PAPM EAGER: A Plant Observatory for remote sensing of biochemical reactions in vivo

在现实世界条件下对植物进行表型分析是极具挑战性的。Frommer实验室（斯坦福大学）开发了一套基因编码的生物传感器，可以报告亚细胞水平的离子或代谢物（如离子、糖），或者以高时间分辨率报告特定转运体的活性。通常，用荧光显微镜分析表达这些传感器的植物。该项目将探索是否可以使用远程成像系统量化植物叶片特定区域的离子水平（这里的信号中间体钙作为概念证明）。密歇根州立大学的克莱默实验室开发了一种生长室，可以模拟和回放现场条件，同时使用荧光成像系统显示光合参数的表型。此次合作将这两个创新平台结合在一起：动态环境成像系统（DEPI）和基因编码超灵敏荧光生物传感器技术。该项目旨在开发一种新的系统，该系统可以以前所未有的深度监测完整植物中的遗传编码传感器，并可用于光合作用的高通量表型分析。该项目将为建立系统和工具奠定基础，作为社区资源，有可能改变世界各地的光合作用研究项目。这一高风险项目将为拟南芥和作物的遗传变异表型分析奠定基础，并将遗传编码生物传感器的用途扩大到大规模筛选。此外，本项目将培养一名具有物理化学表型研究经验的博士后科学家。该项目还将培训高中生和本科生，在可能的情况下，少数民族学生也将参与其中。这种成像系统将为完整植物分子事件的表型分析提供一种全新的工具，从而为筛选遗传变异和在整个植物水平上发现新的生物学提供一种新的工具。该项目将通过监测新型超灵敏钙传感器来证明该技术的潜力，以测试长期存在的关于钙在信号传导过程中的作用以及叶片在波动环境条件和特定信号传导过程中的反应模式的假设。其中一个挑战是组合植物成像系统的灵敏度。Frommer实验室开发了一种新型的超灵敏钙传感器，将在这里使用，它可以使我们同时观察100种植物种群在整个生长周期中的钙动态。如果成功，该方法可以扩展到其他荧光生物传感器，并用于作物筛选。同时，该系统还可能在植物细胞信号和叶绿体离子动力学领域揭示新的生物学。

Phenotyping plants under real world conditions is highly challenging. The Frommer lab (Stanford) developed a suite of genetically encoded biosensors that report subcellular levels of ions or metabolites (e.g. ions, sugars) or that report the activity of particular transporters with high temporal resolution. Typically, plants expressing these sensors are analyzed using fluorescence microscopy. This project will explore whether ion levels can be quantified (here the signaling intermediate calcium as a proof of concept) in specific regions of plant leaves using a remote imaging system. The Kramer lab at MSU developed a growth chamber that can mimic and replay field conditions and simultaneously phenotype photosynthetic parameters using a fluorescence imaging system. This collaboration brings together these two innovative platforms: the dynamic environmental imaging system (DEPI), and genetically encoded ultrasensitive fluorescent biosensor technology. The project aims to develop a novel system that can monitor genetically encoded sensors in intact plants with unprecedented depth and the parallel option for high throughput phenotyping of photosynthesis. The project will lay the groundwork for establishing systems and tools as community resources with the potential to transform photosynthesis research programs around the world. This high-risk project will lay the basis for phenotyping genetic variants in Arabidopsis as well as crops and expand the usefulness of genetically encoded biosensors to large scale screening. In addition, this project will train a postdoctoral scientist with experience in physical chemistry in phenotyping. The project will also train high school students and undergraduate students, and where possible minority students will be engaged in this endeavor.Such an imaging system would present a completely novel tool for phenotyping molecular events in intact plants and thus present a new tool for screening genetic variants and to discover new biology at the whole plant level. The project will demonstrate the potential of this technology by monitoring novel ultrasensitive calcium sensors to test long-standing hypotheses regarding the role of calcium in signaling processes and the response patterns in leaves in fluctuating environmental conditions and specific signaling processes. One of the challenges is the sensitivity of the combined plant-imaging system. The Frommer lab developed novel ultrasensitive calcium sensors that will be used here and that may enable us to observe calcium dynamics over the whole growth cycle in populations of 100s of plants simultaneously. This approach, if successful, could be expanded to other fluorescent biosensors and implemented for crop plant screening. At the same time, such a system may uncover new biology in the areas of plant cell signaling and chloroplast ion dynamics.