Convective control of long-range coherence in plant growth regulation.

It is hypothesized that morphogenetic control in plants depends on convective transport of biochemically important substances, where streaming velocity and cell shapes jointly determine spatial and temporal coherence, and where the streaming velocity in turn is affected by the gravitational field. The relative magnitudes of diffusive and convective effects are considered, and it is shown that in some plant cells for which cell sizes and streaming velocities have been measured convection could be the dominant transport mode. The consequences of this hypothesis in the presence and absence of a gravitational field are considered and permit its experimental verification or rejection.