Both Casparian strips and suberin lamellae, two extracellular hydrophobic barriers located in the wall of endodermal cells of the root, play key roles in restricting the movement of solutes and water into the vascular system and also their back flow out. The Casparian strip is a belt-like structure formed of lignin that surrounds endodermal cells, running parallel to the root surface. It is tightly adhered to the plasma membrane and bridges the extracellular space between adjacent cells to form a tight junction between them. On the other hand, suberin forms a waxy coatings around endodermal cells that limits transport across the plasma membrane. Cross-talk between the Casparian strip and suberin exists, with suberin being deposited in response to disruption of Casparian strips. Our understanding of the molecular machinary that builds Casparian strips, and the signalling mechanisms that mediate cross-talk between these strips and suberin deposition is still in its infancy. However, recent molecular genetic and cell biological work is starting to unravel some of these mysteries.