Large scale in silico identification of MYB family genes from wheat expressed sequence tags

The MYB proteins constitute one of the largest transcription factor families in plants. Much research has been performed to determine their structures, functions, and evolution, especially in the model plants, Arabidopsis, and rice. However, this transcription factor family has been much less studied in wheat (Triticum aestivum), for which no genome sequence is yet available. Despite this, expressed sequence tags are an important resource that permits opportunities for large scale gene identification. In this study, a total of 218 sequences from wheat were identified and confirmed to be putative MYB proteins, including 1RMYB, R2R3-type MYB, 3RMYB, and 4RMYB types. A total of 36 R2R3-type MYB genes with complete open reading frames were obtained. The putative orthologs were assigned in rice and Arabidopsis based on the phylogenetic tree. Tissue-specific expression pattern analyses confirmed the predicted orthologs, and this meant that gene information could be inferred from the Arabidopsis genes. Moreover, the motifs flanking the MYB domain were analyzed using the MEME web server. The distribution of motifs among wheat MYB proteins was investigated and this facilitated subfamily classification.