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Updated: Jun 18, 2026

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Translating Ribosome Affinity Purification (TRAP) to Investigate Arabidopsis thaliana Root Development at a Cell Type-Specific Scale
Published on: May 14, 2020
ARF19 acts as a transient auxin response enhancer during root gravitropism
Erfan Ghafouri1, Kristine Hill2, Nathan Mellor2
1Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK.
Cell Reports
|June 16, 2026
Summary
Auxin response factors (ARFs) regulate root gravitropism. ARF7 and ARF8 activate ARF19, which enhances ARF7
Area of Science:
- Plant biology
- Molecular genetics
- Plant hormones
Background:
- Root gravitropism guides root growth downwards.
- Auxin response factors (ARFs) are key regulators of auxin signaling.
- ARF7 and ARF19 are essential for root gravitropism, but their relationship is unclear.
Purpose of the Study:
- To elucidate the regulatory relationship between ARF7 and ARF19 in root gravitropism.
- To investigate the role of ARF19 upregulation during gravitropic stimulus.
Main Methods:
- Analysis of ARF gene expression and function in Arabidopsis thaliana.
- Investigating the transcriptional regulation of ARF19 by ARF7 and ARF8.
- Identifying and comparing target genes of ARF7 and ARF19.
Main Results:
- ARF19 is rapidly and transiently upregulated during gravitropism.
- ARF7 and ARF8 activate ARF19 expression via auxin response elements.
- ARF7 can functionally replace ARF19, but not vice versa.
- ARF7 and ARF19 have both overlapping and distinct target genes.
- ARF19 acts as an enhancer for a subset of ARF7 target genes.
Conclusions:
- ARF7 and ARF19 have sub-functionalized roles in root gravitropism.
- ARF19 acts as a crucial enhancer for specific ARF7-mediated auxin responses.
- This study clarifies the intricate regulatory network of ARFs in gravitropism.
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