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Boycheva I, Bonchev G, Manova V, Stoilov L, Vassileva V. How Histone Acetyltransferases Shape Plant Photomorphogenesis and UV Response. Int J Mol Sci 2024; 25:7851. [PMID: 39063093 PMCID: PMC11276938 DOI: 10.3390/ijms25147851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/15/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Higher plants have developed complex mechanisms to adapt to fluctuating environmental conditions with light playing a vital role in photosynthesis and influencing various developmental processes, including photomorphogenesis. Exposure to ultraviolet (UV) radiation can cause cellular damage, necessitating effective DNA repair mechanisms. Histone acetyltransferases (HATs) play a crucial role in regulating chromatin structure and gene expression, thereby contributing to the repair mechanisms. HATs facilitate chromatin relaxation, enabling transcriptional activation necessary for plant development and stress responses. The intricate relationship between HATs, light signaling pathways and chromatin dynamics has been increasingly understood, providing valuable insights into plant adaptability. This review explores the role of HATs in plant photomorphogenesis, chromatin remodeling and gene regulation, highlighting the importance of chromatin modifications in plant responses to light and various stressors. It emphasizes the need for further research on individual HAT family members and their interactions with other epigenetic factors. Advanced genomic approaches and genome-editing technologies offer promising avenues for enhancing crop resilience and productivity through targeted manipulation of HAT activities. Understanding these mechanisms is essential for developing strategies to improve plant growth and stress tolerance, contributing to sustainable agriculture in the face of a changing climate.
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Affiliation(s)
| | | | | | | | - Valya Vassileva
- Department of Molecular Biology and Genetics, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (I.B.); (G.B.); (V.M.); (L.S.)
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2
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Fang F, Lin L, Zhang Q, Lu M, Skvortsova MY, Podolec R, Zhang Q, Pi J, Zhang C, Ulm R, Yin R. Mechanisms of UV-B light-induced photoreceptor UVR8 nuclear localization dynamics. THE NEW PHYTOLOGIST 2022; 236:1824-1837. [PMID: 36089828 PMCID: PMC9825989 DOI: 10.1111/nph.18468] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Light regulates the subcellular localization of plant photoreceptors, a key step in light signaling. Ultraviolet-B radiation (UV-B) induces the plant photoreceptor UV RESISTANCE LOCUS 8 (UVR8) nuclear accumulation, where it regulates photomorphogenesis. However, the molecular mechanism for the UV-B-regulated UVR8 nuclear localization dynamics is unknown. With fluorescence recovery after photobleaching (FRAP), cell fractionation followed by immunoblotting and co-immunoprecipitation (Co-IP) assays we tested the function of UVR8-interacting proteins including CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 in the regulation of UVR8 nuclear dynamics in Arabidopsis thaliana. We showed that UV-B-induced rapid UVR8 nuclear translocation is independent of COP1, which previously was shown to be required for UV-B-induced UVR8 nuclear accumulation. Instead, we provide evidence that the UV-B-induced UVR8 homodimer-to-monomer photo-switch and the concurrent size reduction of UVR8 enables its monomer nuclear translocation, most likely via free diffusion. Nuclear COP1 interacts with UV-B-activated UVR8 monomer, thereby promoting UVR8 nuclear retention. Conversely, RUP1and RUP2, whose expressions are induced by UV-B, inhibit UVR8 nuclear retention via attenuating the UVR8-COP1 interaction, allowing UVR8 to exit the nucleus. Collectively, our data suggest that UV-B-induced monomerization of UVR8 promotes its nuclear translocation via free diffusion. In the nucleus, COP1 binding promotes UVR8 monomer nuclear retention, which is counterbalanced by the major negative regulators RUP1 and RUP2.
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Affiliation(s)
- Fang Fang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Li Lin
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
- Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai Jiao Tong UniversityShanghai200240China
- Joint Center for Single Cell BiologyShanghai Jiao Tong UniversityShanghai200240China
| | - Qianwen Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Min Lu
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China
| | - Mariya Y. Skvortsova
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
| | - Roman Podolec
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3)University of GenevaCH‐1211Geneva 4Switzerland
| | - Qinyun Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Jiahao Pi
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Chunli Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3)University of GenevaCH‐1211Geneva 4Switzerland
| | - Ruohe Yin
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
- Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai Jiao Tong UniversityShanghai200240China
- Joint Center for Single Cell BiologyShanghai Jiao Tong UniversityShanghai200240China
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3
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Alachkar A. Aromatic patterns: Tryptophan aromaticity as a catalyst for the emergence of life and rise of consciousness. Phys Life Rev 2022; 42:93-114. [PMID: 35905538 DOI: 10.1016/j.plrev.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 11/28/2022]
Abstract
Sunlight held the key to the origin of life on Earth. The earliest life forms, cyanobacteria, captured the sunlight to generate energy through photosynthesis. Life on Earth evolved in accordance with the circadian rhythms tied to sensitivity to sunlight patterns. A unique feature of cyanobacterial photosynthetic proteins and circadian rhythms' molecules, and later of nearly all photon-sensing molecules throughout evolution, is that the aromatic amino acid tryptophan (Trp) resides at the center of light-harvesting active sites. In this perspective, I review the literature and integrate evidence from different scientific fields to explore the role Trp plays in photon-sensing capabilities of living organisms through its resonance delocalization of π-electrons. The observations presented here are the product of apparently unrelated phenomena throughout evolution, but nevertheless share consistent patterns of photon-sensing by Trp-containing and Trp-derived molecules. I posit the unique capacity to transfer electrons during photosynthesis in the earliest life forms is conferred to Trp due to its aromaticity. I propose this ability evolved to assume more complex functions, serving as a host for mechanisms underlying mental aptitudes - a concept which provides a theoretical basis for defining the neural correlates of consciousness. The argument made here is that Trp aromaticity may have allowed for the inception of the mechanistic building blocks used to fabricate complexity in higher forms of life. More specifically, Trp aromatic non-locality may have acted as a catalyst for the emergence of consciousness by instigating long-range synchronization and stabilizing the large-scale coherence of neural networks, which mediate functional brain activity. The concepts proposed in this perspective provide a conceptual foundation that invites further interdisciplinary dialogue aimed at examining and defining the role of aromaticity (beyond Trp) in the emergence of life and consciousness.
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Affiliation(s)
- Amal Alachkar
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, CA 92697, USA; UC Irvine Center for the Neurobiology of Learning and Memory, University of California-Irvine, Irvine, CA 92697, USA; Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California, Irvine, CA 92697, USA.
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4
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Liao X, Jenkins GI. Cysteines have a role in conformation of the UVR8 photoreceptor. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:583-594. [PMID: 35608127 PMCID: PMC9546227 DOI: 10.1111/tpj.15841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
The UV RESISTANCE LOCUS 8 (UVR8) photoreceptor mediates plant responses to Ultraviolet-B (UV-B) wavelengths. The UVR8 dimer dissociates into monomers following UV-B photoreception, a process accompanied by conformational changes that facilitate interaction of UVR8 with proteins that initiate responses. However, the importance of particular amino acids in maintaining UVR8 conformation and modulating protein interactions is poorly understood. Here we examine the roles of cysteine amino acids C231 and C335 in UVR8 structure and function. UVR8C231S,C335S mutant protein forms dimers and monomerizes similarly to wild-type UVR8. UVR8C231S,C335S interacts with CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) in plants to initiate photomorphogenic responses to UV-B, although the interaction is weaker when examined in yeast two-hybrid assays. Similarly, the interaction of UVR8C231S,C335S with REPRESSOR OF UV-B PHOTOMORPHOGENESIS (RUP) proteins is weaker in both plants and yeast compared with wild-type UVR8. Re-dimerization of UVR8 in plants, which is mediated by RUP proteins, occurs with reduced efficiency in UVR8C231S,C335S . Fluorescence resonance energy transfer analysis indicates that UVR8C231S,C335S has an altered conformation in plants, in that the N- and C-termini appear closer together, which may explain the altered protein interactions.
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Affiliation(s)
- Xinyang Liao
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower BuildingUniversity of GlasgowGlasgowG12 8QQUK
| | - Gareth I. Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower BuildingUniversity of GlasgowGlasgowG12 8QQUK
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5
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Yang G, Zhang C, Dong H, Liu X, Guo H, Tong B, Fang F, Zhao Y, Yu Y, Liu Y, Lin L, Yin R. Activation and negative feedback regulation of SlHY5 transcription by the SlBBX20/21-SlHY5 transcription factor module in UV-B signaling. THE PLANT CELL 2022; 34:2038-2055. [PMID: 35188198 PMCID: PMC9048894 DOI: 10.1093/plcell/koac064] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 01/31/2022] [Indexed: 05/04/2023]
Abstract
In tomato (Solanum lycopersicum) and other plants, the photoreceptor UV-RESISTANCE LOCUS 8 regulates plant UV-B photomorphogenesis by modulating the transcription of many genes, the majority of which depends on the transcription factor ELONGATED HYPOCOTYL 5 (HY5). HY5 transcription is induced and then rapidly attenuated by UV-B. However, neither the transcription factors that activate HY5 transcription nor the mechanism for its attenuation during UV-B signaling is known. Here, we report that the tomato B-BOX (BBX) transcription factors SlBBX20 and SlBBX21 interact with SlHY5 and bind to the SlHY5 promoter to activate its transcription. UV-B-induced SlHY5 expression and SlHY5-controlled UV-B responses are normal in slbbx20 and slbbx21 single mutants, but strongly compromised in the slbbx20 slbbx21 double mutant. Surprisingly, UV-B responses are also compromised in lines overexpressing SlBBX20 or SlBBX21. Both SlHY5 and SlBBX20 bind to G-box1 in the SlHY5 promoter. SlHY5 outcompetes SlBBX20 for binding to the SlHY5 promoter in vitro, and inhibits the association of SlBBX20 with the SlHY5 promoter in vivo. Overexpressing 35S:SlHY5-FLAG in the WT background inhibits UV-B-induced endogenous SlHY5 expression. Together, our results reveal the critical role of the SlBBX20/21-SlHY5 module in activating the expression of SlHY5, the gene product of which inhibits its own gene transcription under UV-B, forming an autoregulatory negative feedback loop that balances SlHY5 transcription in plants.
