Regulation of anisotropic cell elongation in Arabidopsis

If a plant wants to grow, it needs reliable anisotropic cell elongation*. Getting the cells to elongate has a couple of constraints. There is vacuolar turgor pressure, the pressure from the vacuole in the cell pushing the contents of the cell up against the cell wall. And there’s the cell wall, which needs to limit the contents of the cell to keep everything in.

Turgor in cells
Image Le et al. (2018)

The strength in a cell wall mainly comes from cellulose microfibrils. These are strands aligned perpendicular to the axis of elongation, allowing the cell wall to stretch in the right direction.

Le et al. set out to characterize the molecular function of AtDICE1 encoding a novel transmembrane protein involved in anisotropic cell elongation in Arabidopsis. They found that gain-of-function mutation of AtDICE1, a gene encoding a putative ER-localized membrane protein, causes defects in anisotropic cell elongation by disturbing cell wall integrity in Arabidopsis. Further genetic, biochemical and transcriptomic observations suggest that AtDICE1 contributes to the proper anisotropic cell elongation process in the vascular tissue possibly through the process of cell wall formation.

*Stretching in along a specific axis of the cell, for example growing longer, instead of just inflating.