Data_Sheet_1_Microbiome Variation Across Two Hemlock Species With Hemlock Woolly Adelgid Infestation.docx

The hemlock woolly adelgid (Adelges tsugae, HWA), an invasive insect, is devastating native hemlock populations in eastern North America, and management outcomes have so far had limited success. While many plant microbiomes influence and even support plant immune responses to insect herbivory, relatively little is known about the hemlock microbiome and its interactions with pathogens or herbivores such as HWA. Using 16S rRNA and ITS gene amplicon sequencing, we characterized the needle, branch, root, and rhizosphere microbiome of two hemlock species, Tsuga canadensis and T. sieboldii, that displayed low and high levels of HWA populations. We found that both archaeal/bacterial and fungal needle communities, as well as the archaeal/bacterial branch and root communities, varied in composition in both hemlock species relative to HWA population levels. While host species and plant-associated habitats explained a greater proportion of the variance in the microbiome than did HWA population level, high HWA populations were associated with enrichment of 100 likely fungal pathogen sequence variants across the four plant-associated habitats (e.g., needle, branch, root, rhizosphere) compared to trees with lower HWA populations. This work contributes to a growing body of literature linking plant pathogens and pests with the changes in the associated plant microbiome and host health. Furthermore, this work demonstrates the need to further investigate plant microbiome effects across multiple plant tissues to understand their influences on host health.

东北美洲东部地区，入侵性昆虫——东北松毛蚧（Adelges tsugae, HWA）正在对本地东北松种群造成严重破坏，而目前的管理措施成效有限。众多植物微生物组对植物的免疫反应产生显著影响，甚至提供支持，然而关于东北松微生物组及其与病原体或食草动物如东北松毛蚧的相互作用，了解相对较少。本研究通过16S rRNA和ITS基因扩增子测序技术，对两种东北松物种——加拿大铁杉（Tsuga canadensis）和Siebold铁杉（T. sieboldii）的针叶、枝条、根系及根际微生物组进行了表征，这两种物种分别表现出低和高水平的东北松毛蚧种群。研究发现，在两种东北松物种中，与东北松毛蚧种群水平相比，古菌/细菌和真菌针叶群落，以及古菌/细菌枝条和根系群落，其组成存在差异。尽管宿主物种和植物相关生境在微生物组变异中所占比重高于东北松毛蚧种群水平，但高东北松毛蚧种群与四个植物相关生境（例如，针叶、枝条、根系、根际）中100种可能的真菌病原体序列变异的富集有关，与东北松毛蚧种群水平较低的树木相比。本研究丰富了将植物病原体和害虫与相关植物微生物组变化以及宿主健康变化联系起来的文献。此外，本研究还表明，有必要进一步调查植物微生物组对多种植物组织的影响，以了解其对宿主健康的影响。