caa a22 4500 397522436 CHVBK 20180308164636.0 cr unu---uuuuu 161202e199510 xx s 000 0 eng 10.1093/jxb/46.10.1585 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.10.1585 Diurnal regulation of NO3− uptake in soybean plants I. Changes in NO3− influx, efflux, and N utilization in the plant during the day/night cycle [Elektronische Daten] [Patricia Delhon, Alain Gojon, Pascal Tillard, Lucien Passama] The effect of light on NO3− utilization was investigated in non-nodulated soybean (Clycine max L. Merr., cv. Kingsoy) plants during a 14/10 h light/dark period at a constant temperature of 26°C. A 30-50% decrease of net NO3− uptake rate was observed 2-6 h after the lights were turned off. This was specifically due to an inhibition of NO3− influx as measured by 15N incorporation during 5 min. The absolute values of NO3− efflux depended on whether the labelling protocol involved manipulation of the plants or not, but were not affected by illumination of the shoots. Darkness had an even more marked effect in lowering the reduction of 15NO3− in both roots and shoots, as well as xylem transport of 15NO3− and reduced 15N. Concurrently with this slowing down of transport and metabolic processes, accumulations of NO3− and Asn were significantly stimulated in roots during the dark period. These data are discussed in view of the hypothesis that darkness adversely affects NO3− uptake through specific feedback control, in response to alterations in the later steps of N utilization which are more directly dependent on light. © Oxford University Press Research Papers nationallicence Glycine max nationallicence light/dark cycles nationallicence nitrate uptake nationallicence nitrate reduction nationallicence Delhon Patricia Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Gojon Alain Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Tillard Pascal Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Passama Lucien Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1585-1594 0022-0957 46:10<1585 1995 46 exbotj https://doi.org/10.1093/jxb/46.10.1585 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.10.1585 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Delhon Patricia Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Gojon Alain Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Tillard Pascal Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Passama Lucien Biochimie et Physiologie Vegetates, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1585-1594 0022-0957 46:10<1585 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