Data from: Systemic enrichment of antifungal traits in the rhizosphere microbiome after pathogen attack

1. Plant-associated microbial communities are crucial for plant growth and play an important role in disease suppression. Community composition and function change upon pathogen attack, yet to date we do not know if these changes are a side effect of the infection or actively driven by the plant. 2. Here we used a split-root approach to test whether barley plants recruit bacteria carrying antifungal traits upon infestation with Fusarium graminearum. Split-root systems allow disentangling local infection effects, such as root damage, from systemic, plant-driven effects on microbiome functionality. We assessed the recruitment of fluorescent pseudomonads, a taxon correlated with disease suppression, and of two well-described antifungal genes (phlD coding for 2,4-DAPG and hcnAB coding for HCN). 3. We show an enrichment of fluorescent pseudomonads, phlD and hcnAB upon pathogen infection. This effect was only measurable in the uninfected root compartment. We link these effects to an increased chemotaxis of pseudomonads towards exudates of infected plants. 4. Synthesis. We conclude that barley plants selectively recruited bacteria carrying antifungal traits upon pathogen attack and that the pathogen application locally interfered with this process. By disentangling these two effects we set the base for enhancing strategies unravelling how pathogens and plant hosts jointly shape microbiome functionality.

1. 植物相关微生物群落（plant-associated microbial communities）对植物生长至关重要，同时在病害抑制过程中发挥关键作用。当宿主植物受到病原菌（pathogen）侵染时，群落的组成与功能均会发生改变，但截至目前，学界仍未明确这些改变究竟是病原菌侵染带来的附带效应，还是由植物主动介导的调控结果。
2. 本研究采用分根法（split-root approach），探究大麦在受禾谷镰孢菌（Fusarium graminearum）侵染时，是否会主动招募携带抗真菌性状的细菌。分根系统（split-root system）可将局部侵染引发的直接效应（如根系损伤）与宿主植物介导的、对微生物群落功能的系统性调控效应区分开来。我们针对两类目标进行了评估：一是荧光假单胞菌（fluorescent pseudomonads，一类与病害抑制相关的分类单元（taxon））的招募情况；二是两个已被充分解析的抗真菌基因——编码2,4-二乙酰基间苯三酚（2,4-DAPG）的phlD，以及编码氰化氢（HCN）的hcnAB。
3. 研究结果表明，病原菌侵染后，荧光假单胞菌、phlD与hcnAB的丰度均显著升高，且该效应仅在未受侵染的根系分区中可被检测到。我们进一步将上述效应与假单胞菌对侵染植物根系分泌物的趋化性增强建立了关联。
4. 综合分析。本研究证实，大麦在遭受病原菌侵染时，会选择性招募携带抗真菌性状的细菌，而病原菌的局部侵染会对这一选择性招募过程产生干扰。通过区分上述两类效应，本研究为解析病原菌与宿主植物如何共同塑造微生物群落功能的相关研究策略奠定了理论基础。