假单胞菌铁载体不产生突变体形成的进化机理

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

摘要:

假单胞菌铁载体（Pvd）的产生是社会微生物学研究的一个重要模式系统：产生菌是合作者，而不产生菌是欺诈者。欺诈者可以不用付出Pvd合成的能量代价，而利用其他细菌产生的Pvd来获取生长所需的铁离子，因而处于竞争优势地位。合作与欺诈成为了当前解释自然界广泛存在的Pvd不产生菌进化形成的主要原理。本文将阐述荧光假单胞菌Pvd不产生菌形成的多条进化途径，并在此基础上剖析合作与欺诈原理的普遍适用性问题。

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.