The recombinant enzyme from Vitis vinifera forms 49.5% (+)-valencene (cf. EC 184.108.40.206, valencene synthase) and 35.5% (-)-7-epi-alpha-selinene. Initial cyclization gives (+)-germacrene A in an enzyme bound form which is not released to the medium.
male flower parts of grapevines are responsible for sesquiterpenoid floral scent formation. Sesquiterpene volatiles, which are emitted with a light-dependent diurnal pattern early in the morning at prebloom and bloom, are localized to anthers and, more specifically, within the developing pollen grains
Vitis vinifera terpenoid cyclases: functional identification of two sesquiterpene synthase cDNAs encoding (+)-valencene synthase and (-)-germacrene D synthase and expression of mono- and sesquiterpene synthases in grapevine flowers and berries