Molecular Characterization and Expression of CmobHLH Genes in Pumpkin

The transcription factor bHLH gene family plays fundamental roles in plant development and mitigating diverse biotic and abiotic stresses. However, the information of bHLH genes in pumpkin (Cucurbita moschata) is still unknown. In this current study, 222 CmobHLH genes were identified and mapped onto different chromosomes through bioinformatics analysis in pumpkin. CmobHLH and AtbHLH proteins could be classified into 19 subfamilies according to the phylogenetic tree. CmobHLH proteins within the same subfamily had similar motif composition and gene structures. Gene ontology (GO), cis-regulatory elements (CREs) and protein-protein interaction analyses suggested the potential regulatory roles of CmobHLH genes during the plant development process and abiotic stresses response in pumpkin. Tissue expression patterns based on transcriptome data demonstrated that CmobHLH genes were involved in pumpkin development process, and they had unique functions in different tissues. The expression patterns of five selected CmobHLH genes after exposure to abiotic stresses showed that the CmobHLH genes played varied roles in the stress responses of pumpkin to NaCl, waterlogging, cold, ABA and drought. In brief, these findings offer important information for further functional research of CmobHLH genes and resistance breeding in pumpkin.