Genome-wide analysis of the MYB-CC gene family of maize

The MYB-CC gene family encode proteins that harbor a combination of characteristic myeloblastosis (MYB) and coiled-coil (CC) domain structures. Some MYB-CC genes have been demonstrated to represent transcription factors regulating phosphate uptake and controlling the starvation response in plants. Despite their physiological importance, a systematic analysis of MYB-CC genes has not been reported in maize. In our study, we identified and characterized maize MYB-CC genes at whole-genome level. A total of 12 maize MYB-CC genes (ZmMYB-CC1 to ZmMYB-CC12) were identified located in six out of the 10 chromosomes of maize. Their gene structures showed similar splicing patterns and large variations of intron length. Multiple sequence alignments revealed that all MYB-CC proteins in maize shared conserved sequence cores corresponding to the MYB and CC domains, respectively. The family expanded in maize partly due to tandem and segmental duplication events. Phylogenetic analysis of MYB-CC genes indicated that the MYB-CC gene family can be divided into two subfamilies and that gene members with same functions were found in the same groups. Results provide a very useful reference for cloning and functional analysis of PHR-like genes in maize and suggest a method to predict and select appropriate candidate genes for functional genomic analysis of useful traits in crop plants.