microRNA(miRNA)已被证实是植物用于调控逆境应答的一类重要因子，但目前园艺作物miRNA响应低温胁迫的规律及其调控采后果实低温应答的机制并不清楚。采后香蕉果实在低温胁迫下会产生果皮褐变、无法后熟等冷害症状，造成严重的经济损失。我们的前期研究发现香蕉miR528及其靶基因PPO的表达模式与采后果实的冷害进程密切相关，因此推测miR528参与了采后香蕉果实低温应答的调控。为证实这一假说，本项目将以香蕉miR528为研究核心，首先明确其响应低温信号的方式，接着分析其在香蕉果实发生冷害不同阶段的表达特性，同时从核酸、蛋白及酶活性水平上系统地研究香蕉miR528所调控的靶基因的变化规律，并揭示其与冷害症状的关联性；进而通过转基因体系验证香蕉miR528的生物学功能，最终阐明miR528调控采后果实冷害的分子机制，为研发果实冷害防控新技术提供理论基础和新思路。

MicroRNA is an important factor in the regulation of plant stress response, but so far little is known about the role of miRNAs in regulating cold stress response in horticultural crops. Banana fruit show chilling injury symptoms under low temperature, such as peel browning and ripening disorders, causing serious economic losses. In previous study we found that the expression pattern of banana miR528 and its target gene PPO was closely related to the occurrence of chilling injury of banana, so we speculated that miR528 may regulate the chilling stress response of the banana fruit. To test this hypothesis, how miR528 responds to cold signal will be investigated and how its targets change during chilling injury occurrence will be investigated at mRNA, protein and enzyme levels. Finally, functional verification will be attempted to elucidate the molecular mechanism of miR528 in the regulation of banana fruit chilling injury, and to provide a theoretical basis for the development of new technologies for prevention of fruit quality deterioration caused by low temperature.