Collaborative Research: Cellular and Biomechanical Mechanisms of Rapid Stomatal Dynamics in Grasses

气孔是植物表面的微观孔隙，是控制作物光合作用的门户，为人类提供食物和可持续材料。该项目研究了禾本科植物（包括玉米和小麦等主要粮食作物）的气孔是如何根据环境条件的变化而快速打开和关闭以调节光合作用和水分运输的。该项目将提供跨学科的研究生培训，并支持基于发现的本科生研究课程，包括分子遗传学、植物细胞生物学、计算机视觉、生物力学实验和建模，扩大不同早期职业科学家在这些领域的参与。植物中令人兴奋的气孔动力学生物学，以及理解和设计气孔如何帮助解决紧迫的社会挑战，如粮食安全和气候变化，将通过中学夏令营与K-12学生分享，并指导将设计和完成独立研究项目的高中生。这项工作的结果有望帮助提高植物捕获二氧化碳并将其转化为食物和有用材料（如纤维和木材）的效率。据推测，草的四细胞气孔复合体通过一种“跷跷板”机制发挥作用，通过这种机制，哑铃形保护细胞的扩张与保护细胞侧面圆形附属细胞的收缩相匹配，从而能够根据环境变化快速调整气孔的大小。然而，这一假设尚未得到严格的验证，我们对禾本科植物气孔生物力学和功能的了解有限。该项目结合了分子遗传学、细胞生物学、计算机视觉、力学测试和气孔生物力学的计算机建模，剖析了模式草物种短茅（Brachypodium distachyon）快速气孔动力学的分子、生理和细胞基础。通过先进的基因工程技术，将对短柄藻的保护细胞和辅助细胞的细胞壁组成进行调控。由此产生的变化将在气孔功能方面进行检查，转基因植物的生物力学特性将被测量和建模，计算机视觉管道将用于量化细胞体积和形状的变化。有了这些方法，正常和改变的气孔复合体的实验可测试的计算模型将有助于预测气孔功能如何进一步优化，以提高作物产量，水利用效率和碳减少。该项目由NSF/BIO/MCB细胞动力学与功能计划和促进竞争性研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Stomata, which are microscopic pores on the surfaces of plants, are gateways that control photosynthesis in the crops that provide humanity with food and sustainable materials. This project investigates how stomata in grasses, which include staple food crops such as maize and wheat, are constructed with the capability to rapidly open and close to regulate photosynthesis and water transport in response to changing environmental conditions. The project will provide interdisciplinary graduate training and support discovery-based undergraduate research courses in molecular genetics, plant cell biology, computer vision, and biomechanics experimentation and modeling, expanding participation in these fields for diverse early-career scientists. The exciting biology of stomatal dynamics in plants and how understanding and engineering stomata can help address pressing societal challenges such as food security and climate change will be shared with K-12 students through a middle school summer camp and mentoring of high school students who will design and complete independent research projects. The outcomes of this work promise to help improve the efficiency with which plants capture carbon dioxide and convert it into food and useful materials such as fibers and wood.The four-celled stomatal complexes of grasses have been hypothesized to function via a “see-saw” mechanism by which the expansion of dumbbell-shaped guard cells is matched by deflation of the round subsidiary cells that flank the guard cells, enabling rapid adjustment of the size of the stomatal pore in response to environmental shifts. However, this hypothesis has not been rigorously tested, and our understanding of stomatal biomechanics and function in grasses is limited. This project combines molecular genetics, cell biology, computer vision, mechanical testing, and computer modeling of stomatal biomechanics to dissect the molecular, physiological, and cellular underpinnings of rapid stomatal dynamics in a model grass species, Brachypodium distachyon. The composition of the cell walls in guard and subsidiary cells will be manipulated in Brachypodium distachyon through advanced genetic engineering. The resulting changes will be examined with respect to stomatal function, biomechanical properties of the modified plants will be measured and modeled, and computer vision pipelines will be used to quantify changes in cell volumes and shapes. With these approaches, experimentally testable computational models of normal and altered stomatal complexes will help predict how stomatal function might be further optimized to enhance crop yields, water use efficiency, and carbon drawdown.This project is jointly funded by the NSF/BIO/MCB Cell Dynamics & Function Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.