Phosphate status metabolically cues root apical stem cell maintenance via the RGF1-PLT2 regulatory network

Abstract

Plant root growth rates and patterns reflect their above- and below-ground environment, which exquisitely cues physiology and metabolism. Despite decades of work identifying signals involved in controlling meristem maintenance, direct mechanistic links between environmental and metabolic cues that inform the patterning and growth-regulatory mechanisms underpinning stem and transient-amplifying cell homeostasis remain poorly understood. Recent work by many groups has identified the RGF1-PLT2 regulatory network as central to the dynamic control of root meristems. This network’s activity is modulated by pathways that regulate protein stability and meristem maintenance. By regulating the sulfation of RGF peptides, and thus the abundance of PLT2 in the primary meristem, tyrosyl protein sulfo-transferase (TPST) influences primary root meristem sink strength. We find that the environmental and metabolic cue of low phosphate availability controls TPST activity. Thus, the RGF1-PLT2 regulatory network is at the intersection of growth and metabolism regulation by underpinning primary root sink strength, to control the distribution of growth activity across the root system and mediate responsiveness to a key limiting nutrient, phosphate.

Authors

Xin Tian1,†, Yuanyuan Li1,†, Frank Machin1, Fan Lai1, Thibaut Bonpart1, Cristobal Concha1, Ingrid Robertson1, Naveen Joshi2, Alireza Omumi3, Juliette Jouhet2, Thomas Keller1, John Danku4, Chengxia Li1, Scott Taylor3, David Salt4, Maryse Block2,Eric Marechal2 and Peter Doerner1,2,*

1Institute for Molecular Plant Science, University of Edinburgh, Edinburgh, EH9 3BF, Scotland. 2 Laboratoire de Physiologie Cellulaire & Végétale, Univ. Grenoble Alpes, CNRS, CEA, INRA, BIG-LPCV, 38000 Grenoble, France. 3Department of Chemistry, University of Waterloo, Waterloo, N2L 3G1, Ontario, Canada. 4Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 3UU Scotland,