Arabidopsis 2010: Nitrogen Networks in Plants

拟南芥基因组计划发现了大量涉及氮吸收，代谢和分配的基因（600+）。 一个小的子集的表达研究表明，氮的状态调节许多这些基因的转录。建议的信号包括硝酸盐、铵、谷氨酰胺和C：N平衡。目前，人们对植物生长过程中参与氮素状态信号传导和氮素代谢整合的调控分子或网络的了解很少或根本没有。我们建议使用表达阵列来识别受N-状态调控的基因回路（无机氮和有机氮），使用生物信息学序列分析来鉴定N响应顺式元件，为了确定关键基因的功能，我们通过定义缺乏每个基因的突变体的表型和通过确定表达蛋白的生化性质来鉴定，包括描述与其他大分子的有意义的相互作用，在哪里和什么时候表达。我们的分析将使我们能够将这些基因和N-调控网络的活性置于植物生长和发育的背景下。 一个计算机集群将存储在这个项目中产生的大量数据，我们将提供一个公开访问的网页，其中包括表达数据库，基因识别信息，以及在拟议的项目中开发的所有软件。 该社区资源将与主要的植物数据库链接，以便尽可能广泛地传播信息。 预计我们的研究结果将大大推进我们对植物生长背景下氮代谢的理解，并为我们对复杂调控网络的理解提供新的见解。 考虑到氮的有效性和代谢在作物生产力中的核心作用，这些结果也将对农业产生广泛的影响。

The Arabidopsis genome project uncovered a large set of genes involved in nitrogen uptake, metabolism, and allocation (600+). Expression studies on a small subset showed that nitrogen status regulates the transcription of many of these genes. Proposed signals include nitrate, ammonium, glutamine, and C:N balance. At present, there is little or no understanding of the regulatory molecules or networks involved in signaling N-status and integrating N metabolism in plant growth. We propose to use expression arrays to identify circuits of genes regulated by N-status (inorganic-N and organic-N), to use bioinformatic sequence analysis to identify N-responsive cis-elements, and to determine the function of key genes we identify by defining the phenotype of mutants lacking each gene and by determining the biochemical properties of the expressed proteins including describing meaningful interactions with other macromolecules and determining where and when each is expressed. Our analysis will allow us to place the activity of these genes and N-regulatory networks in the context of plant growth and development. A computer cluster will store the large amounts of data generated in this project and we will provide a publicly accessible Web page that will include expression databases, gene identification information, and all software developed in the proposed project. This community resource will be linked to the major plant databases for the widest possible distribution of information. It is expected that our results will substantially advance our understanding of nitrogen metabolism in the context of plant growth, as well as provide new insights into our understanding of complex regulatory networks. Given the central role of nitrogen availability and metabolism in crop productivity, these results will also have broad agricultural impacts.