caa a22 4500 397521480 CHVBK 20180308164634.0 cr unu---uuuuu 161202e199510 xx s 000 0 eng 10.1093/jxb/46.10.1595 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.10.1595 Diurnal regulation of NO3−uptake in soybean plants II. Relationship with accumulation of NO and asparagine in the roots [Elektronische Daten] [Patricia Delhon, Alain Gojon, Pascal Tillard, Lucien Passama] Experiments were performed with soybean plants to test the hypothesis that the inhibition of NO3− uptake in darkness is due to feedback control by NO3− and/or Asn accumulating in the roots. Xylem export of N compounds was shown to depend on water flux in both excised root systems and 15N-labelled intact plants, suggesting that the shortage of transpiration in darkness may be responsible for the retention of NO3− and Asn in the roots. This was verified in experiments where the light/dark pattern of transpiration was modulated in intact plants by changing the relative humidity of the atmosphere. Any decrease of transpiration at night was associated with a concurrent stimulation of NO3− and Asn accumulations in the roots. However, the light/dark rhythmicity of NO3− uptake was only marginally affected by these treatments, and thusappeared quite independent from transpiration and root NO3− or Asn levels. Typically, the maintainance of a constant transpiration during the day/night cycle did not suppress the inhibition of NO3− uptake in darkness, whereas it almost prevented the dark increase in root NO3− and Asn contents. These data strongly support the conclusion that the effect of light on NO3− uptake is not mediated by changes in translocation and accumulation of N compounds. © Oxford University Press Research Papers nationallicence Glycine max nationallicence light/dark nationallicence cycles nationallicence nitrate uptake nationallicence transpiration nationallicence transport of N compounds nationallicence accumulation of N compounds nationallicence Delhon Patricia Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Gojon Alain Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Tillard Pascal Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut Passama Lucien Biochimie et Physiologie Vegetales, 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), 1595-1602 0022-0957 46:10<1595 1995 46 exbotj https://doi.org/10.1093/jxb/46.10.1595 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.10.1595 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Delhon Patricia Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Gojon Alain Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Tillard Pascal Biochimie et Physiologie Vegetales, ENSA-M/INRA/CNRS URA 573, Place Viala, F-34060 Montpellier cedex, France aut NATIONALLICENCE 700 1- Passama Lucien Biochimie et Physiologie Vegetales, 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), 1595-1602 0022-0957 46:10<1595 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