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Abstract Insulators arecis-regulatory elements that separate transcriptional units, whereas silencers are elements that repress transcription regardless of their position. In plants, these elements remain largely uncharacterized. Here, we use the massively parallel reporter assay Plant STARR-seq with short fragments of eight large insulators to identify more than 100 fragments that block enhancer activity. The short fragments can be combined to generate more powerful insulators that abolish the capacity of the strong viral 35S enhancer to activate the 35S minimal promoter. Unexpectedly, when tested upstream of weak enhancers, these fragments act as silencers and repress transcription. Thus, these elements are capable of both insulating or repressing transcription dependent upon regulatory context. We validate our findings in stable transgenicArabidopsis, maize, and rice plants. The short elements identified here should be useful building blocks for plant biotechnology efforts.
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Small DNA elements can act as both insulators and silencers in plants
Abstract Insulators are cis-regulatory elements that separate transcriptional units, whereas silencers are elements that repress transcription regardless of their position. In plants, these elements remain largely uncharacterized. Here, we use the massively parallel reporter assay Plant STARR-seq with short fragments of 8 large insulators to identify more than 100 fragments that block enhancer activity. The short fragments can be combined to generate more powerful insulators that abolish the capacity of the strong viral 35S enhancer to activate the 35S minimal promoter. Unexpectedly, when tested upstream of weak enhancers, these fragments act as silencers and repress transcription. Thus, these elements are capable of insulating or repressing transcription, depending on the regulatory context. We validate our findings in stable transgenic Arabidopsis thaliana, maize (Zea mays), and rice (Oryza sativa) plants. The short elements identified here should be useful building blocks for plant biotechnology.
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« less
- PAR ID:
- 10664358
- Publisher / Repository:
- Oxford University Press on behalf of American Society of Plant Biologists
- Date Published:
- Journal Name:
- The Plant Cell
- Volume:
- 37
- Issue:
- 6
- ISSN:
- 1040-4651
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1093/plcell/koaf084
