Arabidopsis 2010: Phylogenetic and Functional Analysis of Nuclear-encoded Editing Factors and their Chloroplast RNA Targets

知识价值。RNA编辑将被子植物叶绿体转录物中的特定胞苷修饰为尿苷。C-to-U编辑被认为可以纠正叶绿体基因组中有害的T-to-C突变。进化过程塑造了叶绿体中RNA编辑的发生和分子机制，因为这一现象出现在现存种子植物的祖先中。来自拟南芥的基因组信息将为叶绿体编辑靶点和编辑位点转换所需的大型核编码含五肽基序蛋白家族成员的系统发育分析提供基础。更多的编辑因子将在拟南芥中被确定，以获得更全面的核编码机制，致力于叶绿体RNA编辑。将确定十字花科成员中的C-to-U编辑事件，以便与拟南芥中发生的编辑事件进行比较。在十字花科植物中，C靶点的丢失和获得以及它们周围序列的核苷酸变化将被追踪。将详细分析三个编辑反式因子的序列，以了解快速进化的核基因如何与进化较慢的叶绿体基因共同进化。RNA编辑靶标和相应的反式作用蛋白的核苷酸多样性知识将用于核蛋白进化变化和叶绿体RNA编辑后果的功能测试。更广泛的影响。叶绿体对太阳能的有效捕获对于植物生长提供生物质和其他农产品至关重要。该项目将提供一个重要的分子机制的基本信息，该机制可以纠正叶绿体基因组中可能损害光合作用的缺陷。该项目将为康奈尔大学和加州大学欧文分校的博士后、一名研究生和10-12名本科生提供多学科培训。与项目内容相关的主题将由合作pi开发。UCI的NSF GK-12研究生参与者。我们将开发出K-12课堂教师能够在7年级、9年级或AP生物课堂上使用的材料，并将通过UCI GK-12网站（http://port.bio.uci.edu/NSF-GK-12/default.htm）提供。私人调查团将协助康奈尔大学生物教师研究所将这些材料纳入定期在康奈尔大学举行的K-12教师培训的类似讲习班中。

Intellectual Merit. RNA editing modifies specific cytidines in angiosperm chloroplast transcripts to uridine. C-to-U editing is thought to function to correct detrimental T-to-C mutations in the chloroplast genome. Evolutionary processes have shaped the occurrence and molecular mechanism of RNA editing in chloroplasts since the phenomenon arose in an ancestor to extant seed plants. Genomic information available from Arabidopsis thaliana will provide a foundation for a phylogenetic analysis of chloroplast targets of editing and the members of the large nuclear-encoded pentatricopeptide motif-containing protein family that are required for editing site conversion. Additional editing factors will be identified in A. thaliana to gain a more comprehensive picture of the nuclear-encoded machinery devoted to chloroplast RNA editing. C-to-U editing events in members of the Brassicaceae will be identified for comparison to those occurring in A. thaliana. The loss and acquisition of C targets as well as nucleotide changes in the sequences surrounding them will be traced within the Brassicaceae. Sequences of three editing trans-factors will be analyzed in detail to understand how the rapidly evolving nuclear genes coevolve with the more slowly evolving chloroplast genes. Knowledge of nucleotide diversity in both the RNA editing targets and the corresponding trans-acting proteins will be used for functional tests of the consequences of evolutionary change in nuclear proteins and editing of chloroplast RNAs.Broader Impacts. Efficient capture of solar energy by chloroplasts is essential for optimal plant growth to provide biomass and other agricultural products. The project will provide fundamental information about an important molecular mechanism that corrects defects in the chloroplast genome that would otherwise impair photosynthetic activity. The project will provide multidisciplinary training for postdoctoral associates and a graduate student and 10-12 undergraduates at both Cornell University and University of California-Irvine (UCI). Topics related to project content will be developed by the co-P.I. and NSF GK-12 graduate student participants at UCI. Materials will be developed that K-12 classroom teachers will be able to implement in grade 7, 9 or AP biology classrooms and will be available through the UCI GK-12 web site (http://port.bio.uci.edu/NSF-GK-12/default.htm). The P.I. will assist the Cornell Institute for Biology Teachers in incorporating these materials into the comparable workshops that are periodically held at Cornell for K-12 teacher training.