Abstract
Legumes form two different types of intracellular root symbioses, with fungi and bacteria, resulting in arbuscular mycorrhiza and nitrogen-fixing nodules, respectively. Rhizobial signalling molecules, called Nod factors, play a key role in establishing the rhizobium-legume association and genes have been identified in Medicago truncatula that control a Nod factor signalling pathway leading to nodulation. Three of these genes, the so-called DMI1, DMI2 and DMI3 genes, are also required for formation of mycorrhiza, indicating that the symbiotic pathways activated by both the bacterial and the fungal symbionts share common steps. To analyse possible cross-talk between these pathways we have studied the effect of treatment with Nod factors on mycorrhization in M. truncatula. We show that Nod factors increase mycorrhizal colonization and stimulate lateral root formation. The stimulation of lateral root formation by Nod factors requires both the same structural features of Nod factors and the same plant genes (NFP, DMI1, DMI2, DMI3 and NSP1) that are required for other Nod factor-induced symbiotic responses such as early nodulin gene induction and cortical cell division. A diffusible factor from arbuscular mycorrhizal fungi was also found to stimulate lateral root formation, while three root pathogens did not have the same effect. Lateral root formation induced by fungal signal(s) was found to require the DMI1 and DMI2 genes, but not DMI3. The idea that this diffusible fungal factor might correspond to a previously hypothesized mycorrhizal signal, the 'Myc factor', is discussed.
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Claims 6
Claim · model-written summary
Nod factors increased mycorrhizal colonization.
- Taxon
- Medicago truncatula
Medicago truncatulat0 - Treatment
- Nod factorse0
- Interactor
- arbuscular mycorrhizal fungit0symbiont
- Outcome
- mycorrhizal colonizatione0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nod factors increase mycorrhizal colonization”
t0“arbuscular mycorrhizal fungi stimulate lateral root formation in Medicago truncatula”
Claim · model-written summary
Nod factors stimulated lateral root formation.
- Taxon
- Medicago truncatulaMedicago truncatulat0
- Treatment
- Nod factorse0
- Outcome
- lateral root formatione0
- Direction
- stimulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nod factors increase mycorrhizal colonization and stimulate lateral root formation”
t0“Nod factors and a diffusible factor from arbuscular mycorrhizal fungi stimulate lateral root formation in Medicago truncatula”
Claim · model-written summary
Nod factor stimulation of lateral roots required specified plant genes.
- Taxon
- Medicago truncatulaMedicago truncatulat0
- Treatment
- Nod factorse0
- Gene
- NFP, DMI1, DMI2, DMI3 and NSP1e0
- Outcome
- lateral root formatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The stimulation of lateral root formation by Nod factors requires both the same structural features of Nod factors and the same plant genes (NFP, DMI1, DMI2, DMI3 and NSP1)”
t0“Medicago truncatula”
Claim · model-written summary
A fungal diffusible factor stimulated lateral root formation.
- Taxon
- Medicago truncatulaMedicago truncatulat0
- Treatment
- A diffusible factor from arbuscular mycorrhizal fungie0
- Interactor
- arbuscular mycorrhizal fungie0symbiont
- Outcome
- lateral root formatione0
- Direction
- stimulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A diffusible factor from arbuscular mycorrhizal fungi was also found to stimulate lateral root formation”
t0“Medicago truncatula”
Claim · model-written summary
Three root pathogens did not have the same root formation effect.
- Taxon
- Medicago truncatulaMedicago truncatulat0
- Treatment
- three root pathogense0
- Interactor
- root pathogense0pathogen
- Outcome
- lateral root formationt0
- Direction
- did not have the same effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“while three root pathogens did not have the same effect”
t0“lateral root formation in Medicago truncatula”
Claim · model-written summary
Fungal signal induced lateral root formation required DMI1 and DMI2 but not DMI3.
- Taxon
- Medicago truncatulaMedicago truncatulat0
- Interactor
- arbuscular mycorrhizal fungit0symbiont
- Gene
- DMI1 and DMI2e0
- Outcome
- Lateral root formatione0
- Qualifier
- but not DMI3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lateral root formation induced by fungal signal(s) was found to require the DMI1 and DMI2 genes, but not DMI3”
t0“arbuscular mycorrhizal fungi stimulate lateral root formation in Medicago truncatula”
The same questions in other papers
nodulation factor · growth · Medicago truncatula (barrel medic)Positive and negative results
1 in the opposite direction
- negative
mycorrhiza · growth · Medicago truncatula (barrel medic)Results differ
7 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
5 papers more in this group
See all 9 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.