N-Acyl Homoserine Lactones in Diverse Pectobacterium and Dickeya Plant Pathogens: Diversity, Abundance, and Involvement in Virulence

Alexandre Crepin (1, 2) , Amelie Beury-Cirou (1, 2) , Corinne Barbey (1) , Christine Farmer (1) , Valerie Hélias (3, 4) , Jean-Francois Burini (1) , Denis Faure (5) , Xavier Latour (1)

1 LMSM - Laboratoire de Microbiologie Signaux et Microenvironnement
2 Stn Rech & Creat Varietale
3 IGEPP - Institut de Génétique, Environnement et Protection des Plantes
4 FN3PT - Fédération Nationale des Producteurs de Plants de Pomme de Terre
5 ISV - Institut des sciences du végétal

Soft-rot bacteria Pectobacterium and Dickeya use N-acyl homoserine lactones (NAHSLs) as diffusible signals for coordinating quorum sensing communication. The production of NAHSLs was investigated in a set of reference strains and recently-collected isolates, which belong to six species and share the ability to infect the potato host plant. All the pathogens produced different NAHSLs, among which the 3-oxo-hexanoyl- and the 3-oxo-octanoyl-L-homoserine lactones represent at least 90% of total produced NAHSL-amounts. The level of NAHSLs varied from 0.6 to 2 pg/cfu. The involvement of NAHSLs in tuber maceration was investigated by electroporating a quorum quenching vector in each of the bacterial pathogen strains. All the NAHSL-lactonase expressing strains produced a lower amount of NAHSLs as compared to those harboring the empty vector. Moreover, all except Dickeya dadantii 3937 induced a lower level of symptoms in potato tuber assay. Noticeably, aggressiveness appeared to be independent of both nature and amount of produced signals. This work highlights that quorum sensing similarly contributed to virulence in most of the tested Pectobacterium and Dickeya, even the strains had been isolated recently or during the past decades. Thus, these key regulatory-molecules appear as credible targets for developing anti-virulence strategies against these plant pathogens.

Mots clés: BACTERIA; SP-NOV.; DADANTII 3937; EXTRACELLULAR PROTEINS; AGROBACTERIUM-TUMEFACIENS; ACYLHOMOSERINE LACTONES; RHODOCOCCUS-ERYTHROPOLIS; soft-rot bacteria; Solanum tuberosum L.; N-acyl homoserine lactones; quorum sensing; AttM lactonase; quorum quenching; QUORUM-SENSING SIGNAL; III SECRETION SYSTEM; ERWINIA-CHRYSANTHEMI

Domaines: Sciences du Vivant [q-bio]

Alexandre Crepin, Amelie Beury-Cirou, Corinne Barbey, Christine Farmer, Valerie Hélias, et al.. N-Acyl Homoserine Lactones in Diverse Pectobacterium and Dickeya Plant Pathogens: Diversity, Abundance, and Involvement in Virulence. Sensors, 2012, 12 (3), pp.3484 - 3497. ⟨10.3390/s120303484⟩. ⟨hal-01208667⟩