SHORT CHAIN FATTY ACIDS IN APPLE, AND THEIR POSSIBLE SIGNIFICANCE AS GROWTH INHIBITORS

The in vitro evaluation of the inhibitory properties of the C₁ to C₁₂ saturated carboxylated acids on apple bud break revealed a strong correlation between the length of the alkyl chain of these compounds and their effectiveness as inhibitors. Acids with chain lengths of 8, 9 and 10 were most inhibitory and phytotoxic and the protonated molecules were more active than the corresponding anions. Under orchard conditions these compounds did not delay bud break when applied in the spring to dormant buds. Lipid bodies in the cotyledons of apple seeds were investigated as a model system for testing the inhibitory action of these carboxylated acids. Rapid disappearance of the NMR lipid signal occurred during germination, but this process was inhibited by 10 mM nonanoate. The inhibition of the rate of hydrolysis of olive oil emulsion by nonanoate was detected. The isolation of free octanoic and nonanoic acids from apple seeds was accomplished.