Organization and regulation of triterpene saponin biosynthesis in Medicago truncatula

Medicago truncatula is an established model plant, not only for legume biology, but also for the study of specialized metabolism, which serves to create defense barriers and responses to biotic and abiotic external threats. Triterpene saponins (TS) and flavonoids are the two major classes of specialized metabolites in M. truncatula. Here, we provide a detailed overview of TS biosynthesis and regulation and link this to the spatial and functional organization of TS in M. truncatula. Depending on specific oxidations of the triterpene aglycone backbone, M. truncatula TS can be divided further into two types, the hemolytic and non‐hemolytic TS. TS biosynthesis is positively regulated by jasmonate phytohormones, which is mediated, at least in part, through specific basic helix‐loop‐helix transcription factors. Furthermore, TS production is subjected to post‐translational regulation by protein‐protein interactions or endoplasmic reticulum‐associated degradation of key enzymes of the TS biosynthesis pathway, which allows surveying appropriate TS balances.

ISBN:9781119409144

Publication year:2020

Accessibility:Closed