BACKGROUND Wheat residues are a crucial determinant of the epidemiology of Septoria tritici blotch, as they support the sexual reproduction of the causal agent Zymoseptoria tritici. We aimed to characterize the effect of infection with this fungal pathogen on the microbial communities present on wheat residues and to identify microorganisms interacting with it. We used metabarcoding to characterize the microbiome associated with wheat residues placed outdoors, with and without preliminary Z. tritici inoculation, comparing the first set of residues in contact with the soil and a second set without contact with the soil, on four sampling dates in two consecutive years. RESULTS The diversity of the tested conditions, leading to the establishment of different microbial communities according to the origins of the constitutive taxa (plant only, or plant and soil), highlighted the effect of Z. tritici on the wheat residue microbiome. Several microorganisms were affected by Z. tritici infection, even after the disappearance of the pathogen. Linear discriminant analyses and ecological network analyses were combined to describe the communities affected by the infection. The number of fungi and bacteria promoted or inhibited by inoculation with Z. tritici decreased over time and was smaller for residues in contact with the soil. The interactions between the pathogen and other microorganisms appeared to be mostly indirect, despite the strong position of the pathogen as a keystone taxon in networks. Direct interactions with other members of the communities mostly involved fungi, including other wheat pathogens. Our results provide essential information about the alterations to the microbial community in wheat residues induced by the mere presence of a fungal pathogen, and vice versa. Species already described as beneficial or biocontrol agents were found to be affected by pathogen inoculation. CONCLUSIONS The strategy developed here can be viewed as a proof-of-concept focusing on crop residues as a particularly rich ecological compartment, with a high diversity of fungal and bacterial taxa originating from both the plant and soil compartments, and for Z. tritici-wheat as a model pathosystem. By revealing putative antagonistic interactions, this study paves the way for improving the biological control of residue-borne diseases.

中文翻译：

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微生物群落网络的差异动力学有助于识别与残留病原体相互作用的微生物：以小麦中的小麦发酵斑孢菌为例。

背景技术小麦残留物是小麦壳针孢斑病流行病学的关键决定因素，因为它们支持致病因子小麦发酵壳孢菌的有性繁殖。我们的目的是表征这种真菌病原体感染对小麦残留物上存在的微生物群落的影响，并鉴定与其相互作用的微生物。我们使用元条形码来表征与放置在室外的小麦残留物相关的微生物组，无论是否预先接种小麦小麦，比较了与土壤接触的第一组残留物和不与土壤接触的第二组残留物，在两个样本的四个采样日期连续几年。结果测试条件的多样性导致根据组成类群的起源（仅植物，或植物和土壤）建立不同的微生物群落，突出了小麦小麦对小麦残留微生物组的影响。即使在病原体消失后，一些微生物仍受到小麦小麦感染的影响。线性判别分析和生态网络分析相结合来描述受感染影响的社区。通过接种小麦小麦促进或抑制的真菌和细菌的数量随着时间的推移而减少，并且对于与土壤接触的残留物来说更小。尽管病原体作为网络中的关键分类单元具有重要地位，但病原体与其他微生物之间的相互作用似乎大多是间接的。与群落其他成员的直接相互作用主要涉及真菌，包括其他小麦病原体。我们的结果提供了有关仅因真菌病原体的存在而引起的小麦残留物中微生物群落变化的重要信息，反之亦然。已被描述为有益或生物防治剂的物种被发现受到病原体接种的影响。结论 这里开发的策略可以被视为概念验证，重点关注作物残留物作为一个特别丰富的生态区室，具有源自植物和土壤区室的高度多样性的真菌和细菌类群，以及小麦小麦。小麦作为模型病理系统。通过揭示假定的拮抗相互作用，这项研究为改善残留传播疾病的生物控制铺平了道路。