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Cunningham N, Crestani G, Csepregi K, Coughlan NE, Jansen MAK. Exploring the complexities of plant UV responses; distinct effects of UV-A and UV-B wavelengths on Arabidopsis rosette morphology. Photochem Photobiol Sci 2024:10.1007/s43630-024-00591-w. [PMID: 38736023 DOI: 10.1007/s43630-024-00591-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024]
Abstract
UV-B radiation can substantially impact plant growth. To study UV-B effects, broadband UV-B tubes are commonly used. Apart from UV-B, such tubes also emit UV-A wavelengths. This study aimed to distinguish effects of different UV-B intensities on Arabidopsis thaliana wildtype and UVR8 mutant rosette morphology, from those by accompanying UV-A. UV-A promotes leaf-blade expansion along the proximal-distal, but not the medio-lateral, axis. Consequent increases in blade length: width ratio are associated with increased light capture. However, petiole length is not affected by UV-A exposure. This scenario is distinct from the shade avoidance driven by low red to far-red ratios, whereby leaf blade elongation is impeded but petiole elongation is promoted. Thus, the UV-A mediated elongation response is phenotypically distinct from classical shade avoidance. UV-B exerts inhibitory effects on petiole length, blade length and leaf area, and these effects are mediated by UVR8. Thus, UV-B antagonises aspects of both UV-A mediated elongation and classical shade avoidance. Indeed, this study shows that accompanying UV-A wavelengths can mask effects of UV-B. This may lead to potential underestimates of the magnitude of the UV-B induced morphological response using broadband UV-B tubes.
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Affiliation(s)
- Natalie Cunningham
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, University College Cork, North Mall, Cork, Ireland
| | - Gaia Crestani
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, University College Cork, North Mall, Cork, Ireland
| | - Kristóf Csepregi
- Department of Plant Biology, Institute of Biology, University of Pécs, Ifjúság u. 6, 7624, Pecs, Hungary
| | - Neil E Coughlan
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, University College Cork, North Mall, Cork, Ireland
| | - Marcel A K Jansen
- School of Biological, Earth and Environmental Sciences, Environmental Research Institute, University College Cork, North Mall, Cork, Ireland.
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2
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Fitzner M, Schreiner M, Baldermann S. Between eustress and distress: UVB induced changes in carotenoid accumulation in halophytic Salicornia europaea. JOURNAL OF PLANT PHYSIOLOGY 2023; 291:154124. [PMID: 37944241 DOI: 10.1016/j.jplph.2023.154124] [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: 07/05/2023] [Revised: 10/13/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023]
Abstract
Halophytes are potential future crops with a valuable nutritional profile. Produced in indoor farming, they are considered to contribute to sustainable and resilient food systems. Indoor farms operate using artificial light. In this context narrowband and low dose UVB radiation can be used to increase plant secondary metabolites, such as carotenoids, and provide an improved nutritional profile for a human diet. UVB radiation can cause eustress or distress in the plant depending on the lighting situation. The aim of this study was to identify the doses of UVB that lead to either eustress or distress and to analyze these responses in Salicornia europaea. Therefore, S. europaea plants were exposed to different UVB radiation levels, low, medium and high, and analyzed for reactive oxygen species (ROS), plant hormones, amino acids, and photosynthetic pigments. High UVB treatment was found to affect phenotype and growth, and the metabolite profile was affected in a UVB dose-dependent manner. Specifically, medium UVB radiation resulted in an increase in carotenoids, whereas high UVB resulted in a decrease. We also observed an altered oxidative stress status and increased SA and decreased ABA contents in response to UVB treatment. This was supported by the results of menadione treatment that induces oxidative stress in plants, which also indicated an altered oxidative stress status in combination with altered carotenoid content. Thus, we show that a moderate dose of UVB can increase the carotenoid content of S. europaea. Furthermore, the UVB stress-dependent response led to a better understanding of carotenoid accumulation upon UVB exposure, which can be used to improve lighting systems and in turn the nutritional profile of future crops in indoor farming.
