关键词: 水稻, 干旱胁迫, small RNA, 转录组, 已知miRNA, 新miRNA, 靶基因

Abstract: Small RNAs play important regulatory roles in response to environmental stress. However, miRNAs involve in the complex process of drought response and their regulatory mechanism remain to be further identified and explored. In this study, small RNA library of root, stem and leaf tissues from rice treated with drought was constructed and high throughput transcriptome was sequenced. The results showed that a total of 403 miRNAs were detected at genome-wide scale in all samples, including 352 known miRNAs and 51 new predicted miRNAs. There were 37, 35 and 56 miRNAs differentially expressed in roots, stems and leaves at 24 h after drought treatment, while 35, 62 and 65 miRNAs were differentially expressed in roots, stems and leaves at 96 h,  respectively. Moreover, 15 miRNAs were differentially expressed in each tissue at two time points after drought treatment, among which Osa-miR159f, Osa-miR164f, Osa-miR5082 and Osa-miR5493 were up-regulated during drought treatment. Thus, they might be key modulators in drought response. A total of 4 537 predicted target genes of miRNAs were obtained, and their functional annotation and GO/KEGG enrichment analysis were further carried out. Collectively, these results provided theoretical reference and data resource for the identification of new drought responsive miRNAs, and would contribute to the comprehensive mechanisms dissection of miRNAs involvement in drought tolerance regulation in plants.

Key words: rice, drought stress, small RNA, transcriptome, known miRNA, novel miRNA, target gene