Microsymbiont discrimination mediated by a host-secreted peptide in Medicago truncatula

Shengming Yang, Qi Wang, Elena Fedorova, Jinge Liu, Qiulin Qin, Qiaolin Zheng, Paul A. Price, Huairong Pan, Dong Wang, Joel S. Griffitts, Ton Bisseling, Hongyan Zhu

Research output: Contribution to journalArticlepeer-review

85 Scopus citations


The legume-rhizobial symbiosis results in the formation of root nodules that provide an ecological niche for nitrogen-fixing bacteria. However, plant-bacteria genotypic interactions can lead to wide variation in nitrogen fixation efficiency, and it is not uncommon that a bacterial strain forms functional (Fix+) nodules on one plant genotype but nonfunctional (Fix-) nodules on another. Host genetic control of this specificity is unknown. We herein report the cloning of the Medicago truncatula NFS1 gene that regulates the fixation-level incompatibility with the microsymbiont Sinorhizobium meliloti Rm41. We show that NFS1 encodes a nodulespecific cysteine-rich (NCR) peptide. In contrast to the known role of NCR peptides as effectors of endosymbionts' differentiation to nitrogen-fixing bacteroids, we demonstrate that specific NCRs control discrimination against incompatible microsymbionts. NFS1 provokes bacterial cell death and early nodule senescence in an allele-specific and rhizobial strain-specific manner, and its function is dependent on host genetic background.

Original languageEnglish
Pages (from-to)6848-6853
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number26
StatePublished - Jun 27 2017


  • Legumes
  • NCR peptides
  • Nitrogen fixation specificity
  • Nodulation
  • Symbiosis persistence

ASJC Scopus subject areas

  • General


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