caa a22 4500 397520476 CHVBK 20180308164631.0 cr unu---uuuuu 161202e199511 xx s 000 0 eng 10.1093/jxb/46.11.1685 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.11.1685 Tracing uptake and assimilation of NO2 in spruce needles with 13N [Elektronische Daten] [M. Ammann, M. Stalder, M. Suter, C. Brunold, U. Baltensperger, D. T. Jost, A. Türler, H.W. Gäggeler] For the first time, spruce shoots (Picea abies [L.] Karst.) were fumigated in vivo with 13N-labelled NO2 with the aim of elucidating the mechanism of NO2− trapping in the apoplast of the substomatal cavity. Uptake by the needles could be monitored on-line, and a quantitative analysis of the activity records delivered a deposition velocity in agreement with the common dry deposition estimates and ruled out rapid export processes. A fast extraction procedure was applied which revealed that NO2 did not produce any detectable traces of nitrite. In needles in which the enzymes of nitrate reduction were not induced by prior fumigation with NO2, incorporation of NO2 was partially inhibited as compared to the fully induced shoots which took up and assimilated NO2 as expected from a constant influx. The only labelled inorganic species found in the extracts was nitrate (60%), whereas the rest of the label (40%) was assimilated organic nitrogen.A quantitative analysis of the data shows that the reaction of NO2 in the apoplast yields at least three times more nitrate than nitrite, so that the existing models about the apoplastic trapping reaction, disproportionation or antioxidant scavenging, which both postulate substantial production of nitrite, have to be reconsidered. © Oxford University Press RESEARCH PAPERS nationallicence 13N nationallicence nitrogen dioxide nationallicence spruce nationallicence air pollutants nationallicence deposition nationallicence Ammann M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut Stalder M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut Suter M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut Brunold C. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut Baltensperger U. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut Jost D. T. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut Türler A. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut Gäggeler H.W. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut Journal of Experimental Botany Oxford University Press 46/11(1995-11), 1685-1691 0022-0957 46:11<1685 1995 46 exbotj https://doi.org/10.1093/jxb/46.11.1685 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.11.1685 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ammann M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut NATIONALLICENCE 700 1- Stalder M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut NATIONALLICENCE 700 1- Suter M. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut NATIONALLICENCE 700 1- Brunold C. Institute of Plant Physiology, University of Bern CH-3013 Bern, Switzerland aut NATIONALLICENCE 700 1- Baltensperger U. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut NATIONALLICENCE 700 1- Jost D. T. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut NATIONALLICENCE 700 1- Türler A. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut NATIONALLICENCE 700 1- Gäggeler H.W. Paul Scherrer Institute, Radio- and Environmental Chemistry CH-5232 Villigen, Switzerland aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/11(1995-11), 1685-1691 0022-0957 46:11<1685 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford