Data from: Unpredicted impacts of insect endosymbionts on interactions between soil organisms, plants and aphids

Ecologically significant symbiotic associations are frequently studied in isolation, but such studies of two-way interactions cannot always predict the responses of organisms in a community setting. To explore this issue, we adopt a community approach to examine the role of plant–microbial and insect–microbial symbioses in modulating a plant–herbivore interaction. Potato plants were grown under glass in controlled conditions and subjected to feeding from the potato aphid Macrosiphum euphorbiae. By comparing plant growth in sterile, uncultivated and cultivated soils and the performance of M. euphorbiae clones with and without the facultative endosymbiont Hamiltonella defensa, we provide evidence for complex indirect interactions between insect– and plant–microbial systems. Plant biomass responded positively to the live soil treatments, on average increasing by 15% relative to sterile soil, while aphid feeding produced shifts (increases in stem biomass and reductions in stolon biomass) in plant resource allocation irrespective of soil treatment. Aphid fecundity also responded to soil treatment with aphids on sterile soil exhibiting higher fecundities than those in the uncultivated treatment. The relative allocation of biomass to roots was reduced in the presence of aphids harbouring H. defensa compared with plants inoculated with H. defensa-free aphids and aphid-free control plants. This study provides evidence for the potential of plant and insect symbionts to shift the dynamics of plant–herbivore interactions.

具有生态重要性的共生关联常被单独开展研究，但这类针对双向互作的探究往往无法预测群落环境中生物体的响应。为解决这一问题，本研究采用群落研究范式，探讨植物-微生物与昆虫-微生物共生体在调控植物-植食性昆虫互作中的作用。本实验在可控条件下的玻璃温室中种植马铃薯植株，并接种马铃薯长管蚜（Macrosiphum euphorbiae）进行取食处理。通过比较无菌土壤、未耕作土壤与耕作土壤中马铃薯植株的生长状况，以及携带与不携带兼性内共生体汉密尔顿菌（Hamiltonella defensa）的M. euphorbiae克隆株的适合度表现，本研究揭示了昆虫-微生物与植物-微生物系统间存在复杂间接互作的证据。相较于无菌土壤，活土壤处理组的植株生物量呈现正向响应，平均提升15%；而无论土壤处理类型如何，蚜虫取食均会改变植株的资源分配模式（茎部生物量增加，匍匐茎生物量减少）。蚜虫的繁殖力同样受土壤处理的影响：无菌土壤上的蚜虫繁殖力高于未耕作土壤处理组的蚜虫。与接种无H. defensa蚜虫的植株以及无蚜虫的对照组植株相比，携带H. defensa的蚜虫取食会降低植株对根部的生物量相对分配比例。本研究证实，植物与昆虫共生体具备调控植物-植食性昆虫互作动态的潜在能力。