Molecular dissection of local and systemic responses to phosphate starvation in Arabidopsis thaliana

Abstract

Phosphate (pi) is a crucial and often limiting nutrient for plant growth. it is also a very insoluble ion heterogeneously distributed in soil. to cope with such a situation, plants have evolved a complex network of morphological and biochemical processes controlled by various regulatory systems. These signaling pathways are triggered either by pi concentration in the growth medium or by plant cells internal pi. A split-root assay performed to mimic an heterogeneous environment combined with a transcriptomic analysis was used to identify clusters of genes locally or systemically regulated by pi starvation . The combination of genetic tools and physiological analysis revealed distinct regulatory roles for the internal and the external pi. They also pointed out a central role of the transcription factor phr1 for genes systemically controlled by low pi. In addition, results obtained with a set of tools including chemical genetics and manipulations of the entire family of the high affinity Pi transporters will be presented. These tools offer novel powerful approaches to dissect Pi perception pathways.