Identification and Expression Analysis of Transcription Factor Family in Highland Barley Seedlings Under Na₂SeO₃...

Transcription factors (TFs) are ubiquitously distributed in plants and play pivotal roles in regulating plant growth and development. The present study aims to elucidate the function of transcription factors (TFs) in highland barley's response to selenium stress. The results show that 89, 218, 141, 92, 23, and 34 genes were identified from the bHLH, MYB, NAC, WRKY, GATA, and HSF families, respectively. We analyzed the physicochemical properties of the transcription factor family, including amino acid number and molecular weight, theoretical PI, instability index, hydrophilicity index, and subcellular location. The majority of proteins encoded by these gene families are hydrophilic and predominantly localized in the nucleus. Structural analysis demonstrates that each family contains conserved motifs and domains. Most bHLH genes, such as KAE8811666.1 and KAE8789390.1, contain bHLH_SF superfamily domains. 45 MYB genes possess the myb_SHAQKYF domain. Most NAC genes possess typical NAM domains. Most WRKY proteins showed the WRKY superfamily domain. The 22 members of GATA possess the ZnF_GATA domain. HSF gene family showed that 24 gene family members contained HSF domains. Systematic evolutionary analysis indicates that the bHLH and NAC families can each be divided into nine subfamilies, while the remaining four families are categorized into five to eight subfamilies, respectively. Based on transcriptome data, under low selenium treatment, 56.25%, 76%, 67.39%, 47.37%, 50%, and 56.25% of the genes belonging to the bHLH, MYB, NAC, WRKY, GATA, and HSF transcription factor families were significantly upregulated, respectively. In contrast, under high selenium treatment, the proportions of upregulated genes in these families were 81.25%, 80%, 65.22%, 63.16%, 75%, and 75%, respectively. Additionally, qRT-PCR results were consistent with the trends of the transcriptome expression data, corroborating the reliability and accuracy of the transcriptomic findings. These results elucidate the molecular characteristics and response patterns of six transcription factor families to selenium stress in highland barley, laying a foundation for further in-depth research on the functions of transcription factors in highland barley plants.