Abstract Detail

Physiology

Schulte, Paul [1].

Fluid and solute flow through the phloem tissue of plants.

The phloem of plants has been studied for nearly a century from an anatomical perspective with regard to cellular structures and from a physiological to molecular perspective with regard to the processes associated with fluid and solute movements. Early work from Münch described the phloem path as having source and sink regions connected with a pipe. More recently, the possible roles for aquaporins mediating water exchange along the transport path have started to be considered. The current work presented here features a model of the phloem that couples the physical processes of fluid flow based on forces and accelerations as described by the classical Navier-Stokes equation with solute transport processes including diffusion (Fick’s Law) and convection. Coupling between these processes occurs through the fluid velocity. But the processes are also coupled because the solute uptake in source regions and the solute unloading at sink regions drives water entry and exit. Thus water entry and exit from the phloem is driven in the model by water potential differences which are determined by fluid pressures and by solute concentrations. Therefore, a treatment of the overall transport process necessitates a coupling of the fluid and solute realms. The model will be described in detail. Solutions to the model demonstrate that the coupling of flow and solute processes leads to enhanced solute transport while maintaining pressure-driven flow over long distances that could not otherwise be achieved if flow only occurred between source and sink through phloem sieve cells without lateral water exchange.

1 - University Of Nevada, School Of Life Sciences, Las Vegas, NV, 89154, United States

Keywords:
phloem transport
computational model
diffusion.

Presentation Type: Poster
Session: P, Physiology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPS007
Abstract ID:882
Candidate for Awards:None