caa a22 4500 397521634 CHVBK 20180308164634.0 cr unu---uuuuu 161202e199512 xx s 000 0 eng 10.1093/jxb/46.12.1797 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.12.1797 Chloroplast ultrastructure of sugar beet (Beta vulgaris L.) cultivated in normal and elevated CO2 concentrations with two contrasted nitrogen supplies [Elektronische Daten] [Jaromír Kutík, Lubomír Nátr, H.H. Demmers-Derks, David W. Lawlor] Sugar beet (Beta vulgaris L., cultivar Celt) plants were grown under simulated field conditions in pots and supplied with adequate or deficient nitrogen (HN and LN, respectively) combined with two CO2 concentrations, ambient (c. 350μmol mol−1 C02—AC), or elevated CO2 (c. 600 μmol mol−1 CO2—HC). Chloroplast structure in mesophyll palisade cells of mature leaves (leaf number 19 in HN and 9 in LN), sampled at midday on 16 August 1993 was studied by transmission electron microscopy and quantified stereologically. The ultrastructure of palisade parenchyma chloroplasts was affected by the elevated CO2 concentration and strikingly affected by nitrogen supply. Chloroplast diameter (cross-sectional length) was slightly, but not significantly, greater in HC than AC treatments within an N treatment, but was smaller in LN than HN; chloroplast cross-sectional area also increased with HC in both N treatments, but only significantly so in LN. Elevated CO2 reduced the proportion of total thylakoids (significant at 5% and 0.1% in HN and LN, respectively) due to decreased granal thylakoids, but the proportion of inter-granal (stromal) thylakoid membranes was not affected compared to chloroplasts from plants grown with ambient CO2. Chloroplast stroma increased as a proportion of chloroplast volume with elevated compared to ambient CO2 with HN but not LN. Starch inclusions were not significantly different with elevated compared to ambient CO2 at HN, but the proportion of starch increased considerably at elevated compared to ambient C02 at LN, indicating an over-production of assimilates. Plastoglobuli in chloroplasts increased with deficient N, but decreased with elevated CO2. Larger chloroplasts with a greater proportion of stroma, but a smaller proportion of granal thylakoids, suggest increased CO2 assimilating capacity and decreased light harvesting/PSII capacity with elevated CO2. © Oxford University Press Research Papers nationallicence Chloroplast nationallicence ultrastructure nationallicence elevated CO2 concentration nationallicence nitrogen deficiency nationallicence sugar beet nationallicence Beta vulgaris nationallicence Kutík Jaromír Department of Plant Physiology, Charles University Viničná5, 128 44 Praha 2, Czech Republic aut Nátr Lubomír Department of Plant Physiology, Charles University Viničná5, 128 44 Praha 2, Czech Republic aut Demmers-Derks H.H. Biochemistry and Physiology Department IACR-Rothamsted, Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, UK aut Lawlor David W. Biochemistry and Physiology Department IACR-Rothamsted, Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, UK aut Journal of Experimental Botany Oxford University Press 46/12(1995-12), 1797-1802 0022-0957 46:12<1797 1995 46 exbotj https://doi.org/10.1093/jxb/46.12.1797 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.12.1797 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kutík Jaromír Department of Plant Physiology, Charles University Viničná5, 128 44 Praha 2, Czech Republic aut NATIONALLICENCE 700 1- Nátr Lubomír Department of Plant Physiology, Charles University Viničná5, 128 44 Praha 2, Czech Republic aut NATIONALLICENCE 700 1- Demmers-Derks H.H. Biochemistry and Physiology Department IACR-Rothamsted, Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, UK aut NATIONALLICENCE 700 1- Lawlor David W. Biochemistry and Physiology Department IACR-Rothamsted, Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, UK aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/12(1995-12), 1797-1802 0022-0957 46:12<1797 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