Journal Article

The Populus holobiont: dissecting the effects of plant niches and genotype on the microbiome

Crouch, M. J., Cregger, M. A., Vilgalys, R., Yang, Z. K., Veach, A. M., Tuskan, G. A., Schadt, C. W.

2018

Overview

Background Microorganisms serve important functions within numerous eukaryotic host organisms. An understanding of the variation in the plant niche-level microbiome, from rhizosphere soils to plant canopies, is imperative to gain a better understanding of how both the structural and functional processes of microbiomes impact the health of the overall plant holobiome. Using Populus trees as a model ecosystem, we characterized the archaeal/bacterial and fungal microbiome across 30 different tissue-level niches within replicated Populus deltoides and hybrid Populus trichocarpa × deltoides individuals using 16S and ITS2 rRNA gene analyses. Results Our analyses indicate that archaeal/bacterial and fungal microbiomes varied primarily across broader plant habitat classes (leaves, stems, roots, soils) regardless of plant genotype, except for fungal communities within leaf niches, which were greatly impacted by the host genotype. Differences between tree genotypes are evident in the elevated presence of two potential fungal pathogens, Marssonina brunnea and Septoria sp., on hybrid P. trichocarpa × deltoides trees which may in turn be contributing to divergence in overall microbiome composition. Archaeal/bacterial diversity increased from leaves, to stem, to root, and to soil habitats, whereas fungal diversity was the greatest in stems and soils. Conclusions This study provides a holistic understanding of microbiome structure within a bioenergy relevant plant host, one of the most complete niche-level analyses of any plant. As such, it constitutes a detailed atlas or map for further hypothesis testing on the significance of individual microbial taxa within specific niches and habitats of Populus and a baseline for comparisons to other plant species.

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: 16S rRNA / Analysis / Archaea - classification / Archaea - genetics / Archaea - isolation & purification / Bacteria - classification / Bacteria - genetics / Bacteria - isolation & purification / BASIC BIOLOGICAL SCIENCES / Bioinformatics / Biomedical and Life Sciences / Biomedicine / DNA, Ribosomal - genetics / Ecosystems / Fungal pathogen / Fungi / Fungi - classification / Fungi - genetics / Fungi - isolation & purification / Genetic aspects / Genotype / High-Throughput Nucleotide Sequencing - methods / Host-microbiota interactions: from holobiont theory to analysis / ITS2 / Medical Microbiology / Microbial Ecology / Microbial Genetics and Genomics / Microbiology / Microbiota / Organ Specificity / Plant Leaves - microbiology / Plant Roots - microbiology / Plant Stems - microbiology / Populus - genetics / Populus - microbiology / Populus deltoides / Populus trichocarpa × deltoides hybrid / Rhizosphere / RNA / Sequence Analysis, DNA - methods / Soil Microbiology / Virology