Local and systemic regulation of plant root system architecture and symbiotic nodulation by a receptor-like kinase

PLoS Genet. 2014 Dec 18;10(12):e1004891. doi: 10.1371/journal.pgen.1004891. eCollection 2014 Dec.

Abstract

In plants, root system architecture is determined by the activity of root apical meristems, which control the root growth rate, and by the formation of lateral roots. In legumes, an additional root lateral organ can develop: the symbiotic nitrogen-fixing nodule. We identified in Medicago truncatula ten allelic mutants showing a compact root architecture phenotype (cra2) independent of any major shoot phenotype, and that consisted of shorter roots, an increased number of lateral roots, and a reduced number of nodules. The CRA2 gene encodes a Leucine-Rich Repeat Receptor-Like Kinase (LRR-RLK) that primarily negatively regulates lateral root formation and positively regulates symbiotic nodulation. Grafting experiments revealed that CRA2 acts through different pathways to regulate these lateral organs originating from the roots, locally controlling the lateral root development and nodule formation systemically from the shoots. The CRA2 LRR-RLK therefore integrates short- and long-distance regulations to control root system architecture under non-symbiotic and symbiotic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Medicago truncatula / genetics*
  • Medicago truncatula / growth & development
  • Medicago truncatula / microbiology
  • Meristem / genetics
  • Meristem / growth & development
  • Meristem / microbiology
  • Phylogeny
  • Plant Proteins / physiology*
  • Receptor Protein-Tyrosine Kinases / physiology*
  • Rhizobium / physiology
  • Root Nodules, Plant / genetics*
  • Root Nodules, Plant / growth & development
  • Root Nodules, Plant / microbiology
  • Symbiosis

Substances

  • Plant Proteins
  • Receptor Protein-Tyrosine Kinases

Grant support

Work in the FF laboratory was funded by the CNRS and the ANR project “LEGUMICS”, which additionally provided a fellowship to EH; at INRA-UMR1347 Agroécologie by the EU FP6 Grain legumes integrated project (GLIP); and in KSM and JW laboratories by the National Science Foundation Plant Genome Research Program (Grants DBI-0703285 and IOS-1127155). This work has also benefited from the facilities and expertise of the Imagif Cell Biology Unit of the Gif-sur-Yvette (France) campus (www.imagif.cnrs.fr) supported by the “Infrastructures en Biologie Sante et Agronomie” (IBiSA), the ANR "France-BioImaging infrastructure" (ANR-10-INSB-04-01), the "Saclay Plant Sciences" (ANR-10-LABX-0040-SPS) programs, and the “Conseil Général de l'Essonne”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.