Publication Abstracts

Nakad et al. 2023

Nakad, M., J.-C. Domec, S. Sevanto, and G. Katul, 2023: Toward a realistic representation of sucrose transport in the phloem of plants. J. Geophys. Res. Biogeosci., 128, no. 3, e2022JG007361, doi:10.1029/2022JG007361.

The significance of phloem hydrodynamics to plant mortality and survival, which impacts ecosystem-scale carbon and water cycling, is not in dispute. The phloem provides the conduits for products of photosynthesis to be transported to different parts of the plant for consumption or storage. The Mnch pressure flow hypothesis (PFH) is the leading framework to mathematically represent this transport. It assumes that osmosis provides the necessary pressure differences to drive water and sucrose within the phloem. Mathematical models utilizing the PFH approximate the phloem by a relatively rigid slender semi-permeable tube. However, the phloem consists of living cells that contract and expand in response to pressure fluctuations. The effect of membrane elasticity on osmotically driven sucrose front speed has rarely been considered and frames the scope here. Laboratory experiments were conducted to elucidate the elastic-to-plastic pressure-deformation relation in membranes and their effect on sucrose front speeds. It is demonstrated that membrane elasticity acts to retard the sucrose front speed. The retardation emerges because of two effects: (a) part of the osmotic pressure is diverted to perform mechanical work to expand the membrane instead of pressurizing water, and (b) expansion of the membrane reduces the sucrose concentration driving osmotic potential due to volume increases and concomitant dilution effects. These results offer a novel perspective about the much discussed presence of sieve plates throughout the phloem acting as structural expansion dampers.

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BibTeX Citation

  author={Nakad, M. and Domec, J.-C. and Sevanto, S. and Katul, G.},
  title={Toward a realistic representation of sucrose transport in the phloem of plants},
  journal={J. Geophys. Res. Biogeosci.},

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RIS Citation

ID  - na09500h
AU  - Nakad, M.
AU  - Domec, J.-C.
AU  - Sevanto, S.
AU  - Katul, G.
PY  - 2023
TI  - Toward a realistic representation of sucrose transport in the phloem of plants
JA  - J. Geophys. Res. Biogeosci.
VL  - 128
IS  - 3
SP  - e2022JG007361
DO  - 10.1029/2022JG007361
ER  -

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