Genome-Wide Identification, Structure Characterization, and Expression Profiling of Dof Transcription Factor Gene Family in Wheat (Triticum aestivum L.)

DNA binding with one finger (Dof) proteins are plant-specific transcription factors with crucial roles in plant growth and stress response. Even so, little is known about them in wheat. In this study, 108 wheat Dof (TaDof) genes across 21 chromosomes were detected. Although variable in sequence length, molecular weight, and isoelectric point, all TaDof proteins contained conserved zinc-finger structures and were phylogenetically divided into 7 sub-groups. Exon/intron and motif analyses suggested that TaDof structures and conserved motifs were similar within sub-groups but diverse among sub-groups. Many segmental duplications were identified and Ka/Ks and inter-species synthetic analyses indicated that polyploidization was main reason for increased number of TaDofs. Prediction and experimental confirmation revealed that TaDofs functioned as transcription factors in the nucleus. Expression pattern profiling showed that TaDofs specifically affected growth and development, and biotic and abiotic stress responses. Wheat miRNAs and cis-regulator were predicted as essential players in molding TaDofs expression patterns. qRT-PCR analysis revealed that TaDofs were induced by salt and drought stresses. Customized annotation revealed that TaDofs were widely involved in phytohormone response, defense, growth and development, and metabolism. Our study provided a comprehensive understanding to wheat TaDofs.