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Flavonoids and Auxin Transport Inhibitors Rescue Symbiotic Nodulation in the Medicago truncatula Cytokinin Perception Mutant cre1.
- Source :
-
The Plant cell [Plant Cell] 2015 Aug; Vol. 27 (8), pp. 2210-26. Date of Electronic Publication: 2015 Aug 07. - Publication Year :
- 2015
-
Abstract
- Initiation of symbiotic nodules in legumes requires cytokinin signaling, but its mechanism of action is largely unknown. Here, we tested whether the failure to initiate nodules in the Medicago truncatula cytokinin perception mutant cre1 (cytokinin response1) is due to its altered ability to regulate auxin transport, auxin accumulation, and induction of flavonoids. We found that in the cre1 mutant, symbiotic rhizobia cannot locally alter acro- and basipetal auxin transport during nodule initiation and that these mutants show reduced auxin (indole-3-acetic acid) accumulation and auxin responses compared with the wild type. Quantification of flavonoids, which can act as endogenous auxin transport inhibitors, showed a deficiency in the induction of free naringenin, isoliquiritigenin, quercetin, and hesperetin in cre1 roots compared with wild-type roots 24 h after inoculation with rhizobia. Coinoculation of roots with rhizobia and the flavonoids naringenin, isoliquiritigenin, and kaempferol, or with the synthetic auxin transport inhibitor 2,3,5,-triiodobenzoic acid, rescued nodulation efficiency in cre1 mutants and allowed auxin transport control in response to rhizobia. Our results suggest that CRE1-dependent cytokinin signaling leads to nodule initiation through the regulation of flavonoid accumulation required for local alteration of polar auxin transport and subsequent auxin accumulation in cortical cells during the early stages of nodulation.<br /> (© 2015 American Society of Plant Biologists. All rights reserved.)
- Subjects :
- Biological Transport drug effects
Chalcones metabolism
Chalcones pharmacology
Cytokinins metabolism
Flavanones metabolism
Flavanones pharmacology
Flavonoids pharmacology
Host-Pathogen Interactions drug effects
Kaempferols metabolism
Kaempferols pharmacology
Medicago truncatula metabolism
Medicago truncatula microbiology
Microscopy, Fluorescence
Plant Growth Regulators metabolism
Plant Growth Regulators pharmacology
Plant Proteins metabolism
Plant Root Nodulation drug effects
Plant Roots drug effects
Plant Roots genetics
Plant Roots metabolism
Plant Roots microbiology
Plants, Genetically Modified
Reverse Transcriptase Polymerase Chain Reaction
Sinorhizobium meliloti physiology
Symbiosis drug effects
Triiodobenzoic Acids pharmacology
Flavonoids metabolism
Indoleacetic Acids metabolism
Medicago truncatula genetics
Mutation
Plant Proteins genetics
Plant Root Nodulation genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1532-298X
- Volume :
- 27
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 26253705
- Full Text :
- https://doi.org/10.1105/tpc.15.00231