SitS: Decoding microbial interactions in soil systems using subsurface sensors for volatile organic compounds

生物体在新陈代谢、交流和防御中产生并使用多种化合物。土壤微生物是其中一种挥发性有机化合物的活跃生产者和消费者，但我们对这些化学物质在土壤中的存在如何影响养分流动、土壤健康和植物生长的理解有限。土壤微生物以极低的浓度释放出数百种不同种类的挥发性有机化合物，使其在土壤中的综合测量变得困难。快速和非侵入性测量挥发性有机化合物的挑战限制了我们利用土壤中挥发性有机化合物的全套来推断微生物和植物之间的相互作用以及评估土壤健康的能力。土壤中挥发性有机化合物的高分辨率测量和监测需要新的方法和技术，以更好地了解植物-微生物相互作用如何影响土壤中的碳和氮动态、土壤健康和作物生产。为了满足这一需求，本项目旨在：1)开发一种新的传感系统来测量土壤中的挥发性有机化合物；2)促进对如何“解码”微生物活动的挥发性有机化合物信号的理解。本研究的广泛影响包括为可持续农业和生态系统服务提供管理工具。推广策略的重点是：1)让高中生和本科生参与研究；2)设计传感器和数据分析的研究和教育项目，通过亚利桑那大学生物圈2号应用程序和现场活动进行传播。亚利桑那大学（UA）的研究人员与Aerodyne Research， Inc. （ARI）和QuantAQ， Inc.的行业研究人员合作，计划开发一种地下实时、原位传感平台，以测量土壤中的挥发性有机化合物（VOC）信号。为了开发该平台，该项目将生成训练集，并针对高分辨率分析仪验证新兴的低成本VOC传感器。验证活动将使用在土壤“挥发性”（惰性基质、土壤、土壤和植物）中增加复杂程度的受控土壤柱，并控制特定挥发性有机化合物的添加。为了解码土壤中的VOC信号，本项目将：1)表征土壤VOC组成对散装土壤和根际湿润的动态响应；2)添加挥发性有机化合物，诱导和测量土壤和根际挥发物的响应。项目成果包括：1)高分辨率VOC土壤采样，对地下VOC信号产生新的认识；2)训练集，2)低成本VOC传感器的开发和验证。研究结果将有助于实现低成本、地下VOC传感器网络的长期愿景。该奖项是通过“土壤信号”征集活动获得的，该征集活动是美国国家科学基金会和美国农业部国家粮食和农业研究所（USDA NIFA）之间的合作伙伴关系。“这个奖项反映了国家科学基金会的法定使命，并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，被认为值得支持。

Organisms produce and use many types of chemical compounds in metabolism, communication, and defense. Soil microorganisms are vigorous producers and consumers of one such type, volatile organic compounds, but our understanding of how the presence of these chemicals in the soil influences nutrient flux, soil health, and plant growth is limited. Soil microbes emit volatile organic compounds at exceedingly low concentrations in hundreds of different varieties, making their comprehensive measurement in soil difficult. Challenges associated with measuring volatile organic compounds quickly and non-invasively have limited our capacity to use the full suite of volatile organic compounds in soil to infer interactions between microbes and plants, and to assess soil health. New approaches and technology for high resolution measurement and monitoring of volatile organic compounds in the soil are needed to better understand how plant-microbe interactions influence carbon and nitrogen dynamics in soil, soil health, and crop production. To address this need, this project aims to: 1) develop a new sensing system to measure volatile organic compounds in soil; and 2) advance understanding of how to ‘decode’ volatile organic compounds signals of microbial activity. Broader impacts of this research include providing management tools for sustainable agriculture and ecosystem services. The outreach strategy is focused on 1) engaging high school and undergraduate students in research; and 2) designing research and education projects on sensors and data analytics for dissemination through the University of Arizona Biosphere 2 App and on-site activities.Researchers at the University of Arizona (UA) in collaboration with industry researchers at Aerodyne Research, Inc. (ARI) and QuantAQ, Inc. plan to develop a subsurface real-time, in-situ sensing platform to measure volatile organic compound (VOC) signals in the soil. To develop the platform, the project will generate training sets and validate an emerging low-cost VOC sensor against a high-resolution analyzer. Validation activities will use controlled soil columns with increasing degrees of complexity in the soil 'volatilome' (inert matrix, soil, soil and plants), and controlled addition of specific VOCs. To decode VOC signals in soil, the project will: 1) characterize dynamic response of soil VOC composition to wetting in bulk soil and in the rhizosphere; and 2) add VOCs to induce and measure responses in the soil and rhizosphere volatilome. Deliverables of the project include 1) high-resolution VOC soil sampling to generate new understanding of subsurface VOC signals; 2) training sets, and 2) low cost VOC sensor development and validation. The results will contribute to a long-term vision of achieving low-cost, subsurface VOC sensor networks.This award was made through the "Signals in the Soil (SitS)" solicitation, a collaborative partnership between the National Science Foundation and the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA)."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.