Fig. 1

(A) Amino acid sequence comparison between NtbHLH1 and six flavonoid-related bHLHs. Two conserved domains (bHLH-MYC_N domain and HLH domain) among known bHLH TFs regulating anthocyanin flavonoid biosynthesis are underlined. (B) A neighbor-joining phylogenetic tree of IIIf subfamily plant bHLHs. Numbers next to the nodes are bootstrap values from 1,000 replications. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances that were used to infer the phylogenetic tree. The following deduced amino acid sequences were retrieved from GenBank databases: Arabidopsis thaliana AtTT8 (NP_192720.2), AtEGL3 (NP_001332705.1), AtGL3 (NP_001185302.1); Asparagus officinalis EGL1-like (XP_020260845.1); Elaeis guineensis GLABRA 3 (XP_010918535.1); Ananas comosus EGL1-like (XP_020084606.1); Chinese narcissus NtbHLH1 (QDS02912.1). Zea mays ZmLC (P13526.1), ZmB-Peru (CAA40544.1), ZmIN1 (AAB03841.1); Lilium hybrid division I LhbHLH1(BAE20057.1), LhbHLH2(BAE20058.1); Chinese narcissus NtbHLH1 (QDS02912.1); Malus domestica MdbHLH33 (ABB84474.1), MdbHLH3 (ADL36597.1); Fragaria vesca subsp. vesca FvEGL1 (XP_004308377.1); Vitis vinifera VvMYC1 (NP_001268182.1), VvMYCA1 (NP_001267954.1); Arabidopsis thaliana AtMYC (NP_191957.2), Lotus japonicus LjGL3 (BAJ10680.1), LjTT8 (BAH28881.1); Perilla frutescens PfMYC-RP (BAA75513.1), PfF3G1 (BAC56998.1); Antirrhinum majus AmDEL (AAA32663.1); Ipomoea nil InDEL (XP_019171149.1), InIVS (XP_019197480.1); Petunia x hybrida phJAF13 (AAC39455.1), PhAN1 (AAG25927.1); Solanum tuberosum StGL3-like (NP_001275132.1), StAN1 (ALA13578.1); Nicotiana tabacum NtAN1a (NP_001312042.1), NtAN1b (NP_001312452.1), NtJAF13a (NP_001311775.1), NtJAF13b (AHY00341.1); Fragaria x ananassa FabHLH3 (AFL02463.1); Nicotiana sylvestris NsAN1 (NP_001289495.1); Nicotiana tomentosiformis NtAN1 (NP_001289454.1)