Evolutionary insights into the emergence of pyoverdine non-producing mutants in Pseudomonas

Abstract:

Pyoverdine (Pvd)-a diffusible iron-chelating agent produced by bacteria in the genus of Pseudomonas-has recently become a model system for studying sociomicrobiology. The sociobiology framework (specifically, cooperation and cheating) is used to explain the emergence of Pvd nonproducing mutants that are commonly found in natural environments. Pvd producing and nonproducing cells are considered cooperators and cheaters, respectively. Non-producers can receive the benefit of cooperation by taking up Pvd produced by other cells, but they do not pay the full cost of Pvd biosynthesis. Thus, nonproducing mutants are advantageous in direct competition with the producing cells. This review summarizes the multiple evolutionary pathways of Pvd nonproducing mutants, and further discusses the generality of the conclusion that Pvd production is a cooperative behaviour.