Discovery of MicroRNAs and Their Target Genes Related to Drought in Paulownia “Yuza 1” by High-Throughput Sequencing

摘要

Understanding the role of miRNAs in regulating the molecular mechanisms responsive to drought stress was studied in Paulownia“yuza 1.” Two small RNA libraries and two degradome libraries were, respectively, constructed and sequenced in order to detectmiRNAs and their target genes associated with drought stress. A total of 107 miRNAs and 42 putative target genes wereidentified in this study. Among them, 77 miRNAs were differentially expressed between drought-treated Paulownia “yuza 1”and the control (60 downregulated and 17 upregulated). The predicted target genes were annotated using the GO, KEGG, andNr databases. According to the functional classification of the target genes, Paulownia “yuza 1” may respond to drought stressvia plant hormone signal transduction, photosynthesis, and osmotic adjustment. Furthermore, the expression levels of sevenmiRNAs (ptf-miR157b, ptf-miR159b, ptf-miR398a, ptf-miR9726a, ptf-M2153, ptf-M2218, and ptf-M24a) and theircorresponding target genes were validated by quantitative real-time PCR. The results provide relevant information forunderstanding the molecular mechanism of Paulownia resistance to drought and reference data for researching droughtresistance of other trees.