Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland.
Department of Ecosystems in the Barents Region, Norwegian Institute of Bioeconomy Research, Svanvik, Norway.
Genome. 2021 Jun;64(6):615-626. doi: 10.1139/gen-2020-0018. Epub 2021 Apr 7.
While free-living herbivorous insects are thought to harbor microbial communities composed of transient bacteria derived from their diet, recent studies indicate that insects that induce galls on plants may be involved in more intimate host-microbe relationships. We used 16S rDNA metabarcoding to survey larval microbiomes of 20 nematine sawfly species that induce bud or leaf galls on 13 species. The 391 amplicon sequence variants (ASVs) detected represented 69 bacterial genera in six phyla. Multi-variate statistical analyses showed that the structure of larval microbiomes is influenced by willow host species as well as by gall type. Nevertheless, a "core" microbiome composed of 58 ASVs is shared widely across the focal galler species. Within the core community, the presence of many abundant, related ASVs representing multiple distantly related bacterial taxa is reflected as a statistically significant effect of bacterial phylogeny on galler-microbe associations. Members of the core community have a variety of inferred functions, including degradation of phenolic compounds, nutrient supplementation, and production of plant hormones. Hence, our results support suggestions of intimate and diverse interactions between galling insects and microbes and add to a growing body of evidence that microbes may play a role in the induction of insect galls on plants.
虽然自由生活的草食性昆虫被认为拥有由其饮食中的瞬态细菌组成的微生物群落，但最近的研究表明，在植物上诱导虫瘿的昆虫可能与微生物有着更密切的关系。我们使用 16S rDNA 宏条形码技术调查了 20 种诱导芽或叶瘿的线虫叶蜂幼虫的微生物组，这些叶蜂寄生在 13 种植物上。检测到的 391 个扩增子序列变异体 (ASV) 代表了六个门中的 69 个细菌属。多变量统计分析表明，幼虫微生物组的结构受柳树宿主物种和瘿类型的影响。然而，由 58 个 ASV 组成的“核心”微生物组在焦点类瘿物种中广泛共享。在核心群落中，存在许多大量的相关 ASV，代表多个远缘细菌分类群，这反映了细菌系统发育对类瘿微生物相关性的统计学显著影响。核心群落的成员具有多种推断的功能，包括酚类化合物的降解、营养补充和植物激素的产生。因此，我们的研究结果支持了关于昆虫与微生物之间密切和多样化的相互作用的观点，并为越来越多的证据表明，微生物可能在昆虫对植物产生虫瘿的过程中发挥作用提供了依据。
