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Lopez L, Fasano C, Perrella G, Facella P. Cryptochromes and the Circadian Clock: The Story of a Very Complex Relationship in a Spinning World. Genes (Basel) 2021; 12:672. [PMID: 33946956 PMCID: PMC8145066 DOI: 10.3390/genes12050672] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/19/2021] [Accepted: 04/27/2021] [Indexed: 01/16/2023] Open
Abstract
Cryptochromes are flavin-containing blue light photoreceptors, present in most kingdoms, including archaea, bacteria, plants, animals and fungi. They are structurally similar to photolyases, a class of flavoproteins involved in light-dependent repair of UV-damaged DNA. Cryptochromes were first discovered in Arabidopsis thaliana in which they control many light-regulated physiological processes like seed germination, de-etiolation, photoperiodic control of the flowering time, cotyledon opening and expansion, anthocyanin accumulation, chloroplast development and root growth. They also regulate the entrainment of plant circadian clock to the phase of light-dark daily cycles. Here, we review the molecular mechanisms by which plant cryptochromes control the synchronisation of the clock with the environmental light. Furthermore, we summarise the circadian clock-mediated changes in cell cycle regulation and chromatin organisation and, finally, we discuss a putative role for plant cryptochromes in the epigenetic regulation of genes.
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Affiliation(s)
| | | | | | - Paolo Facella
- Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), TERIN-BBC-BBE, Trisaia Research Center, 75026 Rotondella, Matera, Italy; (L.L.); (C.F.); (G.P.)
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Kusuma P, Swan B, Bugbee B. Does Green Really Mean Go? Increasing the Fraction of Green Photons Promotes Growth of Tomato but Not Lettuce or Cucumber. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10040637. [PMID: 33801682 PMCID: PMC8066606 DOI: 10.3390/plants10040637] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
The photon flux in the green wavelength region is relatively enriched in shade and the photon flux in the blue region is selectively filtered. In sole source lighting environments, increasing the fraction of blue typically decreases stem elongation and leaf expansion, and smaller leaves reduce photon capture and yield. Photons in the green region reverse these blue reductions through the photoreceptor cryptochrome in Arabidopsis thaliana, but studies in other species have not consistently shown the benefits of photons in the green region on leaf expansion and growth. Spectral effects can interact with total photon flux. Here, we report the effect of the fraction of photons in the blue (10 to 30%) and green (0 to 50%) regions at photosynthetic photon flux densities of 200 and 500 µmol m-2 s-1 in lettuce, cucumber and tomato. As expected, increasing the fraction of photons in the blue region consistently decreased leaf area and dry mass. By contrast, large changes in the fraction of photons in the green region had minimal effects on leaf area and dry mass in lettuce and cucumber. Photons in the green region were more potent at a lower fraction of photons in the blue region. Photons in the green region increased stem and petiole length in cucumber and tomato, which is a classic shade avoidance response. These results suggest that high-light crop species might respond to the fraction of photons in the green region with either shade tolerance (leaf expansion) or shade avoidance (stem elongation).
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53
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Duan HD, Khan SA, Miller AF. Photogeneration and reactivity of flavin anionic semiquinone in a bifurcating electron transfer flavoprotein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148415. [PMID: 33727071 DOI: 10.1016/j.bbabio.2021.148415] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 02/15/2021] [Accepted: 03/10/2021] [Indexed: 02/04/2023]
Abstract
Electron transfer bifurcation allows production of a strongly reducing carrier at the expense of a weaker one, by redistributing energy among a pair of electrons. Thus, two weakly-reducing electrons from NADH are consumed to produce a strongly reducing ferredoxin or flavodoxin, paid for by reduction of an oxidizing acceptor. The prevailing mechanism calls for participation of a strongly reducing flavin semiquinone which has been difficult to observe with site-certainly in multi-flavin systems. Using blue light (450 nm) to photoexcite the flavins of bifurcating electron transfer flavoprotein (ETF), we demonstrate accumulation of anionic flavin semiquinone in excess of what is observed in equilibrium titrations, and establish its ability to reduce the low-potential electron acceptor benzyl viologen. This must occur at the bifurcating flavin because the midpoint potentials of the electron transfer (ET) flavin are not sufficiently negative. We show that bis-tris propane buffer is an effective electron donor to the flavin photoreduction, but that if the system is prepared with the ET flavin chemically reduced, so that only the bifurcating flavin is oxidized and photochemically active, flavin anionic semiquinone is formed more rapidly. Thus, excited bifurcating flavin is able to draw on an electron stored at the ET flavin. Flavin semiquinone photogenerated at the bifurcation site must therefore be accompanied by additional semiquinone formation by oxidation of the ET flavin. Consistent with the expected instability of bifurcating flavin semiquinone, it subsides immediately upon cessation of illumination. However comparison with yields of semiquinone in equilibrium titrations suggest that during continuous illumination at pH 9 a steady state population of 0.3 equivalents of bifurcating flavin semiquinone accumulates, and then undergoes further photoreduction to the hydroquinone. Although transient, the population of bifurcating flavin semiquinone explains the system's ability to conduct light-driven electron transfer from bis-tris propane to benzyl viologen, in effect trapping energy from light.
