Macaya-Sanz David, Witzell Johanna, Collada Carmen, Gil Luis, Martín Juan A
Departamento de Ecología y Genética Forestal, Instituto de Ciencias Forestales (ICIFOR-INIA), CSIC, Madrid, Spain.
Department of Forestry and Wood Technology, Linnaeus University, Växjö, Sweden.
Front Plant Sci. 2023 Feb 28;14:1125942. doi: 10.3389/fpls.2023.1125942. eCollection 2023.
The core microbiota of plants exerts key effects on plant performance and resilience to stress. The aim of this study was to identify the core endophytic mycobiome in stems and disentangle associations between its composition and the resistance to Dutch elm disease (DED). We also defined its spatial variation within the tree and among distant tree populations. Stem samples were taken i) from different heights of the crown of a 168-year-old elm tree, ii) from adult elm trees growing in a common garden and representing a gradient of resistance to DED, and iii) from trees growing in two distant natural populations, one of them with varying degrees of vitality. Endophyte composition was profiled by high throughput sequencing of the first internal transcribed spacer region (ITS1) of the ribosomal DNA. Three families of yeasts (Buckleyzymaceae, Trichomeriaceae and Bulleraceae) were associated to DED-resistant hosts. A small proportion (10%) of endophytic OTUs was almost ubiquitous throughout the crown while tree colonization by most fungal taxa followed stochastic patterns. A clear distinction in endophyte composition was found between geographical locations. By combining all surveys, we found evidence of a core mycobiome, pervasive within the tree and ubiquitous across locations, genotypes and health status.
植物的核心微生物群对植物性能和抗逆能力具有关键影响。本研究旨在鉴定茎中的核心内生真菌群落，并理清其组成与荷兰榆树病（DED）抗性之间的关联。我们还确定了其在树内以及不同树种群之间的空间变异。茎样本采集于：i）一棵168年树龄榆树树冠的不同高度；ii）生长在一个共同园地里、代表对DED抗性梯度的成年榆树；iii）生长在两个遥远自然种群中的树木，其中一个种群具有不同程度的活力。通过对核糖体DNA的第一个内部转录间隔区（ITS1）进行高通量测序来分析内生菌组成。酵母的三个科（巴克利酵母科、毛壳酵母科和布勒酵母科）与抗DED宿主相关。一小部分（10%）内生OTU在整个树冠中几乎普遍存在，而大多数真菌类群在树上的定殖遵循随机模式。在地理位置之间发现了内生菌组成的明显差异。通过综合所有调查，我们发现了一个核心真菌群落的证据，它在树内普遍存在，且在不同位置、基因型和健康状况下都存在。
