Review: Diffuse growth of plant cell walls

In order for a cell to expand, its volume needs to increase and the cell wall needs to loosen up. There are multiple processes resulting in cell wall loosening, but not all of them result in extension. Cosgrove differentiates different structural, mechanical and physiocochemical processes that lead to cell wall loosening. The interaction between cellulose microfibrils is proposed to be main load-bearing network, which interacts with expansins, xyloglucans and pectins, which modify bundle packing, slippage and cell expansion. The movement of microfibrils relative to each other differs depending on the bundle orientation, ranging from increased distance between the bundles to straightening of the bundles and increased slippage. How the mechanical junctions between the cellulose microfibrils are regulated remains to be unveiled. (Summary by Magdalena Julkowska) Plant Physiol. 10.1104/pp.17.01541