title: Functions and origin of plasmids inErwiniaspecies that are pathogenic to or epiphytically associated with pome fruit trees.
abstract: The genusErwiniaincludes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees (E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwiniasp. from Japan) cause similar symptoms, but differ in their degrees of aggressiveness, i.e. in symptoms, host range or both. The presence of plasmids of similar size, in the range of 30 kb, is a common characteristic that they possess. Besides, they share some genetic content with high homology in several genes associated with exopolysaccharide production and hence, with virulence, as well as in some other genes. Knowledge of the content of these plasmids and comparative genetic analyses may provide interesting new clues to understanding the origin and evolution of these pathogens and the level of symptoms they produce. Furthermore, genetic similarities observed among some of the plasmids (and genomes) from the above indicated pathogenic species andE. tasmaniensisorE. billingiae, which are epiphytic on the same hosts, may reveal associations that could expose the mechanisms of origin of pathogens. A summary of the current information on their plasmids and the relationships among them is presented here.
authors.affiliation: Instituto Valenciano de Investigaciones Agrarias (IVIA), Ctra. Moncada-Náquera Km 4.5, 46113 Moncada, Valencia Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Llop
authors.affiliation: Instituto Valenciano de Investigaciones Agrarias (IVIA), Ctra. Moncada-Náquera Km 4.5, 46113 Moncada, Valencia Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Barbé
authors.affiliation: Instituto Valenciano de Investigaciones Agrarias (IVIA), Ctra. Moncada-Náquera Km 4.5, 46113 Moncada, Valencia Spain.
authors.forename: María M
authors.initials: MM
authors.lastname: López
keywords: Evolution; Functions; Genetic relatedness; Origin; Plasmids