| title: | Physical, chemical and biological barriers to gaseous diffusion from leaf intercellular air space to chloroplasts in forest trees |
|---|---|
| reg no: | ETF5702 |
| project type: | Estonian Science Foundation research grant |
| subject: |
1.9. Genetics, Physiology and Microbiology 1.14. Ecology 4.3. Sylviculture, Forestry |
| status: | accepted |
| institution: | University of Tartu |
| head of project: | Ülo Niinemets |
| duration: | 01.01.2004 - 31.12.2007 |
| description: | Leaf internal resistance to gaseous diffusion limits CO2 entry into the chloroplasts and volatile organic compound (VOC) emission from plant leaves. According to previous studies, tree leaves possess an especially large diffusion resistance, which significantly limits their photosynthesis rates and affects diurnal courses of VOC emission. Systematic understanding of the extent, variation patterns and mechanisms of internal diffusion resistance from intercellular air spaces to chloroplasts (Ri) as well as understanding of the genetic and phenotypic controls over Ri is currently lacking. It is also not clear whether Ri is entirely a physico-chemical variable, or whether it also depends on biological factors (aquaporin conductance). The project links detailed whole leaf photosynthesis estimations, and microscale leaf and cell anatomical measurements to (1) determine the actual limits in Ri in natural communities; (2) assess to which extent anatomical leaf modifications alter Ri and leaf photosynthetic characteristics; (3) study the mechanisms leading to various Ri values during leaf growth; (4) determine the mechanisms and estimate plant potential for modification of Ri values in fully-developed leaves. The specific experiments conducted by us will provide important information of the variation in Ri, and mechanistic insight into the determinants of Ri. The data collected and model developed allow more realistic simulation of foliar photosynthetic and VOC emission rates at a leaf, canopy, stand and biome level. In particular, (1) simulation of foliar photosynthetic potentials in leaves of varying structure; (2) prediction of year-to-year variability in foliar photosynthetic and VOC emission capacities resulting from variable environmental conditions during leaf growth and development; and (3) prediction of changes in foliage photosynthesis rates during the season. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Katja Hüve | TÜ MRI | erakorraline teadur | |
| 2. | Ülo Niinemets | University of Tartu | Assoc. Prof. | |
| 3. | Hugo Pettai | TÜ MRI | erak. teadur | |
| 4. | Angelika Portsmuth | TÜ MRI | teadur | |
| 5. | Mari Tobias | TÜ MRI | teadur | |
| 6. | Vivian Vislap | TÜ MRI | doktorant | |