caa a22 4500 397520964 CHVBK 20180308164632.0 cr unu---uuuuu 161202e199509 xx s 000 0 eng 10.1093/jxb/46.9.1185 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.9.1185 The respiratory energy requirements involved in nocturnal carbohydrate export from starch-storing mature source leaves and their contribution to leaf dark respiration [Elektronische Daten] [T.J. Bouma, R. De Visser, P.H. Van Leeuwen, M.J. De Kock, H. Lambers] The present study explores the potential contribution of the energy requirements associated with nocturnal carbohydrate export to (1) the fraction of dark respiration correlating with leaf nitrogen concentration and (2) the dark respiration of mature source leaves. To this end, we determined the nocturnal carbohydrate-export rates from leaves with an optimal nitrogen supply, and the correlation between the nitrogen concentration and the dark respiration of leaves. The specific energy costs of carbohydrate export from starch-storing source leaves were determined both experimentally and theoretically. The present estimate of the specific energy cost involved in carbohydrate export as obtained by linear regression (0.70 mol CO2 [mol sucrose]−1), agrees well with both literature data obtained by different methods (0.47 to 1.26 mol CO2 [mol sucrose]−1) and the theoretically calculated range for starch-storing species (0.40 to 1.20 mol CO2 [mol sucrose]−1). The conversion of starch in the chloroplast to sucrose in the cytosol is a major energy-requiring process. Maximally 42 to ‘107'% of the slope of the relationship between respiration rate and organic nitrogen concentration of primary bean leaves, may be ascribed to the energy costs associated with nocturnal export of carbohydrates. Total energy costs associated with export were derived from the product of the specific costs of carbohydrate export and the export rates, either measured on full-grown (primary) leaves of potato and bean or derived from the literature. These export costs account, on average, for 29% of the dark respiration rate in starch-storing species. We conclude that nocturnal carbohydrate export is a major energy-requiring process in starch-storing species © Oxford University Press RESEARCH PAPERS nationallicence Carbohydrate export nationallicence leaf dark respiration nationallicence nitrogen concentration nationallicence respiratory costs nationallicence specific energy cost nationallicence Bouma T.J. Department of Theoretical Production Ecology, Wageningen Agricultural University PO Box 430, NL-6700 AK Wageningen, The Netherlands aut De Visser R. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut Van Leeuwen P.H. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut De Kock M.J. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut Lambers H. Department of Plant Ecology and Evolutionary Biology, Utrecht University Sorbonnelaan 16, NL-3584 CA Utrecht, The Netherlands aut Journal of Experimental Botany Oxford University Press 46/9(1995-09), 1185-1194 0022-0957 46:9<1185 1995 46 exbotj https://doi.org/10.1093/jxb/46.9.1185 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.9.1185 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bouma T.J. Department of Theoretical Production Ecology, Wageningen Agricultural University PO Box 430, NL-6700 AK Wageningen, The Netherlands aut NATIONALLICENCE 700 1- De Visser R. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut NATIONALLICENCE 700 1- Van Leeuwen P.H. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut NATIONALLICENCE 700 1- De Kock M.J. DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO) PO Box 14, NL-6700 AA Wageningen, The Netherlands aut NATIONALLICENCE 700 1- Lambers H. Department of Plant Ecology and Evolutionary Biology, Utrecht University Sorbonnelaan 16, NL-3584 CA Utrecht, The Netherlands aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/9(1995-09), 1185-1194 0022-0957 46:9<1185 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