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Affiliation(s)
- H Diessel Duan
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Sharique A Khan
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
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Express Arabidopsis Cryptochrome in Sf9 Insect Cells Using the Baculovirus Expression System. Methods Mol Biol 2021. [PMID: 33656679 DOI: 10.1007/978-1-0716-1370-2_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The Bac-to-Bac® Baculovirus Expression System provides a rapid and efficient method to generate recombinant cryptochrome (CRY) proteins with chromophore flavin (FAD), which showed blue light response in vitro.
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55
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Roeber VM, Bajaj I, Rohde M, Schmülling T, Cortleven A. Light acts as a stressor and influences abiotic and biotic stress responses in plants. PLANT, CELL & ENVIRONMENT 2021; 44:645-664. [PMID: 33190307 DOI: 10.1111/pce.13948] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/19/2020] [Accepted: 11/09/2020] [Indexed: 05/18/2023]
Abstract
Light is important for plants as an energy source and a developmental signal, but it can also cause stress to plants and modulates responses to stress. Excess and fluctuating light result in photoinhibition and reactive oxygen species (ROS) accumulation around photosystems II and I, respectively. Ultraviolet light causes photodamage to DNA and a prolongation of the light period initiates the photoperiod stress syndrome. Changes in light quality and quantity, as well as in light duration are also key factors impacting the outcome of diverse abiotic and biotic stresses. Short day or shady environments enhance thermotolerance and increase cold acclimation. Similarly, shade conditions improve drought stress tolerance in plants. Additionally, the light environment affects the plants' responses to biotic intruders, such as pathogens or insect herbivores, often reducing growth-defence trade-offs. Understanding how plants use light information to modulate stress responses will support breeding strategies to enhance crop stress resilience. This review summarizes the effect of light as a stressor and the impact of the light environment on abiotic and biotic stress responses. There is a special focus on the role of the different light receptors and the crosstalk between light signalling and stress response pathways.
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Affiliation(s)
- Venja M Roeber
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany
| | - Ishita Bajaj
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany
| | - Mareike Rohde
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany
| | - Thomas Schmülling
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany
| | - Anne Cortleven
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany
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56
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Chandrasekaran S, Schneps CM, Dunleavy R, Lin C, DeOliveira CC, Ganguly A, Crane BR. Tuning flavin environment to detect and control light-induced conformational switching in Drosophila cryptochrome. Commun Biol 2021; 4:249. [PMID: 33637846 PMCID: PMC7910608 DOI: 10.1038/s42003-021-01766-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Light-induction of an anionic semiquinone (SQ) flavin radical in Drosophila cryptochrome (dCRY) alters the dCRY conformation to promote binding and degradation of the circadian clock protein Timeless (TIM). Specific peptide ligation with sortase A attaches a nitroxide spin-probe to the dCRY C-terminal tail (CTT) while avoiding deleterious side reactions. Pulse dipolar electron-spin resonance spectroscopy from the CTT nitroxide to the SQ shows that flavin photoreduction shifts the CTT ~1 nm and increases its motion, without causing full displacement from the protein. dCRY engineered to form the neutral SQ serves as a dark-state proxy to reveal that the CTT remains docked when the flavin ring is reduced but uncharged. Substitutions of flavin-proximal His378 promote CTT undocking in the dark or diminish undocking in the light, consistent with molecular dynamics simulations and TIM degradation activity. The His378 variants inform on recognition motifs for dCRY cellular turnover and strategies for developing optogenetic tools. Chandrasekaran et al. engineered the Drosophila circadian clock protein Cryptochrome (dCRY) to form the neutral semiquinone, which serves as a dark-state proxy. They find that the C-terminal tail of dCRY remains docked when the flavin ring is reduced but uncharged. dCRY His378 variants provide insights into the recognition motifs for dCRY turnover and strategies for optogenetic tools.
