SGER: Stable Isotope Fingerprinting: A Novel Approach to Identifying Amino Acid Biosynthetic Sources, Using Stable Isotope Variation Among Amino Acids.

SGER：稳定同位素指纹图谱：利用氨基酸之间的稳定同位素变异来识别氨基酸生物合成来源的新方法。

• 批准号: 0552014
• 负责人: Diane O'Brien
• 金额: --
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0552014&HistoricalAwards=false
• 关键词: SGER; Stable; Isotope; Fingerprinting; Novel

Understanding nutrient flow is a central goal of both organismal biology and ecosystem ecology. In nutritional physiology, for example, researchers are only starting to appreciate the complexity of how animals meet requirements for essential amino acids and fatty acids, and how meeting those requirements can generate physiological interdependency. In arctic ecosystems, amino acids are a key source of nitrogen for boreal plant communities, but how they are supplied to soil is unclear. Nutritional associations between plants and root-fungi (mycorrhizae) are common, but the details of nutrient exchange between the partners are not well known. In all these cases, progress is limited by the available tools for tracing nutrient exchange. This research develops a new approach to tracing amino acid biosynthetic sources, using the variation generated by organismal metabolism in the carbon isotopic signatures of amino acids. These suites of isotopic signatures can be thought of as a biosynthetic "fingerprint," and these fingerprints may be diagnostic of the type of organism that produced them. The proposed research will characterize the amino acid isotopic fingerprints of select microorganisms, plants, and fungi. These organisms can synthesize de novo all twenty amino acids found in proteins, and potentially supply amino acids to animals, soil nutrient pools, or symbiotic partners. If these fingerprints prove to be robust, reproducible indicators of biosynthetic sources, they would transform the ability of researchers to address questions about nutrient flow in natural systems that cannot be answered with present technology. Such a tool will be of great interest to scientists studying physiological ecology, evolutionary ecology, plant-insect interactions, plant biology, ecosystem ecology, and biogeochemistry. The analyses used to measure isotope signatures in amino acids are becoming increasingly available. However, the lack of comparative data has contributed to a growing literature that is rife with poorly validated assumptions. Thus, this research will significantly advance our understanding of the variability of amino acid signatures within and among organisms, and will provide the foundation for a methodology with wide ranging applicability. This research project will involve training of a graduate student in the development of this novel tool.

了解养分流动是生物生物学和生态系统生态学的中心目标。例如，在营养生理学方面，研究人员才刚刚开始认识到动物如何满足必需氨基酸和脂肪酸的需求，以及满足这些需求如何产生生理上的相互依赖性。在北极生态系统中，氨基酸是北方植物群落氮的主要来源，但它们是如何供应给土壤的尚不清楚。植物和根真菌（菌根）之间的营养联系是常见的，但伙伴之间的营养交换的细节并不为人所知。在所有这些情况下，进展都受到追踪营养交换的现有工具的限制。本研究开发了一种利用氨基酸碳同位素特征的有机代谢变化来追踪氨基酸生物合成来源的新方法。这些同位素特征可以被认为是生物合成的“指纹”，这些指纹可以诊断产生它们的生物类型。提出的研究将表征选定的微生物，植物和真菌的氨基酸同位素指纹图谱。这些生物可以从头合成蛋白质中发现的所有20种氨基酸，并可能为动物、土壤养分池或共生伙伴提供氨基酸。如果这些指纹被证明是生物合成来源的可靠、可重复的指标，它们将改变研究人员解决有关自然系统中营养流动问题的能力，这些问题目前的技术无法回答。这样的工具将对研究生理生态学、进化生态学、植物-昆虫相互作用、植物生物学、生态系统生态学和生物地球化学的科学家产生极大的兴趣。用于测量氨基酸同位素特征的分析方法正变得越来越可行。然而，由于缺乏比较数据，导致越来越多的文献充斥着未经验证的假设。因此，这项研究将大大促进我们对生物内部和生物之间氨基酸特征变异性的理解，并将为广泛适用的方法提供基础。这个研究项目将包括培训一名研究生开发这种新工具。