紫外线-B介导采后药用菊花花序中有效成分累积及其机制

The thinning of stratospheric ozone layer led to the increased penetration of ultraviolet-B (UV-B, 280-320 nm) radiation to the earth's surface, which could induce the biosynthesis of UV-B absorbing compounds (mainly including phenolic and flavonoid compounds), and affect the processes of secondary metabolism in plants. Secondary metabolites are usually the main active ingredients and quality base in medicinal plants and the pharmacological effects of many Chinese herbal medicines are related to the content of secondary metabolites. Some researches have reported the application of UV-B radiation in medical plants. Previous studies were mainly concerned with UV-B-induced effects on active ingredients in medicinal plants, but it was not clear about the induced mechanism. In addition, UV-B treatment was carried out on plant growth periods, which required the large costs, and was difficult to operate, especially for the remote areas. The project, using medicinal chrysanthemum as test materials, mainly studies the effects of UV-B radiation on active ingredient accumulation in postharvest chrysanthemum capitulum, exploring the relationship between intensity and time of UV-B radiation and active ingredient and nutrient components content, and revealing its regulation sites and regulation mechanism by the analysis of differential proteomics and the key enzymes and substrates in secondary metabolism processes of chrysanthemum capitulum before and after UV-B induction. The study further broadens the research field of UV-B radiation, and puts forward a kind of simple and feasible method to improve active ingredient accumulation in postharvest medicinal plant organs, which will better promote the development and utilization of medicinal plant resources.

臭氧层减薄导致地球表面紫外线-B（UV-B, 280-320 nm）辐射增强，增强的UV-B辐射能够诱导植物体内紫外吸收物质的合成（主要是酚类和黄酮类化合物），影响植物体内次生代谢过程。在药用植物中, 次生代谢产物通常是中药的主要活性成分和药材品质的物质基础，许多植物药的药理作用与其所含的次生代谢物质有关。本项目以药用菊花（祁菊和怀菊）为供试材料，系统研究UV-B辐射对采后菊花花序中有效成分的诱导效应，探索辐射剂量和辐射时间与菊花花序中有效成分和营养成分含量的关系。通过对诱导前后菊花花序中差异蛋白质组学及次生代谢过程中关键酶和底物分析，确定UV-B辐射对采后菊花花序中次生代谢过程的调节位点并揭示其介导机制。本研究进一步拓宽了UV-B辐射研究领域，提出一种投入少，操作简单，生产中易行的提高药用植物有效成分含量的新思路，将有力地促进药用植物资源更好的开发利用。

大气臭氧的损耗导致了地球表面具有生物学效应的紫外线-B(UV-B)辐射增强。紫外线-B（UV-B）辐射能够影响植物体内次生代谢过程，提高次生代谢产物含量。药用植物中有效成分主要是次生代谢产物，然而，药用植物中有效成分含量大多不高，这在一定程度上限制了药用植物作为药材的开发利用。本论文以药用菊花为供试材料，系统研究了UV-B 辐射对采后菊花花序的生理特性、活性成分和差异蛋白质组的影响，及菊花花序发育时期对UV-B辐射的响应。主要结果如下：. 1.UV-B 辐射能够促进采后菊花花序中的次生代谢过程，提高花序中有效成分含量。UV-B 辐射对采后药用菊花生理特征和有效成分累积影响依赖于UV-B 辐射强度和辐射时间。在本试验条件下，最佳的UV-B 辐射强度为200-600 μW cm-2，最佳UV-B 辐射时间为30-120min。. 2.用2D-E 技术对辐射前后差异蛋白质组进行研究，得到43 个差异点（>1.5倍），其中19 个点下调，24 个点上调。用MALDI-TOF-MS 进行分析，鉴定了其中19 个差异蛋白，其中6 个与植物光合作用有关，2 个与呼吸作用有关，5 个与蛋白质的合成与降解有关，4个与植物防御有关，1 个与维生素的合成有关，1 个与次生代谢有关。. 3.不同发育时期菊花花序中生理活性存在显著差异，菊米和胎菊生理活性相对旺盛。UV-B 辐射能显著促进不同发育时期菊花花序中次生代谢过程。UV-B 辐射显著提高了采后不同发育时期菊花花序中有效成分和营养成分的含量。通过对参数综合分析表明：菊花花序最佳采收期为胎菊-幼菊时期。. 本研究进一步拓宽了UV-B 辐射研究领域，提出一种投入少，操作简单，生产中易行的提高药用植物有效成分含量的新方法，并且，初步从蛋白水平上揭示了UV-B 辐射介导采后菊花花序中生理生化变化的原因。这将有力地促进药用植物资源更好的开发利用。

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