Arabidopsis 2010: Nitrogen Networks in Plants

New York University, New York NY

Investigators

Abstract

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.