The Control of Reproductive Onset and the Circadian Clock by GIGANTEA

生物钟控制着植物和动物许多发育和生理过程的时间。航空旅客经历的不舒服但熟悉的时差效应是生物钟无法在到达时立即重置到新的当地时间的直接结果。在植物中，生物钟控制着开花的开始和光合作用等关键事件的时间安排。最近由美国国家科学基金会资助的研究表明，植物时钟的两个先前不相关的成分，ZEITLUPE(ZTL)和Gigantea(GI)，凭借其新颖的光吸收特性，以蓝光依赖的方式相互作用。GI稳定ZTL蛋白的降解，首次定义了GI的作用。这一建议将通过确定哪些结构域对ZTL的相互作用和稳定有效，进一步定义GI的生化功能。第二个目标是确定其他GI相互作用因子，因为GI可能稳定其他蛋白质，并可能需要其他辅助因子才能有效发挥作用。将使用酵母双杂交分析和GI-TAP标记复合体的质谱分析等技术。这些研究的结果将更好地确定拟南芥时钟中央振荡器的分子和生化成分。这项工作将为研究生和博士后研究人员提供一个在交互环境中学习当代分子生物学和植物生化技术的机会。此外，本科生学习技术和分子技能，他们在职业生涯的后期使用，由更有经验的实验室工作人员指导。该项目人员的研究经验将拓宽他们的科学专长，并为他们未来的PI、博士后和教师的发展做出贡献。

The circadian clock controls the timing of many developmental and physiological processes in both plants and animals. The uncomfortable but familiar effects of jet lag experienced by air travelers is a direct result of the inability of the circadian clock to immediately reset to the new local time upon arrival. In plants, the circadian clock controls the onset of flowering and the timing of essential events like photosynthesis. In this way its function is crucial to efficient plant, and crop, growth and reproduction.Recent NSF-funded research has shown that two previously unconnected components of the plant clock, ZEITLUPE (ZTL) and GIGANTEA (GI), interact in a blue-light dependent way, by virtue of the novel photoabsorptive properties of ZTL. GI stabilizes the ZTL protein from degradation, defining a role for GI for the first time. This proposal will further define the biochemical function of GI by identifying which domains are effective for the interaction and stabilization of ZTL. A second aim is to identify other GI interactors, as it is likely that GI stabilizes other proteins, and may require other cofactors to function effectively. Techniques such as yeast two-hybrid analysis and mass spectrometric analysis of GI-TAP-tagged complexes will be used. Results from these studies will better define the molecular and biochemical components of the central oscillator of the clock in Arabidopsis. In turn, findings in this model system will lead to better understanding and control of crop physiology and reproduction.This work will provide an opportunity for the graduate student and postdoctoral researchers involved to learn contemporary molecular biology and plant biochemical techniques in an interactive environment. Additionally, undergraduates, who learn technical and molecular skills that they use later in their careers, are mentored by the more experienced lab workers. The research experiences of the personnel in this project will broaden their scientific expertise, and contribute to their development as future PI's, post-docs and teachers.