Perception of root-active CLE peptides requires CORYNE function in the phloem vasculature

EMBO Rep. 2017 Aug;18(8):1367-1381. doi: 10.15252/embr.201643535. Epub 2017 Jun 12.

Abstract

Arabidopsis root development is orchestrated by signaling pathways that consist of different CLAVATA3/EMBRYO SURROUNDING REGION (CLE) peptide ligands and their cognate CLAVATA (CLV) and BARELY ANY MERISTEM (BAM) receptors. How and where different CLE peptides trigger specific morphological or physiological changes in the root is poorly understood. Here, we report that the receptor-like protein CLAVATA 2 (CLV2) and the pseudokinase CORYNE (CRN) are necessary to fully sense root-active CLE peptides. We uncover BAM3 as the CLE45 receptor in the root and biochemically map its peptide binding surface. In contrast to other plant peptide receptors, we found no evidence that SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK) proteins act as co-receptor kinases in CLE45 perception. CRN stabilizes BAM3 expression and thus is required for BAM3-mediated CLE45 signaling. Moreover, protophloem-specific CRN expression complements resistance of the crn mutant to root-active CLE peptides, suggesting that protophloem is their principal site of action. Our work defines a genetic framework for dissecting CLE peptide signaling and CLV/BAM receptor activation in the root.

Keywords: CLAVATA; SERK; CLE45; MAKR5; receptor kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Gene Expression Regulation, Plant
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Peptides / genetics
  • Peptides / metabolism
  • Phloem / genetics
  • Phloem / physiology*
  • Plant Roots / physiology
  • Plants, Genetically Modified
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Signal Transduction

Substances

  • Arabidopsis Proteins
  • CLE45 protein, Arabidopsis
  • CLV2 protein, Arabidopsis
  • Membrane Proteins
  • Peptides
  • Receptors, Cell Surface
  • BAM3 protein, Arabidopsis
  • CORYNE protein, Arabidopsis
  • Protein-Serine-Threonine Kinases