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Affiliation(s)
| | - Connor M Schneps
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Robert Dunleavy
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Changfan Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | | | - Abir Ganguly
- Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ, USA
| | - Brian R Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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57
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Goett-Zink L, Klocke JL, Kottke T. Resolving Structural Changes of Photoreceptors in Living Escherichia coli via In-cell Infrared Difference Spectroscopy. Bio Protoc 2021; 11:e3909. [PMID: 33732796 DOI: 10.21769/bioprotoc.3909] [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: 09/22/2020] [Revised: 11/12/2020] [Accepted: 11/18/2020] [Indexed: 11/02/2022] Open
Abstract
Several in-cell spectroscopic techniques have been developed recently to investigate the structure and mechanism of proteins in their native environment. Conditions in vivo differ dramatically from those selected for in vitro experiments. Accordingly, the cellular environment can affect the protein mechanism for example by molecular crowding or binding of small molecules. Fourier transform infrared (FTIR) difference spectroscopy is a well-suited method to study the light-induced structural responses of photoreceptors including changes in cofactor, side chains and secondary structure. Here, we describe a protocol to study the response of cofactor and protein in living E. coli cells via in-cell infrared difference (ICIRD) spectroscopy using the attenuated total reflection (ATR) configuration. Proteins are overexpressed in E. coli, the cells are transferred into saline solution and the copy number per cell is determined using fluorescence spectroscopy. The suspension is centrifuged and the concentrated cells transferred onto the ATR cell inside the FTIR spectrometer. The thermostatted cell is sealed and illuminated from the top with an LED. Intensity spectra are recorded before and after illumination to generate the difference spectrum of the receptor inside the living cell. With ICIRD spectroscopy, structural changes of soluble photoreceptors are resolved in a near-native environment. The approach works in H2O at ambient conditions, is label free, without any limitations in protein size and does not require any purification step. Graphic abstract: In-cell infrared difference spectroscopy on photoreceptors in living E. coli using attenuated total reflection.
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Affiliation(s)
- Lukas Goett-Zink
- Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Jessica L Klocke
- Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Tilman Kottke
- Department of Chemistry, Bielefeld University, Bielefeld, Germany.,Medical School OWL, Bielefeld University, Bielefeld, Germany
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Photoreaction Mechanisms of Flavoprotein Photoreceptors and Their Applications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:189-206. [PMID: 33398814 DOI: 10.1007/978-981-15-8763-4_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Three classes of flavoprotein photoreceptors, cryptochromes (CRYs), light-oxygen-voltage (LOV)-domain proteins, and blue light using FAD (BLUF)-domain proteins, have been identified that control various physiological processes in multiple organisms. Accordingly, signaling activities of photoreceptors have been intensively studied and the related mechanisms have been exploited in numerous optogenetic tools. Herein, we summarize the current understanding of photoactivation mechanisms of the flavoprotein photoreceptors and review their applications.
