Insights into the diversification of subclade IVa bHLH transcription factors in Fabaceae

Abstract Background Fabaceae plants appear to contain larger numbers of subclade IVa basic-helix-loop-helix (bHLH) transcription factors than other plant families, and some members this have been identified as saponin biosynthesis regulators. We aimed systematically elucidate the diversification obtain insights into evolutionary history regulation in Fabaceae. Results In study, we collected sequences bHLH proteins from 40 species, including fabids plants, found greater bHLHs confirmed conservation domain, C-terminal ACT-like exon-intron organisation among almost all model legumes, supporting results our classification. Phylogenetic tree-based classification revealed presence three different groups. Interestingly, most fell group 1, which contained legume regulators date. These observations support co-occurrence Fabaceae-specific Comparing expression orthologous genes Glycine max , Medicago truncatula Lotus japonicus orthologues MtTSAR1 (the first soyasaponin regulatory factor) were not expressed same tissues, suggesting that 1 gained patterns contributions during their duplication divergence. On hand, groups 2 3 possessed fewer members, phylogenetic relationships highly conserved, indicating activities may be conserved across Conclusions This study suggests subdivision plants. The will useful for candidate selection unidentified Furthermore, functions are interesting targets clarifying evolution