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Affiliation(s)
- Maria Fitzner
- Department Plant Quality and Food Security, Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany; Institute of Nutritional Science, Food Chemistry, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558, Nuthetal, Germany; Food4Future (F4F), C/o Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Department Plant Quality and Food Security, Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany.
| | - Monika Schreiner
- Department Plant Quality and Food Security, Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany; Food4Future (F4F), C/o Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Department Plant Quality and Food Security, Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany
| | - Susanne Baldermann
- Department Plant Quality and Food Security, Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany; Faculty of Life Science: Food, Nutrition and Health, Food Metabolome, University of Bayreuth, Fritz-Hornschuch-Straße 13, 95326, Kulmbach, Germany; Food4Future (F4F), C/o Leibniz Institute of Vegetable and Ornamental Crops (IGZ), Department Plant Quality and Food Security, Theodor-Echtermeyer-Weg 1, 14979, Großbeeren, Germany
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Gururani MA. Photobiotechnology for abiotic stress resilient crops: Recent advances and prospects. Heliyon 2023; 9:e20158. [PMID: 37810087 PMCID: PMC10559926 DOI: 10.1016/j.heliyon.2023.e20158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 09/05/2023] [Accepted: 09/13/2023] [Indexed: 10/10/2023] Open
Abstract
Massive crop failures worldwide are caused by abiotic stress. In plants, adverse environmental conditions cause extensive damage to the overall physiology and agronomic yield at various levels. Phytochromes are photosensory phosphoproteins that absorb red (R)/far red (FR) light and play critical roles in different physiological and biochemical responses to light. Considering the role of phytochrome in essential plant developmental processes, genetically manipulating its expression offers a promising approach to crop improvement. Through modulated phytochrome-mediated signalling pathways, plants can become more resistant to environmental stresses by increasing photosynthetic efficiency, antioxidant activity, and expression of genes associated with stress resistance. Plant growth and development in adverse environments can be improved by understanding the roles of phytochromes in stress tolerance characteristics. A comprehensive overview of recent findings regarding the role of phytochromes in modulating abiotic stress by discussing biochemical and molecular aspects of these mechanisms of photoreceptors is offered in this review.
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Affiliation(s)
- Mayank Anand Gururani
- Biology Department, College of Science, UAE University, Al Ain, United Arab Emirates
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BBX24 Interacts with DELLA to Regulate UV-B-Induced Photomorphogenesis in Arabidopsis thaliana. Int J Mol Sci 2022; 23:ijms23137386. [PMID: 35806395 PMCID: PMC9266986 DOI: 10.3390/ijms23137386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 02/01/2023] Open
Abstract
UV-B radiation, sensed by the photoreceptor UVR8, induces signal transduction for plant photomorphogenesis. UV-B radiation affects the concentration of the endogenous plant hormone gibberellin (GA), which in turn triggers DELLA protein degradation through the 26S proteasome pathway. DELLA is a negative regulator in GA signaling, partially relieving the inhibition of hypocotyl growth induced by UV-B in Arabidopsis thaliana. However, GAs do usually not work independently but integrate in complex networks linking to other plant hormones and responses to external environmental signals. Until now, our understanding of the regulatory network underlying GA-involved UV-B photomorphogenesis had remained elusive. In the present research, we investigate the crosstalk between the GA and UV-B signaling pathways in UV-B-induced photomorphogenesis of Arabidopsis thaliana. Compared with wild type Landsberg erecta (Ler), the abundance of HY5, CHS, FLS, and UF3GT were found to be down-regulated in rga-24 and gai-t6 mutants under UV-B radiation, indicating that DELLA is a positive regulator in UV-B-induced photomorphogenesis. Our results indicate that BBX24 interacts with RGA (one of the functional DELLA family members). Furthermore, we also found that RGA interacts with HY5 (the master regulator in plant photomorphogenesis). Collectively, our findings suggest that the HY5−BBX24−DELLA module serves as an important signal regulating network, in which GA is involved in UV-B signaling to regulate hypocotyl inhibition.
