Quantification of methane sources and sinks in a plant-soil system

近年来，在好氧条件下，没有产甲烷菌的帮助下，植物，真菌和土壤中的甲烷（CH 4）生产已经被证明。但这些科学发现大部分是在无菌条件下获得的。自然条件下（包括动物饲养、氧气和湿度条件变化、与其他生物的相互作用等）的甲烷产生率可能与无菌培养物的排放率不同。通过本项目，我们希望在受控的实验室条件下，首次研究通气的植物-土壤系统（包括真菌和微生物）中CH 4的产生和同时的微生物消耗。第一个目标是开发一个封闭的模块化结构系统，在该系统中，可以研究植物-土壤系统的特定组分及其相互作用对CH 4产生的影响。首先，将探讨植物和相关真菌的相互作用。土壤中CH 4源的分离将通过使用选择性抑制剂来实现。我们解决的问题，植物的存在如何影响土壤内源CH 4的生产，并将使用稳定的同位素标记来跟踪光合固定的CO2转化为CH 4。此外，我们感兴趣的CH 4通量在系统内。为了检验内源CH 4生产和CH 4消费之间是否存在可能的联系，我们将同时量化CH 4生产和消费。同位素标记技术与分子方法相结合，将被用来跟踪甲烷氧化细菌内的植物源甲烷。本研究旨在通过对CH 4产生和消耗的定量分析，进一步了解CH 4在植物-土壤系统中的通量变化，并探讨温度对CH 4排放的影响。此外，我们的研究结果可能有助于解释陆地生态系统的变异性，并可能改善气候引起的生态系统CH 4通量变化的预测。

In recent years methane (CH4) production under oxic conditions and without the help of methanogenic Archaea has been shown for plants, fungi, and soil. But the scientific findings were largely obtained under sterile conditions. Likely, CH4 production rates under natural conditions (including e.g. animal feeding, changing oxygen and moisture conditions, interaction with other organisms) will differ from the emission rates obtained from sterile cultures. With this project we want to investigate for the first time the CH4 production and simultaneous microbial consumption in an aerated plant-soil system including fungi and microbes under controlled laboratory conditions.The first goal is to develop a closed-chamber modular construction system where specific components of the plant-soil system and their interaction can be investigated with regard to CH4 production. Primarily, the interaction of plants and associated fungi will be explored. Separation of CH4 sources in soil will be achieved by using selective inhibitors. We address the questions how the presence of plants affects soil endogenic CH4 production and will use stable isotope labeling to trace the conversion of photosynthetically fixed CO2 to CH4. Moreover, we are interested in CH4 fluxes within the system. To test the existence of a possible connection between endogenic CH4 production and CH4 consumption we will simultaneously quantify CH4 production and consumption. A combination of isotope labelling techniques with molecular methods will be used to trace plant-derived CH4 within methanotrophic bacteria. The response of plant-derived CH4 emissions after caterpillar feeding and vermin infestation will be tested and temperature-induced changes in CH4 emissions will be related to metabolic activity.The aim of this research project is to improve our understanding of CH4 fluxes in the plant-soil system via the quantification of CH4 production and consumption. Furthermore, our results might contribute to explain the variability of terrestrial ecosystems and may improve predictions of climate induced changes of ecosystem CH4 fluxes.