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Affiliation(s)
- Guoqian Yang
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chunli Zhang
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huaxi Dong
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaorui Liu
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huicong Guo
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Boqin Tong
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fang Fang
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yiyang Zhao
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yunji Yu
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yue Liu
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li Lin
- Shanghai Cooperative Innovation Center for Modern Seed Industry/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China
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6
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Zhang Z, Xu C, Zhang S, Shi C, Cheng H, Liu H, Zhong B. Origin and adaptive evolution of UV RESISTANCE LOCUS 8-mediated signaling during plant terrestrialization. PLANT PHYSIOLOGY 2022; 188:332-346. [PMID: 34662425 PMCID: PMC8774840 DOI: 10.1093/plphys/kiab486] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
UV RESISTANCE LOCUS 8 (UVR8) mediates photomorphogenic responses and acclimation to UV-B radiation by regulating the transcription of a series of transcription factors (TFs). However, the origin and evolution of UVR8-mediated signaling pathways remain largely unknown. In this study, we investigated the origin and evolution of the major components of the UVR8-mediated signaling pathway (UVR8, REPRESSOR OF UV-B PHOTOMORPHOGENESIS [RUP], BRI1-EMS-SUPPRESSOR1 [BES1], BES1-INTERACTING MYC-LIKE 1 (BIM1), WRKY DNA-BINDING PROTEIN 36 (WRKY36), MYB DOMAIN PROTEIN 73/77/13 [MYB73/MYB77/MYB13], and PHYTOCHROME INTERACTING FACTOR 4/5 [PIF4 and PIF5]) using comparative genomics and phylogenetic approaches. We showed that the central regulator UVR8 presented a conservative evolutionary route during plant evolution, and the evolutionary history of downstream negative regulators and TFs was different from that of green plant phylogeny. The canonical UVR8-CONSTITUTIVELY PHOTOMORPHOGENIC 1(COP1)/SUPPRESSOR OF PHYA-105 (SPA)-ELONGATED HYPOCOTYL 5 (HY5)-RUP signaling pathway originated in chlorophytes and conferred green algae the additional ability to cope with UV-B radiation. Moreover, the emergence of multiple UVR8-mediated signaling pathways in charophytes laid the foundations for the cross-talk between UV-B signals and endogenous hormone responses. Importantly, we observed signatures that reflect plant adaptations to high UV-B irradiance in subaerial/terrestrial environments, including positive selection in UVR8 and RUPs and increased copy number of some vital TFs. These results revealed that green plants not only experienced adaptive modifications in the canonical UVR8-COP1/SPA-HY5-RUP signaling pathway, but also diversified their UV-B signal transduction mechanisms through increasing cross-talk with other pathways, such as those associated with brassinosteroids and auxin. This study greatly expands our understanding of molecular evolution and adaptive mechanisms underlying plant UV-B acclimation.
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Affiliation(s)
- Zhenhua Zhang
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Chenjie Xu
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Shiyu Zhang
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Chen Shi
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences, Shanghai 200032, China
| | - Hong Cheng
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Hongtao Liu
- National Key Laboratory of Plant Molecular Genetics (NKLPMG), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology (SIPPE), Chinese Academy of Sciences, Shanghai 200032, China
| | - Bojian Zhong
- College of Life Sciences, Nanjing Normal University, Nanjing 210023, China
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7
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Dwijayanti A, Zhang C, Poh CL, Lautier T. Toward Multiplexed Optogenetic Circuits. Front Bioeng Biotechnol 2022; 9:804563. [PMID: 35071213 PMCID: PMC8766309 DOI: 10.3389/fbioe.2021.804563] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022] Open
Abstract
Owing to its ubiquity and easy availability in nature, light has been widely employed to control complex cellular behaviors. Light-sensitive proteins are the foundation to such diverse and multilevel adaptive regulations in a large range of organisms. Due to their remarkable properties and potential applications in engineered systems, exploration and engineering of natural light-sensitive proteins have significantly contributed to expand optogenetic toolboxes with tailor-made performances in synthetic genetic circuits. Progressively, more complex systems have been designed in which multiple photoreceptors, each sensing its dedicated wavelength, are combined to simultaneously coordinate cellular responses in a single cell. In this review, we highlight recent works and challenges on multiplexed optogenetic circuits in natural and engineered systems for a dynamic regulation breakthrough in biotechnological applications.
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Affiliation(s)
| | - Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Chueh Loo Poh
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Thomas Lautier
- CNRS@CREATE, Singapore, Singapore
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
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8
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Miao T, Li D, Huang Z, Huang Y, Li S, Wang Y. Gibberellin regulates UV-B-induced hypocotyl growth inhibition in Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2021; 16:1966587. [PMID: 34463604 PMCID: PMC8526026 DOI: 10.1080/15592324.2021.1966587] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Plant response to light is a complex and diverse phenomenon. Several studies have elucidated the mechanisms via which light and hormones regulate hypocotyl growth. However, the hormone-dependent ultraviolet-B (UV-B) response in plants remains obscure. Involvement of gibberellins (GAs) in UV-B-induced hypocotyl inhibition and its mechanisms in Arabidopsis thaliana were investigated in the present research. UV-B exposure remarkably decreased the endogenous GA3 content through the UV RESISTANCE LOCUS 8 (UVR8) receptor pathway, and exogenous GA3 partially restored the hypocotyl growth. UV-B irradiation affected the expression levels of GA metabolism-related genes (GA20ox1, GA2ox1 and GA3ox1) in the hy5-215 mutant, resulting in increased GA content.ELONGATED HYPOCOTYL 5 (HY5) promoted the accumulation of DELLA proteins under UV-B radiation; HY5 appeared to regulate the abundance of DELLAs at the transcriptional level under UV-B. As a result, the GA3 content decreased, which eventually led to the shortening of the hypocotyl. To conclude, the present study provides new insight into the regulation of plant photomorphogenesis under UV-B.
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Affiliation(s)
- Tingting Miao
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China
| | - Dezhi Li
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China
| | - Ziyuan Huang
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China
| | - Yuewei Huang
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China
| | - Shaoshan Li
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou, China
- CONTACT Shaoshan Li Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou510631, China
| | - Yan Wang
- College of Life Science and Technology, Jinan University, Guangzhou, China
- Yan Wang College of Life Science and Technology, Jinan University, Guangzhou, China
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9
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Podolec R, Demarsy E, Ulm R. Perception and Signaling of Ultraviolet-B Radiation in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:793-822. [PMID: 33636992 DOI: 10.1146/annurev-arplant-050718-095946] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Ultraviolet-B (UV-B) radiation is an intrinsic fraction of sunlight that plants perceive through the UVR8 photoreceptor. UVR8 is a homodimer in its ground state that monomerizes upon UV-B photon absorption via distinct tryptophan residues. Monomeric UVR8 competitively binds to the substrate binding site of COP1, thus inhibiting its E3 ubiquitin ligase activity against target proteins, which include transcriptional regulators such as HY5. The UVR8-COP1 interaction also leads to the destabilization of PIF bHLH factor family members. Additionally, UVR8 directly interacts with and inhibits the DNA binding of a different set of transcription factors. Each of these UVR8 signaling mechanisms initiates nuclear gene expression changes leading to UV-B-induced photomorphogenesis and acclimation. The two WD40-repeat proteins RUP1 and RUP2 provide negative feedback regulation and inactivate UVR8 by facilitating redimerization. Here, we review the molecular mechanisms of the UVR8 pathway from UV-B perception and signal transduction to gene expression changes and physiological UV-B responses.
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Affiliation(s)
- Roman Podolec
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
| | - Emilie Demarsy
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
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10
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Fernández MB, Lukaszewicz G, Lamattina L, Cassia R. Selection and optimization of reference genes for RT-qPCR normalization: A case study in Solanum lycopersicum exposed to UV-B. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 160:269-280. [PMID: 33529802 DOI: 10.1016/j.plaphy.2021.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/18/2021] [Indexed: 05/11/2023]
Abstract
Quantitative RT- PCR is one of the most common methods to study gene expression in response to stress. Therefore, it is crucial to have suitable reference genes (RGs) for result normalization. Although several reports describe UV-B-modulated gene expression in Solanum lycopersicum, there are no suitable RGs identified until now. The aim of this work was to evaluate the suitability of seven traditional genes: actin (ACT), tubulin (TUB), ubiquitin (UBI), glyceraldehyde- 3 phosphate dehydrogenase (GAPDH), elongation factor 1α (EF1α), phosphatase 2A catalytic subunit (PP2A) and GAGA binding transcriptional activator (GAGA); and two non-traditional genes: thioredoxin h1 (TRX h1) and UV-B RESISTANCE LOCUS 8 (UVR8), as candidate RGs for their potential use as reliable internal controls in leaves, stems and roots of tomato seedlings exposed to acute and chronic UV-B. The stability of these genes expression was evaluated using five statistical algorithms: geNorm, NormFinder, BestKeeper, Delta Ct and ANOVA. Considering the comprehensive stability ranking, we recommend ACT+TUB as the best pair of RGs for leaves, PP2A+GAPDH+TRX h1 for stems and TUB+UVR8 for roots. The reliability of the selected RGs for each tissue was verified amplifying tomato chalcone synthase 1 (CHS1) and cyclobutane pyrimidine dimer (CPD) photolyase (PHR1-LIKE). Under UV-B treatment, CHS1 was upregulated in leaves, stems and roots whereas PHR1-LIKE was only upregulated in leaves and stems. This interpretation differs when the most and least stable RGs are chosen. This is the first report regarding suitable RGs selection for accurate normalization of gene expression in tomato seedlings exposed to UV-B irradiation.
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Affiliation(s)
- María Belén Fernández
- Instituto de Investigaciones Biológicas- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar Del Plata- Consejo Nacional de Investigaciones Científicas y Técnicas, CC1245 7600, Mar Del Plata, Buenos Aires, Argentina.
| | - Germán Lukaszewicz
- Instituto de Investigaciones Biológicas- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar Del Plata- Consejo Nacional de Investigaciones Científicas y Técnicas, CC1245 7600, Mar Del Plata, Buenos Aires, Argentina
| | - Lorenzo Lamattina
- Instituto de Investigaciones Biológicas- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar Del Plata- Consejo Nacional de Investigaciones Científicas y Técnicas, CC1245 7600, Mar Del Plata, Buenos Aires, Argentina
| | - Raúl Cassia
- Instituto de Investigaciones Biológicas- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar Del Plata- Consejo Nacional de Investigaciones Científicas y Técnicas, CC1245 7600, Mar Del Plata, Buenos Aires, Argentina
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11
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A constitutively monomeric UVR8 photoreceptor confers enhanced UV-B photomorphogenesis. Proc Natl Acad Sci U S A 2021; 118:2017284118. [PMID: 33542100 PMCID: PMC8017708 DOI: 10.1073/pnas.2017284118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Coping with UV-B is crucial for plant survival in sunlight. The UV-B photoreceptor UVR8 regulates gene expression associated with photomorphogenesis, acclimation, and UV-B stress tolerance. UV-B photon reception by UVR8 homodimers results in monomerization, followed by interaction with the key signaling protein COP1. We have discovered a UV-B hypersensitive UVR8 photoreceptor that confers strongly enhanced UV-B tolerance and generated a UVR8 variant based on the underlying mutation that shows extremely enhanced constitutive signaling activity. Our findings provide key mechanistic insight into how plants respond and acclimate to UV-B radiation. The plant ultraviolet-B (UV-B) photoreceptor UVR8 plays an important role in UV-B acclimation and survival. UV-B absorption by homodimeric UVR8 induces its monomerization and interaction with the E3 ubiquitin ligase COP1, leading ultimately to gene expression changes. UVR8 is inactivated through redimerization, facilitated by RUP1 and RUP2. Here, we describe a semidominant, hyperactive allele, namely uvr8-17D, that harbors a glycine-101 to serine mutation. UVR8G101S overexpression led to weak constitutive photomorphogenesis and extreme UV-B responsiveness. UVR8G101S was observed to be predominantly monomeric in vivo and, once activated by UV-B, was not efficiently inactivated. Analysis of a UVR8 crystal structure containing the G101S mutation revealed the distortion of a loop region normally involved in stabilization of the UVR8 homodimer. Plants expressing a UVR8 variant combining G101S with the previously described W285A mutation exhibited robust constitutive photomorphogenesis. This work provides further insight into UVR8 activation and inactivation mechanisms and describes a genetic tool for the manipulation of photomorphogenic responses.
