The plant pathogen Erwinia amylovora produces acyl-homoserine lactone signal molecules in vitro and in planta

Bacteriology Group, International Centre for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, 34012 Trieste, Italy.
FEMS Microbiology Letters (Impact Factor: 2.12). 01/2005; 241(2):179-83. DOI: 10.1016/j.femsle.2004.10.015
Source: PubMed


We report for the first time the production of acyl homoserine lactones (AHLs) by Erwina amylovora, an important quarantine bacterial pathogen that causes fire blight in plants. E. amylovora produces one N-acyl homoserine lactone [a N-(3-oxo-hexanoyl)-homoserine lactone or a N-(3-hydroxy-hexanoyl)-homoserine lactone] quorum sensing signal molecule both in vitro and in planta (pear plant). Given the involvement of AHLs in plant pathogenesis, we speculate that AHL-dependent quorum sensing could play an important role in the regulation of E. amylovora virulence.

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Available from: Claudio Aguilar, Jul 15, 2015
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    • "Therefore, we propose that a complete rhlR/rhlI pair was acquired horizontally with the deletion of rhlI after divergence of Escherichia, Salmonella, and close relatives, from Pantoea and Erwinia. ExpI and PhzI produce oxoC6 [23], [24], an AHL detected with high sensitivity by SdiA [9], which is consistent with ExpI and PhzI representing descendants of the ancient LuxI protein paired with SdiA. "
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    ABSTRACT: SdiA of E. coli and Salmonella is a LuxR homolog that detects N-acyl homoserine lactones (AHLs). Most LuxR homologs function together with a cognate AHL synthase (a LuxI homolog), but SdiA does not. Instead, SdiA detects AHLs produced by other bacterial species. In this report, we performed a phylogenetic analysis of SdiA. The results suggest that one branch of the Enterobacteriaceae obtained a rhlR/rhlI pair by horizontal transfer. The Erwinia and Pantoea branches still contain the complete pair where it is known as expR/expI and phzR/phzI, respectively. A deletion event removed the luxI homolog from the remainder of the group, leaving just the luxR homolog known as sdiA. Thus ExpR and PhzR are SdiA orthologs and ExpI and PhzI are descendants of the long lost cognate signal synthase of SdiA.
    Full-text · Article · Oct 2012 · PLoS ONE
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    • "), Erwinia amylovora lacks a corresponding signalgenerating enzyme. This contradicts previous reports for AHLsignaling in E. amylovora (Venturi et al. 2004; Molina et al. 2005). Nearby gene EAMY_1411 has low sequence identity (29%) with the AI-1 synthesis protein PhzI of Pseudomonas chlororaphis. "
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    ABSTRACT: Fire blight, caused by the enterobacterium Erwinia amylovora, is a devastating disease of rosaceous plants that has global economic importance for apple and pear production and trade. The complete genome of E. amylovora CFBP 1430 was sequenced, annotated, and compared with the genomes of other Erwinia spp. Several singleton and shared features of the E. amylovora CFBP 1430 genome were identified that offer a first view into evolutionary aspects within the genus Erwinia. Comparative genomics identified or clarified virulence and fitness determinants and secretion systems. Novel insights revealed in the genome of E. amylovora CFBP 1430 hold potential for exploitation to improve the design of more effective fire blight control strategies.
    Full-text · Article · Apr 2010 · Molecular Plant-Microbe Interactions
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    • "Numerous attempts have been made to demonstrate an AHL from the fire blight pathogen Erwinia amylovora. In two recent reports (Venturi et al., 2004; Molina et al., 2005), the existence of an Erwinia amylovora AHL has been claimed. As a consequence of several assays discussed here, these findings could not be confirmed. "
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    ABSTRACT: Autoinducers are important for cellular communication of bacteria. The luxS gene has a central role in the synthesis of autoinducer-2 (AI-2). The gene was identified in a shotgun library of Erwinia amylovora and primers designed for PCR amplification from bacterial DNA. Supernatants of several Erwinia amylovora strains were assayed for AI-2 activity with a Vibrio harveyi mutant and were positive. Many other plant-associated bacteria also showed AI-2 activity such as Erwinia pyrifoliae and Erwinia tasmaniensis. The luxS genes of several bacteria were cloned, sequenced, and complemented Escherichia coli strain DH5alpha and a Salmonella typhimurium mutant, both defective in luxS, for synthesis of AI-2. Assays to detect AI-2 activity in culture supernatants of several Pseudomonas syringae pathovars failed, which may indicate the absence of AI-2 or synthesis of another type. Several reporter strains did not detect synthesis of an acyl homoserine lactone (AHL, AI-1) by Erwinia amylovora, but confirmed AHL-synthesis for Erwinia carotovora ssp. atroseptica and Pantoea stewartii.
    Full-text · Article · Feb 2007 · FEMS Microbiology Letters
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