Abstract
Premise: Plant endophytic bacterial strains can influence plant traits such as leaf area and root length. Yet, the influence of more complex bacterial communities in regulating overall plant phenotype is less explored. Here, in two complementary experiments, we tested whether we can predict plant phenotype response to changes in microbial community composition. Methods: In the first study, we inoculated a single genotype of Populus deltoides with individual root endophytic bacteria and measured plant phenotype. Next, data from this single inoculation were used to predict phenotypic traits after mixed three-strain community inoculations, which we tested in the second experiment. Results: By itself, each bacterial endophyte significantly but weakly altered plant phenotype relative to noninoculated plants. In a mixture, bacterial strain Burkholderia BT03, constituted at least 98% of community relative abundance. Yet, plant resource allocation and tissue nutrient concentrations were disproportionately influenced by Pseudomonas sp. GM17, GM30, and GM41. We found a 10% increase in leaf mass fraction and an 11% decrease in root mass fraction when replacing Pseudomonas GM17 with GM41 in communities containing both Pseudomonas GM30 and Burkholderia BT03. Conclusions: Our results indicate that interactions among endophytic bacteria may drive plant phenotype over the contribution of each strain individually. Additionally, we have shown that low-abundance strains contribute to plant phenotype challenging the assumption that the dominant strains will drive plant function.
Original language | English |
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Pages (from-to) | 1423-1434 |
Number of pages | 12 |
Journal | Applications in Plant Sciences |
Volume | 106 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1 2019 |
Funding
The authors thank Quentin Read, Megan Rúa, Leigh Moorhead, and Alex Strauss for useful comments, discussions, and proofreading while writing this paper. Additionally, we thank two anonymous reviewers for their helpful comments that greatly improved our manuscript. This work was supported by Office of Science, Biological and Environmental Research as part of the Plant-Microbe Interfaces Scientific Focus Area (http://pmi.ornl.gov). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725 and in part, by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Terrestrial Ecosystem Sciences Program under Award Number DE-SC0010562 and The University of Tennessee Department of Ecology & Evolutionary Biology.
Keywords
- Burkholderia
- Populus deltoides
- Pseudomonas
- Salicaceae
- allocation
- bacterial endophytes
- constructed communities
- mass–ratio hypothesis
- plant traits