Production of virulence factors and secondary metabolites is regulated in the phytopathogen Erwinia carotovora by quorum sensing involving N-acylated homoserine lactone (AHL) signaling molecules. Non-hydrolyzable AHL analogues were synthesized and screened in vivo. The biological activity of each compound was correlated with its ability to bind Erwinia AHL receptor proteins (LuxR homologues) in...

RpoS (sigma-S or sigma-38) controls a large array of genes that are expressed during stationary phase and under various stress conditions in Escherichia coli and other bacteria. We document here that plant pathogenic and epiphytic Erwinia species, such as E. amylovora; E. carotovora subsp. atroseptica, betavasculorum, and carotovora; E. chrysanthemi; E. herbicola; E. rhapontici; and E. stewarti...

In Erwinia carotovora subspecies, N-acyl homoserine lactone (AHL) controls the expression of various traits, including extracellular enzyme/protein production and pathogenicity. We report here that E. carotovora subspecies possess two classes of quorum-sensing signaling systems defined by the nature of the major AHL analog produced as well as structural and functional characteristics of AHL syn...

The out genes of the enterobacterial plant pathogen Erwinia chrysanthemi are responsible for the efficient extracellular secretion of multiple plant cell wall-degrading enzymes, including four isozymes of pectate lyase, exo-poly-alpha-D-galacturonosidase, pectin methylesterase, and cellulase. Out- mutants of Er. chrysanthemi are unable to export any of these proteins beyond the periplasm and ar...

The lysis of Erwinia carotovora by bacteriophage has been reported by Coons and Kotila (1925), but the morphological characteristics of the virus could not be studied at that time, prior to the methods of electron microscopy, and some of the important physiological characteristics have not been investigated. In undertaking to obtain further data on these aspects of the problem, we have obtained...

We used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen Erwinia carotovora subsp. carotovora. The results obtained with each method showed that E. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. A comparison of 23 partial mdh sequences revealed a...

The purified obelin was electrophoresed on 7 % polyacrylamide gels in Tris-glycine buffer, pH 8.3, containing 0.1 mM-EDTA. Gels stained with Coomassie Brilliant Blue showed a single band at the buffer front, which correlated in position with luminescent activity. This activity could be eluted from unstained gel slices by soaking them overnight in 0.1 mM-EDTA-lOmM-Hepes, pH 7.0, at 4°C. Obelin i...

1. The distribution of phosphatidylethanolamine, the major lipid of Erwinia carotovora, was investigated in intact bacteria, spheroplasts and outer- and inner-membrane preparations, with the amino-group reagent 2,4,6-trinitrobenzenesulphonic acid. Only 4% was found on the external surface of the outer membrane with 30% on the internal surface, whereas the inner membrane had 27 and 38% on its e...