Identification and characterization of heat-responsive microRNAs at the booting stage in two rice varieties 9311 and Nagina 22
Abstract: MicroRNAs (miRNAs) are small, non-coding, regulatory RNAs that play important roles in abiotic stress responses in plants. but their regulatory roles in the adaptive response to heat stress at the booting stage in two rice varieties 9311 and Nagina 22, remain largely unknown. In this study, 464 known miRNAs and 123 potential novel miRNAs were identified. Of these miRNAs, a total of 90 differential expressed miRNAs were obtained with 9311 libraries as control group, of which 54 upregulated and 36 downregulated miRNAs. To gain insight into functional significance, 2773 potential target genes of these 90 differentially expressed miRNAs were predicted. GO enrichment showed that the predicted target genes of differentially expressed miRNAs including NACs, LACs, CSD, and Hsp40. KEGG pathway analysis showed that target genes of these differentially expressed miRNAs were significantly enriched in plant hormone signal transduction pathway. The expression levels of ten differentially expressed miRNAs and their target genes obtained by qRT-PCR were largely consistent with the sequencing results. This study lays a foundation for the elucidation of the miRNA-mediated regulatory mechanism in rice at elevated temperatures. Key words: rice, heat-responsive, microRNA, target gene, booting stage, high-throughput sequencing