Abstract
AbstractFlavonoids are secondary metabolites associated with seed and flower color. A ternary MBW protein complex consisting of interfacingMYB,beta-helix-loop-helix (bHLH), andWD40 repeat (WDR) proteins controls the expression of late biosynthetic genes in the flavonoid pathway.P, the master regulator gene of flavonoid expression in common bean (Phaseolus vulgarisL.) was recently determined to encode a bHLH protein. Two other genes,TandZ, are also historically considered regulators since they determine the distribution of color in seeds and flowers. These two genes were cloned using reverse genetics based on genetic mapping, candidate gene selection, phylogenetic analysis, and mutant analysis. Domain and AlphaFold2 structure analyses determinedTencoded a seven-bladed β-propeller WDR protein, whileZencoded a R2R3 MYB protein. Modeling of the Z MYB/P bHLH/T WDR MBW complex identified interfacing sequence domains and motif in all three genes that are conserved in dicots. One Z MYB motif is a possible β-MoRF that only appears in a structured state when Z MYB is modeled in a MBW complex. Complexes containing mutant T and Z proteins changed the interaction of members of the complex in ways that would alter their role in regulating expression of genes in the flavonoid pathway.HighlightThe MBW complex of bean comprised of the classicZ,P, andTgenes associated with seed coat patterning defines critical proteins interactions for flavonoid gene expression.
Publisher
Cold Spring Harbor Laboratory
Reference65 articles.
1. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV
2. Inheritance of the Fib gene (from 5-593) for fibula arcs pattern of partly colored seed coat in the background genotype t P [C r] Z J G B V Rk;Annual Report of the Bean Improvement Cooperative,2001
3. Genetics of seed coat color and pattern in common bean;Plant Breeding Reviews,2007
4. The genetics of the color pattern of seed coats in G19833, a Liborino class common bean;Annual Report of the Bean Improvement Cooperative,2011
5. Allelism found between two common bean genes, hilum ring color ( D) and partly colored seedcoat pattern (Z), formerly assumed to be independent;Journal of the American Society for Horticultural Science,1999