ApiaceaeFNS Ioriginated fromF3Hthrough tandem gene duplication

Abstract

AbstractBackgroundFlavonoids are specialized metabolites with numerous biological functions in stress response and reproduction of plants. Flavones are one subgroup that is produced by the flavone synthase (FNS). Two distinct enzyme families evolved that can catalyze the biosynthesis of flavones. While the membrane-bound FNS II is widely distributed in seed plants, one lineage of soluble FNS I appeared to be unique to Apiaceae species.ResultsWe show through phylogenetic and comparative genomic analyses that ApiaceaeFNS Ievolved through tandem gene duplication of flavanone 3-hydroxylase (F3H)followed by neofunctionalization. Currently available datasets suggest that this event happened within the Apiaceae in a common ancestor ofDaucus carotaandApium graveolens. The results also support previous findings thatFNS Iin the Apiaceae evolved independent ofFNS Iin other plant species.ConclusionWe validated a long standing hypothesis about the evolution of Apiaceae FNS I and predicted the phylogenetic position of this event. Our results explain how an Apiaceae-specificFNS Ilineage evolved and confirm independence from otherFNS Ilineages reported in non-Apiaceae species.