Root-derived CLE glycopeptides control nodulation by direct binding to HAR1 receptor kinase.
Leguminous plants establish a symbiosis with rhizobia to enable nitrogen fixation in root nodules under the control of the presumed root-to-shoot-to-root negative feedback called autoregulation of nodulation. In Lotus japonicus, autoregulation is mediated by CLE-RS genes that are specifically expressed in the root, and the receptor kinase HAR1 that functions in the shoot. However, the mature functional structures of CLE-RS gene products and the molecular nature of CLE-RS/HAR1 signalling governed by these spatially distant components remain elusive. Here we show that CLE-RS2 is a post-translationally arabinosylated glycopeptide derived from the CLE domain. Chemically synthesized CLE-RS glycopeptides cause significant suppression of nodulation and directly bind to HAR1 in an arabinose-chain and sequence-dependent manner. In addition, CLE-RS2 glycopeptide specifically produced in the root is found in xylem sap collected from the shoot. We propose that CLE-RS glycopeptides are the long sought mobile signals responsible for the initial step of autoregulation of nodulation.
National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan.
Satoru
S
Okamoto
Hidefumi
H
Shinohara
Tomoko
T
Mori
Yoshikatsu
Y
Matsubayashi
Masayoshi
M
Kawaguchi
D016960:Agrobacterium tumefaciens / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D006020:Glycopeptides / Q000378:metabolism*; D000070116:Lotus / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D055170:Plant Root Nodulation / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000378:metabolism; D011485:Protein Binding; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D053204:Root Nodules, Plant / Q000378:metabolism; D015398:Signal Transduction
D006020:Glycopeptides; D010940:Plant Proteins; D020794:Receptor Protein-Tyrosine Kinases