Collenchyma: a versatile mechanical tissue with dynamic cell walls

Collenchyma has remained in the shadow of commercially exploited mechanical tissues such as wood and fibres, and therefore has received little attention since it was first described. However, collenchyma is highly dynamic, especially compared with sclerenchyma. It is the main supporting tissue of growing organs with walls thickening during and after elongation. In older organs, collenchyma may become more rigid due to changes in cell wall composition or may undergo sclerification through lignification of newly deposited cell wall material. While much is known about the systematic and organographic distribution of collenchyma, there is rather less information regarding the molecular architecture and properties of its cell walls.