This title appears in the Scientific Report :
2015
Please use the identifier:
http://dx.doi.org/10.1093/treephys/tpv020 in citations.
Please use the identifier: http://hdl.handle.net/2128/26557 in citations.
Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance
Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance
In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, shape...
Saved in:
Personal Name(s): | Liesche, J. (Corresponding author) |
---|---|
Windt, C. / Bohr, T. / Schulz, A. / Jensen, K. H. | |
Contributing Institute: |
Pflanzenwissenschaften; IBG-2 |
Published in: | Tree physiology, 35 (2015) 4, S. 376 - 386 |
Imprint: |
Victoria, BC
Heron
2015
|
PubMed ID: |
25787331 |
DOI: |
10.1093/treephys/tpv020 |
Document Type: |
Journal Article |
Research Program: |
Plant Science |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/26557 in citations.
In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, shape and connectivity. Whether these differences have an effect on the physiology of carbohydrate transport, however, is not clear. A meta-analysis of the experimental data on phloem transport speed in trees yielded average speeds of 56 cm h−1 for angiosperm trees and 22 cm h−1 for gymnosperm trees. Similar values resulted from theoretical modeling using a simple transport resistance model. Analysis of the model parameters clearly identified sieve element (SE) anatomy as the main factor for the significantly slower carbohydrate transport speed inside the phloem in gymnosperm compared with angiosperm trees. In order to investigate the influence of SE anatomy on the hydraulic resistance, anatomical data on SEs and sieve pores were collected by transmission electron microscopy analysis and from the literature for 18 tree species. Calculations showed that the hydraulic resistance is significantly higher in the gymnosperm than in angiosperm trees. The higher resistance is only partially offset by the considerably longer SEs of gymnosperms. |