caa a22 4500 605517711 CHVBK 20210128100721.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10533-015-0130-3 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0130-3 Organic nitrogen uptake by plants: reevaluation by position-specific labeling of amino acids [Elektronische Daten] Reevaluation of organic N uptake by plants by position-specific labeling [Daniel Moran-Zuloaga, Michaela Dippold, Bruno Glaser, Yakov Kuzyakov] Current studies suggest that many plants are able to take up not only inorganic nitrogen (N) but also organic N. We used the novel tool of position-specific isotope labeling to improve the quantification of intact amino acid uptake and to deepen our understanding of the processes occurring at the root-soil-microorganism interface. Position-specific 14C and 15N labeled alanine enabled us to trace the uptake of C from individual molecule positions by Zea mays, Lupinus albus and Cichorium intybus. Uniformly 14C labeled alanine and acetate and inorganic 15NH4 + and 15NO3 − were applied as controls. Equal uptake of uniformly 14C labeled alanine and acetate showed that plant uptake of low molecular weight organic substances (LMWOS) is independent of N in the molecule. 14C uptake from individual molecule positions of alanine strongly differed: this confirmed that soil microorganisms cleaved alanine within 6h into transformation products, which were then taken up by the plants. Microbial utilization strongly outcompeted the plant uptake of LMWOS in agricultural soils. This study revealed that position-specific labeling is an innovative tool that enables separation of the intact uptake from the uptake of molecule fragments and improves the understanding of competing processes for LMWOS utilization in the rhizosphere. Springer International Publishing Switzerland, 2015 Alanine nationallicence Chicory nationallicence Lupine nationallicence Maize nationallicence Organic N uptake nationallicence Position-specific labeling nationallicence Moran-Zuloaga Daniel Department of Agroecosystem Research, BayCEER, University of Bayreuth, Bayreuth, Germany aut Dippold Michaela Department of Agroecosystem Research, BayCEER, University of Bayreuth, Bayreuth, Germany aut Glaser Bruno Department of Soil Biogeochemistry, Institute of Agricultural and Nutritional Science, Martin-Luther University Halle-Wittenberg, Halle, Germany aut Kuzyakov Yakov Department of Agricultural Soil Science, Georg-August-University Goettingen, Göttingen, Germany aut Biogeochemistry Springer International Publishing 125/3(2015-09-01), 359-374 0168-2563 125:3<359 2015 125 10533 https://doi.org/10.1007/s10533-015-0130-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0130-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moran-Zuloaga Daniel Department of Agroecosystem Research, BayCEER, University of Bayreuth, Bayreuth, Germany aut NATIONALLICENCE 700 1- Dippold Michaela Department of Agroecosystem Research, BayCEER, University of Bayreuth, Bayreuth, Germany aut NATIONALLICENCE 700 1- Glaser Bruno Department of Soil Biogeochemistry, Institute of Agricultural and Nutritional Science, Martin-Luther University Halle-Wittenberg, Halle, Germany aut NATIONALLICENCE 700 1- Kuzyakov Yakov Department of Agricultural Soil Science, Georg-August-University Goettingen, Göttingen, Germany aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 125/3(2015-09-01), 359-374 0168-2563 125:3<359 2015 125 10533