Bacterial c-di-GMP plays a key role in the evolution of host-association

Abstract

AbstractMost microbes evolve faster than their hosts and should therefore drive evolution of host-microbe interactions1–3. However, relatively little is known about the characteristics that define the adaptive path of microbes to host-association. In this study we have identified microbial traits that mediate adaptation to hosts by experimentally evolving the bacteriumPseudomonas luridawith the nematodeCaenorhabditis elegans. We repeatedly observed the evolution of beneficial host-specialist bacteria with improved persistence in the nematode, achieved by mutations that uniformly upregulate the universal second messenger c-di-GMP. We subsequently upregulated c-di-GMP in differentPseudomonasspecies, consistently causing increased host-association. Comparison of Pseudomonad genomes from various environments revealed that c-di-GMP underlies adaptation to a variety of hosts, from plants to humans, suggesting that it is fundamental for establishing host-association.