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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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Mironov VL. Unknown effects of daily-scale solar activity on the plant growth: Data from 6-year growth monitoring of Sphagnum riparium. PHYSIOLOGIA PLANTARUM 2022; 174:e13733. [PMID: 35699602 DOI: 10.1111/ppl.13733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/02/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The influence of solar activity on plant growth has been studied for over 100 years, however, this phenomenon is still poorly understood on a daily scale. The data from extensive monitoring of the growth of peat moss Sphagnum riparium, which we are conducting in the mires of Karelia (Russia), may shed light on this issue. During the 6 years of observation, 161,190 shoots were measured, and 1075 growth rates were obtained. Considering together the growth rates with the sunspot number and involving data on seasonal temperature, we found previously unknown effects of daily-scale solar activity on plant growth. It was found that the sunspot number weakly but significantly inhibits the growth of Sphagnum. The extreme sunspot number in the 4 days before the growth rate values have a stronger influence. The involvement of temperature data showed that inhibition in growth is observed only in the temperature range from 6.7°C to 15.3°C and disappears beyond these limits. In addition, the data obtained showed that the influence of sunspot number on the growth of Sphagnum is progressively increasing along the gradient from the minimum to the maximum of the 11-year solar cycle. The study provides one of the first results on the effect of solar activity on plant growth on a daily scale. The results expand our knowledge of the biological effects of solar activity. Indirectly, they can also be useful to better our understanding of the ozone layer's involvement in this process.
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Affiliation(s)
- Victor L Mironov
- Institute of Biology of the Karelian Research Centre of the Russian Academy of Sciences, Petrozavodsk, Russia
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Tsurumoto T, Fujikawa Y, Onoda Y, Ochi Y, Ohta D, Okazawa A. Transcriptome and metabolome analyses revealed that narrowband 280 and 310 nm UV-B induce distinctive responses in Arabidopsis. Sci Rep 2022; 12:4319. [PMID: 35279697 PMCID: PMC8918342 DOI: 10.1038/s41598-022-08331-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 02/28/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractIn plants, the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8) perceives UV-B and induces UV-B responses. UVR8 absorbs a range of UV-B (260–335 nm). However, the responsiveness of plants to each UV-B wavelength has not been intensively studied so far. Here, we performed transcriptome and metabolome analyses of Arabidopsis using UV light emitting diodes (LEDs) with peak wavelengths of 280 and 310 nm to investigate the differences in the wavelength-specific UV-B responses. Irradiation with both UV-LEDs induced gene expression of the transcription factor ELONGATED HYPOCOTYL 5 (HY5), which has a central role in the UVR8 signaling pathway. However, the overall transcriptomic and metabolic responses to 280 and 310 nm UV-LED irradiation were different. Most of the known UV-B-responsive genes, such as defense-related genes, responded only to 280 nm UV-LED irradiation. Lipids, polyamines and organic acids were the metabolites most affected by 280 nm UV-LED irradiation, whereas the effect of 310 nm UV-LED irradiation on the metabolome was considerably less. Enzymatic genes involved in the phenylpropanoid pathway upstream in anthocyanin biosynthesis were up-regulated only by 280 nm UV-LED irradiation. These results revealed that the responsivenesses of Arabidopsis to 280 and 310 nm UV-B were significantly different, suggesting that UV-B signaling is mediated by more complex pathways than the current model.
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8
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Rácz A, Hideg É. Narrow-Band 311 nm Ultraviolet-B Radiation Evokes Different Antioxidant Responses from Broad-Band Ultraviolet. PLANTS 2021; 10:plants10081570. [PMID: 34451615 PMCID: PMC8400681 DOI: 10.3390/plants10081570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/03/2022]
Abstract
Supplemental narrow-band 311 nm UV-B radiation was applied in order to study the effect of this specific wavelength on tobacco as a model plant. UV-B at photon fluxes varying between 2.9 and 9.9 μmol m−2 s−1 was applied to supplement 150 μmol m−2 s−1 photosynthetically active radiation (PAR) for four hours in the middle of the light period for four days. Narrow-band UV-B increased leaf flavonoid and phenolic acid contents. In leaves exposed to 311 nm radiation, superoxide dismutase activity increased, but phenolic peroxidase activity decreased, and the changes were proportional to the UV flux. Ascorbate peroxidase activities were not significantly affected. Narrow-band UV-B caused a dose-dependent linear decrease in the quantum efficiency of photosystem II, up to approximately 10% loss. A parallel decrease in non-regulated non-photochemical quenching indicates potential electron transfer to oxygen in UV-treated leaves. In addition to a flux-dependent increase in the imbalance between enzymatic H2O2 production and neutralization, this resulted in an approximately 50% increase in leaf H2O2 content under 2.9–6 μmol m−2 s−1 UV-B. Leaf H2O2 decreased to control levels under higher UV-B fluxes due to the onset of increased non-enzymatic H2O2- and superoxide-neutralizing capacities, which were not observed under lower fluxes. These antioxidant responses to 311 nm UV-B were different from our previous findings in plants exposed to broad-band UV-B. The results suggest that signaling pathways activated by 311 nm radiation are distinct from those stimulated by other wavelengths and support the heterogeneous regulation of plant UV responses.
