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Identification of two tobacco genes encoding MYB3R proteins with repressor function and showing cell cycle-regulated
Hirotomo Takatsuka1, Yuji Nomoto1, Satoshi Araki2
1School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
Plant Biotechnology (Tokyo, Japan)
|August 16, 2021
Summary
Researchers identified two new tobacco MYB3R transcription factors, NtmybC1 and NtmybC2, that repress G2/M-specific genes. These repressors are cell cycle-regulated, highlighting their role in plant cell division.
Area of Science:
- Plant Molecular Biology
- Gene Regulation
- Cell Cycle Control
Background:
- MYB3R transcription factors regulate G2/M-specific genes in Arabidopsis thaliana.
- MYB3R repressors are conserved in plants, but their functions are not well understood outside of Arabidopsis.
Purpose of the Study:
- To isolate and characterize novel MYB3R proteins from tobacco.
- To investigate the role of these tobacco MYB3Rs in gene regulation and cell cycle progression.
Main Methods:
- Isolation and sequencing of tobacco cDNA clones encoding MYB3R proteins (NtmybC1, NtmybC2).
- Phylogenetic analysis to determine evolutionary relationships.
- Transient expression assays in tobacco BY-2 protoplasts to assess transcriptional activity.
- Analysis of gene expression patterns in synchronized BY-2 cell cultures.
Main Results:
- NtmybC1 and NtmybC2 were identified as MYB3R repressors, closely related to Arabidopsis MYB3R3 and MYB3R5.
- NtmybC1 and NtmybC2 repressed target promoters and blocked activation by NtmybA2, a MYB3R activator.
- Unlike their Arabidopsis counterparts, NtmybC1 and NtmybC2 expression was cell cycle-regulated, peaking in G2/M phases.
Conclusions:
- NtmybC1 and NtmybC2 function as transcriptional repressors of G2/M-specific genes in tobacco.
- Their cell cycle-regulated expression suggests a specific role in controlling cell division.
- These findings indicate potential divergence in the regulatory mechanisms of MYB3R repressors across plant species.
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