Comparative Analysis of Dof Transcription Factor Family in Maize

Deoxyribonucleic acid binding with one finger (Dof) family, a kind of plant-specific transcription factor family, is involved in a variety of biological processes including signal transduction, morphogenesis, and environmental stress responses. In the present study, 46 putative Dof genes were identified from maize (Zea mays subsp. mays). The predicted ZmDof genes were non-randomly distributed within their chromosomes, and segmental duplication seemed to be the prevalent mechanism for their expansion. Most of these genes lacked introns and some only possessed one intron. Here, we classified 140 Dof proteins from Arabidopsis, rice, sorghum, and maize into seven groups by means of phylogenetic analysis. In addition, many cis-elements responding to light, endosperm specific gene expression, hormone, meristem specific expression, and stress were also found in the 1,000 bps upstream sequences of promoter regions. Selection analysis also identified some significant site-specific constraints acted on most Dof paralogs. Expression profiles based on microarray data provided insights into the functional divergence of different tissues. Results by quantitative reverse transcription polymerase chain reaction analysis indicated that some ZmDofs responded to some abiotic stresses. Taken together, our study will provide some useful information for biological evolution and functional characterization of the maize Dof genes.