium / Q000502:physiology; D036226:Seedlings / Q000378:metabolism* / Q000382:microbiology; D013696:Temperature
chemical_list: C104908:N-hexanoyl-L-homoserine lactone; D015107:4-Butyrolactone