Genome-wide identification and characterization of the Dof gene family in cassava (Manihot esculenta)

Dof proteins comprise a plant-specific transcription factor family involved in regulation of many plant processes. Despite their diverse roles, little information is available in cassava (Manihot esculenta, Euphorbiaceae), the sixth major staple crop in the world. This study presents the first genome-wide identification of Dof family genes in cassava, resulting in 45 family members that are unevenly distributed across 17 out of the 18 chromosomes. Phylogenetic analysis assigned these genes into eight groups representing four subfamilies. Synteny analysis and BRH (Best Reciprocal Hit) method were also adopted to study evolutionary relationships. Among 21 MeDof duplicates identified, the majority of them were derived from the recent whole-genome duplication (WGD), whereas only one from local duplication. Transcriptional profiling revealed diverse expression patterns among various tissues, and further comparison of conserved motifs and expression profiles revealed divergence of MeDof duplicates. These findings provide valuable information for functional analysis of Dof genes in cassava.