title: Short-term exposure to elevated atmospheric CO2 benefits the growth of a facultative annual root hemiparasite, Rhinanthus minor (L.), more than that of its host, Poa pratensis (L.).
abstract: The effects of elevated CO2 (650 ppm) on interactions between a chlorophyllous parasitic angiosperm, Rhinanthus minor (L.) and a host, Poa pratensis (L.) were investigated. R. minor benefited from elevated CO2, with both photosynthesis and biomass increasing, and transpiration and tissue N concentration remaining unaffected. However, this did not alleviate the negative effect of the parasite on the host; R. minor reduced host photosynthesis, transpiration, leaf area and biomass, irrespective of CO2 concentration. Elevated CO2 resulted in increased host photosynthesis, but there was no concomitant increase in biomass and foliar N decreased. It appears that the parasite may reduce host growth more by competition for nitrogen than for carbon. Contrary to expectation, R. minor did not reduce the productivity of the host-parasite association, and it actually contributed to the stimulation of productivity of the association by elevated CO2.
authors.affiliation: School of Biological Sciences, Department of Plant and Soil Science, University of Aberdeen, Aberdeen AB24 3UU, UK.
authors.forename: Jun-Kwon
authors.initials: JK
authors.lastname: Hwangbo
authors.forename: Wendy E
authors.initials: WE
authors.lastname: Seel
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Woodin
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D018533:Biomass; D002245:Carbon Dioxide / Q000494:pharmacology*; D006790:Host-Parasite Interactions; D019686:Lamiaceae / Q000187:drug effects* / Q000254:growth & development*; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000469:parasitology*; D018526:Plant Transpiration / Q000187:drug effects; D031785:Poa / Q000187:drug effects* / Q000254:growth & development / Q000469:parasitology*
chemical_list: D002245:Carbon Dioxide