摘要:近年来，虽然人们对植物叶绿体和有色体的生物合成已经有了比较深入的了解，但我们对绿色组织以及各种有色体在生理、生化和分子生物学的差异了解还不够深入。在本次研究中，我们分析了油菜的花和叶子中叶绿素和类胡萝卜素的含量和参与叶绿素合成的相关基因的表达。结果表明，花瓣中叶绿素含量较少且叶绿素a/b比值较低，但类胡萝卜素含量较高。相反，叶子中叶绿素含量较高且叶绿素a/b比值也较高。此外，我们的生理数据与相关基因的表达水平密切相关，定量PCR结果表明，叶子中几乎所有的叶绿素生物合成相关基因（尤其是下游结构基因）的表达都比花瓣中的高。以上结果加深了我们对特定组织中叶绿体发育调控机制的理解。51852

毕业论文关键词: 油菜, 叶绿体发育, 有色体, 基因表达

Physiological and molecular differences of chloroplast biogenesis between leaf and flower in rapeseed

Abstract:Although much information regarding the chloroplast and chromoplast biogenesis has been accumulated in recent years, details of the physiological, biochemical, and molecular differences between green tissues and colorful chromoplast tissues are still poorly understood. In the present study, we analyzed the content of chlorophyll and carotenoid in the flowers and leaves of rape, as well as the expression of genes involved in chlorophyll biosynthesis. The results showed that both petals contained much less chlorophyll contents and a lower ratio of Chl a/b, but contained higher carotenoid contents compared with that of leaves as expected. In contrast，the leaves have higher chlorophyll content and chlorophyll a/b ratio is higher. In addition, data obtained from biochemical studies were correlated with those at the mRNA level, the transcripts of almost all the chlorophyll biosynthetic genes (especially the downstream structural genes) and plastid genes required for early chloroplast development and photosynthesis were higher in leaves than in petals. Collectively, the results increase our understanding of the molecular mechanisms underlying tissue-specific chloroplast development in plants.

Keywords:rape, chloroplast development, chromoplast , gene expression

目录

前言 4

1、材料与试剂 6

1.1 植物材料 6

1.2 试剂 6

2、仪器与方法 6

2.1 仪器 6

2.2 实验方法 6

2.2.1叶绿素和类胡萝卜素的测定 6

2.2.2油菜花叶总RNA提取 7

2.2.3油菜总RNA反转录 7

2.2.4定量RT-PCR分析.....8

3、数据分析与结论 8

3.1 不同组织中叶绿素和类胡萝卜素的积累量 8

3.2 叶子与花中叶绿素生物合成基因的表达分析 9

4、讨论 13

5、致谢 14

参考文献 15

前言：

叶绿体是植物重要的细胞器，用于一些真核光合生物光合作用和许多其他生物合成过程。叶绿体的生物合成包括一系列复杂过程，可分为三个步骤 (Mullet, 1993)。第一步是质体复制和DNA合成的激活。第二步，核编码的质体RNA聚合酶（NEP）优先转录编码质体基因表达的质体基因，是叶绿体的“堆积” (Hajdukiewicz et al., 1997)。第三步，编码光合器官的细胞核与质体基因高度表达，而质体基因主要由质体编码RNA聚合酶(PEP)转录(Kusumi et al., 2010)。叶绿素还是植物最重要的色素之一，在光合天线系统中吸收太阳能，在反应中心进行电荷分离和电子运输。它的生物合成也是经过大量酶协同催化反应的复杂过程(Beale, 1999)。最近有研究已经证实，以拟南芥为代表的被子植物叶绿素生物合成的步骤：二十七个基因编码十五种酶，叶绿素合成的早期步骤与血红素生物合成途径共享(Beale, 2005; Tanaka and Tanaka, 2006)。