光对番茄果实成熟衰老的调控及其作用机制研究

Environmental conditions are important factors affecting fruit ripening and senescence. As an vital environmental factor, light plays a crucial role in fruit ripening and quality formation. However, there is little evidence about the effects of light on fruit postharvest storage. So relevant study has not only theoretical significances, but also potential application values. E3 ubiquitin ligase COP1 and transcription factor HY5 are two pivotal components in light signal pathway. In this study, wild-type tomato will be used to generate cop1 and hy5 mutants via CRISPR/Cas9 system. Then, the effects of white light, red light, far-red light, blue light on postharvest tomato fruits will be tested, especially focus on fruit ripening, senescence and the contents of sugar, acid, pigment, aromatic compound, etc. Subsequently, multi-omics analysis combining transcriptome, proteomics and metabolomics will be applied to explain the relationship among gene expression, protein expression and metabolites level in the light treated tomato fruit. Furthermore, molecular biological or biochemical assays will be performed to identify the substrates of COP1 and the target genes of HY5. Finally, we will reveal the effects of light on tomato fruit during postharvest storage, as well as the intrinsic mechanism. Our results will provide reference for developing fruit postharvest technology.

环境条件是影响果实成熟衰老和贮藏性能的重要因素。光作为重要的环境因素，在果实成熟和品质形成过程中发挥重要作用，然而关于光是否影响果实采后贮藏保鲜及其调控机制还少见报道。相关研究不仅具有重要的理论意义，而且具备潜在的应用价值。在光信号通路中，E3泛素连接酶COP1和转录因子HY5发挥重要作用。本项目拟以番茄为研究材料，通过CRISPR/Cas9技术构建cop1和hy5基因敲除突变体植株，研究不同光处理（白光、红光、远红光、蓝光）对突变体番茄果实成熟衰老和糖、酸、色素、芳香化合物等品质成分的影响；利用转录组学、蛋白质组学和代谢组学等多组学联合分析光处理后果实中的基因表达、蛋白水平的内在联系及变化规律，并通过分子生物学和生物化学试验进一步鉴定COP1的底物蛋白和HY5的靶基因，最终揭示光对果实采后贮藏保鲜的影响及其作用机制，为果实贮藏保鲜技术的研发提供参考。

环境条件是影响果实成熟衰老的重要因素，光是重要的环境因素，然而光对果实成熟和品质形成的调控机制还少见报道。转录因子HY5和E3泛素连接酶COP1在光信号通路中发挥重要作用。本研究以番茄为研究材料，利用CRISPR/Cas9技术构建的Slhy5突变体，解析了SlHY5调控果实成熟的分子机制。研究表明，转录因子SlHY5通过直接调控参与类胡萝卜素合成、花青素合成和乙烯合成及信号转导途径关键基因的表达，参与调控番茄果实类胡萝卜素、花青素和乙烯的合成，影响果实成熟和品质形成。研究还发现，转录因子SlHY5通过直接或间接地方式调控核糖体蛋白基因的表达，进而影响成熟相关基因的翻译效率，在翻译水平上调控番茄果实成熟和品质形成。同时我们还利用CRISPR/Cas9技术构建的Slcop1突变体，解析了SlCOP1的基因功能。SlCOP1参与调控番茄果实成熟以及对灰霉的抗性，其具体机制暂不明确。通过酵母双杂交筛库，鉴定到6个SlCOP1的互作蛋白，其中一个bZIP转录因子可能是SlCOP1调控抗病性的靶点。本研究对揭示光对果实成熟和抗病性的影响具有重要意义，能够为果实贮藏保鲜技术的研发提供参考。