Integrated Molecular, Dynamic Imaging, and Modeling Analysis of Stomatal Guard Cell Walls

该项目旨在确定保卫细胞基于碳水化合物的细胞壁如何动态改变形状以控制气孔大小，从而使植物能够控制二氧化碳(CO2)的吸收和水分损失。气孔是植物表面的小开口，它调节二氧化碳光合作用转化为植物生物量，作为可再生的食物、材料和生物能源来源。更深入地了解气孔保卫细胞的细胞壁结构、力学和动力学将有助于识别能够更有效地利用水分的植物，这是全球农业生产的一个主要限制因素。该项目将开发的计算图像分析和建模工具将为科学家提供解释和理解实验数据的新方法。由于气孔保卫细胞是植物细胞工程的一个令人惊叹的例子，所有年龄段的科学家都可以接触和观察到，因此将开发和部署一个学习模块，允许4到8年级的学生第一手观察气孔动力学，并挑战他们构建和优化气孔保卫细胞的功能宏观模型，帮助激励未来的科学家和工程师。该项目还将培训两名博士生和一名研究助理，掌握跨越生物学、计算机和信息科学以及工程学边界的跨学科研究技能。在植物中，气孔保卫细胞起着动态守门人的作用，控制二氧化碳和水分通量，以维持动态平衡。为了控制蒸腾作用和光合作用，气孔的发育、形态和机械都受到严格的调控。然而，我们对气孔如何发育和功能的了解存在两个很大的差距。首先，气孔孔是通过姐妹保卫细胞的受控分离形成的，但这是如何完成的尚不清楚。其次，保卫细胞的壁必须高度灵活，以便能够反复打开和关闭气孔，但必须足够坚固，以承受驱动其变形的巨大膨胀压力。保卫细胞壁是如何通过分子构造来满足这些相互竞争的要求的，目前在很大程度上还没有确定。这个项目将使用一套互补的方法，包括分子遗传学、高分辨率显微镜和计算图像分析，分析气孔孔形成的分子和力学要求，以及保卫细胞壁的动态分子结构，保卫细胞壁是它们独特的机械特性的基础。从这些分析中获得的数据和见解将被用来构建保卫细胞壁的计算力学模型，该模型可以用新的实验结果反复改进，最终导致能够预测一系列物种、保卫细胞壁组成和信号输入的保卫细胞动力学。

This project seeks to determine how the carbohydrate-based cell walls of guard cells dynamically change shape to control stomatal pore size, thus allowing plants to control carbon dioxide (CO2) uptake and water loss. Stomata are small openings in the surfaces of plants that regulate the photosynthetic conversion of CO2 into plant biomass, which serves as a renewable source of food, materials, and bioenergy. A deeper understanding of cell wall structure, mechanics, and dynamics in stomatal guard cells will help identify plants that can more efficiently use water, a major limiting factor in global agricultural production. The computational image analysis and modeling tools that will be developed in this project will provide scientists with new ways of interpreting and understanding experimental data. Because stomatal guard cells are an amazing example of cellular engineering by plants and are accessible and observable by scientists of all ages, a learning module will be developed and deployed that allows 4th through 8th graders to observe stomatal dynamics first-hand and challenges them to construct and optimize functioning macro-scale models of stomatal guard cells, helping to inspire future scientists and engineers. This project will also train two PhD students and a research associate in interdisciplinary research skills that cross the boundaries of biology, computer and information science, and engineering.In plants, stomatal guard cells function as dynamic gatekeepers that control CO2 and water flux to maintain homeostasis. To control transpiration and photosynthesis, stomatal development, morphology, and mechanics are tightly regulated. However, two large gaps exist in our knowledge of how stomata develop and function. First, stomatal pores form via controlled separation of sister guard cells, but how this is accomplished is unknown. Second, the walls of guard cells must be highly flexible to enable repeated stomatal opening and closing, but strong enough to withstand the enormous turgor pressure that drives their deformation. How guard cell walls are molecularly constructed to meet these competing requirements remains largely undefined. This project will analyze the molecular and mechanical requirements for stomatal pore formation, and the dynamic molecular architecture of guard cell walls that underlie their unique mechanical properties, using a complementary set of approaches including molecular genetics, high-resolution microscopy, and computational image analysis. The data and insights gained from these analyses will be used to construct computational mechanical models of guard cell walls that can be iteratively refined with new experimental results, ultimately resulting in the ability to predict guard cell dynamics across a range of species, wall compositions, and signaling inputs.