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Dong H, Liu X, Zhang C, Guo H, Liu Y, Chen H, Yin R, Lin L. Expression of Tomato UVR8 in Arabidopsis reveals conserved photoreceptor function. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 303:110766. [PMID: 33487351 DOI: 10.1016/j.plantsci.2020.110766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/27/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
UV RESISTANCE LOCUS 8 (UVR8) is a photoreceptor that regulates UV-B photomorphogenesis in plants. UV-B photon perception promotes UVR8 homodimer dissociation into monomer, which is reverted to homodimer post UV-B, forming a complete photocycle. UVR8 monomer interacts with CONSTITUTIVELY PHOTOMORPHOGENEIC 1 (COP1) to initiate UV-B signaling. The function and mechanism of Arabidopsis UVR8 (AtUVR8) are extensively investigated, however, little is known about UVR8 and its signaling mechanisms in other plant species. Tomato is a widely used model plant for horticulture research. In this report we tested whether an ortholog of AtUVR8 in Tomato (SIUVR8) can complement Arabidopsis uvr8 mutant and whether the above-mentioned key signaling mechanisms of UVR8 are conserved. Heterologous expressed SIUVR8 in an Arabidopsis uvr8 null mutant rescued the uvr8 mutant in the tested UV-B responses including hypocotyl elongation, UV-B target gene expression and anthocyanin accumulation, demonstrating that the SIUVR8 is a putative UV-B photoreceptor. Moreover, in response to UV-B, SIUVR8 forms a protein complex with Arabidopsis COP1 in plants, suggesting conserved signaling mechanism. SIUVR8 exhibits similar photocycle as AtUVR8 in plants, which highlights conserved photoreceptor activation and inactivation mechanisms.
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Affiliation(s)
- Huaxi Dong
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Xiaorui Liu
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Chunli Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Huicong Guo
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Yang Liu
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Huoying Chen
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Ruohe Yin
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China; Key Laboratory of Urban Agriculture, Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
| | - Li Lin
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, PR China.
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13
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Li X, Liu Z, Ren H, Kundu M, Wang L, Gao J, Zhong D. Dynamics and mechanism of light harvesting in UV photoreceptor UVR8. Chem Sci 2020; 11:12553-12569. [PMID: 34094455 PMCID: PMC8163212 DOI: 10.1039/d0sc04909c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Photosynthetic pigments form light-harvesting networks to enable nearly perfect quantum efficiency in photosynthesis via excitation energy transfer. However, similar light-harvesting mechanisms have not been reported in light sensing processes in other classes of photoreceptors during light-mediated signaling. Here, based on our earlier report, we mapped out a striking energy-transfer network composed of 26 structural tryptophan residues in the plant UV-B photoreceptor UVR8. The spectra of the tryptophan chromophores are tuned by the protein environments, funneling all excitation energy to a cluster of four tryptophan residues, a pyramid center, where the excitation-induced monomerization is initiated for cell signaling. With extensive site-directed mutagenesis, various time-resolved fluorescence techniques, and combined QM/MM simulations, we determined the energy-transfer rates for all donor–acceptor pairs, revealing the time scales from tens of picoseconds to nanoseconds. The overall light harvesting quantum efficiency by the pyramid center is significantly increased to 73%, compared to a direct excitation probability of 35%. UVR8 is the only photoreceptor discovered so far using a natural amino-acid tryptophan without utilizing extrinsic chromophores to form a network to carry out both light harvesting and light perception for biological functions. The light-harvesting network from distal and peripheral to central tryptophans with transfer efficiencies determined from measured energy-transfer rates.![]()
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Affiliation(s)
- Xiankun Li
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University Columbus OH 43210 USA .,Center for Ultrafast Science and Technology, School of Physics and Astronomy, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University Shanghai 200240 China
| | - Zheyun Liu
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Haisheng Ren
- Department of Chemistry and Supercomputing Institute, University of Minnesota Minneapolis MN 55455 USA .,College of Chemical Engineering, Sichuan University Chengdu 610065 China
| | - Mainak Kundu
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Lijuan Wang
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Jiali Gao
- Department of Chemistry and Supercomputing Institute, University of Minnesota Minneapolis MN 55455 USA .,School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School Shenzhen 518055 China.,Institute of Systems and Physical Biology, Shenzhen Bay Laboratory Shenzhen 518055 China
| | - Dongping Zhong
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University Columbus OH 43210 USA .,Center for Ultrafast Science and Technology, School of Physics and Astronomy, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University Shanghai 200240 China
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14
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Lin L, Dong H, Yang G, Yin R. The C-terminal 17 amino acids of the photoreceptor UVR8 is involved in the fine-tuning of UV-B signaling. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:1327-1340. [PMID: 32492260 DOI: 10.1111/jipb.12977] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 06/01/2020] [Indexed: 05/26/2023]
Abstract
Plant UV-B responses are mediated by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8). In response to UV-B irradiation, UVR8 homodimers dissociate into monomers that bind to the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1). The interaction of the C27 domain in the C-terminal tail of UVR8 with the WD40 domain of COP1 is critical for UV-B signaling. However, the function of the last 17 amino acids (C17) of the C-terminus of UVR8, which are adjacent to C27, is unknown, although they are largely conserved in land plants. In this study, we established that Arabidopsis thaliana UVR8 C17 binds to full-length UVR8, but not to COP1, and reduces COP1 binding to the remaining portion of UVR8, including C27. We hypothesized that overexpression of C17 in a wild-type background would have a dominant negative effect on UVR8 activity; however, C17 overexpression caused strong silencing of endogenous UVR8, precluding a detailed analysis. We therefore generated YFP-UVR8N423 transgenic lines, in which C17 was deleted, to examine C17 function indirectly. YFP-UVR8N423 was more active than YFP-UVR8, suggesting that C17 inhibits UV-B signaling by attenuating binding between C27 and COP1. Our study reveals an inhibitory role for UVR8 C17 in fine-tuning UVR8-COP1 interactions during UV-B signaling.
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Affiliation(s)
- Li Lin
- Joint Center for Single Cell Biology, Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Huaxi Dong
- Joint Center for Single Cell Biology, Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Guoqian Yang
- Joint Center for Single Cell Biology, Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ruohe Yin
- Joint Center for Single Cell Biology, Key Laboratory of Urban Agriculture Ministry of Agriculture, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
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15
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Li X, Ren H, Kundu M, Liu Z, Zhong FW, Wang L, Gao J, Zhong D. A leap in quantum efficiency through light harvesting in photoreceptor UVR8. Nat Commun 2020; 11:4316. [PMID: 32859932 PMCID: PMC7455749 DOI: 10.1038/s41467-020-17838-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/17/2020] [Indexed: 11/09/2022] Open
Abstract
Plants utilize a UV-B (280 to 315 nm) photoreceptor UVR8 (UV RESISTANCE LOCUS 8) to sense environmental UV levels and regulate gene expression to avoid harmful UV effects. Uniquely, UVR8 uses intrinsic tryptophan for UV-B perception with a homodimer structure containing 26 structural tryptophan residues. However, besides 8 tryptophans at the dimer interface to form two critical pyramid perception centers, the other 18 tryptophans’ functional role is unknown. Here, using ultrafast fluorescence spectroscopy, computational methods and extensive mutations, we find that all 18 tryptophans form light-harvesting networks and funnel their excitation energy to the pyramid centers to enhance light-perception efficiency. We determine the timescales of all elementary tryptophan-to-tryptophan energy-transfer steps in picoseconds to nanoseconds, in excellent agreement with quantum computational calculations, and finally reveal a significant leap in light-perception quantum efficiency from 35% to 73%. This photoreceptor is the first system discovered so far, to be best of our knowledge, using natural amino-acid tryptophans to form networks for both light harvesting and light perception. Photoreceptor UVR8 in plants senses environmental UV levels through 26 structural tryptophan residues, but the role of 18 of them was unknown. The authors show, by experiments and computations, how these form a light-harvesting network that funnels the excitation to the pyramid centers enhancing the light-perception efficiency.
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Affiliation(s)
- Xiankun Li
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.,Center for Ultrafast Science and Technology, School of Physics and Astronomy, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haisheng Ren
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,College of Chemical Engineering, Sichuan University, Chengdu, 610065, China
| | - Mainak Kundu
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Zheyun Liu
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Frank W Zhong
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.,Cell and Molecular Biology Program, University of Chicago, Chicago, IL, 60637, USA
| | - Lijuan Wang
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Jiali Gao
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN, 55455, USA. .,School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
| | - Dongping Zhong
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA. .,Center for Ultrafast Science and Technology, School of Physics and Astronomy, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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16
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Liao X, Liu W, Yang HQ, Jenkins GI. A dynamic model of UVR8 photoreceptor signalling in UV-B-acclimated Arabidopsis. THE NEW PHYTOLOGIST 2020; 227:857-866. [PMID: 32255498 DOI: 10.1111/nph.16581] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/20/2020] [Indexed: 05/20/2023]
Abstract
The photoreceptor UVR8 mediates numerous photomorphogenic responses of plants to UV-B wavelengths by regulating transcription. Studies with purified UVR8 and seedlings not previously exposed to UV-B have generated a model for UVR8 action in which dimeric UVR8 rapidly monomerises in response to UV-B exposure to initiate signalling. However, the mechanism of UVR8 action in UV-B-acclimated plants growing under photoperiodic conditions, where UVR8 exists in a dimer/monomer photo-equilibrium, is poorly understood. We examined UVR8 dimer/monomer status, gene expression responses, amounts of key UVR8 signalling proteins and their interactions with UVR8 in UV-B-acclimated Arabidopsis. We show that in UV-B-acclimated plants UVR8 can mediate a response to a 15-fold increase in UV-B without any increase in abundance of UVR8 monomer. Following transfer to elevated UV-B, monomers show increased interaction with both COP1, to initiate signalling and RUP2, to maintain the photo-equilibrium when the dimer/monomer cycling rate increases. Native RUP1 is present in low abundance compared with RUP2. We present a model for UVR8 action in UV-B-acclimated plants growing in photoperiodic conditions that incorporates dimer and monomer photoreception, dimer/monomer cycling, abundance of native COP1 and RUP proteins, and interactions of the monomer population with COP1, RUP2 and potentially other proteins.
