Functional characterization of wheat ent-kaurene(-like) synthases indicates continuing evolution of labdane-related diterpenoid metabolism in the cereals

► Biochemical characterization of ent-kaurene(-like) synthases from wheat and barley. ► Functional diversity provides rationale for expanded gene family. ► Stereospecificity highlighted variation in upstream copalyl diphosphate synthases. ► Molecular phylogenetic analysis indicates continuing diterpenoid evolution within the cereals.