Plant peptides govern terminal differentiation of bacteria in symbiosis.
Legume plants host nitrogen-fixing endosymbiotic Rhizobium bacteria in root nodules. In Medicago truncatula, the bacteria undergo an irreversible (terminal) differentiation mediated by hitherto unidentified plant factors. We demonstrated that these factors are nodule-specific cysteine-rich (NCR) peptides that are targeted to the bacteria and enter the bacterial membrane and cytosol. Obstruction of NCR transport in the dnf1-1 signal peptidase mutant correlated with the absence of terminal bacterial differentiation. On the contrary, ectopic expression of NCRs in legumes devoid of NCRs or challenge of cultured rhizobia with peptides provoked symptoms of terminal differentiation. Because NCRs resemble antimicrobial peptides, our findings reveal a previously unknown innovation of the host plant, which adopts effectors of the innate immune system for symbiosis to manipulate the cell fate of endosymbiotic bacteria.
Van de Velde
Willem
W
Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette Cedex, France.
Zehirov
Grigor
G
Szatmari
Agnes
A
Debreczeny
Monika
M
Ishihara
Hironobu
H
Kevei
Zoltan
Z
Farkas
Attila
A
Mikulass
Kata
K
Nagy
Andrea
A
Tiricz
Hilda
H
Satiat-Jeunemaître
Beatrice
B
Alunni
Benoit
B
Bourge
Mickael
M
Kucho
Ken-ichi
K
Abe
Mikiko
M
Kereszt
Attila
A
Maroti
Gergely
G
Uchiumi
Toshiki
T
Kondorosi
Eva
E
Mergaert
Peter
P
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D017343:Genes, Plant; D000070116:Lotus / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D021381:Protein Transport; D053204:Root Nodules, Plant / Q000378:metabolism / Q000382:microbiology; D016962:Sinorhizobium meliloti / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D013559:Symbiosis
D000900:Anti-Bacterial Agents; D010455:Peptides; D010940:Plant Proteins