Signalling across the divide: A wider perspective of cuticular structure-function relationships

The cuticle is designed to keep water and solutes in, but to keep invaders out. Contrary to traditional thought, the cuticle's thickness and overall wax load do not control water transport across it, Why then are some cuticles very thick or made with apparently excessive amounts of waxes? A more comprehensive approach to understanding cuticular structure-function relationships is called for, taking into account the maintenance of barrier properties as well as a range of other functions, which include offering a medium for communication between potential invaders and the plant, impeding penetration by insects and fungi, and reducing water retention by leaf surfaces.