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Affiliation(s)
- Xinyang Liao
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow,, G12 8QQ, UK
| | - Wei Liu
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow,, G12 8QQ, UK
| | - Hong-Quan Yang
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow,, G12 8QQ, UK
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17
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Rai N, O'Hara A, Farkas D, Safronov O, Ratanasopa K, Wang F, Lindfors AV, Jenkins GI, Lehto T, Salojärvi J, Brosché M, Strid Å, Aphalo PJ, Morales LO. The photoreceptor UVR8 mediates the perception of both UV-B and UV-A wavelengths up to 350 nm of sunlight with responsivity moderated by cryptochromes. PLANT, CELL & ENVIRONMENT 2020; 43:1513-1527. [PMID: 32167576 DOI: 10.1111/pce.13752] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 05/27/2023]
Abstract
The photoreceptors UV RESISTANCE LOCUS 8 (UVR8) and CRYPTOCHROMES 1 and 2 (CRYs) play major roles in the perception of UV-B (280-315 nm) and UV-A/blue radiation (315-500 nm), respectively. However, it is poorly understood how they function in sunlight. The roles of UVR8 and CRYs were assessed in a factorial experiment with Arabidopsis thaliana wild-type and photoreceptor mutants exposed to sunlight for 6 or 12 hr under five types of filters with cut-offs in UV and blue-light regions. Transcriptome-wide responses triggered by UV-B and UV-A wavelengths shorter than 350 nm (UV-Asw ) required UVR8 whereas those induced by blue and UV-A wavelengths longer than 350 nm (UV-Alw ) required CRYs. UVR8 modulated gene expression in response to blue light while lack of CRYs drastically enhanced gene expression in response to UV-B and UV-Asw . These results agree with our estimates of photons absorbed by these photoreceptors in sunlight and with in vitro monomerization of UVR8 by wavelengths up to 335 nm. Motif enrichment analysis predicted complex signaling downstream of UVR8 and CRYs. Our results highlight that it is important to use UV waveband definitions specific to plants' photomorphogenesis as is routinely done in the visible region.
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Affiliation(s)
- Neha Rai
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Andrew O'Hara
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Daniel Farkas
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Omid Safronov
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Khuanpiroon Ratanasopa
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Fang Wang
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Anders V Lindfors
- Meteorological Research, Finnish Meteorological Institute, Helsinki, Finland
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Tarja Lehto
- School of Forest Sciences, University of Eastern Finland, Joensuu, Finland
| | - Jarkko Salojärvi
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Mikael Brosché
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Åke Strid
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Pedro J Aphalo
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Luis O Morales
- Organismal and Evolutionary Biology, Faculty of Biological and Environmental Sciences, and Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
- Örebro Life Science Center, School of Science and Technology, Örebro University, Örebro, Sweden
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18
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O'Hara A, Headland LR, Díaz-Ramos LA, Morales LO, Strid Å, Jenkins GI. Regulation of Arabidopsis gene expression by low fluence rate UV-B independently of UVR8 and stress signaling. Photochem Photobiol Sci 2019; 18:1675-1684. [PMID: 31218318 DOI: 10.1039/c9pp00151d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UV-B exposure of plants regulates expression of numerous genes concerned with various responses. Sudden exposure of non-acclimated plants to high fluence rate, short wavelength UV-B induces expression via stress-related signaling pathways that are not specific to the UV-B stimulus, whereas low fluence rates of UV-B can regulate expression via the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8). However, there is little information about whether non-stressful, low fluence rate UV-B treatments can activate gene expression independently of UVR8. Here, transcriptomic analysis of wild-type and uvr8 mutant Arabidopsis exposed to low fluence rate UV-B showed that numerous genes were regulated independently of UVR8. Moreover, nearly all of these genes were distinct to those induced by stress treatments. A small number of genes were expressed at all UV-B fluence rates employed and may be concerned with activation of eustress responses that facilitate acclimation to changing conditions. Expression of the gene encoding the transcription factor ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN 13 (ANAC13) was studied to characterise a low fluence rate, UVR8-independent response. ANAC13 is induced by as little as 0.1 μmol m-2 s-1 UV-B and its regulation is independent of components of the canonical UVR8 signaling pathway COP1 and HY5/HYH. Furthermore, UV-B induced expression of ANAC13 is independent of the photoreceptors CRY1, CRY2, PHOT1 and PHOT2 and phytochromes A, B, D and E. ANAC13 expression is induced over a range of UV-B wavelengths at low doses, with maximum response at 310 nm. This study provides a basis for further investigation of UVR8 and stress independent, low fluence rate UV-B signaling pathway(s).
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Affiliation(s)
- Andrew O'Hara
- Örebro Life Science Center, School of Science and Technology, Örebro University, SE-70182 Örebro, Sweden and Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Lauren R Headland
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - L Aranzazú Díaz-Ramos
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Luis O Morales
- Örebro Life Science Center, School of Science and Technology, Örebro University, SE-70182 Örebro, Sweden
| | - Åke Strid
- Örebro Life Science Center, School of Science and Technology, Örebro University, SE-70182 Örebro, Sweden
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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19
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Liao X, Zhang B, Blatt MR, Jenkins GI. A FRET method for investigating dimer/monomer status and conformation of the UVR8 photoreceptor. Photochem Photobiol Sci 2019; 18:367-374. [PMID: 30534791 PMCID: PMC6374739 DOI: 10.1039/c8pp00489g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/03/2018] [Indexed: 11/21/2022]
Abstract
The photoreceptor UVR8 has a pivotal role in mediating plant responses to UV-B wavelengths. Dimeric UVR8 dissociates into monomers following UV-B photoreception, and there is evidence that this process is accompanied by conformational changes that may facilitate interaction of UVR8 with other proteins to initiate signaling. Hence monitoring UVR8 dimer/monomer status and conformation is key to understanding UVR8 action. Here we have used Fluorescence Resonance Energy Transfer (FRET) to study these processes in both wild-type and mutant UVR8 proteins in vivo. UVR8 was fused to GFP and mCherry at the C- and N-termini, respectively and both the FRET efficiency and loss of GFP fluorescence after photobleaching were measured. In addition, measurements were made for UVR8 fused to either GFP or mCherry to eliminate intra-molecular FRET signals. The results indicate that dissociation of UVR8 dimer to monomer principally accounts for the loss of FRET signal for wild-type UVR8 and there is little evidence of a contribution from conformational change in vivo. Examination of plants expressing UVR8W285F and UVR8D96N,D107N are consistent with these mutant proteins being constitutively dimeric and monomeric, respectively. The methods employed here will be valuable for monitoring UVR8 dimer/monomer status in vivo in relation to signaling, and will facilitate characterization of dimer/monomer status and conformation of further UVR8 mutants.
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Affiliation(s)
- Xinyang Liao
- Institute of Molecular
, Cell and Systems Biology
, College of Medical
, Veterinary and Life Sciences
, Bower Building
, University of Glasgow
,
Glasgow G12 8QQ
, UK
.
| | - Ben Zhang
- Institute of Molecular
, Cell and Systems Biology
, College of Medical
, Veterinary and Life Sciences
, Bower Building
, University of Glasgow
,
Glasgow G12 8QQ
, UK
.
| | - Michael R. Blatt
- Institute of Molecular
, Cell and Systems Biology
, College of Medical
, Veterinary and Life Sciences
, Bower Building
, University of Glasgow
,
Glasgow G12 8QQ
, UK
.
| | - Gareth I. Jenkins
- Institute of Molecular
, Cell and Systems Biology
, College of Medical
, Veterinary and Life Sciences
, Bower Building
, University of Glasgow
,
Glasgow G12 8QQ
, UK
.
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20
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Buglak AA, Telegina TA. A theoretical study of 5,6,7,8-tetrahydro-6-hydroxymethylpterin: insight into intrinsic photoreceptor properties of 6-substituted tetrahydropterins. Photochem Photobiol Sci 2019; 18:516-523. [PMID: 30543247 DOI: 10.1039/c8pp00322j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tetrahydropterins are essential biological cofactors, which play a crucial role in DNA and RNA syntheses, NO synthesis, hydroxylation of aromatic amino acids, etc. In the last few years, it has been shown that 6-substituted "unconjugated" tetrahydropterins can also play a photoreceptor chromophoric role in plants and cyanobacteria. However, the nature of the initial light signal transduction act in which H4pterins participate is unknown. Our quantum chemical calculations have shown the possibility of the fast internal conversion of excited states of H4pterins. The potential energy surface scan along the 1ππ* state shows no energy barrier leading to 1ππ*/S0 conical intersection, this explains the absence of fluorescence for H4pterins. Other trajectories of the internal conversion relate to the stretching vibrations of the N-H bonds of the pyrimidine ring for the Rydberg state. The presence of several trajectories of nonradiative quenching of the photoexcited singlet states provides the photostability of the molecule. It was demonstrated for the first time that the nature of the excited states of H4pterins is similar to the nature of the excited states of guanine.
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Affiliation(s)
- A A Buglak
- St Petersburg State University, St. Peterburg, Russia.
| | - T A Telegina
- Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
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21
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Tossi VE, Regalado JJ, Iannicelli J, Laino LE, Burrieza HP, Escandón AS, Pitta-Álvarez SI. Beyond Arabidopsis: Differential UV-B Response Mediated by UVR8 in Diverse Species. FRONTIERS IN PLANT SCIENCE 2019; 10:780. [PMID: 31275337 PMCID: PMC6591365 DOI: 10.3389/fpls.2019.00780] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 05/28/2019] [Indexed: 05/04/2023]
Abstract
Ultraviolet-B radiation (UV-B, 280-315 nm) is an important environmental signal that regulates growth and development in plants. Two dose-dependent UV-B response pathways were described in plants: a specific one, mediated by UVR8 (the specific UV-B receptor) and an unspecific one, activated by the oxidative damage produced by radiation. The constitutively expressed receptor appears inactive as a dimer, with the two monomers dissociating upon UV-B irradiation. The monomer then interacts with COP1, an ubiquitin ligase, hindering its ability to poly-ubiquitinate transcriptional factor HY5, thus averting its degradation and activating the photomorphogenic response. HY5 induces the synthesis of proteins RUP1 and RUP2, which interact with UVR8, releasing COP1, and inducing the re-dimerization of UVR8. This mechanism has been thoroughly characterized in Arabidopsis, where studies have demonstrated that the UVR8 receptor is key in UV-B response. Although Arabidopsis importance as a model plant many mechanisms described in this specie differ in other plants. In this paper, we review the latest information regarding UV-B response mediated by UVR8 in different species, focusing on the differences reported compared to Arabidopsis. For instance, UVR8 is not only induced by UV-B but also by other agents that are expressed differentially in diverse tissues. Also, in some of the species analyzed, proteins with low homology to RUP1 and RUP2 were detected. We also discuss how UVR8 is involved in other developmental and stress processes unrelated to UV-B. We conclude that the receptor is highly versatile, showing differences among species.
