title: Increased plant productivity and decreased microbial respiratory C loss by plant growth-promoting rhizobacteria under elevated CO₂.
abstract: Increased plant productivity and decreased microbial respiratory C loss can potentially mitigate increasing atmospheric CO₂, but we currently lack effective means to achieve these goals. Soil microbes may play critical roles in mediating plant productivity and soil C/N dynamics under future climate scenarios of elevated CO₂ (eCO₂) through optimizing functioning of the root-soil interface. By using a labeling technique with (13)C and (15)N, we examined the effects of plant growth-promoting Pseudomonas fluorescens on C and N cycling in the rhizosphere of a common grass species under eCO₂. These microbial inoculants were shown to increase plant productivity. Although strong competition for N between the plant and soil microbes was observed, the plant can increase its capacity to store more biomass C per unit of N under P. fluorescens addition. Unlike eCO₂ effects, P. fluorescens inoculants did not change mass-specific microbial respiration and accelerate soil decomposition related to N cycling, suggesting these microbial inoculants mitigated positive feedbacks of soil microbial decomposition to eCO₂. The potential to mitigate climate change by optimizing soil microbial functioning by plant growth-promoting Pseudomonas fluorescens is a prospect for ecosystem management.
authors.affiliation: 1] Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY 82071, USA [2] Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK.
authors.forename: Ming
authors.initials: M
authors.lastname: Nie
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Colin
authors.initials: C
authors.lastname: Bell
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Wallenstein
authors.affiliation: 1] Department of Botany and Program in Ecology, University of Wyoming, Laramie, WY 82071, USA [2] Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 Australia.
authors.forename: Elise
authors.initials: E
authors.lastname: Pendall
mesh_terms: D018533:Biomass; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D002245:Carbon Dioxide / Q000494:pharmacology*; D002247:Carbon Isotopes / Q000737:chemistry / Q000378:metabolism; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D006109:Poaceae / Q000187:drug effects / Q000254:growth & development* / Q000382:microbiology; D011551:Pseudomonas fluorescens / Q000187:drug effects* / Q000378:metabolism; D058441:Rhizosphere; D012988:Soil Microbiology
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen