Cytoplasmic streaming in plant cells: the role of wall slip

TL;DR

This study uses lattice Boltzmann simulations to model cytoplasmic streaming in plant cells, demonstrating that wall slip effects and viscous flow alone can explain observed streaming velocities.

Contribution

It introduces a simplified microscopic model incorporating wall slip and viscous flow, explaining streaming without complex motor-cytoplasm coupling.

Findings

Wall slip significantly influences streaming velocity.

Viscous Stokes flow suffices to replicate observed velocities.

Motor activity modeled as directed spheres explains streaming magnitude.

Abstract

We present a computer simulation study, via lattice Boltzmann simulations, of a microscopic model for cytoplasmic streaming in algal cells such as those of Chara corallina. We modelled myosin motors tracking along actin lanes as spheres undergoing directed motion along fixed lines. The sphere dimension takes into account the fact that motors drag vesicles or other organelles, and, unlike previous work, we model the boundary close to which the motors move as walls with a finite slip layer. By using realistic parameter values for actin lane and myosin density, as well as for endoplasmic and vacuole viscosity and the slip layer close to the wall, we find that this simplified view, which does not rely on any coupling between motors, cytoplasm and vacuole other than that provided by viscous Stokes flow, is enough to account for the observed magnitude of streaming velocities in intracellular fluid in living plant cells.