Plant Invasions Associated with Change in Root-Zone Microbial Community Structure and Diversity

• Published in: PloS one 2015-10, Vol.10 (10), p.e0141424-e0141424
• Main Authors: Rodrigues, Richard R, Pineda, Rosana P, Barney, Jacob N, Nilsen, Erik T, Barrett, John E, Williams, Mark A
• Format: Article
• Language: English
• Subjects: Abundance; Actinobacteria - genetics; Ailanthus - genetics; Ailanthus - microbiology; Ailanthus altissima; Ammonia; Ammonium; Analysis; Animals; Bacteria; Biodiversity; Bioinformatics; Biological indicators; Biology; Communities; Community structure; Cycles; Ecological monitoring; Ecology; Ecosystem biology; Ecosystems; Functional analysis; Fungi; Fungi - genetics; Genetic Variation; Horticulture; Hypotheses; Indicator species; Influence; Interdisciplinary aspects; Introduced Species; Invasions; Invasive plants; Invasive species; Microbial activity; Microbial colonies; Microbiomes; Microorganisms; Microstegium vimineum; Native species; Nitrogen; Nitrogen Cycle; Nonnative species; Oxidation; Pathogens; Phylogeny; Plant communities; Plant diversity; Plant Roots - metabolism; Plant Roots - microbiology; Plant sciences; Poaceae - genetics; Poaceae - microbiology; Proteobacteria - genetics; Relative abundance; Rhamnus - genetics; Rhamnus - microbiology; RNA, Ribosomal, 16S - genetics; rRNA 16S; Soil Microbiology; Soil properties; Soil sciences; Sorghum; Species diversity; Virginia; VOCs; Volatile organic compounds
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0141424

The importance of plant-microbe associations for the invasion of plant species have not been often tested under field conditions. The research sought to determine patterns of change in microbial communities associated with the establishment of invasive plants with different taxonomic and phenetic traits. Three independent locations in Virginia, USA were selected. One site was invaded by a grass (Microstegium vimineum), another by a shrub (Rhamnus davurica), and the third by a tree (Ailanthus altissima). The native vegetation from these sites was used as reference. 16S rRNA and ITS regions were sequenced to study root-zone bacterial and fungal communities, respectively, in invaded and non-invaded samples and analyzed using Quantitative Insights Into Microbial Ecology (QIIME). Though root-zone microbial community structure initially differed across locations, plant invasion shifted communities in similar ways. Indicator species analysis revealed that Operational Taxonomic Units (OTUs) closely related to Proteobacteria, Acidobacteria, Actinobacteria, and Ascomycota increased in abundance due to plant invasions. The Hyphomonadaceae family in the Rhodobacterales order and ammonia-oxidizing Nitrospirae phylum showed greater relative abundance in the invaded root-zone soils. Hyphomicrobiaceae, another bacterial family within the phyla Proteobacteria increased as a result of plant invasion, but the effect associated most strongly with root-zones of M. vimineum and R. davurica. Functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed bacteria responsible for nitrogen cycling in soil increased in relative abundance in association with plant invasion. In agreement with phylogenetic and functional analyses, greater turnover of ammonium and nitrate was associated with plant invasion. Overall, bacterial and fungal communities changed congruently across plant invaders, and support the hypothesis that nitrogen cycling bacteria and functions are important factors in plant invasions. Whether the changes in microbial communities are driven by direct plant microbial interactions or a result of plant-driven changes in soil properties remains to be determined.