Saponin glycosylation in cereals

摘要

Triterpene saponins are glycosylated plant secondary metabolites that are common in dicotyledonous species but rare in monocots.These compounds are antimicrobial and are important for plant defence.They also have a variety of pharmaceutical and industrial applications.Oat (Avena spp.) produces triterpene saponins called avenacins,specialised metabolites that are not represented in other cereals.The avenacins are synthesised and stored in roots and provide protection against soil-borne fungal pathogens.Glycosylation is often critical for bioactivity of saponins.We are using a combination of mutant analysis,database mining,expression profiling and functional characterisation to identify glycosyltransferases required for addition of sugar units to avenacins.By identifying the molecular machinery required for avenacin biosynthesis we hope to understand the broader elements of the evolution of specialised metabolic pathways.