PJB-2019-505
IDENTIFICATION OF WILLOW (SALIX MATSUDANA KOIDZ) MIRNAS AND THEIR TARGET GENES UNDER SALT STRESS
Dong Xu
Abstract
Salix matsudana Koidz, a widely distributed and deciduous willow species, can endure a range of adversities. However, little is known about the functions of miRNAs and their targets on salt stress in S.matsudana. Here, high-throughput sequencing was performed to identify miRNAs and their targets in cuttings (30-day-old) treated with 100 mM NaCl for 0 d and 2 d. A total of 205 miRNAs were discovered in two small libraries. Among them, 163 conserved miRNAs belonged to 51 miRNA families, while 42 novel miRNAs were between 18 and 25 nt in length, with 52.2% being 21 nt long. Besides, 66 differentially expressed miRNAs were found including 50 known miRNAs and 16 novel miRNAs under salt stress. Furthermore, 981 targets of 100 miRNAs were validated by degradome sequencing. An enrichment analysis of miRNA targets showed that transcription factors, auxin, defense response and oxidoreductase activity possibly played an important role in salt stress. Eight chosen miRNA precursors from S. matsudana were clustered to the same branch with homologs in Populus trichocarpa by homologous relationships; however, there was a little difference in their 3D structures between S. matsudana and P. trichocarpa. Nine miRNA-target pairs presented negative or positive correlations in roots and stems under salt stress, and the opposite expression trends were also displayed in roots and stems, which indicated the complexities and flexibilities in miRNA-medicated target regulation. These results systematically identified the salt-responsive miRNAs and their targets in S. matsudana, and will lay the foundation for further genetic engineering with salt tolerance.
To Cite this article:
Download
