The Casuarina NIN gene is transcriptionally activated throughout Frankia root infection as well as in response to bacterial diffusible signals.

Academic Article

Abstract

  • Root nodule symbioses (RNS) allow plants to acquire atmospheric nitrogen by establishing an intimate relationship with either rhizobia, the symbionts of legumes or Frankia in the case of actinorhizal plants. In legumes, NIN (Nodule INception) genes encode key transcription factors involved in nodulation. Here we report the characterization of CgNIN, a NIN gene from the actinorhizal tree Casuarina glauca using both phylogenetic analysis and transgenic plants expressing either ProCgNIN::reporter gene fusions or CgNIN RNAi constructs. We have found that CgNIN belongs to the same phylogenetic group as other symbiotic NIN genes and CgNIN is able to complement a legume nin mutant for the early steps of nodule development. CgNIN expression is correlated with infection by Frankia, including preinfection stages in developing root hairs, and is induced by culture supernatants. Knockdown mutants were impaired for nodulation and early root hair deformation responses were severely affected. However, no mycorrhizal phenotype was observed and no induction of CgNIN expression was detected in mycorrhizas. Our results indicate that elements specifically required for nodulation include NIN and possibly related gene networks derived from the nitrate signalling pathways.
  • Authors

  • Clavijo, Fernando
  • Diedhiou, Issa
  • Vaissayre, Virginie
  • Brottier, Laurent
  • Acolatse, Jennifer
  • Moukouanga, Daniel
  • Crabos, Amandine
  • Auguy, Florence
  • Franche, Claudine
  • Gherbi, Hassen
  • Champion, Antony
  • Hocher, Valerie
  • Barker, David
  • Bogusz, Didier
  • Tisa, Louis
  • Svistoonoff, Sergio
  • Status

    Publication Date

  • November 2015
  • Published In

  • New Phytologist  Journal
  • Keywords

  • Amino Acid Sequence
  • Fabaceae
  • Frankia
  • Magnoliopsida
  • Molecular Sequence Data
  • Mycorrhizae
  • Plant Proteins
  • Plant Root Nodulation
  • Root Nodules, Plant
  • Sequence Homology, Amino Acid
  • Symbiosis
  • actinorhiza
  • biological nitrogen fixation
  • mycorrhiza
  • nodule inception
  • plant-microbe signalling
  • root hair deformation
  • root nodule symbioses
  • Digital Object Identifier (doi)

    Pubmed Id

  • 26096779
  • Start Page

  • 887
  • End Page

  • 903
  • Volume

  • 208
  • Issue

  • 3