title: Effects of rhizopheric nitric oxide (NO) on N uptake in Fagus sylvatica seedlings depend on soil CO2 concentration, soil N availability and N source.
abstract: Rhizospheric nitric oxide (NO) and carbon dioxide (CO2) are signalling compounds known to affect physiological processes in plants. Their joint influence on tree nitrogen (N) nutrition, however, is still unknown. Therefore, this study investigated, for the first time, the combined effect of rhizospheric NO and CO2 levels on N uptake and N pools in European beech (Fagus sylvatica L.) seedlings depending on N availability. For this purpose, roots of seedlings were exposed to one of the nine combinations (i.e., low, ambient, high NO plus CO2 concentration) at either low or high N availability. Our results indicate a significant effect of rhizospheric NO and/or CO2 concentration on organic and inorganic N uptake. However, this effect depends strongly on NO and CO2 concentration, N availability and N source. Similarly, allocation of N to different N pools in the fine roots of beech seedlings also shifted with varying rhizospheric gas concentrations and N availability.
authors.affiliation: Institute of Forest Sciences, University of Freiburg, Georges-Koehler-Allee 53/54, 79119 Freiburg, Germany.
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.affiliation: Institute of Forest Sciences, University of Freiburg, Georges-Koehler-Allee 53/54, 79119 Freiburg, Germany Present address: Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany judy.simon@uni-konstanz.de.
authors.forename: Judy
authors.initials: J
authors.lastname: Simon
authors.affiliation: Institute of Forest Sciences, University of Freiburg, Georges-Koehler-Allee 53/54, 79119 Freiburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rienks
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lindermayr
authors.affiliation: Institute of Forest Sciences, University of Freiburg, Georges-Koehler-Allee 53/54, 79119 Freiburg, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Rennenberg
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism*; D029964:Fagus / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology*; D009584:Nitrogen / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D058441:Rhizosphere; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D014197:Trees
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D009569:Nitric Oxide; D009584:Nitrogen
keywords: amino acids; ammonium; fine roots; nitrate; nitrogen pools; soluble protein