Nonstructural carbohydrate-balance response to long-term elevated CO2 exposure in European beech and Norway spruce mixed cultures: biochemical and ultrastructural responses

0483637 - FGÚ 2018 RIV CA eng J - Journal Article
Mašková, P. - Radochová, Barbora - Lhotáková, Z. - Michálek, Jan - Lipavská, H.
Nonstructural carbohydrate-balance response to long-term elevated CO2 exposure in European beech and Norway spruce mixed cultures: biochemical and ultrastructural responses.
Canadian Journal of Forest Research. Roč. 47, č. 11 (2017), s. 1498-1494. ISSN 0045-5067. E-ISSN 1208-6037
R&D Projects: GA ČR(CZ) GAP501/10/0340
Institutional support: RVO:67985823
Keywords : chloroplast ultrastructure * CO2 enrichment * forest trees * soluble carbohydrates * starch
OECD category: Forestry
Impact factor: 1.887, year: 2017

Two dominant central European tree species (Fagus sylvatica L. and Picea abies (L.) Karst.), in a mixed culture in semi-open glass domes, were used to simulate the reaction of forests to long-term elevated CO2 (EC) in a mountainous area (Beskydy Mountains, the Czech Republic). We investigated the effects of EC on soluble carbohydrate levels and composition. Starch content was evaluated using two methods: biochemical (glucose content after enzymatic hydrolysis) and stereological (starch grain proportion, size, and number in chloroplasts). In beech and spruce foliage, no significant changes in total soluble carbohydrate levels were observed. In spruce, starch content determined biochemically increased under EC, whereas no changes were detected in beech. The starch content determined stereologically increased only in beech. In spruce, EC exposure caused comparable starch increases in current-year and previous-year needles, although the former had a higher starch content and numerous larger starch grains regardless of CO2 concentration. In both species, the biochemical determination of carbohydrates exhibited greater individual tree uniformity, in contrast to large intraspecies variability. No changes in leaf soluble carbohydrates under long-term elevated CO2 demonstrate the ability of the studied tree species to efficiently allocate the photosynthates among the sinks. Thus, no photosynthetic downregulation via carbohydrate-level signalling can be expected.
Permanent Link: http://hdl.handle.net/11104/0278851