Molecular genetic analysis of the Arabidopsis circadian clock

植物利用内部的生物钟来在时间上协调生物化学和生理活动与地球绕其轴旋转所施加的每日循环。 这种内部时钟与日常环境周期的匹配对最佳的现场性能有很大的贡献。 本研究探讨了植物时钟机制的两个关键方面。 第一个是对温度补偿的遗传和生化分析，这是一种生物钟功能在一定温度范围内保持一致的特性。 第二个是生物钟对基因表达的全局调节。 突变分析已经确定了一种新的时钟组件AtPRMT5，它编码一种染色质修饰酶，作为基因表达的关键调节因子。 具体的实验目标包括识别时钟机制本身内PRMT5活性的靶点，以及阐明PRMT5的调节机制。 昼夜节律钟整合时间信息并协调生物学的许多方面，包括基础代谢、生长素信号传导和反应以及对生物和非生物胁迫的反应。 深入了解生物钟机制的分子细节将有助于理解生物钟机制本身以及调控网络，通过该网络，来自生物钟的时间信息用于调控基因组的表达并协调生化途径的活动。 这反过来将为培育其时钟功能针对特定环境（例如，纬度）条件。 教育工作将强调培养本科生、研究生和博士后科学家，使他们能够在复杂的范围内自如地工作，从调节单个基因的表达到在全球基因组一级进行分析。

Plants use an internal circadian clock to temporally coordinate biochemical and physiologic activities with the daily cycle imposed by the rotation of the earth on its axis. The matching of this internal clock with the daily environmental cycle contributes significantly to optimal field performance. This research investigates two key aspects of the plant clock mechanism. The first is a genetic and biochemical analysis of temperature compensation, the property by which clock function remains consistent across a range of temperatures. The second is the global regulation of gene expression by the circadian clock. Mutational analysis has identified a novel clock component, AtPRMT5, which encodes a chromatin modification enzyme that serves as a key regulator of gene expression. Specific experimental goals include the identification of targets of PRMT5 activity within the clock mechanism itself and the elucidation of the mechanism by which PRMT5 is regulated. The circadian clock integrates temporal information and coordinates many aspects of biology, including basic metabolism, auxin signaling and responses as well as responses to biotic and abiotic stress. Insights into the molecular details of the clock mechanism will inform an understanding of both the clock mechanism itself as well as of the regulatory network by which temporal information from the clock is used to regulate the expression of suites of genes and coordinate the activities of biochemical pathways. This, in turn, will inform and direct efforts to breed crops whose clock function is optimized for specific environmental (e.g., latitudinal) conditions. Educational efforts will emphasize the training of undergraduate, graduate and post-doctoral scientists able to work comfortably across scales of complexity, from the regulation of expression of individual genes through analyses at the global genomic level.