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Affiliation(s)
- Vanesa Eleonora Tossi
- Laboratorio de Cultivo Experimental de Plantas y Microalgas, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Micología y Botánica, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jose Javier Regalado
- Laboratorio de Cultivo Experimental de Plantas y Microalgas, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Micología y Botánica, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jesica Iannicelli
- Instituto de Genética “Ewald A. Favret,” Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina
- CONICET-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Buenos Aires, Argentina
| | - Leandro Ezequiel Laino
- Laboratorio de Cultivo Experimental de Plantas y Microalgas, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Hernan Pablo Burrieza
- Laboratorio de biología del desarrollo de las plantas, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandro Salvio Escandón
- Instituto de Genética “Ewald A. Favret,” Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina
| | - Sandra Irene Pitta-Álvarez
- Laboratorio de Cultivo Experimental de Plantas y Microalgas, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Micología y Botánica, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
- *Correspondence: Sandra Irene Pitta-Álvarez ;
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22
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Fraikin GY, Belenikina NS, Rubin AB. Damaging and Defense Processes Induced in Plant Cells by UVB Radiation. BIOL BULL+ 2018. [DOI: 10.1134/s1062359018060031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Fraikin GY. Signaling Mechanisms Regulating Diverse Plant Cell Responses to UVB Radiation. BIOCHEMISTRY (MOSCOW) 2018; 83:787-794. [PMID: 30200863 DOI: 10.1134/s0006297918070027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
UVB radiation (290-320 nm) causes diverse effects in plant cells that vary with the fluence rate of exposure. High fluence rates of UVB radiation cause damage to DNA and formation of reactive oxygen species in mitochondria and chloroplasts, which lead to oxidation of membrane proteins and lipids and inhibition of cellular functions. In response to oxidative stress, mitochondrial transmembrane potential dissipates, resulting in cytochrome c release and activation of metacaspases. This leads to the apoptosis-like cell death. The signaling mechanism based on UVB DNA damage includes checkpoint activation, cell-cycle arrest, and finally programmed cell death with characteristic DNA fragmentation and morphological hallmarks typical of apoptotic cells. Recently, it was shown that among the components of this signaling mechanism the transcriptional factor SOG1 (suppressor of gamma response 1) plays a key role in regulation of programmed cell death in plants. In contrast to its damaging effects, UVB radiation at low fluence rates can act as a regulatory signal that is specifically perceived by plants to promote acclimation and survival in sunlight. The protective action of UVB is based on expression of various genes, including those encoding flavonoid synthesis enzymes that provide a UVB-absorbing sunscreen in epidermal tissues and DNA photorepair enzymes. These processes are mediated by the UVB photoreceptor UVR8, which has been recently characterized at the molecular level. Now progress is made in uncovering the UVR8-mediated signaling pathway mechanism in the context of UVB photon perception and revealing the biochemical components of the early stages of light signal transduction. In this review, attention is focused on the achievements in studying these UVB-induced signaling processes.
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Affiliation(s)
- G Ya Fraikin
- Lomonosov Moscow State University, Moscow, 119991, Russia.
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25
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Yang Y, Yang X, Jang Z, Chen Z, Ruo X, Jin W, Wu Y, Shi X, Xu M. UV RESISTANCE LOCUS 8 From Chrysanthemum morifolium Ramat (CmUVR8) Plays Important Roles in UV-B Signal Transduction and UV-B-Induced Accumulation of Flavonoids. FRONTIERS IN PLANT SCIENCE 2018; 9:955. [PMID: 30022994 PMCID: PMC6040093 DOI: 10.3389/fpls.2018.00955] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/13/2018] [Indexed: 05/04/2023]
Abstract
UV Resistance Locus 8 (UVR8), an ultraviolet-B (UV-B; 280-315 nm) photoreceptor, participates in the regulation of various plant growth and developmental processes. UV-B radiation is an important factor enhancing the production of active components in medicinal plants. To-date, however, studies on UV-B photoreceptors have largely focused on Arabidopsis, and the functions of UVR8 in medicinal plants are still largely unknown. In the present study, a homolog of Arabidopsis UVR8, CmUVR8, was isolated from Chrysanthemum morifolium Ramat, and its structure and function were analyzed in detail. Protein sequence analysis showed that CmUVR8 contained nine conserved regulators of chromosome condensation 1 repeats, seven conserved bladed propellers, one C27 region, three "GWRHT" motifs and several crucial amino acid residues (such as 14 Trps and 2 Args), similar to AtUVR8. 3-D structural analysis of CmUVR8 indicated that its structure was similar to AtUVR8. Heterologous expression of CmUVR8 could rescued the deficient phenotype of uvr8-6, a mutant of UVR8 in Arabidopsis, indicating the role of CmUVR8 in the regulation of hypocotyl elongation and HY5 gene expression under UV-B irradiation. Moreover, CmUVR8 regulates UV-B-induced expression of four flavonoids biosynthesis-related genes and the UV-B-induced accumulation of flavonoids. Furthermore, the interaction between CmUVR8 and CmCOP1 were confirmed using a yeast two-hybrid assay. These results indicated that CmUVR8 plays important roles in UV-B signal transduction and the UV-B-induced accumulation of flavonoids, as a counterpart of AtUVR8.
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Affiliation(s)
- Yanjun Yang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xiuli Yang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Zhifang Jang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Zhehao Chen
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xiujun Ruo
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Weiyang Jin
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Ying Wu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xiaojing Shi
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Maojun Xu
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, Hangzhou Normal University, Hangzhou, China
- Key Laboratory of Hangzhou City for Quality and Safety of Agricultural Products, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
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26
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Díaz-Ramos LA, O'Hara A, Kanagarajan S, Farkas D, Strid Å, Jenkins GI. Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis. Photochem Photobiol Sci 2018; 17:1108-1117. [DOI: 10.1039/c8pp00138c] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The action spectrum for monomerisation of the plant UV-B photoreceptor UVR8 peaks at a shorter wavelength than that for HY5 transcript accumulation, mediated by UVR8, in the same tissue.
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Affiliation(s)
- L. Aranzazú Díaz-Ramos
- Institute of Molecular
- Cell and Systems Biology
- College of Medical
- Veterinary and Life Sciences
- Bower Building
| | - Andrew O'Hara
- Institute of Molecular
- Cell and Systems Biology
- College of Medical
- Veterinary and Life Sciences
- Bower Building
| | - Selvaraju Kanagarajan
- School of Science & Technology
- Örebro Life Science Center
- Örebro University
- SE-70182 Örebro
- Sweden
| | - Daniel Farkas
- School of Science & Technology
- Örebro Life Science Center
- Örebro University
- SE-70182 Örebro
- Sweden
| | - Åke Strid
- School of Science & Technology
- Örebro Life Science Center
- Örebro University
- SE-70182 Örebro
- Sweden
| | - Gareth I. Jenkins
- Institute of Molecular
- Cell and Systems Biology
- College of Medical
- Veterinary and Life Sciences
- Bower Building
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27
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Soriano G, Cloix C, Heilmann M, Núñez-Olivera E, Martínez-Abaigar J, Jenkins GI. Evolutionary conservation of structure and function of the UVR8 photoreceptor from the liverwort Marchantia polymorpha and the moss Physcomitrella patens. THE NEW PHYTOLOGIST 2018; 217:151-162. [PMID: 28892172 DOI: 10.1111/nph.14767] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 07/29/2017] [Indexed: 05/21/2023]
Abstract
The ultraviolet-B (UV-B) photoreceptor UV RESISTANCE LOCUS 8 (UVR8) mediates photomorphogenic responses to UV-B in Arabidopsis through differential gene expression, but little is known about UVR8 in other species. Bryophyte lineages were the earliest diverging embryophytes, thus being the first plants facing the UV-B regime typical of land. We therefore examined whether liverwort and moss species have functional UVR8 proteins and whether they are regulated similarly to Arabidopsis UVR8. We examined the expression, dimer/monomer status, cellular localisation and function of Marchantia polymorpha and Physcomitrella patens UVR8 in experiments with bryophyte tissue and expression of green fluorescent protein (GFP)-UVR8 fusions in Nicotiana leaves and transgenic Arabidopsis. P. patens expresses two UVR8 genes that encode functional proteins, whereas the single M. polymorpha UVR8 gene expresses two transcripts by alternative splicing that encode functional UVR8 variants. P. patens UVR8 proteins form dimers that monomerise and accumulate in the nucleus following UV-B exposure, similar to Arabidopsis UVR8, but M. polymorpha UVR8 has weaker dimers and the proteins appear more constitutively nuclear. We conclude that liverwort and moss species produce functional UVR8 proteins. Although there are differences in expression and regulation of P. patens and M. polymorpha UVR8, the mechanism of UVR8 action is strongly conserved in evolution.
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Affiliation(s)
- Gonzalo Soriano
- Facultad de Ciencia y Tecnología, Universidad de La Rioja, Madre de Dios 53, Logroño (La Rioja), 26006, Spain
| | - Catherine Cloix
- Institute of Molecular Cell & Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Monika Heilmann
- Institute of Molecular Cell & Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Encarnación Núñez-Olivera
- Facultad de Ciencia y Tecnología, Universidad de La Rioja, Madre de Dios 53, Logroño (La Rioja), 26006, Spain
| | - Javier Martínez-Abaigar
- Facultad de Ciencia y Tecnología, Universidad de La Rioja, Madre de Dios 53, Logroño (La Rioja), 26006, Spain
| | - Gareth I Jenkins
- Institute of Molecular Cell & Systems Biology, College of Medical Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
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28
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Jenkins GI. Photomorphogenic responses to ultraviolet-B light. PLANT, CELL & ENVIRONMENT 2017; 40:2544-2557. [PMID: 28183154 DOI: 10.1111/pce.12934] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/03/2017] [Accepted: 02/04/2017] [Indexed: 05/18/2023]
Abstract
Exposure to ultraviolet B (UV-B) light regulates numerous aspects of plant metabolism, morphology and physiology through the differential expression of hundreds of genes. Photomorphogenic responses to UV-B are mediated by the photoreceptor UV RESISTANCE LOCUS8 (UVR8). Considerable progress has been made in understanding UVR8 action: the structural basis of photoreceptor function, how interaction with CONSTITUTIVELY PHOTOMORPHOGENIC 1 initiates signaling and how REPRESSOR OF UV-B PHOTOMORPHOGENESIS proteins negatively regulate UVR8 action. In addition, recent research shows that UVR8 mediates several responses through interaction with other signaling pathways, in particular auxin signaling. Nevertheless, many aspects of UVR8 action remain poorly understood. Most research to date has been undertaken with Arabidopsis, and it is important to explore the functions and regulation of UVR8 in diverse plant species. Furthermore, it is essential to understand how UVR8, and UV-B signaling in general, regulates processes under natural growth conditions. Ultraviolet B regulates the expression of many genes through UVR8-independent pathways, but the activity and importance of these pathways in plants growing in sunlight are poorly understood.
