Evolutionary compromises in fungal fitness: hydrophobins can hinder the adverse dispersal of conidiospores and challenge their survival
Evolutionary compromises in fungal fitness: hydrophobins can hinder the adverse dispersal of conidiospores and challenge their survival
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DOI：
10.1038/s41396-020-0709-0
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发表时间：
2020-07-06
期刊：
影响因子：
11
通讯作者：
Druzhinina, Irina S.
中科院分区：
文献类型：
--
作者：
Cai, Feng;Gao, Renwei;Druzhinina, Irina S.
真菌进化生物学受到化石稀缺、生命周期不规律、不朽和频繁的无性繁殖的阻碍。简单而微小的真菌在底物内部发育，具有特殊的代谢和生态可塑性，这阻碍了物种的划分。然而，独特的真菌特征可以揭示塑造这些分类群环境适应能力的进化力量。高等丝状真菌通过气生孢子传播，产生两亲性和高度表面活性的蛋白质，称为疏水素(HFBs)，它覆盖孢子并调节环境相互作用。我们从木霉属(Hypocreales)中开发了两种真菌寄生和腐生真菌的HFB缺失突变体文库，并评估了真菌的发育、繁殖潜力和抗逆性。HFB4和HFB10与木霉适合度相关，因为它们可以影响孢子的传播过程，并控制其他适合度性状。矽肺分析表明，除HFB4外，所有病例均有净化选择。Harzianum，它是在很强的正选择压力下进化的。有趣的是，hfb4基因int的缺失。Harzianum显著增加了它与健康相关的特征。反之，hfb4inT的缺失。习惯于与相对较低的适合度相关的特征表型。Hfb4基因对适合度的净贡献被发现是个体特征之间进化权衡的结果。我们对HFB依赖的适应性特征的分析提供了密切相关真菌物种的选择压力和物种形成过程的进化快照。
Fungal evolutionary biology is impeded by the scarcity of fossils, irregular life cycles, immortality, and frequent asexual reproduction. Simple and diminutive bodies of fungi develop inside a substrate and have exceptional metabolic and ecological plasticity, which hinders species delimitation. However, the unique fungal traits can shed light on evolutionary forces that shape the environmental adaptations of these taxa. Higher filamentous fungi that disperse through aerial spores produce amphiphilic and highly surface-active proteins called hydrophobins (HFBs), which coat spores and mediate environmental interactions. We exploited a library of HFB-deficient mutants for two cryptic species of mycoparasitic and saprotrophic fungi from the genusTrichoderma(Hypocreales) and estimated fungal development, reproductive potential, and stress resistance. HFB4 and HFB10 were found to be relevant forTrichodermafitness because they could impact the spore-mediated dispersal processes and control other fitness traits. An analysis in silico revealed purifying selection for all cases except for HFB4 fromT. harzianum, which evolved under strong positive selection pressure. Interestingly, the deletion of thehfb4gene inT. harzianumconsiderably increased its fitness-related traits. Conversely, the deletion ofhfb4inT. guizhouenseled to the characteristic phenotypes associated with relatively low fitness. The net contribution of thehfb4gene to fitness was found to result from evolutionary tradeoffs between individual traits. Our analysis of HFB-dependent fitness traits has provided an evolutionary snapshot of the selective pressures and speciation process in closely related fungal species.