The cost of phage resistance in a plant pathogenic bacterium is context-dependent.
The cost of phage resistance in a plant pathogenic bacterium is context-dependent.
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DOI：
10.1111/evo.12652
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发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Koskella B
中科院分区：
文献类型：
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作者：
Meaden S;Paszkiewicz K;Koskella B
寄生虫是生命系统中普遍存在的特征，许多寄生虫严重降低了宿主的繁殖力或寿命。这种寄生在寄主种群上的选择应该强烈地有利于寄主抗性的进化，但寄主通常面临着在生殖适合性投资和对寄生虫防御投资之间的权衡。这种权衡的大小可能取决于背景，因此，在人工环境中可能不容易观察到在自然界中塑造进化的关键成本。我们开始评估一种植物病原菌在其自然植物寄主中与在营养丰富的人工介质中的抗噬菌体抗性的成本。我们证明，通过单一突变步骤进化出抗性的紫丁香假单胞菌突变株在番茄寄主上生长时，为这种抗性付出了巨大的成本，但在营养丰富的介质中没有实现任何可测量的生长速度成本。这项工作表明，对噬菌体的抗性可以显著改变植物寄主内的细菌生长，因此，自然界中噬菌体介导的选择可能是细菌致病性的重要组成部分。
Parasites are ubiquitous features of living systems and many parasites severely reduce the fecundity or longevity of their hosts. This parasite‐imposed selection on host populations should strongly favor the evolution of host resistance, but hosts typically face a trade‐off between investment in reproductive fitness and investment in defense against parasites. The magnitude of such a trade‐off is likely to be context‐dependent, and accordingly costs that are key in shaping evolution in nature may not be easily observable in an artificial environment. We set out to assess the costs of phage resistance for a plant pathogenic bacterium in its natural plant host versus in a nutrient‐rich, artificial medium. We demonstrate that mutants of Pseudomonas syringae that have evolved resistance via a single mutational step pay a substantial cost for this resistance when grown on their tomato plant hosts, but do not realize any measurable growth rate costs in nutrient‐rich media. This work demonstrates that resistance to phage can significantly alter bacterial growth within plant hosts, and therefore that phage‐mediated selection in nature is likely to be an important component of bacterial pathogenicity.