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对植物生长至关重要，同时在病害抑制中发挥关键作用。病原物侵染会改变群落组成与功能，但截至目前，我们仍不清楚这些改变是侵染的附带效应，还是由植物主动驱动的。
2. 本研究采用分根系统（split-root system）实验方法，探究大麦在被禾谷镰孢菌（Fusarium graminearum）侵染时，是否会招募携带抗真菌性状的细菌。分根系统可将局部侵染效应（如根系损伤）与植物介导的系统效应对微生物组功能的影响区分开来。我们对两类对象的招募情况进行了检测：一类是与病害抑制相关的荧光假单胞菌（fluorescent pseudomonads）类群，另一类是两个已被充分研究的抗真菌基因——编码2,4-二乙酰基间苯三酚（2,4-DAPG）的phlD基因，以及编码氰化氢（HCN）的hcnAB基因。
3. 研究结果显示，病原物侵染后，荧光假单胞菌、phlD基因与hcnAB基因的丰度显著富集。该效应仅在未被侵染的根系区段可被检测到。我们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联系起来。
4. 综合分析：本研究证实，大麦在遭受病原物侵染时，会选择性地招募携带抗真菌性状的细菌，而病原物的局部侵染会干扰这一招募过程。通过解耦这两类效应，本研究为阐明病原物与植物宿主如何共同塑造微生物组功能的策略奠定了基础。