Associations of tree roots with diverse symbiotic mycorrhizal fungi have distinct effects on whole plant functioning. An untested explanation might be that such effect variability is associated with distinct impacts of different fungi on gene expression in local and distant plant organs. Using a large scale transcriptome sequencing approach, we compared the impact of three ectomycorrhizal (EMF) and one orchid mycorrhizal fungi (OMF) on gene regulation in colonized roots (local), non-colonized roots (short distance) and leaves (long distance) of the Quercus robur clone DF159 with reference to the recently published oak genome. Since different mycorrhizal fungi form symbiosis in a different time span and variable extents of apposition structure development, we sampled inoculated but non-mycorrhizal plants, for which however markedly symbiotic effects have been reported. Local root colonization by the fungi was assessed by fungal transcript analysis. The EMF induced marked and species specific effects on plant development in the analysed association stage, but the OMF did not. At local level, a common set of plant differentially expressed genes (DEG) was identified with similar patterns of responses to the three EMF, but not to the OMF. Most of these core DEG were down-regulated and correspond to already described but also new functions related to establishment of EMF symbiosis. Analysis of the fungal transcripts of two EMF in highly colonized roots also revealed onset of a symbiosis establishment. In contrast, in the OMF, the DEG were mainly related to plant defence. Already at short distances, high specificities in transcriptomic responses to the four fungi were detected, which were further enhanced at long distance in leaves, where almost no common DEG were found between the treatments. Notably, no correlation between phylogeny of the EMF and gene expression patterns was observed. Use of clonal oaks allowed us to identify a core transcriptional program in roots colonized by three different EMF, supporting the existence of a common EMF symbiotic pathway. Conversely, the specific responses in non-colonized organs were more closely related to the specific impacts of the different of EMF on plant performance.

中文翻译：

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橡木表现出对不同菌根真菌的共同的局部但特定的遥远基因调控反应。

树根与多种共生菌根真菌的关联对整个植物的功能具有明显的影响。未经检验的解释可能是这种效应的变异性与不同真菌对本地和远处植物器官基因表达的不同影响有关。使用大规模转录组测序方法，我们比较了三种外生菌根（EMF）和一种兰花菌根真菌（OMF）对定殖根（局部），非定殖根（短距离）和叶片（长距离）基因调控的影响栎（Quercus robur）克隆DF159的克隆，参考最近发表的橡树基因组。由于不同的菌根真菌会在不同的时间跨度和并置结构发展的不同程度形成共生关系，因此我们对接种的但非菌根的植物进行了采样，然而，据报道有明显的共生作用。通过真菌转录本分析评估真菌的局部根定植。在分析的关联阶段，EMF诱导了对植物发育的显着和物种特异性影响，但OMF没有。在地方一级，鉴定出一组通用的植物差异表达基因（DEG），它们对三种EMF的反应模式相似，但对OMF的反应却相似。这些核心DEG中的大多数已被下调，并与已经描述的相对应，但也与建立EMF共生有关的新功能。对高度定殖的根中两种EMF的真菌转录本的分析也揭示了共生建立的开始。相反，在OMF中，DEG主要与植物防御相关。已经很近了 检测到对四种真菌的转录组反应具有高特异性，在长距离叶片中进一步增强，在处理之间几乎没有发现常见的DEG。值得注意的是，未观察到EMF的系统发育与基因表达模式之间的相关性。克隆橡树的使用使我们能够鉴定出由三种不同的EMF所定植的根中的核心转录程序，从而支持了常见的EMF共生途径的存在。相反，非殖民化器官中的特定反应与不同EMF对植物性能的特定影响更紧密相关。在EMF的系统发育和基因表达模式之间没有相关性。克隆橡树的使用使我们能够鉴定出由三种不同的EMF所定植的根中的核心转录程序，从而支持了常见的EMF共生途径的存在。相反，非殖民化器官中的特定反应与不同EMF对植物性能的特定影响更紧密相关。在EMF的系统发育和基因表达模式之间没有相关性。克隆橡树的使用使我们能够鉴定出由三种不同的EMF所定植的根中的核心转录程序，从而支持了常见的EMF共生途径的存在。相反，非殖民化器官中的特定反应与不同EMF对植物性能的特定影响更紧密相关。