Biosynthesis of floral scent 2-phenylethanol in rose flowers

Abstract

Plants emit chemically diverse volatile compounds for attracting pollinators or putting up a chemical defense against herbivores. 2-Phenylethanol (2PE) is one of the abundantly emitted scent compounds in rose flowers. Feeding experiments with L-[2 H8] phenylalanine into rose flowers and subsequent analysis using gas chromatography-mass spectrometry analysis revealed the hypothetical biosynthetic intermediates to [2H 8 ]-2PE, and the biochemical and genetic analyses elucidated the principal pathway to [2H 8 ]-2PE. We recently found season-specific 2PE pathway producing [ [2H 7 ]-2PE from L-[2 H8] phenylalanine. This is a unique example where the dominant pathway to a specific compound changes with the seasons. This review focuses on the biosynthesis of floral volatiles and their regulation to adapt to the changes in the environment.