Integrating Environmental Variables in Plant Circadian and Photoperiodic Timing.

植物的进化是对有利和有害的环境变量的反应，如光、温度、湿度和害虫的威胁。为了抵消日常压力，并在白天最大限度地储存能量，植物发展了复杂的调节回路，可以预测日常（昼夜节律）和季节（光周期）节律，从而提供了进化优势和提高生物体适应性。因此，植物的昼夜节律控制着植物生长发育的各个方面，包括开花时间、光合作用、纬度物种分布以及对干旱、寒冷和害虫的抵抗力。据估计，超过三分之一的植物基因受昼夜节律控制，适当的日长测量对维持植物生长、繁殖和作物产量至关重要。这些生物钟是如何测量和适应各种环境信号的，人们知之甚少。这在适应环境光的质量和数量的日常和季节变化方面尤其如此。目前的提案旨在使用多学科方法来模拟植物如何在给定环境中感知和适应蓝光强度的变化。除了获得对控制植物光生物学的化学过程的基本理解之外，该项目还可能为提高作物产量和可再生能源的生物质生产提供新的途径，并开发出更抗旱和抗虫害的新型植物品种。该项目将为本科生提供独特的培训机会，并向当地科学教师和K-12学生提供推广服务。人们对光氧电压蛋白如何整合环境信号知之甚少。提出的研究利用了最近发现的新的信号机制，描述了对环境刺激的适应性反应。协同化学、生物物理和合成生物学方法将提供对复杂信号网络中适应性反应的定量理解。主要的技术目标有三个方面。1)将开发化学动力学和预测数学模型的组合，以获得对光氧电压蛋白在季节和日常时钟中的功能的系统级理解。这些努力的直接结果将是对光氧电压蛋白功能的多种化学输入如何决定信号转导和光遗传工具开发的详细了解。2)本项目将利用对光-氧-电压蛋白信号网络的新认识，设计哺乳动物细胞中的合成基因电路，从而在缺乏可能影响信号转导的外来植物蛋白的情况下，测试对该网络的理解。3)最终目标是结合这一认识来指导构建具有改变昼夜节律功能和植物花期的新拟南芥菌株，以证明光氧电压蛋白化学对触发植物系统级适应性变化的必要性。

Plants evolved in response to advantageous and deleterious environmental variables, such as light, temperature, moisture and the threat of pests. To counteract daily stresses, and to maximize energy storage during the day, plants developed complex regulatory circuits that can predict daily (circadian) and seasonal (photoperiodic) rhythms, thus providing an evolutionary advantage and improved organism fitness. As such, plant circadian rhythms control all facets of plant growth and development, including flowering times, photosynthesis, latitudinal species distribution, and resistance to drought, cold and pests. It is estimated that greater than one third of all plant genes are under circadian control and that proper day-length measurements are imperative to the maintenance of plant growth, reproduction and crop yields. How these circadian clocks measure and adapt to a wide array of environmental signals is poorly understood. This is particularly the case for adaptation to daily and seasonal variations in the quality and quantity of environmental light. The current proposal aims to use a multidisciplinary approach to model how plants sense and adapt to changes in the intensity of blue-light in a given environment. Aside from gaining fundamental understanding of the chemical processes that govern plant photobiology, the project is likely to provide new avenues to improve crop yields and biomass production for renewable energy, and develop novel varieties of plants that are more drought and pest resistant. The project will provide unique training opportunities for undergraduate students and outreach to local science teachers and K-12 students.How Light-Oxygen-Voltage proteins integrate environmental cues is poorly understood. The proposed research leverages recent discoveries of new signaling mechanisms that delineate adaptive responses to environmental stimuli. The concerted chemical, biophysical and synthetic biology approach will provide quantitative understanding of adaptive responses in complex signaling networks. The primary technical objectives are three fold. 1) A combination of chemical kinetics and predictive mathematical models will be developed to gain a systems level understanding of Light-Oxygen-Voltage protein function in seasonal and daily clocks. A direct result of these efforts will be a detailed understanding of how multiple chemical inputs to Light-Oxygen-Voltage protein function dictate signal transduction and optogenetic tool development. 2) The project will use the new understanding of Light-Oxygen-Voltage protein signaling networks to design synthetic gene circuits in mammalian cells, and thus enable the testing of the understanding of the network in the absence of extraneous plant proteins that may affect signal transduction. 3) The ultimate goal is to combine this understanding to guide the construction of new Arabidopsis thaliana strains that exhibit altered circadian function and plant flowering periods to demonstrate how Light-Oxygen-Voltage protein chemistry is essential for triggering systems-level adaptive changes in a plant system.