Characterization, Evolution, Expression and Functional Divergence of the DMP Gene Family in Plants

The <i>DMP</i> (DOMAIN OF UNKNOWN FUNCTION 679 membrane protein) domain, containing a family of membrane proteins specific to green plants, is involved in numerous biological functions including physiological processes, reproductive development and senescence in <i>Arabidopsis</i>, but their evolutionary relationship and biological function in most crops remains unknown. In this study, we scrutinized phylogenetic relationships, gene structure, conserved domains and motifs, promoter regions, gene loss/duplication events and expression patterns. Overall, 240 <i>DMP</i>s were identified and analyzed in 24 plant species selected from lower plants to angiosperms. Comprehensive evolutionary analysis revealed that these <i>DMP</i>s underwent purifying selection and could be divided into five groups (I-V). <i>DMP</i> gene structure showed that it may have undergone an intron loss event during evolution. The five <i>DMP</i> groups had the same domains, which were distinct from each other in terms of the number of <i>DMPs</i>; group III was the largest, closely followed by group V. The <i>DMP</i> promotor region with various <i>cis</i>-regulatory elements was predicted to have a potential role in development, hormone induction and abiotic stresses. Based on transcriptomic data, expression profiling revealed that <i>DMP</i>s were primarily expressed in reproductive organs and were moderately expressed in other tissues. Evolutionary analysis suggested that gene loss events occurred more frequently than gene duplication events among all groups. Overall, this genome-wide study elucidates the potential function of the <i>DMP</i> gene family in selected plant species, but further research is needed in many crops to validate their biological roles.