Identification, Characterization and Expression Profiles of Dof Transcription Factors in Common Walnut (Juglans Regia L.)

Juglans regia is a hardwood tree of economic importance and produced high-quality wood and edible nuts. Dof (DNA binding with one finger) are plant-specific transcription factors (TF) family and has an important role in the development of different tissues. However, no study of the Dof gene family in Persian walnut (J. regia) has been reported to our knowledge. We identified 39 JrDof genes in the genome of J. regia. Dof family genes clustered into 06 groups based on the phylogenetic tree and contain a highly conserved motif. The motif composition and conserved domain analysis showed that the common walnut Dof gene family contains one conserved motif and one conserved domain Zf-Dof. Most of the Dof genes contain 1 and 2 exons, as revealed by structural analysis. All JrDof genes distributed unevenly on 16 chromosomes with the maximum member (4 genes) found on chromosome 3, 4, 6, 7, and 12. High expression of JrDof12-1, JrDof15-3, JrDof6-4, JrDof5-2, and JrDof13-2, (female flowers), JrDof10-1, JrDof3-3, and JrDof14-1, (male flowers), JrDof15-3 and JrDof13-2, (embryo), JrDof4-2, JrDof19-1, JrDof15-2, and JrDof12-4, (leaves, fruit and roots) were identified. RNA-Seq data also confirm that Dof genes play a role in the development of J. regia male and female flowers.