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The circadian clock is a conserved timekeeping mechanism that is essential for integrating different environmental cues such as light and temperature to coordinate biological processes with the time of day. While much is known about transcriptional regulation by the clock, the role of post-transcriptional regulation, particularly through sequestration into biomolecular condensate such as stress granules, remains less understood. Stress granules are dynamic RNA-protein assemblies that play a critical role in the cellular response to stress by sequestering mRNAs to regulate translation during stressful conditions. In animals and fungi, the circadian clock regulates stress granule formation and mRNA translation by controlling key factors such as eIF2α, which orchestrates the rhythmic sequestration and translation of specific mRNAs. In plants, it has been shown that some transcripts, despite coming from arrhythmic expression, are rhythmically translated. In addition, some clock-controlled genes (CCGs) are induced in response to heat stress only at the transcriptional level and not at the translational level. Together this highlights a layer of clock regulation beyond transcription. This review discusses the intersection between the circadian clock and heat stress-related biomolecular condensates across eukaryotes, with a particular focus on plants. We discuss how the clock may regulate stress granule dynamics and preferential translation of mRNAs at specific times of the day or during stress responses, thereby enhancing cellular function and energy efficiency. By integrating evidence from animals, fungi, and plants, we highlight emerging questions regarding the role of biomolecular condensates as post-transcriptional mechanisms in controlling circadian rhythms and stress tolerance in plants.
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Stress-related biomolecular condensates in plants
Abstract Biomolecular condensates are membraneless organelle-like structures that can concentrate molecules and often form through liquid-liquid phase separation. Biomolecular condensate assembly is tightly regulated by developmental and environmental cues. Although research on biomolecular condensates has intensified in the past 10 years, our current understanding of the molecular mechanisms and components underlying their formation remains in its infancy, especially in plants. However, recent studies have shown that the formation of biomolecular condensates may be central to plant acclimation to stress conditions. Here, we describe the mechanism, regulation, and properties of stress-related condensates in plants, focusing on stress granules and processing bodies, two of the most well-characterized biomolecular condensates. In this regard, we showcase the proteomes of stress granules and processing bodies, in an attempt to suggest methods for elucidating the composition and function of biomolecular condensates. Finally, we discuss how biomolecular condensates modulate stress responses and how they might be used as targets for biotechnological efforts to improve stress tolerance.
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- Award ID(s):
- 2226270
- PAR ID:
- 10416281
- Date Published:
- Journal Name:
- The Plant Cell
- 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 Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/plcell/koad127
