EAGER: Exploratory Studies of Metabolic Water in Plants and Microorganisms

EAGER：植物和微生物代谢水的探索性研究

• 批准号: 1623915
• 负责人: George Koch
• 金额: $ 27.29万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1623915&HistoricalAwards=false
• 关键词: EAGER; Exploratory; Studies; Metabolic; Water

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.

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，这种代谢水可能至关重要。该项目将测试代谢水对植物抵御干旱和修复干旱对植物水分运输系统造成的损害的重要性。该项目还将测试代谢水为土壤微生物在干燥土壤中维持活动提供一种手段的想法。该项目将采用基于通过化学上不同的氧形式提供代谢水示踪剂的新技术，该技术可以区分代谢水和非代谢产生的水。 本研究开发的监测复杂活组织代谢的技术具有潜在的应用价值，可用于研究人类疾病和癌症检测的线粒体疾病。 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。 代谢水是在动物、植物和需氧微生物的呼吸代谢过程中产生的。 尽管代谢水在某些动物中的重要性已被充分认识，但对微生物和植物中代谢水的生理或生态意义几乎一无所知。该项目假设代谢水对土壤微生物的水平衡有重要贡献，通过提供内部水源来减缓干燥并延迟休眠的开始，从而延长干燥土壤的活动。 对于植物，假设代谢水通过在正压下提供有助于栓塞细胞再填充的局部水源而有助于栓塞血管细胞中水运输功能的恢复。为了验证这些假设，该项目使用了一套创新的观察，实验和建模活动。一个关键的实验方法涉及在含有富含氧的稳定同位素18-O的氧气的空气中孵育，从而产生富含18-O的代谢水，其可以通过其独特的同位素组成与环境水区分开。 18-O研究得到了两种尖端成像技术的增强：高分辨率X射线计算机断层扫描，以可视化栓塞血管的再填充，以及稳定同位素拉曼光谱，以定位细胞和组织内的18-O标记代谢水。这些研究的新见解将在理解植物和微生物中中央能量代谢和水关系的相互作用方面具有变革性。