532 Lovastatin Inhibits α-Farnesene Synthesis without Affecting Ethylene Production during Fruit Ripening in Apples

Abstract

At harvest, internal ethylene was >0.5 mL·L–1 and α-farnesene concentrations were below detectable levels in `Golden Supreme', `Delicious', and `Granny Smith' apples. After 30 days of storage at 20 °C, control fruit produced high levels of internal ethylene and α-farnesene. Lovastatin at 100 to 1000 mL·L–1 did not affect ethylene synthesis, but significantly inhibited α-farnesene production. In `Golden Delicious', ethephon treatment increased ethylene synthesis in lovastatin-treated fruit but did not stimulate α-farnesene production. In lovastatin-treated fruit peel of `Delicious' and `Granny Smith', mevalonate (MAL) and farnesyl pyrophosphate (FPP) induced α-farnesene production, but hydroxymethylglutaric acid (HMG) did not. The induction of α-farnesene synthesis by MAL and FPP was concentration-dependent. Precursor feeding did not affect ethylene production in fruit peel. When high level of α-farnesene was detected in fruit peel (5 mm thick), it was not found in outer (adjacent to peel) and inner cortex (mid of flesh) tissues. Adding HMG, MAL, and FPP induced α-farnesene biosynthesis in both cortex tissues. When lovastatin was added to the feeding solution, MAL and FPP induced α-farnesene production but HMG did not.