The effects of host age and spatial location on bacterial community composition in the English Oak tree (Quercus robur).
Environmental Microbiology Reports
© 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Drivers of bacterial community assemblages associated with plants are diverse and include biotic factors, such as competitors and host traits, and abiotic factors, including environmental conditions and dispersal mechanisms. We examine the roles of spatial distribution and host size, as an approximation for age, in shaping the microbiome associated with Quercus robur woody tissue using culture-independent 16S rRNA gene amplicon sequencing. In addition to providing a baseline survey of the Q. robur microbiome, we screened for the pathogen of acute oak decline. Our results suggest that age is a predictor of bacterial community composition, demonstrating a surprising negative correlation between tree age and alpha diversity. We find no signature of dispersal limitation within the Wytham Woods plot sampled. Together, these results provide evidence for niche-based hypotheses of community assembly and the importance of tree age in bacterial community structure, as well as highlighting that caution must be applied when diagnosing dysbiosis in a long-lived plant host. This article is protected by copyright. All rights reserved.
This work was supported by a Royal Society Research Grant (to CJEM and BK). SM was funded by a studentship at the University of Exeter, BK by a NERC independent research fellowship (NE/K00879X/1), and CJEM by a Royal Society Fellowship. The authors thank Dr. Rob Jackson at the University of Reading for providing an isolate of Brenneria, Dr. Keith Kirby for providing data on tree age and size and Dr. Konrad Paskiewicz as well as the faculty and participants of the NERC-funded population genomics workshop for training in bioinformatics analyses. The 18-ha Long-Term Forest Monitoring Plot is a collaborative project between the University of Oxford, the Centre for Ecology and Hydrology, and the Smithsonian Institution CTFS Forest-GEO (HSBC Climate Partnership).
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.
Vol. 8, Iss. 5, pp. 649–658