Analysis of the effect of exogenous auxin on the regulatory relationship between miRNAs and their target genes in rose using high-throughput sequencing

Rose (Rosa hybrida L.) is one of the major cut flowers in the world. Studying the molecular mechanism of auxin regulation in growth is of great significance for enhancing the understanding of the growth and development processes in rose and informing accurate exogenous auxin application in rose production. However, the response mechanism of rose to miRNA-mediated auxin signal transduction is unclear. In this study, rose plants were treated with IAA, and 75 known miRNAs and 168 novel miRNAs were identified by small RNA sequencing. Among them, 19 known miRNAs and 42 miRNAs were differentially expressed. Many differential miRNAs demonstrated staged responses to auxin treatment. The targeted relationship between miRNA and key transcription factors regulated by auxin in rose was analysed, and the target genes in the ARF family and AUX/IAA family were screened. By using quantitative real-time PCR(qRT-PCR) to verify the expression patterns of the miRNA regulating the auxin signal transduction pathway and its target gene, we found that miR156a, miR160a, miR164a, miR167d, miR396b-3p, novel_miR_189, novel_miR_74, novel_miR_8, and novel_miR_207 were anti-correlated with the ARF family, and miR390a-3p and novel_miR_101 were anti-correlated with the AUX/IAA family. These results provide a theoretical basis for further studies on the auxin regulatory mechanisms in rose.