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Rai N, Morales LO, Aphalo PJ. Perception of solar UV radiation by plants: photoreceptors and mechanisms. PLANT PHYSIOLOGY 2021; 186:1382-1396. [PMID: 33826733 PMCID: PMC8260113 DOI: 10.1093/plphys/kiab162] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 03/25/2021] [Indexed: 05/04/2023]
Abstract
About 95% of the ultraviolet (UV) photons reaching the Earth's surface are UV-A (315-400 nm) photons. Plant responses to UV-A radiation have been less frequently studied than those to UV-B (280-315 nm) radiation. Most previous studies on UV-A radiation have used an unrealistic balance between UV-A, UV-B, and photosynthetically active radiation (PAR). Consequently, results from these studies are difficult to interpret from an ecological perspective, leaving an important gap in our understanding of the perception of solar UV radiation by plants. Previously, it was assumed UV-A/blue photoreceptors, cryptochromes and phototropins mediated photomorphogenic responses to UV-A radiation and "UV-B photoreceptor" UV RESISTANCE LOCUS 8 (UVR8) to UV-B radiation. However, our understanding of how UV-A radiation is perceived by plants has recently improved. Experiments using a realistic balance between UV-B, UV-A, and PAR have demonstrated that UVR8 can play a major role in the perception of both UV-B and short-wavelength UV-A (UV-Asw, 315 to ∼350 nm) radiation. These experiments also showed that UVR8 and cryptochromes jointly regulate gene expression through interactions that alter the relative sensitivity to UV-B, UV-A, and blue wavelengths. Negative feedback loops on the action of these photoreceptors can arise from gene expression, signaling crosstalk, and absorption of UV photons by phenolic metabolites. These interactions explain why exposure to blue light modulates photomorphogenic responses to UV-B and UV-Asw radiation. Future studies will need to distinguish between short and long wavelengths of UV-A radiation and to consider UVR8's role as a UV-B/UV-Asw photoreceptor in sunlight.
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Affiliation(s)
- Neha Rai
- Organismal and Evolutionary Biology, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Author for communication: . Present address: Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Luis Orlando Morales
- School of Science and Technology, The Life Science Center-Biology, Örebro University, SE-70182 Örebro, Sweden
| | - Pedro José Aphalo
- Organismal and Evolutionary Biology, Viikki Plant Science Center (ViPS), Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
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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: 48] [Impact Index Per Article: 16.0] [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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Takeda J. Molecular Mechanisms of UVR8-Mediated Photomorphogenesis Derived from Revaluation of Action Spectra. Photochem Photobiol 2021; 97:903-910. [PMID: 34097751 DOI: 10.1111/php.13459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/03/2021] [Indexed: 11/27/2022]
Abstract
Considering previously reported action spectra and molecular evidence, I propose a hypothetical model for UV RESISTANCE LOCUS8 (UVR8)-mediated photomorphogenesis. Upon UV-B irradiation, a UVR8 dimer dissociates and accumulates in the nucleus and photomorphogenesis begins following two pathways: one in which the UVR8 monomer binds to transcription factor(s) of gene(s) supporting hypocotyl growth to stop gene expression resulting in hypocotyl growth inhibition and the other in which the UVR8 monomer binds both with CONSTITUTIVELY PHOTOMORPHOGENIC1-SUPPRESSOR OF PHYA (COP1-SPA) to release HY5 (referred to as "stabilized") and WRKY DNA-BINDING PROTEIN 36 (WRKY36) on the ELONGATED HYPOCOTYL 5 (HY5) gene to release HY5 transcription, and both HY5 and another UV-B-activated UV-B sensor (denoted the Hyp sensor in this article) through a self-interacting factor (HIF) associates with the HY5 promoter to initiate HY5 transcription, leading to anthocyanin synthesis. These two pathways can be distinguished by action spectra in the UV-B region, with a single peak at 280 nm and two peaks (or a broad peak near 280-300 nm) for the former and the latter, respectively. Expanding the concept to cyanobacteria and other algae, I discuss the evolution of a UV-B sensor in green plants.
