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Plant Promoter Analysis: Identification and Characterization of Root Nodule Specific Promoter in the Common Bean
Published on: December 23, 2017
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CYCLOPS, a DNA-binding transcriptional activator, orchestrates symbiotic root nodule development
Sylvia Singh1, Katja Katzer1, Jayne Lambert1
1Faculty of Biology, Genetics, University of Munich (LMU), D-82152 Martinsried, Germany.
Cell Host & Microbe
|February 18, 2014
Summary
Plant root symbiosis involves nuclear calcium oscillations. Scientists discovered CYCLOPS, a CCaMK target, activates symbiotic genes like NIN, initiating root nodule development.
Area of Science:
- Plant molecular biology
- Symbiotic signaling pathways
- Plant-microbe interactions
Background:
- Nuclear calcium oscillations are key in plant root symbiotic responses.
- Calcium- and calmodulin-dependent kinase (CCaMK) initiates symbiotic programs, but its signal transduction mechanism was unclear.
Purpose of the Study:
- To elucidate the signal transduction mechanism of CCaMK in plant root symbiosis.
- To identify downstream targets and regulators of CCaMK in the symbiotic pathway.
Main Methods:
- Investigated CYCLOPS as a direct CCaMK phosphorylation substrate.
- Analyzed CYCLOPS DNA-binding and transactivation capabilities.
- Utilized phosphomimetic mutants to assess CYCLOPS function in root nodule organogenesis.
Main Results:
- Identified CYCLOPS as a DNA-binding transcriptional activator.
- Demonstrated that phosphorylation of specific serine residues in CYCLOPS is essential for its activity.
- Showed that CYCLOPS binds DNA sequence-specifically and activates the NODULE INCEPTION (NIN) gene.
- A phosphomimetic CYCLOPS mutant triggered root nodule organogenesis independently of rhizobia and CCaMK.
Conclusions:
- CYCLOPS acts as a crucial link in CCaMK-mediated symbiotic signaling.
- CYCLOPS initiates a transcriptional cascade involving NIN and NF-Y complex for symbiotic root nodule development.
- This discovery clarifies a key mechanism in establishing plant-microbe symbiosis.
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