title: Elevated CO2 decreases both transpiration flow and concentrations of Ca and Mg in the xylem sap of wheat.
abstract: The impact of elevated atmospheric [CO2] (e[CO2]) on plants often includes a decrease in their nutrient status, including Ca and Mg, but the reasons for this decline have not been clearly identified. One of the proposed hypotheses is a decrease in transpiration-driven mass flow of nutrients due to decreased stomatal conductance. We used glasshouse and Free Air CO2 Enrichment (FACE) experiments with wheat to show that, in addition to decrease in transpiration rate, e[CO2] decreased the concentrations of Ca and Mg in the xylem sap. This result suggests that uptake of nutrients is not only decreased by reduced transpiration-driven mass flow, but also by as yet unidentified mechanisms that lead to reduced concentrations in the xylem sap.
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 4 Water Street, Creswick, Victoria 3363, Australia. Electronic address: alirh@student.unimelb.edu.au.
authors.forename: Alireza
authors.initials: A
authors.lastname: Houshmandfar
authors.affiliation: Department of Environment and Primary Industries, Horsham, Victoria 3401, Australia. Electronic address: glenn.fitzgerald@depi.vic.gov.au.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Fitzgerald
authors.affiliation: Department of Forest and Ecosystem Science, The University of Melbourne, 4 Water Street, Creswick, Victoria 3363, Australia. Electronic address: michael.tausz@unimelb.edu.au.
authors.forename: Michael
authors.initials: M
authors.lastname: Tausz
mesh_terms: D018533:Biomass; D002118:Calcium / Q000032:analysis*; D002245:Carbon Dioxide / Q000494:pharmacology*; D008274:Magnesium / Q000032:analysis*; D018526:Plant Transpiration / Q000187:drug effects*; D014908:Triticum / Q000187:drug effects / Q000378:metabolism*; D014867:Water; D052584:Xylem / Q000187:drug effects / Q000378:metabolism*
chemical_list: D014867:Water; D002245:Carbon Dioxide; D008274:Magnesium; D002118:Calcium
keywords: Calcium; Elevated CO(2); Magnesium; Transpiration; Xylem sap