EAGER: Exploratory Studies of Metabolic Water in Plants and Microorganisms

水是生物体细胞在呼吸过程中产生的。该项目旨在了解这种水对植物和土壤微生物的重要性。当外部供水不足时，这种代谢水可能是至关重要的。该项目将验证代谢水在植物抵御干旱和修复干旱对植物水运系统造成的损害方面的重要作用。该项目还将测试这样一种观点，即代谢水为土壤微生物在干燥土壤中维持活动提供了一种手段。该项目将采用新技术，通过化学上不同形式的氧气为代谢水提供示踪剂，从而区分代谢水和非代谢水。本研究中开发的用于监测复杂活组织代谢的技术在研究人类疾病和癌症检测的线粒体疾病方面具有潜在的应用前景。本科生将积极参与研究，接受微生物和植物生态学以及呼吸代谢方面的培训。代谢水是动物、植物和需氧微生物在呼吸代谢过程中产生的。虽然在一些动物中代谢水的重要性已得到充分认识，但对微生物和植物中代谢水的生理或生态意义却几乎一无所知。该项目假设，代谢水对土壤微生物的水分平衡有重要贡献，通过提供减缓干燥和延迟休眠的内部水源来延长干燥土壤中的活动。对于植物来说，我们假设代谢水通过在正压下提供局部水源，有助于栓塞细胞的再填充，从而有助于栓塞血管细胞的水运输功能的恢复。为了验证这些假设，该项目使用了一系列创新的观察、实验和建模活动。一种关键的实验方法是在含有氧稳定同位素18-O富集的氧气的空气中孵育，从而产生富集18-O的代谢水，这种水可以通过其独特的同位素组成与环境水区分开来。18-O研究采用了两种尖端成像技术：高分辨率x射线计算机断层扫描，用于可视化栓塞血管的再填充，稳定同位素拉曼光谱用于定位细胞和组织内18-O标记的代谢水。这些研究的新见解将在理解植物和微生物的中心能量代谢和水关系的相互作用方面具有革命性的意义。

Water is produced in the cells of organisms during respiration. This project seeks to understand the importance of this water for plants and soil microorganisms. This metabolic water is potentially of vital importance when external water supply is low. The project will test the idea that metabolic water is important to plants in withstanding drought and repairing drought-induced damage to the plant water transport system. The project will also test the idea that metabolic water provides a means for soil microbes to sustain activity in dry soils. The project will employ novel techniques based on providing a tracer for metabolic water via a chemically distinct form of oxygen that allows distinguishing metabolic water from water that is not produced by metabolism. The techniques developed in this study to monitor metabolism in complex living tissues have potential applications for studying mitochondrial disorders underlying human disease and cancer detection. Undergraduate students will be active participants in the research, receiving training in microbial and plant ecology, and respiratory metabolism. Metabolic water is produced during respiratory metabolism in animals, plants, and aerobic microorganisms. Although its vital importance is well recognized in some animals, virtually nothing is known about the physiological or ecological significance of metabolic water in microorganisms and plants. The project hypothesizes that metabolic water contributes importantly to the water balance of soil microorganisms, prolonging activity in drying soils by providing an internal source of water that slows desiccation and delays the onset of dormancy. For plants, it's hypothesized that metabolic water contributes to the recovery of water transport function in embolized vascular cells by providing a local source of water under positive pressure that contributes to refilling of embolized cells. To test these hypotheses, the project uses a suite of innovative observations, experiments, and modeling activities. A key experimental methodology involves incubations in air containing oxygen gas enriched in the stable isotope of oxygen, 18-O, resulting in 18-O enriched metabolic water that can be distinguished from environmental water by its distinctive isotopic composition. The 18-O studies are augmented with two cutting-edge imaging techniques: high-resolution x-ray computed tomography to visualize refilling of embolized vessels, and stable isotope Raman spectroscopy to locate 18-O labeled metabolic water within cells and tissues. New insights from these studies will be transformational in terms of understanding the interaction of central energy metabolism and water relations in plants and microorganisms.