NSP1 is a component of the Myc signaling pathway

Authors

  • Pierre-Marc Delaux,

    1. Department of Agronomy, University of Wisconsin Madison, Madison, WI, USA
    Search for more papers by this author
  • Guillaume Bécard,

    Corresponding author
    1. Laboratoire de Recherche en Sciences Végétales, UMR5546, Université de Toulouse, Castanet-Tolosan CEDEX, France
    2. CNRS, UMR5546, Castanet-Tolosan CEDEX, France
    • Department of Agronomy, University of Wisconsin Madison, Madison, WI, USA
    Search for more papers by this author
  • Jean-Philippe Combier

    Corresponding author
    1. Laboratoire de Recherche en Sciences Végétales, UMR5546, Université de Toulouse, Castanet-Tolosan CEDEX, France
    2. CNRS, UMR5546, Castanet-Tolosan CEDEX, France
    • Department of Agronomy, University of Wisconsin Madison, Madison, WI, USA
    Search for more papers by this author

Authors for correspondence:

Jean-Philippe Combier

Tel: +33 (0)5 34 32 38 11

Email: combier@lrsv.ups-tlse.fr

Guillaume Bécard

Tel: +33 (0)5 34 32 38 20

Email: becard@lrsv.ups-tlse.fr

Summary

  • Nodulation and arbuscular mycorrhization require the activation of plant host symbiotic programs by Nod factors, and Myc-LCOs and COs, respectively. The pathways involved in the perception and downstream signaling of these signals include common and distinct components. Among the distinct components, NSP1, a GRAS transcription factor, has been considered for years to be specifically involved in nodulation.
  • Here, we analyzed the degree of conservation of the NSP1 sequence in arbuscular mycorrhizal (AM) host and non-AM host plants and carefully examined the ability of Medicago truncatula nsp1 mutants to respond to Myc-LCOs and to be colonized by an arbuscular mycorrhizal fungus.
  • In AM-host plants, the selection pressure on NSP1 is stronger than in non-AM host ones. The response to Myc-LCOs and the frequency of mycorrhizal colonization are significantly reduced in the nsp1 mutants.
  • Our results reveal that NSP1, previously described for its involvement in the Nod factor signaling pathway, is also involved in the Myc-LCO signaling pathway. They bring additional evidence on the evolutionary relatedness between nodulation and mycorrhization.

Ancillary