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Affiliation(s)
- Junko Takeda
- Laboratory of Applied Microbiology and Biotechnology, Nara Women's University, Nara, Japan
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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: 5] [Impact Index Per Article: 1.3] [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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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: 37] [Impact Index Per Article: 9.3] [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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14
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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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15
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Robson TM, Aphalo PJ, Banaś AK, Barnes PW, Brelsford CC, Jenkins GI, Kotilainen TK, Łabuz J, Martínez-Abaigar J, Morales LO, Neugart S, Pieristè M, Rai N, Vandenbussche F, Jansen MAK. A perspective on ecologically relevant plant-UV research and its practical application. Photochem Photobiol Sci 2019; 18:970-988. [PMID: 30720036 DOI: 10.1039/c8pp00526e] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.
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Affiliation(s)
- T Matthew Robson
- Organismal and Evolutionary Biology, Viikki Plant Science Centre (ViPS), University of Helsinki, Finland.
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16
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Vanhaelewyn L, Bernula P, Van Der Straeten D, Vandenbussche F, Viczián A. UVR8-dependent reporters reveal spatial characteristics of signal spreading in plant tissues. Photochem Photobiol Sci 2019; 18:1030-1045. [PMID: 30838366 DOI: 10.1039/c8pp00492g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The UV Resistance Locus 8 (UVR8) photoreceptor controls UV-B mediated photomorphogenesis in Arabidopsis. The aim of this work is to collect and characterize different molecular reporters of photomorphogenic UV-B responses. Browsing available transcriptome databases, we identified sets of genes responding specifically to this radiation and are controlled by pathways initiated from the UVR8 photoreceptor. We tested the transcriptional changes of several reporters and found that they are regulated differently in different parts of the plant. Our experimental system led us to conclude that the examined genes are not controlled by light piping of UV-B from the shoot to the root or signalling molecules which may travel between different parts of the plant body but by local UVR8 signalling. The initiation of these universal signalling steps can be the induction of Elongated Hypocotyl 5 (HY5) and its homologue, HYH transcription factors. We found that their transcript and protein accumulation strictly depends on UVR8 and happens in a tissue autonomous manner. Whereas HY5 accumulation correlates well with the UVR8 signal across cell layers, the induction of flavonoids depends on both UVR8 signal and a yet to be identified tissue-dependent or developmental determinant.
