Poster abstracts

Poster number 28 submitted by Laura de Lorenzo Barrios

Phosphate starvation response 1 uses a dual cis-regulatory logic and acts as a link between drought responses and phosphate homeostasis in plants

Laura de Lorenzo (Departamento de Genetica Molecular de Plantas, Centro Nacional de Biotecnologia, Madrid, Spain.), Felix Ott, George Coupland, Detlef Weigel (Department of Molecular Biology, Max Plant Institute for Developmental Biology, Tuebingen, Germany.), Javier Paz-Ares (Departamento de Genetica Molecular de Plantas, Centro Nacional de Biotecnologia, Madrid, Spain.)

Abstract:
As sessile organisms, plants are often exposed to stress conditions, and have evolved adaptive responses to protect themselves from different types of stress. One of these adaptive systems is that for phosphate (Pi) starvation stress, in which transcription factor PHR1 from the MYB-CC family plays an important regulatory role. In this work, we identified the in vivo targets of PHR1 transcription factor in Arabidopsis genome, using chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and RNA-seq. PHR1 interacts with 2500 targets, out of which 480 correspond to Pi responsive genes. These targets are enriched in two motifs, P1BS-I and P1BS-II, which are bound by PHR1 using two different modes, as a dimer and as a monomer, respectively. P1BS-I and P1BS-II display different evolutionary constraints, are associated to, in part different P1BS related cis motifs, and their corresponding targets differentially enriched in ontology terms, indicating that PHR1 deploys a dual regulatory logic. We also found that PHR1 targets are enriched in drought induced genes. Physiological, molecular and genetics analysis showed that PHR1 acts as a link between drought responses and Pi homeostasis.

References:
Regla Bustos, Gabriel Castrillo, Francisco Linhares, Maria Isabel Puga, Vicente Rubio, Julian Perez-Perez, Roberto Solano, Antonio Leyva and Javier Paz-Ares (2010) A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis. PLoS Genetics 6, 1-15 e1001102.

Keywords: ChIP-seq, Arabidopsis, PHR1