Genome-wide identification and expression analysis of the trihelix transcription factor family in sesame (Sesamum indicum L.) under abiotic stress

BACKGROUND: The plant trihelix gene family is among the earliest discovered transcription factor families, and it is vital in modulating light, plant growth, and stress responses. METHODS: The identification and characterization of trihelix family members in the sesame genome were analyzed by bioinformatics methods, and the expression patterns of sesame trihelix genes were assessed by quantitative real-time PCR. RESULTS: There were 34 trihelix genes discovered in the genome of sesame, which were irregularly distributed among 10 linkage groups. Also, the genome contained 5 duplicate gene pairs. The 34 trihelix genes were divided into six sub-families through a phylogenetic study. A tissue-specific expression revealed that SiTH genes exhibited spatial expression patterns distinct from other trihelix genes in the same subfamily. The cis-element showed that the SiTHs gene promoter contained various elements associated with responses to hormones and multiple abiotic stresses. Additionally, the expression patterns of 8 SiTH genes in leaves under abiotic stresses demonstrated that all selected genes were significantly upregulated or downregulated at least once in the stress period. Furthermore, the SiTH4 gene was significantly induced in response to drought and salt stress, showing that SiTH genes may be engaged in the stress response mechanisms of sesame. CONCLUSION: These findings establish a foundation for further investigation of the trihelix gene-mediated response to abiotic stress in sesame. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11033-023-08640-w.