春节催花是牡丹产业链条的重要内容，其技术核心是低温解除花芽内休眠，因此深入解析内休眠机理是解决催花不良等生产问题的前提。MicroRNA是重要的基因表达调控因子，其与靶基因互作在植物多个生理过程中具有核心调控作用。课题组利用小RNA测序和转录组分析筛选到休眠进程相关的1个miR172d和AP2基因EST；RACE扩增了PsAP2全长cDNA。生物软件分析和RT-PCR结果暗示两者存在潜在的靶标关系。本项目拟以此为切入点，鉴定miR172d和PsAP2的靶标关系以及miR172d对PsAP2的调控方式；进一步分析VIGS沉默PsAP2后牡丹花芽休眠进程和下游基因PsFT、PsSOC1的表达变化，结合超表达miR172d、PsAP2拟南芥的春化时间和AtFT、AtSOC1基因表达分析，解析miR172d和PsAP2调控内休眠的机理。这将为进一步阐明miRNAs在内休眠进程中的功能奠定理论基础。

MicroRNAs are important factor to regulate gene expression, and the interactions between miRNAs and their targets play core roles in regulation of many physiological process. Antiseason forcing culture is one of the most important contents of tree peony (Paeonia suffruticosa Andr.) industry in china, and the core technology is to accelerate endo-dormancy release of flower bud and flowering early after sufficient chilling treatments. Therefore, the analysis of dormancy mechanism is the base to resolve the practice problems of tree peony industry. One EST sequence of AP2 gene using 454 sequencing and microarray was obtained, and the protein of AP2 was also screened using dimensional electrophoresis and mass spectrum, which were differential expressed and their expression trends during endo-dormancy release were consistent. At the same time one miR172d was obtained after small RNA sequencing and microarray. The full cDNA of PsAP2 had been obtained using RACE amplification method. MiR172d was speculated to be complementary with the exon3 domain of PsAP2 sequence near the stop codon by RNAhybrid software. The expression patterns of PsAP2 and miR172d during dormancy release were corresponding. These results suggested that PsAP2 had potential target relationship with miR172d. This project aims to analyze the target relationship between miR172d and PsAP2 during dormancy release, and make it certein that if miR172d directly acts on PsAP2 and how miR172d regulate PsAP2 in order to affect the dormancy release.The expression patterns of PsAP2,miR172d and the downstream genes, PsFT and PsSOC1, will be detected during dormancy release. The method about miR172s regulating its target gene PsAP2 will be detected using western blot and Northern blot. The time changes of dormancy release will be observed and the expression patterns of PsFT and PsSOC1 will be analyzed using qRT-PCR and Northern blot methods after VIGS technology mediated PsAP2-silencing. At the same time, the over-expression vectors of miR172d and PsAP2 will be constructed and transfect wild Arabidopsis, and the vernalization time and the expression patterns of two downstream genes (AtFT and AtSOC1) will be obtained in over-expression Arabidopsis.In addition, the promoter of the PsFT will be cloned using TAIL-PCR, and the intraction between PsAP2 and PsFT will be analyzed using yeast hybrid technology and electrophoretic mobility shift assay (EMSA). These results will offer theory base of miRNAs regulated the mechanism of dormancy release in tree peony, and provide candidate genes and theoretical direction for forcing culture and molecular breeding.