QEIB: Collaborative Research: Unifying Mechanistic and Dynamic Mathematical Models of Stomatal Behavior and Photosynthesis.

绿色植物叶片中的光合作用是最为人所知和研究最多的生物过程之一。在这一系列的化学反应和物理反应中，光能被用来将大气中的二氧化碳转化为糖，并产生氧气作为副产品。因此，光合作用是生物圈中几乎所有有机物和所有氧气的最终来源。从光捕获到碳水化合物合成的78个离散步骤中的每一个都是比较详细的已知的，并描述了它们的动力学性质。为了进行光合作用，二氧化碳必须通过被称为气孔的微小气孔进入叶片，气孔位于叶片表面。当二氧化碳扩散到叶片中时，水分和氧气也会扩散出去，气孔开度必须在一天中动态变化，以便吸收足够的二氧化碳进行光合作用，同时防止过度的水分损失。尽管对光合作用的了解较少，但控制气孔开放的许多生化和生物物理步骤现已被描述，而且有新的证据表明，光合作用过程可能是许多气孔反应的基础。现在的计算能力和数值方法足以模拟叶片光合作用的完整过程，从二氧化碳和氧气通过气孔交换到光能转化为底层光合作用组织中的碳水化合物。这项工作首次将光合作用过程的完整描述和假想的气孔运动机制结合在一起，产生了一台计算机或用电子计算机表示树叶。这项工作的成果将能够模拟叶片对光、二氧化碳和氧气变化的动态反应，并将与叶片光合作用动态的真实测量进行比较，以测试和改进该模型。它将为研究气孔运动和光合作用之间的动态联系提供一个工作台。更广泛地说，它将为探索异常丰富的可测量性质的复杂自然系统的数学性质提供一种手段。该项目将为教育做出贡献，提供一个进入硅叶的门户，使教室能够研究动态的环境反应和光合作用过程中个别步骤的基因改造。与该项目相关的本科生研究经验将有助于门户网站的实施。

Photosynthesis within the leaves of green plants is one of the best known and most researched of biological processes. In this series of chemical and physical reactions, light energy is used to convert atmospheric CO2 into sugars, producing oxygen as a by-product. Thus, photosynthesis is the ultimate source of essentially all organic matter and all oxygen in the biosphere. Each of the 78 discrete steps from light capture to carbohydrate synthesis is known in some detail and their kinetic properties described. For photosynthesis to occur, CO2 must enter the leaf through tiny pores called stomata, which are found on the surfaces of leaves. As CO2 diffuses into the leaf, water and O2 diffuse out, and stomatal aperture must vary dynamically throughout the day to admit sufficient CO2 for photosynthesis while preventing excessive water loss. Although less well understood than photosynthesis, many of the biochemical and biophysical steps controlling stomatal opening are now described, and there is new evidence that photosynthetic processes may underlie many stomatal responses. Computational power and numerical methods are now sufficient to allow the simulation of the complete process of leaf photosynthesis from carbon dioxide and oxygen exchange through the stomata to light energy transduction into carbohydrate in the underlying photosynthetic tissue. This work, for the first time, brings together the complete description of the photosynthetic process and hypothesized mechanisms of stomatal movements to produce a computer or in silico representation of the leaf. The product of this effort will be capable of mimicking the dynamic responses of leaves to changes in light, carbon dioxide and oxygen, and comparisons to real measurements of the dynamics of leaf photosynthesis will be used to test and improve the model. It will provide a workbench for investigating the dynamic linkages between stomatal movement and photosynthesis. More broadly it will provide a means for exploring the mathematical properties of a complex natural system that is unusually rich in measurable properties. The project will contribute to education by providing a portal to the in silico leaf, allowing classroom investigation of both dynamic environmental responses and genetic modification of individual steps in the photosynthetic process. Undergraduate Research Experiences linked to this project will aid this implementation of the portal.