miRNA参与植物生长发育调控的功能已众所周知，其产生依赖于miRNA 初级体primary miRNA(pri-miRNA)的存在。一直以来，pri-miRNA被认为不编码任何蛋白质。最近发现pri-miRNA能编码功能肽(miPEPs)，开辟了基因调控研究的新领域，然而其功能的挖掘只是冰山一角。因此，本研究利用龙眼体胚发生模式系统，进行pri-miRNA全长序列的分离与鉴定，确定其转录起始位点，分析潜在miPEPs，研究pri-miRNA与miRNA在龙眼体胚中的表达规律；确认龙眼pri-miRNA编码的miPEPs具有生物功能活性；研究候选miPEPs对龙眼体胚miRNA及其靶标的调控作用；研究候选miPEPs、miRNA及其靶标对龙眼体胚形态建成的影响，最终确认pri-miRNA编码的miPEPs在龙眼体胚中的作用机制，以期为龙眼体胚发生的分子机制和胚胎发育的调控研究提供参考。

As we known, miRNA, which produced from primary miRNA(pri-miRNA), plays an important regulatory role in plant development. pri-miRNA, which until now had been assumed not to encode any proteins. But previous study showed that some pri-miRs encode peptides (miPEPs) that enhance production of their miRNAs. However, its function mining is just the tip of the iceberg. In this project, using the system of longan somatic embryogenesis (SE), based on the previous work, we plan to isolate the full length of pri-miRNAs, to identify their transcription start sites and their promoters, to analyze the potential miPEPs, and the expression patterns of pri-miRNA and miRNA during longan somatic embryo development; to confirm the functions of biological activity of longan pri-miRNA en-coding miPEPs; to study the regulation roles among miPEPs, miRNAs and its targets, to detect how miPEPs effect on the longan somatic embryo morphogenesis. Finally, the molecular mechanism of pri-miRNA encoding-miPEPs during longan SE will be systematically clarified. And these results will further provide scientific evidences for regulating the in vivo and in vitro embryogenesis in longan.