Fungi are very successful microorganisms capable of colonizing virtually any ecological niche where they must constantly cope with competitors including fungi, bacteria and nematodes. We have shown previously that the ascomycete Podopora anserina exhibits Hyphal Interference (HI), an antagonistic response triggered by direct contact of competing fungal hyphae. When challenged with Penicillium chrysogenum, P. anserina produces hydrogen peroxide at the confrontation and kills the hyphae of P. chrysogenum. Here, we report the characterization of the PDC2218 mutant affected in HI. When challenged with P. chrysogenum, the PDC2218 mutant produces a massive oxidative burst at the confrontation. However, this increased production of hydrogen peroxide is not correlated to increased cell death in P. chrysogenum. Hence, the oxidative burst and cell death in the challenger are uncoupled in PDC2218. The gene affected in PDC2218 is PaTim54, encoding the homologue of the budding yeast mitochondrial inner membrane import machinery component Tim54p. We show that PaTim54 is essential in P. anserina and that the phenotypes displayed by the PDC2218 mutant, renamed PaTim542218, are the consequence of a drastic reduction in the expression of PaTim54. Among these pleiotropic phenotypes, PDC2218-PaTim542218- displays increased lifespan, a phenotype in line with the observed mitochondrial defects in the mutant.

中文翻译：

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内膜PaTim54的线粒体转位酶参与了Podospora anserina的防御反应和长寿。

真菌是非常成功的微生物，几乎可以在任何生态环境中定殖，因此它们必须不断应对包括真菌，细菌和线虫在内的竞争者。以前我们已经表明，子囊夜蛾Podopora anserina表现出菌丝干扰（HI），这是由竞争性真菌菌丝的直接接触触发的一种拮抗作用。当受到产黄青霉菌攻击时，鹅膏假单胞菌在对峙时产生过氧化氢，并杀死产黄青霉菌丝的菌丝。在这里，我们报告在HI中受影响的PDC2218突变体的表征。当受到产黄青霉刺激时，PDC2218突变体在对抗中产生大量的氧化爆发。但是，这种增加的过氧化氢的产生与产黄青霉中细胞死亡的增加无关。因此，在PDC2218中，攻击者的氧化爆发和细胞死亡是不相关的。在PDC2218中受影响的基因是PaTim54，编码出芽的酵母线粒体内膜导入机制成分Tim54p的同源物。我们显示，PaTim54是必不可少的，在P. anserina中，并且由PDC2218突变体（重命名为PaTim542218）显示的表型是PaTim54表达大幅减少的结果。在这些多效性表型中，PDC2218-PaTim542218-显示寿命增加，该表型与突变体中观察到的线粒体缺陷相符。以及PDC2218突变体（重命名为PaTim542218）显示的表型是PaTim54表达急剧减少的结果。在这些多效性表型中，PDC2218-PaTim542218-显示寿命增加，该表型与突变体中观察到的线粒体缺陷相符。以及PDC2218突变体（重命名为PaTim542218）显示的表型是PaTim54表达急剧减少的结果。在这些多效性表型中，PDC2218-PaTim542218-显示寿命增加，该表型与突变体中观察到的线粒体缺陷相符。