According to the classical understanding of plant gas exchange, the uncontrolled loss of water from plant aerial organs is restricted by epidermis that is covered by a hydrophobic layer called cuticle. Because of these properties, the majority of plant gas exchange occurs through stomata. Consequently, composition of cuticle and fast guard cell signaling are thought to be the major factors limiting transpiration. We are expanding this classical model with the use of forward genetic approaches. Our results indicate that modifications of cell wall structure and composition leading to e.g. loss of cell adhesion, can affect plant gas exchange independently of cuticle synthesis and guard cell function.