First steps in understanding the export of lipids to the plant cuticle

The plant exterior is coated with a specialized hydrophobic cell wall domain called the cuticle. While there is general agreement on the importance of the plant cuticle to the physiology and ecology of the whole plant, there is very little known about how the hydrophobic components making up the cuticle are synthesized and secreted from epidermal cells. Using a forward genetics approach in Arabidopsis thaliana, we have characterized an ABC transporter mutant with reduced wax on the cuticle and abundant lipidic inclusions inside the epidermal cells. This plasma membrane-localized ABC transporter is the first component of the cuticular lipid export system to be found. Many questions remain regarding the preceding and following steps in the transport of cuticular lipids.