Genome-Wide Identification of miR169 Family in Response to ABA and Salt Stress in Poplar

Abstract

The miR169 family is one of the largest families of known miRNAs, which performs important functions in plant growth, development, and responses to biotic/abiotic stresses. However, its functions in response to abiotic stresses are still unclear in poplar. In present study, a total of 33 precursor MIR169s were identified from poplar and divided into 3 groups by evolutionary analysis and multiple sequence alignment, with the members in same group sharing similar motifs. Collinearity analysis revealed miR169s in other species that are homologous to poplar miRNAs. Cis-acting elements predication showed that miR169s may respond to ABA (Abscisic acid) and salt stress, which was verified by qRT-PCR. In addition, 12 pairs of miR169/target gene modules were identified by degradome sequencing and most of these modules responded to ABA and salt stress. Specifically, a part of miRNAs showed opposite expression trends with their targets at a certain period, demonstrating a repressive effect on the target genes. All the results suggest that miR169s perform important functions in response to abiotic stresses in poplar.