NSF Postdoctoral Fellowship in Biology FY 2021: Linking soil microbiome to pulsed trace gas emissions in rewetted drylands

该行动资助了NSF 2021财年生物学博士后研究奖学金，即研究基因组、环境和表型之间相互作用的生命规则的综合研究。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。土壤中碳和氮损失的主要途径是通过土壤中微生物代谢产生的气体排放到大气中;许多是臭名昭著的温室气体（例如，二氧化碳和一氧化二氮）和影响空气质量的气体（例如，挥发性有机化合物和一氧化氮）。然而，目前还不清楚是什么调节土壤中的气体排放：它们是土壤中生物体的具体特征和活动的结果，还是生物体所生活的环境的结果？在炎热干燥的生态系统中，土壤排放量通常较低，但大量排放的“脉冲”通常发生在降雨或灌溉事件之后，此时土壤足够湿润，植物和微生物代谢旺盛。这种气体脉冲现象提供了一个独特的机会，将土壤生物学的同时变化，土壤中营养物质的运动以及释放的代谢气体（副）产品联系起来。该研究项目将结合实验方法，将土壤过程与农业环境中的气体排放联系起来，其结果可用于设计更健康的农业系统，并大规模影响气候和空气质量;这将有利于劳动力发展伙伴关系和参与该项目的不同背景的学生。研究活动将分子和同位素工具与生物地球化学分析相结合，以量化微生物和养分对干燥土壤再润湿的反应，并将这些反应与痕量气体脉冲联系起来。将在农业研究系统中进行两个实验，以比较已知影响痕量气体脉冲并可能延伸到微生物-环境相互作用的土壤调节的不同方面：（1）增量氮添加，和（2）作物基因型。培训活动包括培养基因组、分子和同位素工具和分析方面的技能，所有这些都是土壤生态学的新领域，很少结合起来用于解释与养分循环有关的过程;指导对跨学科问题和方法感兴趣的研究生和本科生;该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. A major pathway of carbon and nitrogen loss from soils is via gaseous emission to the atmosphere that occurs as a result of microbial metabolism in the soil; many are notorious greenhouse gases (e.g., carbon dioxide and nitrous oxide) and gases that affect air quality (e.g., volatile organic compounds and nitric oxide). However, it is still unclear what regulates gaseous emissions from soils: are they the result of specific traits and activities of organisms in the soil or are they the result of the environment in which the organisms are living? In hot, dry ecosystems, soil emissions are generally low, but “pulses” of large emissions usually occur after rain or irrigation events when soils are wet enough for plant and microbial metabolism to thrive. This gas pulse phenomenon provides a unique opportunity to link simultaneous changes in soil biology, movement of nutrients in the soil, and the gaseous (by)products of metabolism that are released. The research project will use a combination of experimental approaches to connect soil processes to gaseous emissions in an agricultural context, where results can be used to engineer healthier farming systems and impact climate and air quality at a large scale; this will benefit workforce development partnerships and students from diverse backgrounds participating in the project. Research activities integrate molecular and isotopic tools with biogeochemical assays to quantify microbial and nutrient responses to rewetting of dry soils and relate these responses to trace gas pulses. Two experiments will be conducted in an agricultural study system to compare different aspects of soil conditioning that are known to affect trace gas pulses and presumably extend to microbe-environment interactions: (1) incremental nitrogen addition, and (2) crop genotype. Training activities include building skillsets in genomic, molecular, and isotopic tools and analyses, all of which are new frontiers of soil ecology and have rarely been used in combination to explain processes associated with nutrient cycling; mentoring graduate and undergraduate students with interest in interdisciplinary questions and approaches; and communicating the importance of soil health to the public and to policymaking and agricultural entities.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.