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PICKLE and HISTONE DEACETYLASE6 coordinately regulate genes and transposable elements in Arabidopsis
Wenjuan Li1,2, Xiaoling Zhang1,3, Qingche Zhang1,2
1State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Plant Physiology
|July 8, 2024
Summary
The PICKLE (PKL) and HISTONE DEACETYLASE6 (HDA6) proteins in Arabidopsis thaliana work together to control gene expression by increasing nucleosome density and reducing histone acetylation (H3K9ac). This coordinated action is crucial for silencing genes and transposable elements.
Area of Science:
- Plant molecular biology
- Epigenetics
- Chromatin regulation
Background:
- Chromatin remodelers like PICKLE (PKL) and histone deacetylases like HISTONE DEACETYLASE6 (HDA6) are vital for gene silencing.
- The precise coordination between PKL and HDA6 in gene repression is not fully understood.
Purpose of the Study:
- To investigate the functional relationship between PKL and HDA6 in transcriptional gene silencing.
- To elucidate the molecular mechanisms underlying their coordinated gene repression in Arabidopsis.
Main Methods:
- Genetic suppressor screen to identify mutations affecting Polycomb repressive complex 1 (PRC1) mutants.
- Analysis of gene expression, nucleosome occupancy, and histone modifications (H3K9ac) at specific loci.
- Biochemical assays to determine protein interactions.
- Genome-wide analysis to assess the scope of PKL and HDA6 function.
Main Results:
- A PKL mutation partially rescued developmental defects in a PRC1 mutant (ring1a-2 ring1b-3) by increasing RING1A expression.
- PKL and HDA6 interact and function similarly in repressing RING1A expression in the ring1a-2 ring1b-3 background.
- PKL and HDA6 increase nucleosome density and decrease H3K9ac to suppress gene and transposable element (TE) expression.
- Genome-wide data suggest PKL and HDA6 may also cooperate in maintaining DNA methylation.
Conclusions:
- PKL and HDA6 function synergistically to regulate gene and transposable element expression in Arabidopsis.
- Their mechanism involves increasing nucleosome occupancy and reducing H3K9ac.
- This study reveals a novel aspect of chromatin regulation by PKL and HDA6 in plants.
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