Structure, gas chromatographic measurement, and function of suberin synthesized by potato tuber tissue slices

The polymeric material (suberin) of the wound periderm of potato tuber slices was analyzed after depolymerization with LiAIH₄ in tetrahydrofuran or BF₃ in methanol with the use of thin layer chromatography, chemical modification, and combined gas-liquid chromatography and mass spectrometry. Fatty acids (C₁₆ to C₂₆), fatty alcohols (C₁₆ to C₂₆), octadec-9-ene-1, 18-dioic acid, and 18-hydroxy-octadec-9-enoic acid were identified to be the major components. Based on the structural information that the two bifunctional C₁₈ molecules constituted a major portion of suberin, a gas chromatographic method of measuring suberization was developed. This method consisted of hydrogenolysis of powdered tissue followed by thin layer chromatography and gas chromatographic measurement of octadecene-1, 18-diol as the trimethylsilyl ether. With this assay it was shown that the development of resistance to water loss by the tissue slices was directly proportional to the quantity of the bifunctional C₁₈ molecules, thus providing evidence that a function of suberin is prevention of water loss.