The regulation of virulence in phytopathogenic Erwinia species: quorum sensing, antibiotics and ecological considerations

摘要: Erwinia carotovora is a Gram-negative bacterial phytopathogen that causes soft-rot disease and potato blackleg. The organism environmentally widespread exhibits an opportunistic plant pathogenesis. ability to secrete multiple cell wall-degrading enzymes key virulence trait exoenzyme production responsive environmental physiological cues. One important cue the population density of pathogen. Cell monitored via acylated homoserine lactone (acyl HSL) signalling molecule, which thought diffuse between cells in process now commonly known as 'quorum sensing'. This molecule also acts chemical communication signal controlling broad-spectrum β-lactam antibiotic (1-carbapen-2-em-3-carboxylic acid; carbapenem) synthesised concert with elaboration, possibly for niche defence. In control, quorum sensing at level transcriptional activation biosynthetic cluster. achieved dedicated LuxR-type protein, CarR bound molecule. molecular relay connecting acyl HSL induction not clear, despite identification multitude global regulatory genes, including those RsmA/rsmB system, impinging on enzyme synthesis. Quorum control mediated by HSLs bacteria responsible regulation diverse phenotypes. Although there still paucity meaningful information availability in-situ biological function, growing evidence such molecules play significant roles microbial ecology.