Genome-wide identification and expression analyses of R2R3-MYB transcription factor genes from two Orchid species.

MYB transcription factors play important roles in different plant biological processes during plant growth, development and stress response. In this study, 101 () and 99 () genes were identified in the genomes of and , respectively. To classify the isolated candidate genes, the genes from were selected as references. As a result, all identified and genes were classified into 22 subfamilies. Phylogenetic analysis revealed that S21 had the largest number of members of all the subfamilies. The numbers of introns, exons and conserved sequences in all of the identified genes are different. In addition, 20 genes from six subfamilies were selected for further analysis of tissue-specific expression and responses to various abiotic stresses treatments. The results showed that all of the genes in S4 and S19 subfamilies exhibited the highest relative expression levels in flowers. And five genes including , , DoMYB49, and , responded to the stress response. These results may provide useful information for further studies of the R2R3-MYB gene family.