A novel role for the root cap in phosphate uptake and homeostasis

• DOI: 10.7554/elife.14577
• Publication Date: 2016-04-05T15:08:43Z
• Authors: Satomi Kanno; Jean-François Arr...; Serge Chiarenza; Vincent Bayle; Richard Berthomé; Benjamin Péret; Hélène Javot; Etienne Delannoy; Elena Marin; Tomoko M Nakanishi; Marie-Christine T...; Laurent Nussaume
• Keywords: 0301 basic medicine; 570; a. thaliana; QH301-705.5; [SDV]Life Sciences [q-bio]; Science; Arabidopsis; Plant Biology; Phosphates; 03 medical and health sciences; phosphate homeostasis; Homeostasis; 33P imaging; Biology (General); 33P imaging;<i>a. thaliana</i>;arabidopsis;mineral nutrition;phosphate homeostasis;plant biology;root cap; 580; plant biology; 2. Zero hunger; mineral nutrition; Q; Optical Imaging; R; Phosphorus Isotopes; 15. Life on land; arabidopsis; Plant Root Cap; Medicine; <i>a. thaliana</i>; root cap

The root cap has a fundamental role in sensing environmental cues as well as regulating root growth via altered meristem activity. Despite this well-established role in the control of developmental processes in roots, the root cap’s function in nutrition remains obscure. Here, we uncover its role in phosphate nutrition by targeted cellular inactivation or phosphate transport complementation in Arabidopsis, using a transactivation strategy with an innovative high-resolution real-time 33P imaging technique. Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%). This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes. These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control.