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Affiliation(s)
- Lucas Vanhaelewyn
- Laboratory of Functional Plant Biology, Department of Biology, Faculty of Sciences, Ghent University, KL Ledeganckstraat 35, B-9000 Gent, Belgium
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17
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Llabata P, Richter J, Faus I, Słomiňska-Durdasiak K, Zeh LH, Gadea J, Hauser MT. Involvement of the eIF2α Kinase GCN2 in UV-B Responses. FRONTIERS IN PLANT SCIENCE 2019; 10:1492. [PMID: 31850012 PMCID: PMC6892979 DOI: 10.3389/fpls.2019.01492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/28/2019] [Indexed: 05/12/2023]
Abstract
GCN2 (general control nonrepressed 2) is a serine/threonine-protein kinase that regulates translation in response to stressors such as amino acid and purin deprivation, cold shock, wounding, cadmium, and UV-C exposure. Activated GCN2 phosphorylates the α-subunit of the eukaryotic initiation factor 2 (eIF2) leading to a drastic inhibition of protein synthesis and shifting translation to specific mRNAs. To investigate the role of GCN2 in responses to UV-B radiation its activity was analyzed through eIF2α phosphorylation assays in mutants of the specific UV-B and stress signaling pathways of Arabidopsis thaliana. EIF2α phosphorylation was detectable 30 min after UV-B exposure, independent of the UV-B photoreceptor UV RESISTANCE LOCUS8 and its downstream signaling components. GCN2 dependent phosphorylation of eIF2α was also detectable in mutants of the stress related MAP kinases, MPK3 and MPK6 and their negative regulator map kinase phosphatase1 (MKP1). Transcription of downstream components of the UV-B signaling pathway, the Chalcone synthase (CHS) was constitutively higher in gcn2-1 compared to wildtype and further increased upon UV-B while GLUTATHIONE PEROXIDASE7 (GPX7) behaved similarly to wildtype. The UVR8 independent FAD-LINKED OXIDOREDUCTASE (FADox) had a lower basal expression in gcn2-1 which was increased upon UV-B. Since high fluence rates of UV-B induce DNA damage the expression of the RAS ASSOCIATED WITH DIABETES PROTEIN51 (RAD51) was quantified before and after UV-B. While the basal expression was similar to wildtype it was significantly less induced upon UV-B in the gcn2-1 mutant. This expression pattern correlates with the finding that gcn2 mutants develop less cyclobutane pyrimidine dimers after UV-B exposure. Quantification of translation with the puromycination assay revealed that gcn2 mutants have an increased rate of translation which was also higher upon UV-B. Growth of gcn2 mutants to chronic UV-B exposure supports GCN2's role as a negative regulator of UV-B responses. The elevated resistance of gcn2 mutants towards repeated UV-B exposure points to a critical role of GCN2 in the regulation of translation upon UV-B.
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Affiliation(s)
- Paula Llabata
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación (CPI), Valencia, Spain
- Institute of Applied Genetics and Cell Biology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
- Bellvitge Biomedical Research Institute IDIBELL, Barcelona, Spain
| | - Julia Richter
- Institute of Applied Genetics and Cell Biology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
| | - Isabel Faus
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación (CPI), Valencia, Spain
| | - Karolina Słomiňska-Durdasiak
- Institute of Applied Genetics and Cell Biology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Lukas Hubert Zeh
- Institute of Applied Genetics and Cell Biology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
| | - Jose Gadea
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación (CPI), Valencia, Spain
| | - Marie-Theres Hauser
- Institute of Applied Genetics and Cell Biology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
- *Correspondence: Marie-Theres Hauser,
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18
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Pescheck F. UV-A screening inCladophorasp. lowers internal UV-A availability and photoreactivation as compared to non-UV screening inUlva intestinalis. Photochem Photobiol Sci 2019; 18:413-423. [DOI: 10.1039/c8pp00432c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV-A screening reduces UV-A-driven photoreactivation of UV-B-induced DNA damage in the green macroalgaCladophorasp.
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Affiliation(s)
- Frauke Pescheck
- Botanical Institute
- Christian-Albrechts-University of Kiel
- 24098 Kiel
- Germany
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19
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Jansen MAK, Bilger W, Hideg É, Strid Å, Urban O. Editorial: Interactive effects of UV-B radiation in a complex environment. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 134:1-8. [PMID: 30385007 DOI: 10.1016/j.plaphy.2018.10.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- Marcel A K Jansen
- School of Biological Earth and Environmental Sciences, University College Cork, Cork, Ireland; Global Change Research Institute CAS, Bělidla 986/4a, CZ-603 00, Brno, Czech Republic
| | - Wolfgang Bilger
- Botanisches Institut, Christian-Albrechts-Universität zu Kiel, Olshausenstr. 40, 24098, Kiel, Germany
| | - Éva Hideg
- Institute of Biology, University of Pécs, Ifjusag u. 6, H-7624, Pécs, Hungary
| | - Åke Strid
- School of Science & Technology, Örebro Life Science Center, Örebro University, SE-70182 Örebro, Sweden
| | - Otmar Urban
- Global Change Research Institute CAS, Bělidla 986/4a, CZ-603 00, Brno, Czech Republic.
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