title: Inorganic nitrogen form: a major player in wheat and Arabidopsis responses to elevated CO2.
abstract: Critical for predicting the future of primary productivity is a better understanding of plant responses to rising atmospheric carbon dioxide (CO2) concentration. This review considers recent results on the role of the inorganic nitrogen (N) forms nitrate (NO3-) and ammonium (NH4+) in determining the responses of wheat and Arabidopsis to elevated atmospheric CO2 concentration. Here, we identify four key issues: (i) the possibility that different plant species respond similarly to elevated CO2 if one accounts for the N form that they are using; (ii) the major influence that plant-soil N interactions have on plant responses to elevated CO2; (iii) the observation that elevated CO2 may favor the uptake of one N form over others; and (iv) the finding that plants receiving NH4+ nutrition respond more positively to elevated CO2 than those receiving NO3- nutrition because elevated CO2 inhibits the assimilation of NO3- in shoots of C3 plants. We conclude that the form and amount of N available to plants from the rhizosphere and plant preferences for the different N forms are essential for predicting plant responses to elevated CO2.
authors.affiliation: Department of Irrigation, Centro de Edafología y Biología Aplicada del Segura, Espinardo, Murcia, Spain.
authors.forename: José S
authors.initials: JS
authors.lastname: Rubio-Asensio
authors.affiliation: Department of Plant Sciences, Mailstop 3, University of California at Davis, Davis, CA 95616, USA.
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Bloom
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D002245:Carbon Dioxide
keywords: Ammonium; CO2 acclimation; biomass; growth; nitrate; plant–soil interactions; protein yield; yield.