title: A comparative proteome analysis reveals flagellin, chemotaxis regulated proteins and amylovoran to be involved in virulence differences between Erwinia amylovora strains.
abstract: Erwinia amylovora is a Gram-negative bacterium that causes the destructive disease fire blight affecting most members of the Rosaceae family, of which apple and pear are economically the most important hosts. E. amylovora has been considered as a homogeneous species in whole, although significant differences in virulence patterns have been observed. However, the underlying causes of the differences in virulence remain to be discovered. In a first-time comparative proteomic approach using E. amylovora, 2D differential in-gel electrophoresis (DIGE) was used to identify proteins that could explain the gradual difference in virulence between four different strains. Two important proteins were identified, FliC and CheY, both involved in flagella structure, motility and chemotaxis, which were more abundant in the least virulent strain. In the highly virulent strains the protein GalF, involved in amylovoran production, was more abundant, which was consistent with the higher expression of the gene and the higher amylovoran content in this strain in vitro. Together, these results confirm the involvement of amylovoran in virulence, but also imply an indirect role of flagellin in virulence as elicitor of plant defence.
  
  
  CONCLUSIONS
  This research provides new insights into our current understanding of the virulence of Erwinia amylovora. This plant-pathogen is considered a homogeneous species although different strains show differences in virulence. Despite the efforts made on the genomic level which resulted in the discovery of virulence factors, the reason for the different virulence patterns between strains has not yet been identified. In our lab we used a comparative proteomic approach, which has never been published before, to identify proteins involved in these differences between strains and hereby possibly involved in virulence. Our results provide interesting insights in virulence and present us with the opportunity to glance into the proteome of E. amylovora.
authors: Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors: M
authors: M
authors: Holtappels
authors: Zoology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium.
authors: K
authors: K
authors: Vrancken
authors: Pomology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium.
authors: H
authors: H
authors: Schoofs
authors: Pomology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium.
authors: T
authors: T
authors: Deckers
authors: Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors: T
authors: T
authors: Remans
authors: Biomedical Research Institute, Hasselt University and Transnational University Limburg, School of Life Sciences, Hasselt, Belgium.
authors: J P
authors: JP
authors: Noben
authors: Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium. Electronic address: roland.valcke@uhasselt.be.
authors: R
authors: R
authors: Valcke
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002633:Chemotaxis; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D044084:Erwinia amylovora / Q000166:cytology* / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism; D005408:Flagellin / Q000378:metabolism*; D020869:Gene Expression Profiling; D005798:Genes, Bacterial; D018515:Plant Leaves / Q000382:microbiology; D018520:Plant Shoots / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D020543:Proteome; D031989:Pyrus / Q000382:microbiology; D013045:Species Specificity; D053719:Tandem Mass Spectrometry; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D020543:Proteome; D037521:Virulence Factors; C100769:amylovoran; D005408:Flagellin
keywords: 2D electrophoresis; Amylovoran; DIGE; Erwinia amylovora; Flagellin