Can fast-growing plantation trees escape biochemical down-regulation of photosynthesis when grown throughout their complete production cycle in the open air under elevated carbon dioxide?
Article first published online: 21 APR 2006
Plant, Cell & Environment
Volume 29, Issue 7, pages 1235–1244, July 2006
How to Cite
DAVEY, P. A., OLCER, H., ZAKHLENIUK, O., BERNACCHI, C. J., CALFAPIETRA, C., LONG, S. P. and RAINES, C. A. (2006), Can fast-growing plantation trees escape biochemical down-regulation of photosynthesis when grown throughout their complete production cycle in the open air under elevated carbon dioxide?. Plant, Cell & Environment, 29: 1235–1244. doi: 10.1111/j.1365-3040.2006.01503.x
- Issue published online: 21 APR 2006
- Article first published online: 21 APR 2006
- Received 21 October 2005; received in revised form 17 January 2006; accepted for publication 27 January 2006
- ADP glucose phosphorylase;
- Calvin cycle enzymes;
- Rubisco protein;
Poplar trees sustain close to the predicted increase in leaf photosynthesis when grown under long-term elevated CO2 concentration ([CO2]). To investigate the mechanisms underlying this response, carbohydrate accumulation and protein expression were determined over four seasons of growth. No increase in the levels of soluble carbohydrates was observed in the young expanding or mature sun leaves of the three poplar genotypes during this period. However, substantial increases in starch levels were observed in the mature leaves of all three poplar genotypes grown in elevated [CO2]. Despite the very high starch levels, no changes in the expression of photosynthetic Calvin cycle proteins, or in the starch biosynthetic enzyme ADP-glucose pyrophosphorylase (AGPase), were observed. This suggested that no long-term photosynthetic acclimation to CO2 occurred in these plants. Our data indicate that poplar trees are able to ‘escape’ from long-term, acclimatory down-regulation of photosynthesis through a high capacity for starch synthesis and carbon export. These findings show that these poplar genotypes are well suited to the elevated [CO2] conditions forecast for the middle of this century and may be particularly suited for planting for the long-term carbon sequestration into wood.