Author
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WANG, PENG - University Of Nebraska |
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MARSCH, ELLEN - University Of Nebraska |
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Ainsworth, Elizabeth - Lisa |
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LEAKEY, ANDREW D B - University Of Illinois |
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SHEFLIN, AMY - Colorado State University |
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SCHACHTMAN, DANIEL - University Of Nebraska |
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/17/2017 Publication Date: 11/3/2017 Citation: Wang, P., Marsch, E.L., Ainsworth, E.A., Leakey, A., Sheflin, A.M., Schachtman, D.P. 2017. Shifts in microbial communities in soil, rhizosphere and roots of two major crop systems under elevated CO2 and O3. Scientific Reports. 7:15109. https://doi.org/10.1038/s41598-017-14936-2. DOI: https://doi.org/10.1038/s41598-017-14936-2 Interpretive Summary: Changes in the atmospheric concentrations of carbon dioxide and ozone alter crop growth and yield. However, the effects of these atmospheric changes on the microbial communities associated with crops is largely unstudied, despite the growing recognition that soil and root-associated microbes are important for plant health. In this study, soybean was grown at elevated carbon dioxide and maize under elevated ozone concentrations at the Free Air Concentration Enrichment (FACE) facility in Urbana, IL. Microbial communities from bulk soil, soil associated with the roots (rhizosphere) and from the root tissues of soybean and maize were investigated. The diversity of the microbial community associated with roots and rhizospere was greater in maize compared to soybean, likely because soybean house N-fixing rhizobia in their nodules. Additionally, the abundance of N-fixing microbes associated with soybean was greater at elevated carbon dioxide concentration. This work demonstrates that global atmospheric changes alter the composition of microbial populations associated with important crops in a species-specific way. Technical Abstract: Rising atmospheric concentrations of CO2 and O3 are key features of global environmental change. To investigate changes in the belowground bacterial community composition in response to elevated CO2 and O3 (eCO2 and eO3) the endosphere, rhizosphere and soil were sampled from soybeans under eCO2 and maize under eO3. The maize rhizosphere and endosphere a-diversity was higher than soybean, which may be due to a high relative abundance of Rhizobiales. Only the rhizosphere microbiome composition of the soybeans changed in response to eCO2, associated with an increased abundance of nitrogen fixing microbes. In maize, the microbiome composition was altered by the genotype and linked to differences in root exudate profiles. The eO3 treatment did not change the microbial communities in the rhizosphere, but altered the soil communities where hybrid maize was grown. In contrast to previous studies that focused exclusively on the soil, this study provides new insights into the effects of plant root exudates on the composition of the belowground microbiome in response to changing atmospheric conditions. Our results demonstrate that plant species and plant genotype were key factors driving the changes in the belowground bacterial community composition in agroecosystems that experience rising levels of atmospheric CO2 and O3. |