Biopolymers serve as physical barriers of plants and protect them from adverse environmental factors including pathogens. Two biopolymers, cutin and suberin, are being investigated by chemical and 13C- NMR methods during plant development. The biosynthesis of these natural products is being studied using enzymology and recombinant DNA approaches. The regulation of the enzyme cutinase is being studied at the gene level by fungal transformation and deletion analysis. The enzymes that degrade pectin will also be similarly studied and their role in fungal pathogenesis will be studied by gene disruption. This project provides basic information on the biochemistry and function of the defensive barriers of plants. This information is needed to devise ways to improve plant protection and production.***//