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Einholz C, Nohr D, Rodriguez R, Topitsch A, Kern M, Goldmann J, Chileshe E, Okasha M, Weber S, Schleicher E. pH-dependence of signaling-state formation in Drosophila cryptochrome. Arch Biochem Biophys 2021; 700:108787. [PMID: 33545100 DOI: 10.1016/j.abb.2021.108787] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 11/30/2022]
Abstract
Cryptochromes, FAD-dependent blue light photoreceptors, undergo a series of electron transfer reactions after light excitation. Time-resolved optical spectroscopy was employed to investigate the pH dependence of all light-dependent reactions in the cryptochrome from fruit flies. Signal state formation experiments on a time scale of seconds were found to be strongly pH dependent, and formation of both anionic and neutral FAD radicals could be detected, with reaction rates increasing by a factor of ~2.5 from basic to neutral pH values. Additionally, the influence of the amino acid His378 was investigated in further detail: Two protein variants, DmCry H378A and H378Q, showed significantly reduced rate constants for signal state formation, which again differed at neutral and alkaline pH values. Hence, His378 was identified as an amino acid responsible for the pronounced pH dependence; however, this amino acid can be excluded as a proton donor for the protonation of the anionic FAD radical. Other conserved amino acids appear to alter the overall polarity of the binding pocket and thus to be responsible for the pronounced pH dependence. Furthermore, the influence of pH and other experimental parameters, such as temperature, glycerol or ferricyanide concentrations, on the intermediately formed FAD-tryptophan radical pair was explored, which deprotonates on a microsecond time scale with a clear pH dependence, and subsequently recombines within milliseconds. Surprisingly, the latter reaction showed no pH dependence; potential reasons are discussed. All results are reviewed in terms of the photoreceptor and potential magnetoreceptor functions of Drosophila cryptochrome.
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Affiliation(s)
- Christopher Einholz
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Daniel Nohr
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Ryan Rodriguez
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Annika Topitsch
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Maria Kern
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Jacqueline Goldmann
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Emma Chileshe
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Moustafa Okasha
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany.
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Abstract
Cryptochromes (CRYs) are evolutionarily conserved photoreceptors that mediate various light-induced responses in bacteria, plants, and animals. Plant cryptochromes govern a variety of critical growth and developmental processes including seed germination, flowering time and entrainment of the circadian clock. CRY's photocycle involves reduction of their flavin adenine dinucleotide (FAD)-bound chromophore, which is completely oxidized in the dark and semi to fully reduced in the light signaling-active state. Despite the progress in characterizing cryptochromes, important aspects of their photochemistry, regulation, and light-induced structural changes remain to be addressed. In this study, we determine the crystal structure of the photosensory domain of Arabidopsis CRY2 in a tetrameric active state. Systematic structure-based analyses of photo-activated and inactive plant CRYs elucidate distinct structural elements and critical residues that dynamically partake in photo-induced oligomerization. Our study offers an updated model of CRYs photoactivation mechanism as well as the mode of its regulation by interacting proteins.
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Bian Z, Wang Y, Zhang X, Grundy S, Hardy K, Yang Q, Lu C. A Transcriptome Analysis Revealing the New Insight of Green Light on Tomato Plant Growth and Drought Stress Tolerance. FRONTIERS IN PLANT SCIENCE 2021; 12:649283. [PMID: 34745154 PMCID: PMC8566944 DOI: 10.3389/fpls.2021.649283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 09/23/2021] [Indexed: 05/13/2023]
Abstract
Light plays a pivotal role in plant growth, development, and stress responses. Green light has been reported to enhance plant drought tolerance via stomatal regulation. However, the mechanisms of green light-induced drought tolerance in plants remain elusive. To uncover those mechanisms, we investigated the molecular responses of tomato plants under monochromatic red, blue, and green light spectrum with drought and well-water conditions using a comparative transcriptomic approach. The results showed that compared with monochromatic red and blue light treated plants, green light alleviated the drought-induced inhibition of plant growth and photosynthetic capacity, and induced lower stomatal aperture and higher ABA accumulation in tomato leaves after 9 days of drought stress. A total of 3,850 differentially expressed genes (DEGs) was identified in tomato leaves through pairwise comparisons. Functional annotations revealed that those DEGs responses to green light under drought stress were enriched in plant hormone signal transduction, phototransduction, and calcium signaling pathway. The DEGs involved in ABA synthesis and ABA signal transduction both participated in the green light-induced drought tolerance of tomato plants. Compared with ABA signal transduction, more DEGs related to ABA synthesis were detected under different light spectral treatments. The bZIP transcription factor- HY5 was found to play a vital role in green light-induced drought responses. Furthermore, other transcription factors, including WRKY46 and WRKY81 might participate in the regulation of stomatal aperture and ABA accumulation under green light. Taken together, the results of this study might expand our understanding of green light-modulated tomato drought tolerance via regulating ABA accumulation and stomatal aperture.
