%0 Journal Article %1 citeulike:10673116 %A Franzaring, J. %A Gensheimer, G. %A Weller, S. %A Schmid, I. %A Fangmeier, A. %D 2012 %J Environmental and Experimental Botany %K citeulikeExport co2, protein, rapeseed, s2 %P 12--22 %R 10.1016/j.envexpbot.2012.03.015 %T Allocation and remobilisation of nitrogen in spring oilseed rape (Brassica napus L. cv. Mozart) as affected by N supply and elevated CO2 %U http://dx.doi.org/10.1016/j.envexpbot.2012.03.015 %V 83 %X CO2 enrichment interacts with the resource economy of plants, but time-integrated studies on N partitioning between different plant parts, C:N ratios and N remobilisation are mostly lacking. The present study addressed the nitrogen use efficiency (NUE) in spring oilseed rape (OSR) grown at three N fertilisation levels and two CO2 concentrations (380 vs. 550 Î¼mol mol−1). N was supplied in three equal gifts at sowing, stem elongation and flowering. One of these gifts was labelled with 15NH415NO3 respectively. Six intermediate harvests and a final harvest were performed to determine dry mass, N concentrations, C:N, N recovery and δ15N signatures in the plant fractions root, main stem, branches, green and senescent leaves, pod walls and seeds. While N concentrations were lower and C:N higher in green leaves under CO2 enrichment, more N remained in the root until the final harvest. Under ambient CO2 concentrations the harvestable product (seeds) contained 50.7\%, 44.5\% and 41\% of the total N supplied in the treatments that received 75, 150 and 225 kg ha−1 N, respectively. Under elevated CO2 these values decreased to 47.4\%, 34.5\% and 15\% reducing the NUE of the seeds by 2\%, 33\% and 65\%, respectively. In CO2 exposed amply fertilised plants much of the N remained in the side stems due to strong outbranching and reduced seed set. However, N remobilisation was more affected by the different N supply than by the CO2 enrichment. The boosted growth of OSR under high availability of N disrupted the source:sink relationships so that benefits from the CO2 enrichment on stem and root growth could not be realised by yield formation. ► The CO2 fertilisation effect may interact with the development of oilseed rape and reduce the overall N recovery to the seeds. ► Source–sink relationships are affected and seed yields are reduced despite the accumulation of more biomass. ► Plant breeding should regard the increased availability of photosynthates, their feedbacks on nitrogen uptake and necessary changes in sink sizes in the future

@article{citeulike:10673116, abstract = {{CO2 enrichment interacts with the resource economy of plants, but time-integrated studies on N partitioning between different plant parts, C:N ratios and N remobilisation are mostly lacking. The present study addressed the nitrogen use efficiency (NUE) in spring oilseed rape (OSR) grown at three N fertilisation levels and two CO2 concentrations (380 vs. 550 \^{I}¼mol mol−1). N was supplied in three equal gifts at sowing, stem elongation and flowering. One of these gifts was labelled with 15NH415NO3 respectively. Six intermediate harvests and a final harvest were performed to determine dry mass, N concentrations, C:N, N recovery and \^{I}´15N signatures in the plant fractions root, main stem, branches, green and senescent leaves, pod walls and seeds. While N concentrations were lower and C:N higher in green leaves under CO2 enrichment, more N remained in the root until the final harvest. Under ambient CO2 concentrations the harvestable product (seeds) contained 50.7\%, 44.5\% and 41\% of the total N supplied in the treatments that received 75, 150 and 225 kg ha−1 N, respectively. Under elevated CO2 these values decreased to 47.4\%, 34.5\% and 15\% reducing the NUE of the seeds by 2\%, 33\% and 65\%, respectively. In CO2 exposed amply fertilised plants much of the N remained in the side stems due to strong outbranching and reduced seed set. However, N remobilisation was more affected by the different N supply than by the CO2 enrichment. The boosted growth of OSR under high availability of N disrupted the source:sink relationships so that benefits from the CO2 enrichment on stem and root growth could not be realised by yield formation. \^{a}–º The CO2 fertilisation effect may interact with the development of oilseed rape and reduce the overall N recovery to the seeds. \^{a}–º Source–sink relationships are affected and seed yields are reduced despite the accumulation of more biomass. \^{a}–º Plant breeding should regard the increased availability of photosynthates, their feedbacks on nitrogen uptake and necessary changes in sink sizes in the future}}, added-at = {2019-03-31T01:14:40.000+0100}, author = {Franzaring, J. and Gensheimer, G. and Weller, S. and Schmid, I. and Fangmeier, A.}, biburl = {https://www.bibsonomy.org/bibtex/2bcc8c8e2f2ff0ff3a210311126ce0be2/dianella}, citeulike-article-id = {10673116}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.envexpbot.2012.03.015}, doi = {10.1016/j.envexpbot.2012.03.015}, interhash = {4898fbc77e7fb424f50353a6d50faa60}, intrahash = {bcc8c8e2f2ff0ff3a210311126ce0be2}, issn = {00988472}, journal = {Environmental and Experimental Botany}, keywords = {citeulikeExport co2, protein, rapeseed, s2}, month = nov, pages = {12--22}, posted-at = {2014-12-01 04:09:32}, priority = {2}, timestamp = {2019-03-31T01:16:26.000+0100}, title = {{Allocation and remobilisation of nitrogen in spring oilseed rape (Brassica napus L. cv. Mozart) as affected by N supply and elevated CO2}}, url = {http://dx.doi.org/10.1016/j.envexpbot.2012.03.015}, volume = 83, year = 2012 }