Regulation of terpenoid and benzenoid production in flowers.

The production and emission of fragrant molecules by flowers are strictly regulated during the floral lifespan and often peak when pollinators are active. The best-studied classes of floral volatiles are benzenoids and terpenoids. The production of these molecules appears to be primarily regulated at the level of precursor biosynthesis. The genes from the petunia floral shikimate pathway, which provides the precursors for the formation of benzenoids, have recently been shown to be regulated by a MYB transcription factor. The floral terpenoids of snapdragon appear to be derived exclusively from the methyl-erythritol-phosphate pathway in plastids. This pathway controls precursor levels for geranyl diphosphate synthase, which in turn is transcriptionally regulated.