Cuphea procumbens: A model system for studying the mechanism of medium-chain fatty acid biosynthesis in plants

Abstract

Seeds of Cuphea procumbens are rich in medium-chain fatty acids. In mature seeds, C10:0 constitutes over 80% of the fatty acid of the triacylglycerol fraction but is only a very minor constituent of the polar lipid fraction. C10:0 was found to a small extent in the neutral lipid fraction of other parts of the Cuphea plant but was absent from the polar lipid fraction — C10:0 thus acts as a marker for seed lipid biosynthesis. The fatty acid composition of maturing Cuphea seeds was analysed. Between 11–14 days after flowering C10:0 biosynthesis increases dramatically. Radioactive incorporation experiments using mature desiccated seeds demonstrate that they still have the capacity to synthesize C10:0. In vitro incorporation experiments demonstrate that 13–16-day-old seeds synthesize almost exclusively C10:0. These observations indicate that C. Procumbens is a good experimental system for studying the mechanism of medium-chain fatty acid biosynthesis in plants.