Abstract
Multiple copies of flavonoid biosynthetic genes with different patterns of expression in several tissue and induction following environmental stimuli were identified in Legume. We are trying to analyze regulatory networks controling flavonoid biosynthesis in Legume. Sequence homology searches in model legume Lotus japonicus revealed gene duplication in the transcription factors regulating proanthocyanidin biosynthesis. Three copies of a homologue of Arabidopsis TRANSPARENT TESTA2 (TT2), which is an MYB transcription factor, were present in the Lotus japonicus genome. Transient assay suggest that three LjTT2s are different in protein-protein interaction property. To understand the protein interaction of LjTT2s, we isolated genes encoding bHLH factors and a WDR protein in Lotus japonicus. We also made chimeric constructs exchanging R2R3-MYB domain and C-terminal region of each LjTT2 and mutated constructs that possess amino acid substitution in R2 domain. Analysis using these constructs and isolated bHLH/WDR factors are in progress.