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Affiliation(s)
- Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
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29
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Yin R, Ulm R. How plants cope with UV-B: from perception to response. CURRENT OPINION IN PLANT BIOLOGY 2017; 37:42-48. [PMID: 28411583 DOI: 10.1016/j.pbi.2017.03.013] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/24/2017] [Accepted: 03/28/2017] [Indexed: 05/19/2023]
Abstract
Ultraviolet-B radiation (UV-B) is an intrinsic part of the solar radiation that reaches the Earth's surface and affects the biosphere. Plants have evolved a specific UV-B signaling pathway mediated by the UVR8 photoreceptor that regulates growth, development, and acclimation. Major recent advances have contributed to our understanding of the UVR8 photocycle, UV-B-responsive protein-protein interactions, regulation of UVR8 subcellular localization, and UVR8-regulated physiological responses. Here, we review the latest progress in our understanding of UVR8 signaling and UV-B responses, which includes studies in the unicellular alga Chlamydomonas reinhardtii and the flowering plant Arabidopsis.
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Affiliation(s)
- Ruohe Yin
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland; Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland.
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30
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Hayes S, Sharma A, Fraser DP, Trevisan M, Cragg-Barber CK, Tavridou E, Fankhauser C, Jenkins GI, Franklin KA. UV-B Perceived by the UVR8 Photoreceptor Inhibits Plant Thermomorphogenesis. Curr Biol 2016; 27:120-127. [PMID: 27989670 PMCID: PMC5226890 DOI: 10.1016/j.cub.2016.11.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 10/07/2016] [Accepted: 11/01/2016] [Indexed: 11/26/2022]
Abstract
Small increases in ambient temperature can elicit striking effects on plant architecture, collectively termed thermomorphogenesis [1]. In Arabidopsis thaliana, these include marked stem elongation and leaf elevation, responses that have been predicted to enhance leaf cooling [2-5]. Thermomorphogenesis requires increased auxin biosynthesis, mediated by the bHLH transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) [6-8], and enhanced stability of the auxin co-receptor TIR1, involving HEAT SHOCK PROTEIN 90 (HSP90) [9]. High-temperature-mediated hypocotyl elongation additionally involves localized changes in auxin metabolism, mediated by the indole-3-acetic acid (IAA)-amido synthetase Gretchen Hagen 3 (GH3).17 [10]. Here we show that ultraviolet-B light (UV-B) perceived by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8) [11] strongly attenuates thermomorphogenesis via multiple mechanisms inhibiting PIF4 activity. Suppression of thermomorphogenesis involves UVR8 and CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1)-mediated repression of PIF4 transcript accumulation, reducing PIF4 abundance. UV-B also stabilizes the bHLH protein LONG HYPOCOTYL IN FAR RED (HFR1), which can bind to and inhibit PIF4 function. Collectively, our results demonstrate complex crosstalk between UV-B and high-temperature signaling. As plants grown in sunlight would most likely experience concomitant elevations in UV-B and ambient temperature, elucidating how these pathways are integrated is of key importance to the understanding of plant development in natural environments.
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Affiliation(s)
- Scott Hayes
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK; Plant Ecophysiology, Institute of Environmental Biology (IEB), Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Ashutosh Sharma
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Donald P Fraser
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Martine Trevisan
- Centre for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - C Kester Cragg-Barber
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Eleni Tavridou
- Department of Botany and Plant Biology, University of Geneva, Sciences III, 30 Quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Christian Fankhauser
- Centre for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Keara A Franklin
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK.
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31
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Qian C, Mao W, Liu Y, Ren H, Lau OS, Ouyang X, Huang X. Dual-Source Nuclear Monomers of UV-B Light Receptor Direct Photomorphogenesis in Arabidopsis. MOLECULAR PLANT 2016; 9:1671-1674. [PMID: 27756574 DOI: 10.1016/j.molp.2016.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/09/2016] [Accepted: 10/07/2016] [Indexed: 05/04/2023]
Affiliation(s)
- Chongzhen Qian
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Weiwei Mao
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yan Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hui Ren
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - On Sun Lau
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Xinhao Ouyang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xi Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian 361102, China.
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32
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Velanis CN, Herzyk P, Jenkins GI. Regulation of transcription by the Arabidopsis UVR8 photoreceptor involves a specific histone modification. PLANT MOLECULAR BIOLOGY 2016; 92:425-443. [PMID: 27534420 PMCID: PMC5080334 DOI: 10.1007/s11103-016-0522-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/02/2016] [Indexed: 05/21/2023]
Abstract
The photoreceptor UV RESISTANCE LOCUS 8 (UVR8) specifically mediates photomorphogenic responses to UV-B wavelengths. UVR8 acts by regulating transcription of a set of genes, but the underlying mechanisms are unknown. Previous research indicated that UVR8 can associate with chromatin, but the specificity and functional significance of this interaction are not clear. Here we show, by chromatin immunoprecipitation, that UV-B exposure of Arabidopsis increases acetylation of lysines K9 and/or K14 of histone H3 at UVR8-regulated gene loci in a UVR8-dependent manner. The transcription factors HY5 and/or HYH, which mediate UVR8-regulated transcription, are also required for this chromatin modification, at least for the ELIP1 gene. Furthermore, sequencing of the immunoprecipitated DNA revealed that all UV-B-induced enrichments in H3K9,14diacetylation across the genome are UVR8-dependent, and approximately 40 % of the enriched loci contain known UVR8-regulated genes. In addition, inhibition of histone acetylation by anacardic acid reduces the UV-B induced, UVR8 mediated expression of ELIP1 and CHS. No evidence was obtained in yeast 2-hybrid assays for a direct interaction between either UVR8 or HY5 and several proteins involved in light-regulated histone modification, nor for the involvement of these proteins in UVR8-mediated responses in plants, although functional redundancy between proteins could influence the results. In summary, this study shows that UVR8 regulates a specific chromatin modification associated with transcriptional regulation of a set of UVR8-target genes.
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Affiliation(s)
- Christos N Velanis
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Pawel Herzyk
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Switchback Road, Bearsden, G61 1QH, UK
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK.
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33
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Heilmann M, Velanis CN, Cloix C, Smith BO, Christie JM, Jenkins GI. Dimer/monomer status and in vivo function of salt-bridge mutants of the plant UV-B photoreceptor UVR8. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:71-81. [PMID: 27385642 PMCID: PMC5091643 DOI: 10.1111/tpj.13260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 06/24/2016] [Accepted: 06/30/2016] [Indexed: 05/05/2023]
Abstract
UV RESISTANCE LOCUS8 (UVR8) is a photoreceptor for ultraviolet-B (UV-B) light that initiates photomorphogenic responses in plants. UV-B photoreception causes rapid dissociation of dimeric UVR8 into monomers that interact with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) to initiate signal transduction. Experiments with purified UVR8 show that the dimer is maintained by salt-bridge interactions between specific charged amino acids across the dimer interface. However, little is known about the importance of these charged amino acids in determining dimer/monomer status and UVR8 function in plants. Here we evaluate the use of different methods to examine dimer/monomer status of UVR8 and show that mutations of several salt-bridge amino acids affect dimer/monomer status, interaction with COP1 and photoreceptor function of UVR8 in vivo. In particular, the salt-bridges formed between arginine 286 and aspartates 96 and 107 are key to dimer formation. Mutation of arginine 286 to alanine impairs dimer formation, interaction with COP1 and function in vivo, whereas mutation to lysine gives a weakened dimer that is functional in vivo, indicating the importance of the positive charge of the arginine/lysine residue for dimer formation. Notably, a UVR8 mutant in which aspartates 96 and 107 are conservatively mutated to asparagine is strongly impaired in dimer formation but mediates UV-B responses in vivo with a similar dose-response relationship to wild-type. The UV-B responsiveness of this mutant does not correlate with dimer formation and monomerisation, indicating that monomeric UVR8 has the potential for UV-B photoreception, initiating signal transduction and responses in plants.
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Affiliation(s)
- Monika Heilmann
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Christos N Velanis
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Catherine Cloix
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Brian O Smith
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - John M Christie
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK.
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Fraser DP, Hayes S, Franklin KA. Photoreceptor crosstalk in shade avoidance. CURRENT OPINION IN PLANT BIOLOGY 2016; 33:1-7. [PMID: 27060719 DOI: 10.1016/j.pbi.2016.03.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 05/05/2023]
Abstract
Plants integrate a variety of environmental signals to determine the threat of competitor shading and use this information to initiate escape responses, termed shade avoidance. Photoreceptor-mediated light signals are central to this process. Encroaching vegetation is sensed as a reduction in the ratio of red to far-red wavebands (R:FR) by phytochromes. Plants shaded within a canopy will also perceive reduced blue light signals and possibly enriched green light through cryptochromes. The detection of canopy gaps may be further facilitated by blue light sensing phototropins and the UV-B photoreceptor, UVR8. Once sunlight has been reached, phytochrome and UVR8 inhibit shade avoidance. Accumulating evidence suggests that multiple plant photoreceptors converge on a shared signalling network to regulate responses to shade.
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Affiliation(s)
- Donald P Fraser
- School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Scott Hayes
- Plant Ecophysiology, Institute of Environmental Biology (IEB), Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Keara A Franklin
- School of Biological Sciences, Life Sciences Building, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
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35
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Findlay KMW, Jenkins GI. Regulation of UVR8 photoreceptor dimer/monomer photo-equilibrium in Arabidopsis plants grown under photoperiodic conditions. PLANT, CELL & ENVIRONMENT 2016; 39:1706-14. [PMID: 26864532 PMCID: PMC5103188 DOI: 10.1111/pce.12724] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/30/2016] [Indexed: 05/09/2023]
Abstract
The UV RESISTANCE LOCUS 8 (UVR8) photoreceptor specifically mediates photomorphogenic responses to UV-B. Photoreception induces dissociation of dimeric UVR8 into monomers to initiate responses. However, the regulation of dimer/monomer status in plants growing under photoperiodic conditions has not been examined. Here we show that UVR8 establishes a dimer/monomer photo-equilibrium in plants growing in diurnal photoperiods in both controlled environments and natural daylight. The photo-equilibrium is determined by the relative rates of photoreception and dark-reversion to the dimer. Experiments with mutants in REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 show that these proteins are crucial in regulating the photo-equilibrium because they promote reversion to the dimer. In plants growing in daylight, the UVR8 photo-equilibrium is most strongly correlated with low ambient fluence rates of UV-B (up to 1.5 μmol m(-2) s(-1) ), rather than higher fluence rates or the amount of photosynthetically active radiation. In addition, the rate of reversion of monomer to dimer is reduced at lower temperatures, promoting an increase in the relative level of monomer at approximately 8-10 °C. Thus, UVR8 does not behave like a simple UV-B switch under photoperiodic growth conditions but establishes a dimer/monomer photo-equilibrium that is regulated by UV-B and also influenced by temperature.
