Molecular evolution of the poplar MIR169 gene family

MicroRNAs (miRNAs) are a class of short non-coding RNAs found widely in eukaryotic organisms. The ptc-MIR169 gene family, which consists of 33 members, is the largest miRNA gene family in poplar (Populus trichocarpa) It is significant to analyze the evolution of the ptc-MIR169 gene family in order to understand the evolutionary mechanisms of miRNAs in poplar. In the present study, we investigated the molecular phylogeny, duplication, expression and target genes of the MIR169 gene family in poplar. Both tandem duplications and chromosome segmental duplications contributed to the expanding of ptc-MIR169 gene family, and the expression patterns diversified obviously among the gene family. These findings suggest that the ptc-MIR169 gene family is involved in complex regulatory networks, and plays significant roles in development and stress response in poplar. This paper provides a reference for the evolutionary study of miRNAs in poplar and related species in Salicaceae.