Abstract
The composition of the aliphatics of the protective cuticular polymers from different anatomical regions from several plant species was determined by combined gas-liquid chromatography and mass spectrometry of the depolymerization products derived from the polymers. The polymer from the aerial parts of Vicia faba showed similar composition; dihydroxypalmitic acid was the major (>85%) component of the cutin covering leaves, petioles, flower petals and stem with smaller amounts of palmitic acid and omega-hydroxy palmitic acid. On the other hand, the chief components of the polymer from the tap root were omega-hydroxy C(16:0) and C(18:1) acids and/or the corresponding dicarboxylic acids. The positional isomer composition of the dihydroxy C(16) acids was shown to be dependent upon anatomical location, developmental stage, and light. Apple cutin from rapidly expanding organs (flower petal and stigma) was shown to contain predominately C(16) family acids whereas the C(18) family dominated in cutin of slower growing organs (leaf and fruit). The composition of the aliphatic components of cutin found in the seed coats of pea, corn, barley, and lettuce was found to be similar to that of the cuticular polymer of the leaves in each species.