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Affiliation(s)
- Kirsten M W Findlay
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
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36
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Zhao C, Mao K, You CX, Zhao XY, Wang SH, Li YY, Hao YJ. Molecular cloning and functional analysis of a UV-B photoreceptor gene, MdUVR8 (UV Resistance Locus 8), from apple. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 247:115-26. [PMID: 27095405 DOI: 10.1016/j.plantsci.2016.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/29/2016] [Accepted: 03/16/2016] [Indexed: 05/05/2023]
Abstract
UVR8 (UV Resistance Locus 8) is an ultraviolet-B (UV-B; 280-315nm) light receptor that is involved in regulating many aspects of plant growth and development. UV-B irradiation can increase the development of flower and fruit coloration in many fruit trees, such as grape, pear and apple. Previous investigations of the structure and functions of UVR8 in plants have largely focused on Arabidopsis. Here, we isolated the UVR8 gene from apple (Malus domestica) and analyzed its function in transgenic Arabidopsis. Genomic and protein sequence analysis showed that MdUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis, including the conserved seven-bladed β-propeller, the C27 region, the 3 "GWRHT" motifs and crucial amino-acid residues (14 Trps, 2 Args). A point mutation prediction and three-dimensional structural analysis of MdUVR8 indicated that it has a similar structure to AtUVR8 and that the crucial residues are also important in MdUVR8. In terms of transcript levels, MdUVR8 expression was up-regulated by UV-B light, which suggests that its expression follows a 24-h circadian rhythm. Using heterologous expression of MdUVR8 in both uvr8-1 mutant and wild-type (WT) Arabidopsis, we found that MdUVR8 regulates hypocotyl elongation and gene expression under UV-B light. These data provide functional evidence for a role of MdUVR8 in controlling photomorphogenesis under UV-B light and indicate that the function of UVR8 is conserved between Arabidopsis and apple. Furthermore, we examined the interaction between MdUVR8 and MdCOP1 (constitutive photomorphogenic1) using a yeast two-hybrid assay and a co-immunoprecipitation assay. This interaction provides a direction for investigating the regulatory mechanisms of the UV-B-light pathway in apple.
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Affiliation(s)
- Cheng Zhao
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China
| | - Ke Mao
- College of Biological Science and Technology, Beijing Forestry University, Beijing 100083, China
| | - Chun-Xiang You
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China
| | - Xian-Yan Zhao
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China
| | - Shu-Hui Wang
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China
| | - Yuan-Yuan Li
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China.
| | - Yu-Jin Hao
- State Key Laboratory of Crop Biology, Tai-An, Shandong 271018, China; National Research Center for Apple Engineering and Technology, Tai-An, Shandong 271018, China; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018, China.
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37
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Tilbrook K, Dubois M, Crocco CD, Yin R, Chappuis R, Allorent G, Schmid-Siegert E, Goldschmidt-Clermont M, Ulm R. UV-B Perception and Acclimation in Chlamydomonas reinhardtii. THE PLANT CELL 2016; 28:966-83. [PMID: 27020958 PMCID: PMC4863380 DOI: 10.1105/tpc.15.00287] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 03/25/2016] [Indexed: 05/03/2023]
Abstract
Plants perceive UV-B, an intrinsic component of sunlight, via a signaling pathway that is mediated by the photoreceptor UV RESISTANCE LOCUS8 (UVR8) and induces UV-B acclimation. To test whether similar UV-B perception mechanisms exist in the evolutionarily distant green alga Chlamydomonas reinhardtii, we identified Chlamydomonas orthologs of UVR8 and the key signaling factor CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). Cr-UVR8 shares sequence and structural similarity to Arabidopsis thaliana UVR8, has conserved tryptophan residues for UV-B photoreception, monomerizes upon UV-B exposure, and interacts with Cr-COP1 in a UV-B-dependent manner. Moreover, Cr-UVR8 can interact with At-COP1 and complement the Arabidopsis uvr8 mutant, demonstrating that it is a functional UV-B photoreceptor. Chlamydomonas shows apparent UV-B acclimation in colony survival and photosynthetic efficiency assays. UV-B exposure, at low levels that induce acclimation, led to broad changes in the Chlamydomonas transcriptome, including in genes related to photosynthesis. Impaired UV-B-induced activation in the Cr-COP1 mutant hit1 indicates that UVR8-COP1 signaling induces transcriptome changes in response to UV-B. Also, hit1 mutants are impaired in UV-B acclimation. Chlamydomonas UV-B acclimation preserved the photosystem II core proteins D1 and D2 under UV-B stress, which mitigated UV-B-induced photoinhibition. These findings highlight the early evolution of UVR8 photoreceptor signaling in the green lineage to induce UV-B acclimation and protection.
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Affiliation(s)
- Kimberley Tilbrook
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Marine Dubois
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Carlos D Crocco
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Ruohe Yin
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Richard Chappuis
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Guillaume Allorent
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Emanuel Schmid-Siegert
- SIB-Swiss Institute of Bioinformatics, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Michel Goldschmidt-Clermont
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Roman Ulm
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, CH-1211 Geneva 4, Switzerland
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38
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Miyamori T, Nakasone Y, Hitomi K, Christie JM, Getzoff ED, Terazima M. Reaction dynamics of the UV-B photosensor UVR8. Photochem Photobiol Sci 2016; 14:995-1004. [PMID: 25811405 DOI: 10.1039/c5pp00012b] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UVR8 is a recently discovered ultraviolet-B (UV-B) photoreceptor protein identified in plants and algae. In the dark state, UVR8 exists as a homodimer, whereas UV-B irradiation induces UVR8 monomerization and initiation of signaling. Although the biological functions of UVR8 have been studied, the fundamental reaction mechanism and associated kinetics have not yet been fully elucidated. Here, we used the transient grating method to determine the reaction dynamics of UVR8 monomerization based on its diffusion coefficient. We found that the UVR8 photodissociation reaction proceeds in three stages: (i) photoexcitation of cross-dimer tryptophan (Trp) pyramids; (ii) an initial conformational change with a time constant of 50 ms; and (iii) dimer dissociation with a time constant of 200 ms. We identified W285 as the key Trp residue responsible for initiating this photoreaction. Although the C-terminus of UVR8 is essential for biological interactions and signaling via downstream components such as COP1, no obvious differences were detected between the photoreactions of wild-type UVR8 (amino acids 1-440) and a mutant lacking the C-terminus (amino acids 1-383). This similarity indicates that the conformational change associated with stage ii cannot primarily be attributed to this region. A UV-B-driven conformational change with a time constant of 50 ms was also detected in the monomeric mutants of UVR8. Dimer recovery following monomerization, as measured by circular dichroism spectroscopy, was decreased under oxygen-purged conditions, suggesting that redox reactivity is a key factor contributing to the UVR8 oligomeric state.
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Affiliation(s)
- Takaaki Miyamori
- Department of Chemistry, Graduate School of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.
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39
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Fernández MB, Tossi V, Lamattina L, Cassia R. A Comprehensive Phylogeny Reveals Functional Conservation of the UV-B Photoreceptor UVR8 from Green Algae to Higher Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:1698. [PMID: 27895654 PMCID: PMC5108777 DOI: 10.3389/fpls.2016.01698] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/27/2016] [Indexed: 05/03/2023]
Abstract
Ultraviolet-B (UV-B) is present in sunlight (280-315 nm) and has diverse effects on living organisms. Low fluence rate of exposure induces a specific photomorphogenic response regulated by the UV-B response locus 8 (UVR8) receptor. UVR8 was first described in Arabidopsis thaliana. In the absence of stimuli it is located in the cytoplasm as a homodimer. However, upon UV-B irradiation, it switches to a monomer and interacts with the ubiquitin ligase E3 COP1 via the UVR8 β-propeller domain and the VP core. This induces the expression of the transcription factor HY5 leading to changes in the expression of genes associated with UV-B acclimation and stress tolerance. UVR8 senses UV-B through tryptophan residues being Trp233 and 285 the most important. Based on the comparison and analysis of UVR8 functionally important motifs, we report a comprehensive phylogeny of UVR8, trying to identify UVR8 homologs and the ancestral organism where this gene could be originated. Results obtained showed that Chlorophytes are the first organisms from the Viridiplantae group where UVR8 appears. UVR8 is present in green algae, bryophytes, lycophytes, and angiosperms. All the sequences identified contain tryptophans 233 and 285, arginines involved in homodimerization and the VP domain suggesting they are true UVR8 photoreceptors. We also determined that some species from bryophytes and angiosperms contain more than one UVR8 gene copy posing the question if UVR8 could constitute a gene family in these species. In conclusion, we described the functional conservation among UVR8 proteins from green algae to higher plants.
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40
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Changing scenario in plant UV-B research:UV-B from a generic stressor to a specific regulator. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 153:334-43. [DOI: 10.1016/j.jphotobiol.2015.10.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 10/08/2015] [Accepted: 10/11/2015] [Indexed: 11/15/2022]
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41
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Yang X, Montano S, Ren Z. How Does Photoreceptor UVR8 Perceive a UV-B Signal? Photochem Photobiol 2015; 91:993-1003. [PMID: 25996910 PMCID: PMC4560659 DOI: 10.1111/php.12470] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/06/2015] [Indexed: 11/30/2022]
Abstract
UVR8 is the only known plant photoreceptor that mediates light responses to UV-B (280-315 nm) of the solar spectrum. UVR8 perceives a UV-B signal via light-induced dimer dissociation, which triggers a wide range of cellular responses involved in photomorphogenesis and photoprotection. Two recent crystal structures of Arabidopsis thaliana UVR8 (AtUVR8) have revealed unusual clustering of UV-B-absorbing Trp pigments at the dimer interface and provided a structural framework for further mechanistic investigation. This review summarizes recent advances in spectroscopic, computational and crystallographic studies on UVR8 that are directed toward full understanding of UV-B perception at the molecular level.
