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Describing a Transcription Factor Dependent Regulation of the MicroRNA Transcriptome
Published on: June 15, 2016
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A novel MYB transcription factor regulates ascorbic acid synthesis and affects cold tolerance
Caihua Xing1, Yue Liu1, Liangyi Zhao1
1College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China.
Plant, Cell & Environment
|June 22, 2018
Summary
A novel transcription factor, PbrMYB5, enhances plant tolerance to chilling stress by activating ascorbic acid (AsA) biosynthesis through regulating PbrDHAR2 gene expression. This discovery offers insights into plant stress response mechanisms.
Area of Science:
- Plant Molecular Biology
- Plant Physiology
- Biochemistry
Background:
- Dehydroascorbate reductase (DHAR) is crucial for plant stress responses.
- Transcriptional regulation of DHAR under abiotic stress is not well understood.
Purpose of the Study:
- Identify and characterize novel transcription factors involved in plant abiotic stress responses.
- Investigate the role of PbrMYB5 in regulating dehydroascorbate reductase (DHAR) expression and its impact on chilling tolerance.
Main Methods:
- Yeast one-hybrid screening to identify transcription factors.
- Gene silencing (VIGS) and overexpression in model plants (tobacco).
- Gene expression analysis (qRT-PCR) and biochemical assays (ascorbic acid quantification).
Main Results:
- A novel R2R3-MYB transcription factor, PbrMYB5, was identified from Pyrus betulaefolia.
- PbrMYB5 directly binds to the PbrDHAR2 promoter and its expression is induced by cold and salt stress.
- Overexpression of PbrMYB5 enhanced chilling tolerance in tobacco by increasing DHAR2 expression and ascorbic acid levels, while silencing reduced tolerance.
Conclusions:
- PbrMYB5 acts as a positive regulator of ascorbic acid biosynthesis.
- PbrMYB5 plays a significant role in enhancing plant tolerance to chilling stress, partly by modulating PbrDHAR2 expression.
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