linoleic-acid and ethylene

Fruit aroma development depends on ripening. Abscisic acid (ABA) has been reported to be involved in the regulation of tomato fruit ripening. In the present study, the effects of exogenous ABA on aromatic volatiles in tomato fruit during postharvest ripening were studied. The results showed that exogenous ABA accelerated color development and ethylene production as well as the accumulation of carotenoids, total phenolics and linoleic acid in tomato fruit during ripening. Moreover, exogenous ABA increased the accumulation of volatile compounds such as 1-peten-3-one (2.06-fold), β-damascenone (1.64-fold), benzaldehyde (3.29-fold) and benzyl cyanide (4.15-fold); induced the expression of key genes implicated in the biosynthesis pathways of aromatic volatiles, including TomloxC, HPL, ADH2, LeCCD1B and SlBCAT1 (the values of the log

Topics: Abscisic Acid; Alcohol Dehydrogenase; Aldehyde-Lyases; Carotenoids; Chlorophyll; Cytochrome P-450 Enzyme System; Ethylenes; Fatty Acids; Fruit; Gene Expression Regulation, Plant; Linoleic Acid; Lipoxygenase; Phenols; Plant Growth Regulators; Solanum lycopersicum; Volatile Organic Compounds

When rats were fed elaidic (trans-9 18:1) acid at a high load in diets that were otherwise marginally or almost completely deficient in linoleic (cis-9,cis-12 18:2) acid, elaidic acid was desaturated to cis-5,trans-9 18:2 acid. This polymethylene-interrupted acid was then incorporated into most phospholipids from rat mitochondria, cardiolipin being an exception. Its level of esterification in phospholipids followed the increasing order: phosphatidylethanolamine < phosphatidylcholine < phosphatidylinositol (PI). The content of cis-5,trans-9 18:2 acid decreased in organs in the order liver > kidney > heart. The levels of cis-5,trans-9 18:2 acid increased in mitochondria phospholipids as the level of linoleic acid was lowered in the diet. In liver mitochondria PI, it reached 16% of total fatty acids. After hydrolysis of liver mitochondria PI with Naja naja phospholipase A2, we observed that elaidic acid was essentially esterified to position 1 at the expense of saturated acids, whereas cis-5,trans-9 18:2 acid was exclusively esterified to position 2, along with 20:3n-9 and 20:4n-6 acids. As a consequence, the sums of saturated and trans-9 18:1 acids on the one hand, and of 20:3n-9, 20:4n-6, and cis-5,trans-9 18:2 acids on the other hand, remained fairly constant in liver mitochondria PI (ca. 55 and 30%, respectively). Because trans-9 18:1 and cis-5,trans-9 18:2 acids differ only by the cis-5 ethylenic bond, which is also present in 20:3n-9 and 20:4n-6 acids, this distribution pattern indicates that the cis-5 double bond, rather than any other ethylenic bond, may be of major structural importance for channeling fatty acids to position 2 of PI.

Topics: Acylation; Animals; Cardiolipins; Dietary Fats; Esterification; Ethylenes; Fatty Acid Desaturases; Kidney; Linoleic Acid; Linoleic Acids; Male; Mitochondria; Mitochondria, Heart; Mitochondria, Liver; Oleic Acid; Oleic Acids; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylinositols; Phospholipases A; Phospholipases A2; Rats; Rats, Wistar