%0 Journal Article %A ZHENG Xing-wei %A YI Deng-xia %A SHAO Lin-hui %A LI Cong %T In silico genome-wide identification, phylogeny and expression analysis of the R2R3-MYB gene family in Medicago truncatula %D 2017 %R 10.1016/S2095-3119(16)61521-6 %J Journal of Integrative Agriculture %P 1576-1591 %V 16 %N 07 %X     The R2R3-MYB genes make up one of the largest transcription factor families in plants, and play regulatory roles in various biological processes such as development, metabolism and defense response.  Although genome-wide analyses of this gene family have been conducted in several species, R2R3-MYB genes have not been systematically analyzed in Medicago truncatula, a sequenced model legume plant.  Here, we performed a comprehensive, genome-wide computational analysis of the structural characteristics, phylogeny, functions and expression patterns of M. truncatula R2R3-MYB genes.  DNA binding domains are highly conserved among the 155 putative MtR2R3-MYB proteins that we identified.  Chromosomal location analysis revealed that these genes were distributed across all eight chromosomes.  Results showed that the expansion of the MtR2R3-MYB family was mainly attributable to segmental duplication and tandem duplication.  A comprehensive classification was performed based on phylogenetic analysis of the R2R3-MYB gene families in M. truncatula, Arabidopsis thaliana and other plant species.  Evolutionary relationships within clades were supported by clade-specific conserved motifs outside the MYB domain.  Species-specific clades have been gained or lost during evolution, resulting in functional divergence.  Also, tissue-specific expression patterns were investigated.  The functions of stress response-related clades were further verified by the changes in transcript levels of representative R2R3-MYB genes upon treatment with abiotic and biotic stresses.  This study is the first report on identification and characterization of R2R3-MYB gene family based on the genome of M. truncatula, and will facilitate functional analysis of this gene family in the future.   %U https://www.chinaagrisci.com/Jwk_zgnykxen/EN/10.1016/S2095-3119(16)61521-6