Data from: Insect herbivory reshapes a native leaf microbiome

Publication abstract: Insect herbivory is pervasive in plant communities,
but its impact on microbial plant colonizers is not well-studied in
natural systems. By calibrating sequencing-based bacterial detection to
absolute bacterial load, we find that the within-host abundance of most
leaf microbiome (phyllosphere) taxa colonizing a native forb is amplified
within leaves impacted by insect herbivory. Herbivore-associated bacterial
amplification reflects community-wide compositional shifts towards lower
ecological diversity, but the extent and direction of such compositional
shifts can be interpreted only by quantifying absolute abundance.
Experimentally eliciting anti-herbivore defenses reshaped within-host
fitness ranks among Pseudomonas spp. field isolates and amplified a subset
of putative P. syringae phytopathogens in a manner causally consistent
with observed field-scale patterns. Herbivore damage was inversely
correlated with plant reproductive success and was highly clustered across
plants, which predicts tight co-clustering with putative phytopathogens
across hosts. Insect herbivory may thus drive the epidemiology of
plant-infecting bacteria as well as the structure of a native plant
microbiome by generating variation in within-host bacterial fitness at
multiple phylogenetic and spatial scales. This study emphasizes that
'non-focal' biotic interactions between hosts and other
organisms in their ecological settings can be crucial drivers of the
population and community dynamics of host-associated microbiomes.

研究论文摘要：昆虫植食作用广泛存在于植物群落中，但其对植物定殖微生物的影响在自然生态系统中尚未得到充分研究。本研究通过将基于测序的细菌检测方法校准至绝对细菌载量，发现定殖于本土非禾本草本植物的多数叶际微生物组（phyllosphere）类群，在受昆虫植食作用影响的叶片内的宿主内丰度得到显著扩增。植食动物介导的细菌扩增反映了群落整体组成向更低生态多样性方向的转变，但此类组成偏移的程度与方向，仅能通过量化绝对丰度才能得以阐释。实验诱导的植物抗植食防御反应，重塑了假单胞菌属（Pseudomonas）野外分离株的宿主内适合度排名，并扩增了一类疑似丁香假单胞菌（Pseudomonas syringae，简称P. syringae）植物病原菌的类群，其变化模式与野外观测到的群落格局存在因果一致性。植食动物造成的叶片损伤与植物繁殖成功率呈显著负相关，且损伤在不同植株间呈现高度聚集性，这预示着此类损伤与疑似植物病原菌在宿主间同样存在紧密的共聚集模式。由此可见，昆虫植食作用可通过在多个系统发育与空间尺度上调控宿主内细菌适合度的变异，同时驱动植物侵染细菌的流行病学动态与本土植物微生物组的结构组成。本研究强调，宿主与其生态环境中其他生物之间的‘非焦点’生物相互作用，可能是宿主关联微生物组种群与群落动态的关键驱动因素。