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

该项目旨在确定保卫细胞的碳水化合物细胞壁如何动态改变形状以控制气孔孔径，从而使植物能够控制二氧化碳（CO2）吸收和水分流失。气孔是植物表面的小开口，调节CO2到植物生物质的光合作用转化，其作为食物，材料和生物能源的可再生来源。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确定可以更有效地利用水的植物，这是全球农业生产的主要限制因素。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惊人的例子，并且可以被所有年龄段的科学家访问和观察，因此将开发和部署一个学习模块，使4至8年级的学生能够直接观察气孔动态，并挑战他们构建和优化气孔保卫细胞的功能宏观模型，有助于激励未来的科学家和工程师。该项目还将培养两名博士生和一名研究助理，使其具备跨生物学、计算机和信息科学以及工程学的跨学科研究技能。在植物中，气孔保卫细胞作为动态守门人，控制CO2和水通量，维持体内平衡。为了控制蒸腾作用和光合作用，气孔的发育、形态和力学受到严格的调节。然而，在我们对气孔如何发育和功能的认识中存在两个大的空白。首先，气孔通过姐妹保卫细胞的受控分离形成，但这是如何实现的尚不清楚。第二，保卫细胞的壁必须高度柔韧，以使气孔能够重复打开和关闭，但又足够坚固，以承受驱动其变形的巨大膨压。保卫细胞壁是如何在分子上构建以满足这些相互竞争的要求的，这在很大程度上还不清楚。该项目将分析气孔形成的分子和机械要求，以及保卫细胞壁的动态分子结构，这些结构是其独特机械性能的基础，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。从这些分析中获得的数据和见解将用于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迭代改进，最终能够预测一系列物种，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.