A key gene bHLH115 in iron homeostasis: comprehensive bioinformatics analyses in Arabidopsis, tomato, rice, and maize.

bHLH115 transcription factor (TF) is a positive regulator of the Fe-deficiency and plays essential roles in the stress-related regulation network. In this study, orthologous bHLH115 genes in Arabidopsis, tomato, rice, and maize were analyzed using in silico methods. All bHLH115 proteins contained PF00010 (HLH: Helix-loop-helix DNA-binding domain) domain structure and their sub-cellular localizations were predicted as nucleus. The bHLH115 orthologues in monocots and dicots clearly diverged from each other. The expression analyses revealed that orthologous genes of bHLH115 in queried species were highly expressed in seed parts, leaf, stem, and flower parts. The bHLH115 genes were co-expressed with genes in plant defense system, and with genes involving in biotic and abiotic stress responses. In terms of protein structures, OsbHLH115 and ZmbHLH115, and AtbHLH115 and SlbHLH115 had the highest protein structure similarities. In addition, bHLH115 proteins have bZIP, bHLH and MYB transcription factor binding sites strengthens their engagement in various metabolic ways. Molecular docking analyses showed the different binding sites based on plant species, suggesting functional flexibilities of bHLH115 gene.