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Affiliation(s)
- Xiaojing Yang
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Vision Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Sherwin Montano
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Zhong Ren
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
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42
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Mao K, Wang L, Li YY, Wu R. Molecular Cloning and Functional Analysis of UV RESISTANCE LOCUS 8 (PeUVR8) from Populus euphratica. PLoS One 2015; 10:e0132390. [PMID: 26171608 PMCID: PMC4501546 DOI: 10.1371/journal.pone.0132390] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 06/12/2015] [Indexed: 12/03/2022] Open
Abstract
Ultraviolet-B (UV-B; 280–315 nm) light, which is an integral part of the solar radiation reaching the surface of the Earth, induces a broad range of physiological responses in plants. The UV RESISTANCE LOCUS 8 (UVR8) protein is the first and only light photoreceptor characterized to date that is specific for UV-B light and it regulates various aspects of plant growth and development in response to UV-B light. Despite its involvement in the control of important plant traits, most studies on UV-B photoreceptors have focused on Arabidopsis and no data on UVR8 function are available for forest trees. In this study, we isolated a homologue of the UV receptor UVR8 of Arabidopsis, PeUVR8, from Populus euphratica (Euphrates poplar) and analyzed its structure and function in detail. The deduced PeUVR8 amino acid sequence contained nine well-conserved regulator of chromosome condensation 1 (RCC1) repeats and the region 27 amino acids from the C terminus (C27) that interact with COP1 (CONSTITUTIVELY PHOTOMORPHOGENIC1). Secondary and tertiary structure analysis showed that PeUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis thaliana. Using heterologous expression in Arabidopsis, we showed that PeUVR8 overexpression rescued the uvr8 mutant phenotype. In addition, PeUVR8 overexpression in wild-type background seedlings grown under UV-B light inhibited hypocotyl elongation and enhanced anthocyanin accumulation. Furthermore, we examined the interaction between PeUVR8 and AtCOP1 using a bimolecular fluorescence complementation (BiFC) assay. Our data provide evidence that PeUVR8 plays important roles in the control of photomorphogenesis in planta.
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Affiliation(s)
- Ke Mao
- Center for Computational Biology, College of Biological Science and Technologies, Beijing Forestry University, Beijing, 100083, China
| | - Lina Wang
- Center for Computational Biology, College of Biological Science and Technologies, Beijing Forestry University, Beijing, 100083, China
| | - Yuan-Yuan Li
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong, 271018, China
| | - Rongling Wu
- Center for Computational Biology, College of Biological Science and Technologies, Beijing Forestry University, Beijing, 100083, China
- Center for Statistical Genetics, The Pennsylvania State University, Hershey, Pennsylvania, 17033, United States of America
- * E-mail:
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Abstract
Plants are able to sense UV-B through the UV-B photoreceptor UVR8. UV-B photon absorption by a UVR8 homodimer leads to UVR8 monomerization and interaction with the downstream signaling factor COP1. This then initiates changes in gene expression, which lead to several metabolic and morphological alterations. A major response is the activation of mechanisms associated with UV-B acclimation and UV-B tolerance, including biosynthesis of sunscreen metabolites, antioxidants and DNA repair enzymes. To balance the response, UVR8 is inactivated by regulated re-dimerization. Apart from their importance for plants, UVR8 and its interacting protein COP1 have already proved useful for the optogenetic toolkit used to engineer synthetic light-dependent responses.
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Affiliation(s)
- Roman Ulm
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211, Geneva, 4, Switzerland.
| | - Gareth I Jenkins
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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44
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Zeng X, Ren Z, Wu Q, Fan J, Peng PP, Tang K, Zhang R, Zhao KH, Yang X. Dynamic Crystallography Reveals Early Signalling Events in Ultraviolet Photoreceptor UVR8. NATURE PLANTS 2015; 1:14006. [PMID: 26097745 PMCID: PMC4469132 DOI: 10.1038/nplants.2014.6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/23/2014] [Indexed: 05/19/2023]
Abstract
Arabidopsis thaliana UVR8 (AtUVR8) is a long-sought-after photoreceptor that undergoes dimer dissociation in response to UV-B light. Crystallographic and mutational studies have identified two crucial tryptophan residues for UV-B responses in AtUVR8. However, the mechanism of UV-B perception and structural events leading up to dimer dissociation remain elusive at the molecular level. We applied dynamic crystallography to capture light-induced structural events in photoactive AtUVR8 crystals. Here we report two intermediate structures at 1.67Å resolution. At the epicenter of UV-B signaling, concerted motions associated with Trp285/Trp233 lead to ejection of a water molecule, which weakens an intricate network of hydrogen bonds and salt bridges at the dimer interface. Partial opening of the β-propeller structure due to thermal relaxation of conformational strains originating in the epicenter further disrupts the dimer interface and leads to dimer dissociation. These dynamic crystallographic observations provide structural insights into the photo-perception and signaling mechanism of UVR8.
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Affiliation(s)
- Xiaoli Zeng
- Key State Laboratory of Agricultural Microbiology, Huazhong
Agricultural University, Wuhan, Hubei 430070, P.R. China
| | - Zhong Ren
- Renz Research Inc., Westmont, IL 60559, USA
| | - Qi Wu
- Department of Physics and Materials Science, City University of Hong
Kong, Kowloon, Hong Kong
| | - Jun Fan
- Department of Physics and Materials Science, City University of Hong
Kong, Kowloon, Hong Kong
| | - Pan-Pan Peng
- Key State Laboratory of Agricultural Microbiology, Huazhong
Agricultural University, Wuhan, Hubei 430070, P.R. China
| | - Kun Tang
- Key State Laboratory of Agricultural Microbiology, Huazhong
Agricultural University, Wuhan, Hubei 430070, P.R. China
| | - Ruiqin Zhang
- Department of Physics and Materials Science, City University of Hong
Kong, Kowloon, Hong Kong
| | - Kai-Hong Zhao
- Key State Laboratory of Agricultural Microbiology, Huazhong
Agricultural University, Wuhan, Hubei 430070, P.R. China
| | - Xiaojing Yang
- Department of Biochemistry and Molecular Biology, The University of
Chicago, Chicago, IL 60637, USA
- Department of Chemistry, The University of Illinois at Chicago,
Chicago, IL 60607, USA
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45
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Wu Q, Huang B, Niehaus TA, Yang X, Fan J, Zhang RQ. The role of tryptophans in the UV-B absorption of a UVR8 photoreceptor – a computational study. Phys Chem Chem Phys 2015; 17:10786-94. [DOI: 10.1039/c4cp06073c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Absorption spectra of different amino acid models of UVR8.
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Affiliation(s)
- Qi Wu
- Department of Physics and Materials Science
- City University of Hong Kong
- Hong Kong SAR
- China
| | - Bolong Huang
- Department of Physics and Materials Science
- City University of Hong Kong
- Hong Kong SAR
- China
| | - T. A. Niehaus
- Institute I – Theoretical Physics
- University of Regensburg
- D-93040 Regensburg
- Germany
| | - Xiaojing Yang
- Department of Chemistry
- University of Illinois at Chicago
- Chicago
- USA
| | - Jun Fan
- Department of Physics and Materials Science
- City University of Hong Kong
- Hong Kong SAR
- China
| | - Rui-Qin Zhang
- Department of Physics and Materials Science
- City University of Hong Kong
- Hong Kong SAR
- China
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46
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Yin R, Arongaus AB, Binkert M, Ulm R. Two distinct domains of the UVR8 photoreceptor interact with COP1 to initiate UV-B signaling in Arabidopsis. THE PLANT CELL 2015; 27:202-13. [PMID: 25627067 PMCID: PMC4330580 DOI: 10.1105/tpc.114.133868] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/23/2014] [Accepted: 01/09/2015] [Indexed: 05/17/2023]
Abstract
UV-B photon reception by the Arabidopsis thaliana homodimeric UV RESISTANCE LOCUS8 (UVR8) photoreceptor leads to its monomerization and a crucial interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). Relay of the subsequent signal regulates UV-B-induced photomorphogenesis and stress acclimation. Here, we report that two separate domains of UVR8 interact with COP1: the β-propeller domain of UVR8 mediates UV-B-dependent interaction with the WD40 repeats-based predicted β-propeller domain of COP1, whereas COP1 activity is regulated by interaction through the UVR8 C-terminal C27 domain. We show not only that the C27 domain is required for UVR8 activity but also that chemically induced expression of the C27 domain is sufficient to mimic UV-B signaling. We further show, in contrast with COP1, that the WD40 repeat proteins REPRESSOR OF UV-B PHOTOMORPHOGENESIS1 (RUP1) and RUP2 interact only with the UVR8 C27 domain. This coincides with their facilitation of UVR8 reversion to the ground state by redimerization and their potential to interact with UVR8 in a UV-B-independent manner. Collectively, our results provide insight into a key mechanism of photoreceptor-mediated signaling and its negative feedback regulation.
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Affiliation(s)
- Ruohe Yin
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Adriana B Arongaus
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Melanie Binkert
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
| | - Roman Ulm
- Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland
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47
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Structure and function of the UV-B photoreceptor UVR8. Curr Opin Struct Biol 2014; 29:52-7. [DOI: 10.1016/j.sbi.2014.09.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/01/2014] [Accepted: 09/11/2014] [Indexed: 11/18/2022]
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48
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Li X, Chung LW, Morokuma K, Li G. Theoretical Study on the UVR8 Photoreceptor: Sensing Ultraviolet-B by Tryptophan and Dissociation of Homodimer. J Chem Theory Comput 2014; 10:3319-30. [DOI: 10.1021/ct5003362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Xin Li
- State
Key Lab of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Lung Wa Chung
- Fukui
Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
- Department
of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China
| | - Keiji Morokuma
- Fukui
Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Guohui Li
- State
Key Lab of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian 116023, China
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Biever JJ, Brinkman D, Gardner G. UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2949-61. [PMID: 24591052 PMCID: PMC4056539 DOI: 10.1093/jxb/eru035] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280-320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction.
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Affiliation(s)
- Jessica J Biever
- Department of Horticultural Science, University of Minnesota, St Paul, MN 55108, USA
| | - Doug Brinkman
- Department of Horticultural Science, University of Minnesota, St Paul, MN 55108, USA
| | - Gary Gardner
- Department of Horticultural Science, University of Minnesota, St Paul, MN 55108, USA
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50
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Fasano R, Gonzalez N, Tosco A, Dal Piaz F, Docimo T, Serrano R, Grillo S, Leone A, Inzé D. Role of Arabidopsis UV RESISTANCE LOCUS 8 in plant growth reduction under osmotic stress and low levels of UV-B. MOLECULAR PLANT 2014; 7:773-91. [PMID: 24413416 DOI: 10.1093/mp/ssu002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UV RESISTANCE LOCUS 8 (UVR8) gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals.
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Affiliation(s)
- Rossella Fasano
- Department of Pharmacy, University of Salerno, Fisciano, Italy
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