The phosphate starvation response recruits the TOR pathway to regulate growth in Arabidopsis cell cultures

Thomas Dobrenel(1,5), Sunita Kushwah(1), Umarah Mubeen(2), Wouter Jansen(3), Nicolas Delhomme(4), Camila Caldana(2), Johannes Hanson(1,6)

1. Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, S-90187 Umeå, Sweden
2. Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm, Germany
3. Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, 3584CH Utrecht, The Netherlands
4. Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
5. Current address: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
6. Correspondence to: johannes.hanson@umu.se

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Abstract

In eukaryotes, TOR (Target Of Rapamycin) is a conserved regulator of growth that integrates both endogenous and exogenous signals. These signals include the internal nutritional status, and in plants TOR has been shown to be regulated by carbon, nitrogen and sulfur availability. In this study, we show that in Arabidopsis the TOR pathway also integrates phosphorus availability to actively modulate the cell cycle, which in turn regulates the intracellular content of amino acids and organic acids. We observed a substantial overlap between the phenotypic, metabolic and transcriptomic responses of TOR inactivation and phosphorus starvation in Arabidopsis cell culture. Although phosphorus availability modulates TOR activity, changes in the levels of TOR activity do not alter the expression of marker genes for phosphorus status. These data prompted us to place the sensing of phosphorus availability upstream of the modulation of TOR activity which, in turn, regulates the cell cycle and primary metabolism to adjust plant growth.

Repository

This repository contains all the code needed to reproduce the RNA-Seq data analysis of the manuscript. For question, contact nicolasDelhomme on GitHub.

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