Activation of symbiosis signaling by arbuscular mycorrhizal fungi in legumes and rice.
Establishment of arbuscular mycorrhizal interactions involves plant recognition of diffusible signals from the fungus, including lipochitooligosaccharides (LCOs) and chitooligosaccharides (COs). Nitrogen-fixing rhizobial bacteria that associate with leguminous plants also signal to their hosts via LCOs, the so-called Nod factors. Here, we have assessed the induction of symbiotic signaling by the arbuscular mycorrhizal (Myc) fungal-produced LCOs and COs in legumes and rice (Oryza sativa). We show that Myc-LCOs and tetra-acetyl chitotetraose (CO4) activate the common symbiosis signaling pathway, with resultant calcium oscillations in root epidermal cells of Medicago truncatula and Lotus japonicus. The nature of the calcium oscillations is similar for LCOs produced by rhizobial bacteria and by mycorrhizal fungi; however, Myc-LCOs activate distinct gene expression. Calcium oscillations were activated in rice atrichoblasts by CO4, but not the Myc-LCOs, whereas a mix of CO4 and Myc-LCOs activated calcium oscillations in rice trichoblasts. In contrast, stimulation of lateral root emergence occurred following treatment with Myc-LCOs, but not CO4, in M. truncatula, whereas both Myc-LCOs and CO4 were active in rice. Our work indicates that legumes and non-legumes differ in their perception of Myc-LCO and CO signals, suggesting that different plant species respond to different components in the mix of signals produced by arbuscular mycorrhizal fungi.
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Jongho
J
Sun
John Innes Centre, Norwich NR4 7UH, United Kingdom.
J Benjamin
JB
Miller
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Emma
E
Granqvist
Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706.
Audrey
A
Wiley-Kalil
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Enrico
E
Gobbato
INRA, Laboratoire des Interactions Plantes-Microorganismes, UMR441, F-31326 Castanet-Tolosan, France CNRS, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, F-31326 Castanet-Tolosan, France.
Fabienne
F
Maillet
Centre de Recherche sur les Macromolécules Végétales, CNRS (affiliated to Université de Grenoble), 38041 Grenoble Cedex 9, France.
Sylvain
S
Cottaz
Centre de Recherche sur les Macromolécules Végétales, CNRS (affiliated to Université de Grenoble), 38041 Grenoble Cedex 9, France.
Eric
E
Samain
Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706.
Muthusubramanian
M
Venkateshwaran
Centre de Recherche sur les Macromolécules Végétales, CNRS (affiliated to Université de Grenoble), 38041 Grenoble Cedex 9, France.
Sébastien
S
Fort
John Innes Centre, Norwich NR4 7UH, United Kingdom.
Richard J
RJ
Morris
Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin 53706.
Jean-Michel
JM
Ané
INRA, Laboratoire des Interactions Plantes-Microorganismes, UMR441, F-31326 Castanet-Tolosan, France CNRS, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, F-31326 Castanet-Tolosan, France.
Jean
J
Dénarié
John Innes Centre, Norwich NR4 7UH, United Kingdom giles.oldroyd@jic.ac.uk.
Giles E D
GE
Oldroyd
D020013:Calcium Signaling / Q000187:drug effects; D002686:Chitin / Q000031:analogs & derivatives / Q000494:pharmacology; D048271:Chitosan; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005966:Glucuronidase / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D000070116:Lotus / Q000382:microbiology*; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000187:drug effects / Q000502:physiology*; D009844:Oligosaccharides / Q000494:pharmacology; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000382:microbiology*; D036226:Seedlings / Q000187:drug effects / Q000382:microbiology; D015398:Signal Transduction / Q000187:drug effects; D013559:Symbiosis / Q000187:drug effects
D008070:Lipopolysaccharides; D009844:Oligosaccharides; C023023:lipid-linked oligosaccharides; C493484:oligochitosan; D002686:Chitin; C012238:chitotetrose; D048271:Chitosan; D005966:Glucuronidase