| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
|
First published online November 3, 2006; 10.1104/pp.106.090167 Plant Physiology 143:156-171 (2007) © 2007 American Society of Plant Biologists Genome-Wide Analysis of the Arabidopsis Leaf Transcriptome Reveals Interaction of Phosphate and Sugar Metabolism1,[W]Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, DK–1871 Frederiksberg C, Denmark (R.M., M.M., L.N., T.H.N.); Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, Kemitorvet, DK–2800 Lyngby, Denmark (H.J.); and Department of Agricultural Sciences, Crop Science, Royal Veterinary and Agricultural University, 2630 Taastrup, Denmark (R.M.)
Global gene expression was analyzed in Arabidopsis (Arabidopsis thaliana) by microarrays comprising 21,500 genes. Leaf segments derived from phosphorus (P)-starved and P-replenished plants were incubated with or without sucrose (Suc) to obtain tissues with contrasting combinations of P and carbohydrate levels. Transcript profiling revealed the influence of the two factors individually and the interactions between P- and sugar-dependent gene regulation. A large number of gene transcripts changed more than 2-fold: In response to P starvation, 171 genes were induced and 16 repressed, whereas Suc incubation resulted in 337 induced and 307 repressed genes. A number of new candidate genes involved in P acquisition were discovered. In addition, several putative transcription factors and signaling proteins of P sensing were disclosed. Several genes previously identified to be sugar responsive were also regulated by P starvation and known P-responsive genes were sugar inducible. Nearly 150 genes were synergistically or antagonistically regulated by the two factors. These genes exhibit more prominent or contrasting regulation in response to Suc and P in combination than expected from the effect of the two factors individually. The genes exhibiting interactions form three main clusters with different response patterns and functionality of genes. One cluster (cluster 1) most likely represents a regulatory program to support increased growth and development when both P and carbohydrates are ample. Another cluster (cluster 3) represents genes induced to alleviate P starvation and these are further induced by carbohydrate accumulation. Thus, interactions between P and Suc reveal two different signaling programs and novel interactions in gene regulation in response to environmental factors. cis-Regulatory elements were analyzed for each factor and for interaction clusters. PHR1 binding sites were more frequent in promoters of P-regulated genes as compared to the entire Arabidopsis genome, and E2F and PHR1 binding sites were more frequent in interaction clusters 1 and 3, respectively.
1 This work was supported by the Danish National Research Foundation, Center for Molecular Plant Physiology, and by the Danish Research Council for Technology and Production Sciences. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Tom Hamborg Nielsen (thni{at}kvl.dk). [W] The online version of this article contains Web-only data. www.plantphysiol.org/cgi/doi/10.1104/pp.106.090167 * Corresponding author; e-mail thni{at}kvl.dk; fax 45–35283333. Received September 21, 2006; accepted October 17, 2006; published November 3, 2006. This article has been cited by other articles:
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ASPB Publications | PLANT PHYSIOLOGY® | THE PLANT CELL | |
|---|---|---|---|
