AUTHOR=McClean Phillip E. , Lee Rian , Howe Kevin , Osborne Caroline , Grimwood Jane , Levy Shawn , Haugrud Amanda Peters , Plott Chris , Robinson Melanie , Skiba Ryan M. , Tanha Tabassum , Zamani Mariam , Thannhauser Theodore W. , Glahn Raymond P. , Schmutz Jeremy , Osorno Juan M. , Miklas Phillip N. 

TITLE=The Common Bean V Gene Encodes Flavonoid 3′5′ Hydroxylase: A Major Mutational Target for Flavonoid Diversity in Angiosperms

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.869582

DOI=10.3389/fpls.2022.869582

ISSN=1664-462X

ABSTRACT=The classic V (violet, purple) gene of common bean (Phaseolus vulgaris) functions in a complex genetic network that controls seed coat and flower color and flavonoid content.  V was cloned to understand its role in the network and the evolution of its orthologs in the Viridiplantae.  V mapped genetically to a narrow interval on chromosome Pv06.  A candidate gene was selected based on flavonoid analysis and confirmed by recombinational mapping.  Protein and domain modelling determined V encodes flavonoid 3’5’ hydroxylase (F3’5’H), a P450 enzyme required for the expression of dihydromyricetin-derived flavonoids in the flavonoid pathway.  Eight recessive haplotypes, defined by mutations of key functional domains required for P450 activities, evolved independently in the two bean gene pools from a common ancestral gene.  V homologs were identified in Viridiplantae orders by functional domain searches.  A phylogenetic analysis determined F3’5’H first appeared in the Streptophyta and is present in only 41% of Angiosperm reference genomes.  The evolutionarily-related flavonoid pathway gene flavonoid 3’ hydroxylase (F3’H) is found nearly universally in all Angiosperms.  F3’H may be conserved because of its role in abiotic stress, while F3’5’H evolved as a major target gene for the evolution of flower and seed coat color in plants.