白菜叶与花叶绿素合成过程中生理和分子差异分析

菜单

摘要白菜是中国广泛种植的蔬菜作物，甘蓝作为主要蔬菜作物，占据国内市场主导地位蔬菜之一。因为它具有储存方便，耐久贮存的特点，种植面积居世界首位。目前，研究人员对于叶绿体、质体合成虽然已积累了大量的研究成果，但对绿色组织和各种有色体在生理和分子生物学水平上的差异仍了解的很少。在这项研究中，我们分析了白菜的花和叶子中叶绿素和类胡萝卜素的含量，以及参与叶绿素合成相关基因的表达。结果表明，白菜花瓣中含有更少的叶绿素含量,叶绿素a/b比值也较低；但与叶相比，花瓣含有较高的类胡萝卜素。此外，我们的生理数据与相关基因的表达水平密切有关，定量PCR结果表明，白菜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。以上结果帮助我们更好的对特定组织中叶绿体发育调控机制的了解。51864

毕业论文关键词：白菜叶绿体发育质体基因表达

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

Abstract

Cabbage is widely cultivated in China, it takes up domestic market as one of the vegetables. Because it is easy and durable to store, the planting area is the largest in the world. Although much information regarding the chloroplast and chromoplast biogenesis has been accumulated in recent years, details of the physiological and molecular differences between green tissues and colorful chromoplast tissues are still poorly understood. In this study, the levels of pigment accumulation and the expression of genes involved in chloroplast biogenesis were analyzed among the two tissues: leaves and open flowers in cabbage. The results showed that 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 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) were higher in leaves than in petals. Collectively, the results increase our understanding of the molecular mechanisms underlying tissue-speciﬁc chloroplast development in plants.

1.前言 5

2.材料与试剂 6

2.1 植物原料 6

2.2试剂 6

3.仪器与方法叶绿素和类胡萝卜素的测定 6

3.1色素的提取 6

3.2提取RNA 7

3.3.白菜总RNA反转录 8

4.结果分析与讨论 8

4.1.组织中叶绿素和类胡萝卜素的积累 8

4.2.不同组织中叶绿素生物合成基因的表达谱 10

5.讨论 13

致谢 14

参考文献 15

1.前言

叶绿体是植物的重要细胞器，用于某些真核生物的光合作用和许多其他的生物合成过程发生的场所，叶绿体生物合成包括一系列复杂事件，可分为三个步骤 (Mullet, 1993)，第一步涉及质体复制和DNA合成的激活。第二步，核编码叶绿体RNA聚合酶（NEP）优先转录质体基因编码基因的表达，这一步是叶绿体的“堆积”的步骤（hajdukiewicz et al.，1997）。在最后一步中，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的RNA聚合酶转录 (Kusumi et al., 2010)。叶绿素是一种重要的色素，负责吸收太阳能，在反应中心进行电荷分离和电子运输。最近的研究已经确定了被子植物植物拟南芥叶绿素生物合成的全部步骤：二十七基因编码的十五种酶（Beale，2005）。