# Genomic analyses of 238 seed plants reveal the evolutionary mechanisms driving specialization of F3H, ANS, and FLS in flavonoid biosynthesis

## TL;DR

This study explores how three key enzyme families evolved in seed plants, shedding light on how flavonoid biosynthesis pathways diversified over time.

## Contribution

The study reveals the evolutionary mechanisms behind the specialization of F3H, ANS, and FLS enzyme families in flavonoid biosynthesis.

## Key findings

- The three enzyme families originated from a common ancestral gene and diversified through gene duplication events.
- Subfunctionalization resolved ancestral multifunctionality, aligning with the EAC model of evolution.
- Purifying selection and lineage-specific motif variations support functional differentiation in these enzyme families.

## Abstract

Flavonoid metabolism innovation is critical for seed plants’ terrestrial adaptation. Three key 2-oxoglutarate-dependent dioxygenase (2ODD) families—F3H, ANS, FLS—underpin flavonoid biosynthesis, but their evolutionary diversification mechanisms remain unclear.

Comprehensive analyses were performed across 238 seed plant genomes, including phylogenetic/collinearity analyses, conserved motif detection, duplication-type classification, selection pressure assessment, and Brassica napus promoter/expression profiling.

These families originated from a common ancestral gene (ancestor X) and diversified via multiple duplications (TRD/WGD as primary drivers). Their evolution aligns with the EAC model, with subfunctionalization resolving ancestral multifunctionality. Structural conservation and lineage-specific motif variations support functional differentiation, and purifying selection predominates.

Our findings clarify the molecular evolutionary mechanisms of flavonoid pathway diversification, providing novel insights into the origin of flavonol and anthocyanin biosynthesis in seed plants.