BACKGROUND Verticillium wilt of olive (VWO) is caused by the soilborne fungal pathogen Verticillium dahliae. One of the best VWO management measures is the use of tolerant/resistant olive cultivars. Knowledge on the olive-associated microbiome and its potential relationship with tolerance to biotic constraints is almost null. The aims of this work are (1) to describe the structure, functionality, and co-occurrence interactions of the belowground (root endosphere and rhizosphere) microbial communities of two olive cultivars qualified as tolerant (Frantoio) and susceptible (Picual) to VWO, and (2) to assess whether these communities contribute to their differential disease susceptibility level. RESULTS Minor differences in alpha and beta diversities of root-associated microbiota were detected between olive cultivars regardless of whether they were inoculated or not with the defoliating pathotype of V. dahliae. Nevertheless, significant differences were found in taxonomic composition of non-inoculated plants' communities, "Frantoio" showing a higher abundance of beneficial genera in contrast to "Picual" that exhibited major abundance of potential deleterious genera. Upon inoculation with V. dahliae, significant changes at taxonomic level were found mostly in Picual plants. Relevant topological alterations were observed in microbial communities' co-occurrence interactions after inoculation, both at structural and functional level, and in the positive/negative edges ratio. In the root endosphere, Frantoio communities switched to highly connected and low modularized networks, while Picual communities showed a sharply different behavior. In the rhizosphere, V. dahliae only irrupted in the microbial networks of Picual plants. CONCLUSIONS The belowground microbial communities of the two olive cultivars are very similar and pathogen introduction did not provoke significant alterations in their structure and functionality. However, notable differences were found in their networks in response to the inoculation. This phenomenon was more evident in the root endosphere communities. Thus, a correlation between modifications in the microbial networks of this microhabitat and susceptibility/tolerance to a soilborne pathogen was found. Moreover, V. dahliae irruption in the Picual microbial networks suggests a stronger impact on the belowground microbial communities of this cultivar upon inoculation. Our results suggest that changes in the co-occurrence interactions may explain, at least partially, the differential VWO susceptibility of the tested olive cultivars. Video abstract.

中文翻译：

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地下微生物网络的连接对橄榄黄萎病的耐受程度有所不同。

背景技术橄榄黄萎病（VWO）是由土壤传播的真菌病原体大黄萎病引起的。VWO最好的管理措施之一是使用耐性/抗性的橄榄品种。与橄榄相关的微生物组及其与生物限制的耐受性之间的潜在关系的知识几乎为零。这项工作的目的是（1）描述两个合格（Voto耐受）（Frantoio）和（对（Picual））易受污染的橄榄品种的地下（根内球根和根际）微生物群落的结构，功能和共现相互作用， （2）评估这些社区是否有助于其差异性疾病易感性水平。结果在橄榄品种之间检测到根相关微生物群的α和β多样性存在微小差异，无论是否已接种大麦弧菌的脱叶型。然而，未接种植物群落的分类学组成存在显着差异，“ Frantoio”显示出有利的属丰富度，而“ Picual”则显示出潜在有害类属的丰富度。接种大丽弧菌后，主要在Picual植物中发现了分类学水平的重大变化。接种后微生物群落的共现相互作用在结构和功能水平以及正负边缘比率上均观察到相关的拓扑变化。在根内球 Frantoio社区切换到高度连接和低模块化的网络，而Picual社区表现出截然不同的行为。在根际中，大麦弧菌仅在Picual植物的微生物网络中爆发。结论这两个橄榄品种的地下微生物群落非常相似，病原体的引入并未引起其结构和功能的重大改变。然而，在接种方面它们的网络中发现了显着差异。这种现象在根内球根群落中更为明显。因此，发现了该微生物栖息地的微生物网络的修饰与对土壤传播的病原体的敏感性/耐受性之间的相关性。此外，V 在Picual微生物网络中，大丽花的喷发表明接种后对该品种地下微生物群落的影响更大。我们的结果表明，共现相互作用的变化至少可以部分解释被测橄榄品种的VWO敏感性。录像摘要。