Genome-wide identification and expression analysis of the dof (DNA binding with one finger) protein family in monocot and dicot species

Dof (DNA binding with one finger) proteins are widely associated with many kinds of biological processes in plant development. Although Dof proteins have been characterized in many species, little is known about the phylogenetic, collinear relationships and expression patterns among monocot and dicot species. In this study, a genomewide analysis of Dof proteins in 7 monocot and 4 dicot species was performed systematically. In total, 392 Dof proteins were identified and classified into 11 distinct groups based on phylogenetic analysis. Interestingly, the proteins identified from monocots clustered separately from those of dicots. The motif and gene structure analysis suggested that each group had alike conserved motifs and similar exon/intron compositions. In addition, different motifs among groups might indicate different functions. Multiple collinearity analysis and expression patterns in 3 monocot and 2 dicot species illustrated that most of the ortholog pairs shared similar expression patterns. Functional mode diagram and expression patterns showed that Dof proteins' functions were generally associated with their expression patterns. This study offered novel insights in the phylogenetic, collinear, expressional and functional analysis of Dof proteins and contributed to the further investigation of Dof proteins in plants.