【作者】 郭军伟；

【导师】 杜林方；

【作者基本信息】 四川大学 ， 生物化学与分子生物学， 2006， 硕士

【摘要】 叶绿素(Chlorophyll，Chl)是光合生物中含量最多也是最主要的一类光合色素，它不仅是光合器官许多色素蛋白复合物的主要组成，而且还参与了光合作用的许多生理生化活动。因此，叶绿素的改变会导致色素蛋白(如捕光色素复合物LHCs，内周天线复合物CP43、CP47和反应中心蛋白D1、D2等)的合成、转运和折叠等的变化，从而影响到光合作用器官的结构的改变。同时叶绿素在光合系统中承担了光能吸收，光能转化，激发能传递等生物学功能，所以，Chl的减少或成分改变也会引起光系统间激发能在的分配，光合作用效率和电子传递等的改变。研究表明特殊的色素缺乏突变体可以为研究光合作用提供有效的结果。 我们以经快中子辐射和DES化学诱变获得的一种甘蓝型油菜(Brassica napus L．)幼叶叶绿素缺乏突变体(Cr3529)为材料。为探讨该突变体的突变机理与其他突变体的差异，揭示叶绿素缺乏对植物光合作用的影响。本文采用蓝绿温和电泳、Western杂交、低温荧光、叶绿素荧光和热致发光等方法研究了：油菜叶绿素缺乏突变体Cr3529叶片中叶绿素结合蛋白和光合结构的变化情况；并对叶绿素缺乏引起的植物光合机构的光能的扑获、电子传递、激发能的分配和光合作用效率等植物光合作用生理生化性质进行了分析。 通过实验得到以下主要结果： 色素分析显示，突变体的叶绿素a和b含量均有下降，而胡萝卜素的含量相对有所增加。用温和电泳、SDS—PAGE和Western杂交分析了叶绿体的主要更多还原

【Abstract】 We investigated the altered features of Chl-protein complexes in the chlorophyll- deficient oilseed rape mutant as compared with wild type by using techniques of pigment analysis, native gel electrophoresis and SDS-PAGE. The analysis of pigments showed that the mutant had significantly less chlorophyll （Chl） b and lower Chl a content comparison to the wild type. The absence of chlorophyll in the mutant resulted in reduction of the major as well as some minor light-harvesting chlorophyll protein complexes （such as CP29） both in the photosystem II and photosystem I. The native gel electrophoresis showed that the PSII/LHCII and PSI/LHCI complexes were somewhat decreased in the mutant. However, the core antenna complexes （CP43 and CP47） of photosystemII in the mutant were not changed or somewhat increased. This suggested that the reduction or loss of the antenna LHCI and LHCII was compensated by an increment in core component. Furthermore, the Chlorophyll fluorescence characteristics of the mutant indicated the changes of the PSII heterogeneity （the decreased of PSIIa and increased of PSIIβ）.The photosynthetic characteristics and excitation energy distribution of the mutant was examined using thermoilluminscence and chlorophyll a fluorescence measurements at room temperature and at 77 K. The low temperature （77K） fluorescence emission spectrum showed that the light energy absorption drops in the mutant. The increased of F_PSII/F_PSI in the mutant indicated that more excitation energies to assign to photosystem II. At the same time, the changed of the thylakiod membrane protein phosphorylation in the mutant (Immunoblot analysis with phosphothreonine （Thr （P） antibody） showed that the phosphorylation of light更多还原