Discovery of iridoid cyclase completes the iridoid pathway in asterids.

ABSTRACT: Iridoids are specialized monoterpenes ancestral to asterid flowering plants^1,2 that play key roles in defence and are also essential precursors for pharmacologically important alkaloids^3,4. The biosynthesis of all iridoids involves the cyclization of the reactive biosynthetic intermediate 8-oxocitronellyl enol. Here, using a variety of approaches including single-nuclei sequencing, we report the discovery of iridoid cyclases from a phylogenetically broad sample of asterid species that synthesize iridoids. We show that these enzymes catalyse formation of 7S-cis-trans and 7R-cis-cis nepetalactol, the two major iridoid stereoisomers found in plants. Our work uncovers a key missing step in the otherwise well-characterized early iridoid biosynthesis pathway in asterids. Th

SUBMITTER: Colinas M 

PROVIDER: S-EPMC12626888 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature