The composition of cuticular wax of plants is complex and incompletely known, and rather little is known of the biosynthesis of this material(s). Two of the seventeen loci known to be involved in biosynthesis of this wax in maize have been tagged with transposable elements; these genes will be cloned and, using the transposable element as a molecular probe, a study of the biosynthetic pathway (localization, structure, and regulation of the gene products) undertaken. Comparison of the events in maize with those of Arabidopsis is planned; these studies should lead to increased comprehension of the biochemical mechanisms involved in the synthesis of these unique and biologically significant plant lipids. The cuticular waxes of plants constitute the first barrier to the environment and the stresses it imposes on plants, and thus these waxes play an important role in plant survival. The composition of these waxes and the biosynthetic pathways by which they are formed are incompletely known. This project will make use of transposon-tagged cloned genes to examine the gene products of the biosynthetic pathway and thus enlarge our understanding of it.//