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Affiliation(s)
- Zhonghua Bian
- Photobiology Research Center, The Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- School of Animal, Rural and Environment Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, United Kingdom
| | - Yu Wang
- School of Animal, Rural and Environment Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, United Kingdom
| | - Xiaoyan Zhang
- Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Steven Grundy
- School of Animal, Rural and Environment Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, United Kingdom
| | - Katherine Hardy
- School of Animal, Rural and Environment Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, United Kingdom
| | - Qichang Yang
- Photobiology Research Center, The Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, China
- *Correspondence: Qichang Yang
| | - Chungui Lu
- School of Animal, Rural and Environment Sciences, Nottingham Trent University, Brackenhurst Campus, Nottingham, United Kingdom
- Chungui Lu
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62
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Li L, Tong YX, Lu JL, Li YM, Liu X, Cheng RF. Morphology, Photosynthetic Traits, and Nutritional Quality of Lettuce Plants as Affected by Green Light Substituting Proportion of Blue and Red Light. FRONTIERS IN PLANT SCIENCE 2021; 12:627311. [PMID: 34305958 PMCID: PMC8294060 DOI: 10.3389/fpls.2021.627311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 06/07/2021] [Indexed: 05/15/2023]
Abstract
Green light, as part of the photosynthetically active radiation, has been proven to have high photosynthetic efficiency once absorbed by plant leaves and can regulate plant physiological activities. However, few studies have investigated the appropriate and efficient way of using the green light for plant production. Thus, the objective of this study was to investigate a moderate amount of green light, partially replacing red and blue light, for plant growth and development. In this experiment, four treatments were set up by adjusting the relative amount of green light as 0 (RB), 30 (G30), 60 (G60), and 90 (G90) μmol m-2 s-1, respectively, with a total photosynthetic photon flux density of 200 μmol m-2 s-1 and a fixed red-to-blue ratio of 4:1. Lettuce (Lactuca sativa cv. 'Tiberius') plant growth and morphology, stomatal characteristics, light absorptance and transmittance, photosynthetic characteristics, and nutritional quality were investigated. The results showed that: (1) shoot dry weight increased by 16.3 and 24.5% and leaf area increased by 11.9 and 16.2% under G30 and G60, respectively, compared with those under RB. Plant stem length increased linearly with increasing green-to-blue light ratio; (2) light transmittance of lettuce leaf under treatments employing green light was higher than that under RB, especially in the green region; (3) stomatal density increased, whereas stomatal aperture area decreased with the increase in the relative amount of green light; and (4) carbohydrate accumulation increased under G60 and G90. Soluble sugar contents under G60 and G90 increased by 39.4 and 19.4%, respectively. Nitrate contents under G30, G60, and G90 decreased by 26.2, 40.3, and 43.4%, respectively. The above results indicated that 15-30% green light replacing red and blue light effectively increased the yield and nutritional quality of lettuce plants.
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Affiliation(s)
- Lie Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
| | - Yu-xin Tong
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
- *Correspondence: Yu-xin Tong
| | - Jun-ling Lu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
| | - Yang-mei Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
| | - Xin Liu
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
| | - Rui-feng Cheng
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing, China
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63
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Ma L, Guan Z, Wang Q, Yan X, Wang J, Wang Z, Cao J, Zhang D, Gong X, Yin P. Structural insights into the photoactivation of Arabidopsis CRY2. NATURE PLANTS 2020; 6:1432-1438. [PMID: 33199893 DOI: 10.1038/s41477-020-00800-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
The blue-light receptor cryptochrome (CRY) in plants undergoes oligomerization to transduce blue-light signals after irradiation, but the corresponding molecular mechanism remains poorly understood. Here, we report the cryogenic electron microscopy structure of a blue-light-activated CRY2 tetramer at a resolution of 3.1 Å, which shows how the CRY2 tetramer assembles. Our study provides insights into blue-light-mediated activation of CRY2 and a theoretical basis for developing regulators of CRYs for optogenetic manipulation.
