Abstract
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.
| Original language | English |
|---|---|
| Article number | 1528 |
| Journal | Frontiers in Microbiology |
| Volume | 11 |
| DOIs | |
| State | Published - Jul 7 2020 |
Funding
We are extremely grateful for help during a long day in the field from J. Abernathy, A. Cameron, A. Chuang, S. Cooper, C. Fellhoelter, K. Hannahs, W. Hembree, S. Hesbacher, K. Leko, J. Lockyer, C. Miller, A. Nus, B. Nus, D. Nus, R. Simberloff, L. Smith, C. Steele, H. Thompson, K. Troop, and O. Washam. We thank C. Schadt for comments on an earlier version of this manuscript. Funding. This research was supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the United States Department of Energy through a Liane Russell Fellowship awarded to MC, and by the endowment of the Nancy Gore Hunger Professorship in Environmental Studies at the University of Tennessee, and by the National Science Foundation to JF (DEB 1638922). This research was also sponsored by the Genomic Science Program, United States Department of Energy, Office of Science, Biological and Environmental Research, as part of the Plant Microbe Interfaces Scientific Focus Area at ORNL (Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the United States Department of Energy under contract DEAC05-00OR22725. This research was also sponsored by the North Carolina Agriculture Research Service and by the USDA National Institute of Food and Agriculture, Hatch project 1007367. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Keywords
- 16S rRNA
- ITS
- epiphyte
- microbial ecology
- phyllosphere
- plant pathology
- plant-microbe interactions
- rhizosphere