Collaborative Research: Investigating the Role of Cytosolic One-carbon Metabolism in Photorespiration

该项目探讨了光呼吸和一碳代谢之间的交叉点，这两种植物生化途径对植物生长和人类营养至关重要。光呼吸是植物吸收光合作用副产物产生的有毒物质的过程，是植物生长的重要过程。光呼吸的速率与温度升高和二氧化碳浓度有关，这意味着未来的光呼吸速率将随着气候的变化而变化。一碳代谢对植物生长同样至关重要，也是叶酸等必需维生素的来源。该项目的目标是生成预测当前和未来气候条件如何影响植物性能和产量的模型。这些模型将为育种和工程方法提供信息，以优化植物生产力和生产对人类营养和健康至关重要的植物化合物。在这个跨学科项目中，高中，本科，研究生和博士后学员被教授植物生物学的综合方法，扩大了他们在合作科学研究中的教育和学习机会。这一活动的目的是灌输对科学的积极态度，并鼓励创造性和批判性思维，使受训者在教育培训的早期就有更多的机会接触科学进程。代表性不足的本科生和研究生参加几个大学项目，旨在为华盛顿州立大学和密歇根州立大学代表性不足的群体提供现有研究机会的信息。该项目的主要面向公众的外联活动是在华盛顿州立大学举行的“科学之声”表演，这是植物科学家和音乐家之间的一次独特合作，导致了一场TED演讲式的活动，旨在提高人们对植物科学重要性的认识。传统上，光呼吸被认为是定义明确的，代谢灵活性很小。然而，PI的最近的工作表明，光呼吸通量可以选择性地分配到细胞质中的四氢叶酸结合的一碳（C1）单位的代谢。这可能为传统的光呼吸途径提供了一个溢出，并对光呼吸、光合作用和叶片氮同化的能量学和碳平衡具有重要意义。因此，重要的是要确定的贡献胞质C1代谢的光呼吸，特别是在响应的条件下，影响光呼吸率（如干旱和高温）。该项目的目标是确定胞质C1代谢在光呼吸中的作用。据推测，两个胞质C1酶，甲酸-四氢叶酸连接酶和丝氨酸羟甲基转移酶，参与处理过程中产生的甲酸和丝氨酸光呼吸。反向遗传学、叶片气体交换、代谢物分析和标记辅助代谢通量分析用于测试这两种酶在C1和光呼吸途径之间的碳代谢协调中的作用。该奖项反映了NSF的法定使命，并被认为值得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来支持。

This project explores the intersection between photorespiration and one carbon metabolism, two plant biochemical pathways that are of critical importance to plant growth and consequently human nutrition. Photorespiration is a plant process that recycles toxic products created as a byproduct of photosynthesis and is an essential process of plant growth. Rates of photorespiration are linked to elevated temperature and carbon dioxide concentration, meaning that future rates of photorespiration will change with changing climates. One carbon metabolism is similarly vital to plant growth, and also is the source for essential vitamins like folate. The goal of this project is to generate models predicting how current and future climatic conditions influence plant performance and yields. These models would inform breeding and engineering approaches to optimize plant productivity and the production of plant compounds important for human nutrition and health. During this interdisciplinary project, high school, undergraduate, graduate, and post-doctoral trainees are taught integrative approaches to plant biology, broadening their education and learning opportunities in collaborative scientific research. The aim of this activity is to instill positive attitudes towards science, and encourage creative and critical thinking by providing trainees with greater access to the scientific process early in their educational training. Underrepresented undergraduate and graduate students participate in several university programs designed to provide information on existing research opportunities to underrepresented groups at Washington State University and Michigan State University. The main public facing outreach activity of this project is a Sounds of Science performance at Washington State University, a unique collaboration between plant scientists and musicians resulting in a TED-talk styled event aimed to increase awareness of the importance of plant science. Traditionally, photorespiration has been considered well defined with little metabolic flexibility. However, the PI’s recent work suggests that photorespiratory flux can alternatively be partitioned into the metabolism of tetrahydrofolate-bound one-carbon (C1) units in the cytosol. This may provide an overflow for the traditional photorespiratory pathway and has important implications for the energetics and carbon balance of photorespiration, photosynthesis, and foliar nitrogen assimilation. Therefore, it is important to define the contribution of cytosolic C1 metabolism to photorespiration, particularly in response to conditions that influence rates of photorespiration (e.g. drought and high temperature). The goal of the project is to determine the role of cytosolic C1 metabolism in photorespiration. It is hypothesized that two cytosolic C1 enzymes, formate-tetrahydrofolate ligase and serine hydroxymethyltransferase, participate in processing of formate and serine generated during photorespiration. Reverse genetics, leaf gas exchange, metabolite analyses, and labeling-assisted metabolic flux analysis are used to test the role of these two enzymes in the coordination of carbon metabolism between the C1 and photorespiratory pathways.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.