@article{mbs:/content/journal/micro/10.1099/mic.0.043125-0, author = "De Maeyer, K. and D'aes, J. and Hua, G. K. H. and Perneel, M. and Vanhaecke, L. and Noppe, H. and Höfte, M.", title = "N-Acylhomoserine lactone quorum-sensing signalling in antagonistic phenazine-producing Pseudomonas isolates from the red cocoyam rhizosphere", journal= "Microbiology", year = "2011", volume = "157", number = "2", pages = "459-472", doi = "https://doi.org/10.1099/mic.0.043125-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.043125-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "PCA, phenazine-1-carboxylate", keywords = "C8-HSL, N-octanoyl-dl-homoserine lactone", keywords = "3-oxo-C10-HSL, N-3-oxodecanoyl-l-homoserine lactone", keywords = "3-OH-C8-HSL, N-3-hydroxy-octanoyl-l-homoserine lactone", keywords = "QS, quorum sensing", keywords = "3-oxo-C12-HSL, N-3-oxododecanoyl-l-homoserine lactone", keywords = "acyl-HSL, N-acyl-l-homoserine lactone", keywords = "C4-HSL, N-butanoyl-l-homoserine lactone", keywords = "C6-HSL, N-hexanoyl-dl-homoserine lactone", keywords = "ESI+, positive electrospray ionization", keywords = "LC-MS/MS, liquid chromatography-multiple MS", keywords = "C12-HSL, N-dodecanoyl-dl-homoserine lactone", keywords = "PCN, phenazine-1-carboxamide", keywords = "3-OH-C12-HSL, N-3-hydroxy-dodecanoyl-homoserine lactone", keywords = "ACN, acetonitrile", keywords = "3-OH-C6-HSL, N-3-hydroxy-hexanoyl-l-homoserine lactone", keywords = "3-oxo-C8-HSL, N-3-oxooctanoyl-l-homoserine lactone", keywords = "3-oxo-C6-HSL, N-3-oxohexanoyl-dl-homoserine lactone", abstract = "Forty fluorescent Pseudomonas strains isolated from white and red cocoyam roots were tested for their ability to synthesize N-acyl-l-homoserine lactones (acyl-HSLs). Remarkably, only isolates from the red cocoyam rhizosphere that were antagonistic against the cocoyam root rot pathogen Pythium myriotylum and synthesized phenazine antibiotics produced acyl-HSLs. This supports the assumption that acyl-HSL production is related to the antagonistic activity of the strains. After detection, the signal molecules were identified through TLC-overlay and liquid chromatography-multiple MS (LC-MS/MS) analysis. In our representative strain, Pseudomonas CMR12a, production of the signal molecules could be assigned to two quorum-sensing (QS) systems. The first one is the QS system for phenazine production, PhzI/PhzR, which seemed to be well conserved, since it was genetically organized in the same way as in the well-described phenazine-producing Pseudomonas strains Pseudomonas fluorescens 2-79, Pseudomonas chlororaphis PCL1391 and Pseudomonas aureofaciens 30-84. The newly characterized genes cmrI and cmrR make up the second QS system of CMR12a, under the control of the uncommon N-3-hydroxy-dodecanoyl-homoserine lactone (3-OH-C12-HSL) and with low similarity to other Pseudomonas QS systems. No clear function could yet be assigned to the CmrI/CmrR system, although it contributes to the biocontrol capability of CMR12a. Both the PhzI/PhzR and CmrI/CmrR systems are controlled by the GacS/GacA two-component regulatory system.", }