Collaborative Research: Predictive Modeling of Maize Metabolism

该项目将开发和测试化学反应（代谢）的预测数学模型，玉米（玉米）将光合作用过程中产生的糖转化为储存在种子中的淀粉等化合物。目的是更好地了解淀粉代谢，并提供提高粮食产量的方法。该研究将揭示代谢功能和动力学的基本原理，并为从事该项目的学生提供跨学科的培训（数学建模，遗传工程和代谢生物化学）。淀粉胚乳（SE）是谷物中碳水化合物和蛋白质储存的主要场所，但非典型约束使系统的详细解析复杂化。这些包括基本上为零的稳态二氧化碳水平，这与在储存聚合物形成之前结构单元的能量昂贵的分解和再合成一致。SE代谢中的一个主要问题是如何产生ATP以支持淀粉和蛋白质合成，以及光同化物如何在分解代谢和合成代谢途径之间分配。该项目将扩展现有的通量模型，以考虑生物能量参数，并通过损害特定代谢节点的定向遗传修饰来探测系统。将比较来自未改变和突变株系的SE之间的代谢物水平和通量图。这些数据将被应用于完善的数学模型和测试假设的系统如何转移化学资源的存储化合物积累。

This project will develop and test predictive mathematical models of the chemical reactions (metabolism) by which maize (corn) transforms the sugars produced during photosynthesis into compounds such as starch that are stored in the seeds. The goal is to understand starch metabolism better and provide the means for enhancing food production. This study will reveal fundamental principles of metabolic function and dynamics, and provide interdisciplinary training (in mathematical modeling, genetic engineering and metabolic biochemistry) to students engaged in this project.Starchy endosperm (SE) is the major site of carbohydrate and protein storage in cereals, but atypical constraints complicate detailed resolution of the system. These include a steady state carbon dioxide level of essentially zero, coincident with energy-expensive breakdown and re-synthesis of building blocks prior to storage polymer formation. A major question in SE metabolism is how ATP is generated to support starch and protein synthesis, and how the photo-assimilate is divided between catabolic and anabolic pathways. This project will expand upon existing flux models to account for bio-energetic parameters, and probe the system by directed genetic modifications that impair specific metabolic nodes. Metabolite levels and flux maps will be compared between SE from unaltered and mutant lines. These data will be applied to refine the mathematical models and test hypotheses of how the system diverts chemical resources for storage compound accumulation.