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

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 funct...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2017-06, Vol.114 (26), p.6848-6853
Main Authors: Yang, Shengming, Wang, Qi, Fedorova, Elena, Liu, Jinge, Qin, Qiulin, Zheng, Qiaolin, Price, Paul A., Pan, Huairong, Wang, Dong, Griffitts, Joel S., Bisseling, Ton, Zhu, Hongyan
Format: Article
Language:English
Subjects:
Alfalfa
Apoptosis
Bacteria
Bacteroids
Biological Sciences
Cell death
Cloning
Differentiation
Discrimination
Ecological effects
Ecological niches
Endosymbionts
EPS
Genetic control
Host plants
Incompatibility
Laboratorium voor Moleculaire biologie
Laboratory of Molecular Biology
Legumes
Medicago truncatula
Nitrogen
Nitrogen fixation
Nitrogen-fixing bacteria
Nodules
Peptides
Root nodules
Senescence
Sinorhizobium meliloti
Symbiosis
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.1700460114