THE EFFECT OF FLURIDONE ON ACCUMULATION OF CAROTENOIDS, FLAVONOIDS AND PHENOLIC ACIDS IN RIPENING TOMATO FRUIT

We examined the response of maturing tomato fruit exposed for 7 days to fluridone (1-methyl-3-phenyl-5-[3-trifluoromethyl(phenyl)]-4(1H)-pyridinone). Fluridone was applied in lanolin paste in the form of a 2–3 mm wide strip from the top to the base of the fruit. As a control, a similar stripe of lanolin was applied in the same way on the opposite side of the same fruit. The content of major carotenoids, as well as flavonoids, and free and bound phenolic acids were determined using a HPLC and HPLC-MS-MS methods. Fluridone almost completely blocked the biosynthesis of lycopene and substantial declined content of ß-carotene and lutein in the tomato fruit. The fluridone caused a decreased content of quercetin, rutin and naringenin, and increased level of epicatechin. The herbicide did not affect the content of p-coumaric acid, but reduced the level of caffeic acid, both free and ester form, and declined the content of free ferulic and chlorogenic acids. Changes in phenolics composition observed for the first time indicate that fluridone interferes with the biosynthesis of further products of the metabolism of p-coumaric acid, both flavonoids and phenolic acids.