Localized Recombination Drives Diversification of Killing Spectra for Phage Derived Syringacins

Abstract

AbstractTo better understand the potential for detrimental interactions between strains of the same bacterial species, we have surveyed bacteriocin killing activity across a diverse suite of strains of the phytopathogenPseudomonas syringae.Our data demonstrate that killing activity from phage derived bacteriocins ofP. syringae(R-type syringacins) is widespread. Despite a high overall diversity of bacteriocin activity, strains can broadly be classified into five main killing types and two main sensitivity types. Furthermore, we show that killing activity switches frequently between strains, and that switches correlate with localized recombination of two genes that together encode the proteins that specify bacteriocin targeting. Lastly, we demonstrate that phage derived bacteriocin killing activity can be swapped between strains simply through expression of these two genesin trans.Overall, our study characterizes extensive diversity of killing activity for phage derived bacteriocins ofP. syringaeacross strains and highlights the power of localized recombination to alter phenotypes that mediate strain interactions during evolution of natural populations and communities.