Details
| Original language | English |
|---|---|
| Pages (from-to) | 716-733 |
| Number of pages | 18 |
| Journal | New Phytologist |
| Volume | 185 |
| Issue number | 3 |
| Publication status | Published - 1 Feb 2010 |
Abstract
Arbuscular mycorrhiza (AM) is a mutualistic biotrophic association that requires a complex exchange of signals between plant and fungus to allow accommodation of the mycosymbiont in the root cortex. Signal exchange happens even before physical contact, activating the plant symbiotic program. We investigated very early transcriptional responses in Medicago truncatula to inoculation with Glomus intraradices and identified four genes induced by diffusible AM fungal signals before contact. Three of them were previously shown to be mycorrhiza induced at later stages of the symbiosis, while MtMSBP1, encoding a membrane-bound steroid-binding protein, is a novel mycorrhizal marker. Expression analyses in plants defective in the symbiotic receptor kinase DMI2 allowed discrimination of two different signaling cascades involved in the perception of the diffusible signals. Thus, while some of the genes are activated in a DMI2-dependent manner, the induction of one of them encoding a proteinase inhibitor is DMI2-independent. Downregulation of MtMSBP1 by RNAi led to an aberrant mycorrhizal phenotype with thick and septated appressoria, decrease number of arbuscules and distorted arbuscule morphology. This provides genetic evidence that MtMSBP1 is critical for mycorrhiza development. We hypothesize that MtMSBP1 plays a role in sterol homeostasis in the root.
Keywords
- Arbuscular mycorrhiza symbiosis, Diffusible fungal signal, Glomus intraradices, Medicago truncatula (barrel medic), MtMSBP1 membrane steroid-binding protein, SYM Pathway
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physiology
- Agricultural and Biological Sciences(all)
- Plant Science
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In: New Phytologist, Vol. 185, No. 3, 01.02.2010, p. 716-733.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Membrane steroid-binding protein 1 induced by a diffusible fungal signal is critical for mycorrhization in Medicago truncatula
AU - Kuhn, Hannah
AU - Küster, Helge
AU - Requena, Natalia
PY - 2010/2/1
Y1 - 2010/2/1
N2 - Arbuscular mycorrhiza (AM) is a mutualistic biotrophic association that requires a complex exchange of signals between plant and fungus to allow accommodation of the mycosymbiont in the root cortex. Signal exchange happens even before physical contact, activating the plant symbiotic program. We investigated very early transcriptional responses in Medicago truncatula to inoculation with Glomus intraradices and identified four genes induced by diffusible AM fungal signals before contact. Three of them were previously shown to be mycorrhiza induced at later stages of the symbiosis, while MtMSBP1, encoding a membrane-bound steroid-binding protein, is a novel mycorrhizal marker. Expression analyses in plants defective in the symbiotic receptor kinase DMI2 allowed discrimination of two different signaling cascades involved in the perception of the diffusible signals. Thus, while some of the genes are activated in a DMI2-dependent manner, the induction of one of them encoding a proteinase inhibitor is DMI2-independent. Downregulation of MtMSBP1 by RNAi led to an aberrant mycorrhizal phenotype with thick and septated appressoria, decrease number of arbuscules and distorted arbuscule morphology. This provides genetic evidence that MtMSBP1 is critical for mycorrhiza development. We hypothesize that MtMSBP1 plays a role in sterol homeostasis in the root.
AB - Arbuscular mycorrhiza (AM) is a mutualistic biotrophic association that requires a complex exchange of signals between plant and fungus to allow accommodation of the mycosymbiont in the root cortex. Signal exchange happens even before physical contact, activating the plant symbiotic program. We investigated very early transcriptional responses in Medicago truncatula to inoculation with Glomus intraradices and identified four genes induced by diffusible AM fungal signals before contact. Three of them were previously shown to be mycorrhiza induced at later stages of the symbiosis, while MtMSBP1, encoding a membrane-bound steroid-binding protein, is a novel mycorrhizal marker. Expression analyses in plants defective in the symbiotic receptor kinase DMI2 allowed discrimination of two different signaling cascades involved in the perception of the diffusible signals. Thus, while some of the genes are activated in a DMI2-dependent manner, the induction of one of them encoding a proteinase inhibitor is DMI2-independent. Downregulation of MtMSBP1 by RNAi led to an aberrant mycorrhizal phenotype with thick and septated appressoria, decrease number of arbuscules and distorted arbuscule morphology. This provides genetic evidence that MtMSBP1 is critical for mycorrhiza development. We hypothesize that MtMSBP1 plays a role in sterol homeostasis in the root.
KW - Arbuscular mycorrhiza symbiosis
KW - Diffusible fungal signal
KW - Glomus intraradices
KW - Medicago truncatula (barrel medic)
KW - MtMSBP1 membrane steroid-binding protein
KW - SYM Pathway
UR - http://www.scopus.com/inward/record.url?scp=74549172219&partnerID=8YFLogxK
U2 - 10.1111/j.1469-8137.2009.03116.x
DO - 10.1111/j.1469-8137.2009.03116.x
M3 - Article
C2 - 20003073
AN - SCOPUS:74549172219
VL - 185
SP - 716
EP - 733
JO - New Phytologist
JF - New Phytologist
SN - 0028-646X
IS - 3
ER -