Spatiotemporal changes in the Content and Metabolism of 9, 12, 13 – Trihydorxy-10(E)-Octadecenoic Acid in Tomato (Solanum Lycopersicum L. CV Balkonsar) fruits

Abstract

In a previous study, we showed that 9,12,13-trihydroxy-10(E)-octadecenoic acid which is probably involved in plant defense responses is synthesized in tomato fruits and subjected to metabolism. Its catabolism or conversion was thus further characterized. The endogenous level of 9,12,13-trihydroxy-10(E)-octadecenoic acid decreased in the mesocarp and endocarp during the maturation of tomato fruits. The level of this trihydroxy fatty acid in the epicarp declined till the mature-green stage and then increased during the colour change. Injection of buffered solutions of unlabeled 9,12,13-trihydroxy-10(E)-octadecenoic acid into two weeks old fruits while they were still attached to the plants led to the alteration of contents of ten metabolites. After the infiltration of buffered solutions of isotopically labeled 9,12,13-trihydroxy-10(E)-octadecenoic acid into green unripe tomato fruits which were still attached to the plant, the highest radioactivity was found in compounds much more polar than 9,12,13-trihydroxy-10(E)-octadecenoic acid and whose signals in HPLC-UV-chromatogram coincided with the citric acid peak. These results indicated that 9,12,13-trihydroxy-10(E)-octadecenoic acid could be implicated in the control of tomato fruit maturation and β-oxidation might be one of its degradation pathways

Keywords: Ethylene production, fruit maturation, ripening, β-oxidation, pinellic acid, Solanum lycopersicum L. cv Balkonstar