Construction And Significance Analysis Of The Microrna Expression Profile Of Hemerocallis Fulva At Low Temperature

Chilling injury is one of plants major environmental stress, which impact on plant growth and yield. Studies have shown that miRNA’ not only can activate and regulate some of the important functional genes of plant, and largely improve the resistance of plants. Therefore, the study of how to take full advantage of the physiological function of miRNA to improve the cold resistance of plants has important theoretical and practical significance.The resistance genes are particularly more and researchers follow with interest on the cold resistance of Hemerocallis fulva (L.)L.Hongbaoshi Hongbaoshi In this study, we searched and identified the cold stress-related miRNA, analyzed the differentially expressed miR"NA of Hemerocallis fulva (L.)L.Hongbaoshi and forecasted new miRNA and gene regulation pattern under cold stress, deepening the understanding of the molecular mechanisms of cold stress by advanced high-throughput sequencing miRNA and bioinformatics methods. We discussed the role of miRNA regulation in cold resistance of Hemerocallis fulva (L.)L.Hongbaoshi Hongbaoshi and provided a theoretical basis on finding the coldness response gene and their associated components. The results are as follows:1. The proportion and distribution of small molecules RNA length at normal and low temperature were consistant.24nt sRNA are the main types and24nt sRNA samples were45.53and47.42%of the total number of small RNA, respectively.2.14,843,184and16,072,575fragments sequence information were obtained at normal temperature and low temperature, respectively, which includes14,064,385and15,309,725kinds of small RNA fragments.1,055,466and799,994miRNA fragments were obtained after "clean" sequence fragment was classified and filtered by sRNA.3. The match rate was low with the rice genome for small RNA of Hemerocallis fulva (L.)L-Hongbaoshi obtained at two temperatures. There were no correlation with the distribution and repetitive sequence between24nt small molecules RNA and rice genome. In contrast, there were more of21nt small RNA molecules could be matched to the rice genome, thus demonstrating the evolution of21nt small molecule were more conservative than the24nt small RNA molecules. The hotspots area was lack for small RNA molecules of Hemerocallis fulva (L.)L. Hongbaoshi could be matched to rice chromosome.4. By comparing the rice miRNA database, we found miR403, miR472and miR479, which prefered exist in monocotyledon, were not detected in two samples in this study.19miRNA expression levels changed significantly under low temperature, which belong to8miRNA families of rice miRNA database, and11miRNA expression was significantly decreased,8miRNA expression significantly increased. miRNA expression levels showing significant differences in miR167family members is most.5. Comparing with the miRNA database of all plants, only a few miRNA with decreasing temperature appears significant differences under both temperature conditions. Among26miRNA expression levels were significantly upregulated after chilling stress, and30miRNA expression levels were significantly downregulated.9miRNA expression level was significantly downregulated or downregulated expression. Including miRNA families with low temperature stress-related, such as miRNA391, miRNA393, miRNA396, miRNA397; miRNA family and flower development-related, such as miRNA159, miRNA169, miRNA172; miRNA family of high abundance expressed, such as miRNA165family, miRNA168, miRNA2911etc. The difference of most of miRNA expression was not significant.6. Forty-one new specific miRNA of Hemerocallis fulva (L.)L. Hongbaoshi were obtained in the study at normal temperature and low temperature by homologous search. Among25new miRNA were found and20new miRNA target genes could predict the target gene, loci points to197at10℃.16new miRNA were found, and all are predicted to target genes. Moreover, the target gene loci were193. There are21to be able to measure miRNA*among41new miRNA.In this study, miRNA not only involved in environmental stress response process of Hemerocallis fulva (L.)L.Hongbaoshi, but also regulated the growth and development process of Hemerocallis fulva (L.)L. Hongbaoshi by regulating different target genes.