The R2R3-MYB gene family in banana (Musa acuminata): genome-wide identification, classification and expression patterns

The R2R3-MYB genes comprise one of the largest transcription factor gene families in plants, playing regulatory roles in plant-specific developmental processes, defense responses and metabolite accumulation. To date MYB family genes have not yet been comprehensively identified in the major staple fruit crop banana. In this study, we present a comprehensive, genome-wide analysis of the MYB genes from Musa acuminata DH-Pahang (A genome). A total of 286 R2R3-MYB genes as well as genes encoding three other classes of MYB proteins containing multiple MYB repeats were identified and characterised with respect to structure and chromosomal organisation. Organ- an delopment-specific expression patterns were determined from RNA-seq data. For 279 M. acuminata MYB genes for which expression was found in at least one of the analysed samples, a variety of expression patterns were detected. The M. acuminata R2R3-MYB genes were functionally categorised which led to the identification of seven clades containing only M. acuminata R2R3 MYBs. The encoded proteins may have specialised functions that were acquired or expanded in Musa during genome evolution. The presented functional classification and expression analyses of the MYB gene family in banana establish a solid foundation for future comprehensive functional analysis of MaMYBs and can be utilized in banana improvement programmes.