Functions and origin of plasmids in Erwinia species that are pathogenic to or epiphytically associated with pome fruit trees

Abstract

The genus Erwinia includes plant-associated pathogenic and non-pathogenic species. Among them, all species pathogenic to pome fruit trees (E. amylovora, E. pyrifoliae, E. piriflorinigrans, Erwinia sp. 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 and E. tasmaniensis or E. 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.

Sensibilidad de bacterias procedentes de pasifloras a antibióticos y productos cúpricos

“…y Pseudomonas sp. (Llop et al, 2012;Behlau et al, 2012). Otros casos de resistencia a productos como kasugamicina y validamicina Additional key words: Passiflora edulis Sims, antimicrobial, resistance.…”

Conventional and Real-Time PCRs for Detection of Erwinia piriflorinigrans Allow Its Distinction from the Fire Blight Pathogen, Erwinia amylovora

“…Plasmid extraction and restriction analysis confirmed that the plasmid had not integrated into the chromosome or undergone rearrangement under our experimental conditions, demonstrating its stability. Although most Erwinia species from pome fruits have plasmids of similar sizes in variable numbers of copies (27), specific E. piriflorinigrans sequences were selected for the new PCR protocols. The primers and probe designed did not amplify E. pyrifoliae or E. amylovora, or other closely related species that harbor similar-size plasmids, as templates.…”

Genomic variability of Pantoea ananatis in maize white spot lesions assessed by AFLP markers

“…According to Llop et al (2012), plasmids contain versatile bacterial genomes, and acquisition of extra-chromosome genetic elements is an important source of genetic diversification in phytopathogenic bacteria. Plasmids can be transferred between strains, species, and genera, and then passed down through the bacterial strain.…”