High throughput screening of mutants of oat that are defective in triterpene synthesis.

摘要: The triterpenes are a large and diverse group of plant natural products that have important functions in protection food quality, range pharmaceutical other applications. Like sterols, they synthesised from mevalonate via the isoprenoid pathway, two pathways diverging after 2,3-oxidosqualene. During triterpene synthesis 2,3-oxidosqualene is cyclised to one number potential products, most common these being pentacyclic β-amyrin. Plants often produce complex mixtures conjugated glycosides which may be derived single skeleton. delineation, functional analysis exploitation plants therefore represent substantial challenge. Here we carried out high throughput screening identify mutants diploid oat (Avena strigosa) blocked early steps synthesis. We also show affected first committed step β-amyrin-derived triterpenes, so unable cyclise β-amyrin (sad1 mutants), accumulate elevated levels primary sterols. major differences were Δ-7-campesterol Δ-7-avenasterol, both increased several fold relative wild-type levels. This presumably due accumulation squalene consequent feedback into sterol consistent with previous reports specific oxidosqualene cyclase inhibitors elicitors biosynthesis shown inverse effects on flux through pathways.