南果梨是秋子梨系(Pyrus ussuriensis Maxim)的优质品种，为辽宁的特产水果。9月中旬采收后经适度后熟的果实，金黄艳丽、肉质细腻、香气浓郁、品质极佳。南果梨常温货架期仅有15-20天。冷藏可以延缓其后熟衰老进程，延长供应期。申请者研究发现，冷藏南果梨的香气明显变淡，并证明了其主要影响了酯类香气物质的代谢，但是，其分子机制尚不清楚。本项目拟利用RNA-Seq和小RNA测序技术，对常温自然后熟和冷藏后转入常温后熟的南果梨果实的转录组进行深度测序，发掘差异表达的mRNA和miRNA（microRNA）；同时，利用iTRAQ技术对蛋白质组进行平行分析。在差异表达谱关联分析的基础上，结合基因注释、表达模式和相关代谢通路解析，预测与冷藏南果梨酯类香气合成相关的代谢途径和信号通路，在转录组、蛋白质组和代谢三个层面协同分析冷藏南果梨香气变淡的分子机制，为改进南果梨贮藏保鲜技术奠定基础。

Nanguo Pear (Pyrus ussuriensis Maxim) grows mainly in the Liaoning province. It is normally harvested in the middle of September. After appropriate ripening, the picked fruit present golden color with smooth flesh and rich smell in which the fruit is excellent in quality. The shelf-life of Nanguo pear at room temperature is only 15 to 20 days. Refrigeration can effectively retard the senescence of the fruit. However, in the previous study, it was noted that the aroma of the fruit undegone long-term refrigeration obviously light compared with the fruit without refrigeration, which is mainly caused by the influenced mechanism of esters biosynthesis. Up to now the molecular mechanism of this phenomenon is not clear. In this study RNA-seq and Small RNA-Seq techniques will be used to analyze the transcriptome of ripen fruit with or without refrigeration and identify the different in the expression in mRNA and miRNA between them. Meanwhile, the differentially expressed proteins between the ripen fruit with or without refrigeration will be identified through the analysis by use of iTRAQ techniques. Based on the correlation analysis of the differentially expressed spectrum combined with gene annotation, parsing of expression pattern and related metabolic pathways the metabolic and signaling pathways related to the biosynthesis of esters in refrigerated Nanguo Pear will be predicted. These studies are aimed to explore the molecular mechanism of the weakened aroma in Nanguo Pear stored at low temperature through the analysis of the transcriptome, proteome and metabolism. The findings will be valuable for further improving Nanguo pear storage technology.