Cutin and suberin are the structural polymers of plant cuticle, functioning as protective barriers to the environment and also among various plant organs. Although these biopolyesters are composed of known fatty acid constituents, their insolubility has hampered investigations of how the monomer units are linked together chemically. Several new research strategies are proposed herein: (1) 13C NMR spectra and spin relaxation studies (cross-polarization and direct acquisition with magic-angle spinning) of intact cutin to assess cuticular resiliency at extremes of temperature; (2) 13C and 2H NMR investigations of molecular interactions in cutin-wax and cutin-water mixtures; (3) production and spectroscopic identification of cutin oligomers and residues from selective depolymerization treatments; (4) 13C NMR studies of chemical bonding and polymer-polymer interactions in suberin-cell wall assemblies. With this coordinated approach to supramoleclar structure elucidation in plant cuticle polyesters, it should be possible to test existing hypotheses and develop new mechanistic ideas regarding their function in crop protection, plant development, and livestock nutrition.
