Isolation and Characterization of Virescent Mutants in Arabidopsis thaliana

9407920布鲁塞尔这是一项研究计划助学金。本研究的目的是：1、从EMS、快中子和T-DNA诱变的拟南芥中分离出绿色突变体；2、用吸收光谱、荧光发射、透射电子显微镜和天然德里帕特凝胶电泳法表征这些突变体的光合作用器官的发育；3、分析突变体的温度敏感性和对不同光强的敏感性；以及4、进行遗传分析。遗传分析将包括反向回交以确定突变是母系遗传还是通过亲本遗传，不同突变系之间的互补研究，以及突变系与不同生态型野生型系之间的杂交以进行RFLP定位。长期目标是克隆和鉴定其产物与高等植物叶绿体发育调控有关的基因。叶绿体是光合作用和固碳的场所，叶绿体的发育对植物的生存至关重要。叶绿体最初是光合细菌的一种内共生体，随着时间的推移，细菌基因组的许多调节功能被细胞核取代。虽然许多改变叶绿体的突变已经从大量不同的植物物种中分离出来，但到目前为止还没有人清楚地了解调控高等植物叶绿体发育的分子事件。模式植物系统拟南芥提供了一个了解这一过程的机会，因为通过突变鉴定的参与叶绿体发育的基因可以被克隆。这项研究计划拨款中提出的工作的目的是分离拟南芥中表现出绿色表型延迟(称为绿色)的突变体，以便评估最有可能参与叶绿体发育调控的突变。已经获得了几个突变体，并将获得更多突变体。这些植物将在生化、结构和遗传方面进行表征，以确定那些对了解叶绿体发育最具潜力的植物。这项工作的长期目标是克隆导致这些突变的基因，并了解它们的功能。***

9407920 Brusslan This is a Research Planning Grant. The objective are to: 1, isolate virescent mutants from EMS, fast-neutron, and T- DNA mutagenized Arabidopsis; 2, characterize the development of the photosynthetic apparatus in these mutants using absorption spectroscopy, fluorescence emission, transmission electron microscopy, and native Deriphat gel electrophoresis; 3, to analyze mutants with regard to temperature sensitivity as well as sensitivity to differing light intensities; and 4, to perform a genetic analysis. The genetic analysis will include reciprocal backcrosses to determine if mutations are inherited maternally or through either parent, complementation studies between the different mutant lines, and crosses between mutant lines and a wild type line of a different ecotype to permit RFLP mapping. The long term goal is to clone and characterize genes whose products are involved in the regulation of chloroplast development in higher plants. %%% The chloroplast is the site of photosynthesis and carbon fixation, and its development is critical for plant survival. The chloroplast originated as an endosymbiont of photosynthetic bacteria, and over time many regulatory functions of the bacterial genome wre taken over by the nucleus. Although many mutations that alter the chloroplast have been isolated from a large number of different plant species, none so far have led to clear understanding of the molecular events that regulate chloroplast development in higher plants. The model plant system, Arabidopsis thaliana, offers an opportunity to understand this process because genes involved in plastid development that are identified by mutation can be cloned. The objective of the work proposed in this research planning grant is to isolate mutants in Arabidopsis that display a delay in greening phenotype (termed virescent) in order to evaluate mutations most likely to be involved in the regulation of chloroplast development. Several mutants have alr eady been obtained, and more will be obtained. These will be characterized biochemically, structurally, and genetically in order to identify those of the greatest potential for understanding chloroplast development. The long term goal of this work is to clone the genes responsible for these mutations and to understand their functions. ***