Increased lycopene and flavor volatile production in tomato calyces and fruit cultured in vitro and the effect of 2-(4-chlorophenylthio)triethylamine

Earlier it was shown that tomato (Lycopersicon esculentum cv. VFNT Cherry) calyces develop into fruit tissue when cultured at 16-22 degrees C, producing flavor compounds and changes in color and sugar content characteristic of ripening fruit. Here are reported unusually high [580 mu g (g of fresh weight)(-1)] lycopene concentrations in these fruit compared to reports on field-grown tomatoes (similar to 10 times higher). Addition of 2-(4-chlorophenylthio)triethylamine (CPTA) (75 mg L-1) to the culture medium produced further increases in lycopene in fruit and calyces. Some carotenoid-derived flavor volatiles also increased, as well as some not related to carotenoids. The greatest increase in lycopene, however, resulted not from addition of CPTA but from a mechanism triggered by cool temperatures, which was previously shown to involve tomato AGAMOUS (TAG1) gene activation and which seems correlated to ripening. Concentrations of these compounds in fruit and calyces grown in vitro at 26 degrees C with and without CPTA are also given.