Change in Gene Expression in a Forb and an Annual Grass in Response to Elevated CO2, Warming, Precipitation Increase and Nitrogen Deposition in a Mediterranean Annual Grassland.

人类依赖生态系统提供关键的商品和服务。在未来几十年，生态系统将面临一系列新的人类影响，包括气候变化。为了预测这些变化对生物圈的影响，需要详细了解各种生态系统如何响应全球变化参数。这个项目是一个大型的，长期的，跨学科的研究，贾斯珀岭全球变化实验（JRGCE），每年地中海草原生态系统的一个组成部分。JRGCE的广泛目标是发展对生态系统变化的机制理解，以实现二氧化碳升高、降水改变、氮沉积增加和变暖的现实组合，并开发未来生态系统变化的预测模型。这部分项目的总体目标是提供一些对促进该草原生态系统变化的植物的潜在生理过程的见解。在这个项目中，工作将从当前的方法开发阶段转移到数据收集阶段。微阵列将用于测量两个优势物种，Avena barbata和Geranium dissectum的转录物丰度。根据这四个全球变化参数或它们之间的相互作用而表现出显著表达变化的基因清单将每年确定一次，并在项目的最后一年对四年的数据进行总结分析。这些数据将被挖掘以确定与特定生物过程相关的基因是否在任何基因簇中被过度代表。此外，将对选定的基因或基因集以及在相同的JRGCE图中测量的各种生态（如净初级生产力）、生化（如土壤磷酸酶活性）和生物地球化学（如土壤氮化合物）参数进行协方差分析。之所以选择微阵列技术，是因为它是目前可用的以无偏方式测量大量参数（基因）的最佳方法。从这些实验中，将确定表达模式密切反映一个或多个全球变化因素的基因或基因组，并确定在JRGCE图上测量的一些生态和生化过程的诊断基因。其中一些基因组可能暗示了先前研究中未涉及的生物过程，这些研究主要集中在碳和氮代谢上。更广泛的影响：该探索性项目预计将导致一些关于植物对全球变化因素的响应和生态系统水平变化的具体假设，这些假设将在未来的实验中得到验证。这项研究将涉及培训和其他外联活动，这些活动将由“卡内基外联协调员”协调，该协调员将部分由这笔赠款支持。

SOMERVILLE ABSTRACTHumans rely on ecosystems for critical goods and services. In the coming decades, ecosystems will be exposed to a novel range of human impacts, including altered climate. To anticipate the consequences of these changes on the biosphere, detailed knowledge of how various ecosystems respond to global change parameters is needed. This project is a component of a large, long-term, interdisciplinary study, the Jasper Ridge Global Change Experiment (JRGCE), of an annual Mediterranean grassland ecosystem. The broad goals of the JRGCE are to develop a mechanistic understanding of ecosystem changes to realistic combinations of elevated CO2, altered precipitation, increased nitrogen deposition and warming, and to develop predictive models of future ecosystem change. The general goal of this portion of the project is to provide some insight into the underlying physiological processes in plants that contribute to ecosystem change in this grassland. With this project, the work will move from the current methods development phase to the data collection phase. Microarrays will be used to measure transcript abundance for two dominant species, Avena barbata and Geranium dissectum. Lists of genes showing significant changes in expression in response to the four global change parameters or their interactions will be determined yearly and, in a summary analysis of the data from four years, in the final year of the project. These data will be mined to identify whether genes associated with specific biological processes are over- represented in any of the gene clusters. In addition, covariance analysis will be performed with selected genes or genes sets and the various ecological (e.g., net primary productivity), biochemical (e.g., soil phosphatase activity), and biogeochemical (e.g., soil nitrogen compounds) parameters that are measured in the same JRGCE plots. The microarray technology was selected as it is the best currently available method for surveying a very large number of parameters (genes) in a largely unbiased fashion. From these experiments, genes or groups of genes whose expression patterns closely reflect one or more of the global change factors, will be identified and genes that are diagnostic for some of the ecological and biochemical processes measured on the JRGCE plots will be determined. Some of these gene sets may suggest the involvement of biological processes that had not been implicated in prior research, which has focused on carbon and nitrogen metabolism. Broader Impacts: This exploratory project is expected to lead to a number of specific hypotheses about plant responses and ecosystem level changes to global change factors, which will be tested in future experiments. The research will involve training and other outreach activities that will be coordinated by the "Carnegie Outreach Coordinator", who will be supported in part by this grant.