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Affiliation(s)
- Ling Ma
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
- Kobilka Institute of Innovative Drug Discovery, The Chinese University of Hong Kong, Shenzhen, Shenzhen, China
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Zeyuan Guan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Qiang Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Xuhui Yan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Jing Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Zhizheng Wang
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, P. R. China
| | - Jianbo Cao
- Public Laboratory of Electron Microscopy, Huazhong Agricultural University, Wuhan, China
| | - Delin Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Xin Gong
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Ping Yin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
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Meng Q, Runkle ES. Growth Responses of Red-Leaf Lettuce to Temporal Spectral Changes. FRONTIERS IN PLANT SCIENCE 2020; 11:571788. [PMID: 33193506 PMCID: PMC7641902 DOI: 10.3389/fpls.2020.571788] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/30/2020] [Indexed: 05/28/2023]
Abstract
Lighting is typically static for indoor production of leafy greens. However, temporal spectrum differentiation for distinct growth phases can potentially control age-specific desirable traits. Spectral effects can be persistent yet dynamic as plants mature, necessitating characterization of time-dependent responses. We grew red-leaf lettuce (Lactuca sativa L.) "Rouxai" in a growth room at 23°C and under a 20-h photoperiod created by warm-white (WW), blue (B; peak = 449 nm), green (G; peak = 526 nm), red (R; peak = 664 nm), and/or far-red (FR; peak = 733 nm) light-emitting diodes. From day 0 to 11, plants received six static lighting treatments with the same total photon flux density (400-800 nm): WW180, R180, B20R160, B20G60R100, B20R100FR60, or B180 (subscripts denote photon flux densities in μmol⋅m-2⋅s-1). On day 11, plants grown under each of the six treatments were transferred to all treatments, which created 36 temporal spectrum alternations. Plant growth, morphology, and coloration were measured on days 11 and 25. Increasing B radiation from 0 to 100% in static treatments decreased shoot fresh and dry weights and increased foliage redness of seedlings and mature plants. Compared to B20R160, B20R100FR60 increased shoot fresh weight, but not dry weight, on both days. However, other phenotypic responses under static treatments changed over time. For example, leaf length under B180 was 35% lower on day 11 but similar on day 25 compared to that under R180. In the B20 background, substituting G60 for R radiation did not influence shoot weight on day 11 but decreased it by 19% on day 25. When plants were switched from one treatment to another on day 11, the treatments applied before day 11 influenced final shoot weight and, to a lesser extent, leaf length and foliage coloration on day 25. In comparison, effects of the treatments applied after day 11 were more pronounced. We conclude some phenotypic responses to light quality depend on time and sequential light quality treatments had cumulative effects on lettuce growth. The temporal complexity of spectral responses is critical in photobiological research and creates opportunities for time-specific spectrum delivery to optimize crop characteristics.
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65
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Battle MW, Vegliani F, Jones MA. Shades of green: untying the knots of green photoperception. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5764-5770. [PMID: 32619226 PMCID: PMC7541914 DOI: 10.1093/jxb/eraa312] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/30/2020] [Indexed: 05/04/2023]
Abstract
The development of economical LED technology has enabled the application of different light qualities and quantities to control plant growth. Although we have a comprehensive understanding of plants' perception of red and blue light, the lack of a dedicated green light sensor has frustrated our utilization of intermediate wavelengths, with many contradictory reports in the literature. We discuss the contribution of red and blue photoreceptors to green light perception and highlight how green light can be used to improve crop quality. Importantly, our meta-analysis demonstrates that green light perception should instead be considered as a combination of distinct 'green' and 'yellow' light-induced responses. This distinction will enable clearer interpretation of plants' behaviour in response to green light as we seek to optimize plant growth and nutritional quality in horticultural contexts.
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Affiliation(s)
- Martin W Battle
- School of Life Sciences, University of Essex, Colchester, UK
| | - Franco Vegliani
- Institute of Molecular, Cell, and Systems Biology, University of Glasgow, Glasgow, UK
| | - Matthew A Jones
- Institute of Molecular, Cell, and Systems Biology, University of Glasgow, Glasgow, UK
- Correspondence:
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66
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Otsuka H, Mitsui H, Miura K, Okano K, Imamoto Y, Okano T. Rapid Oxidation Following Photoreduction in the Avian Cryptochrome4 Photocycle. Biochemistry 2020; 59:3615-3625. [PMID: 32915550 DOI: 10.1021/acs.biochem.0c00495] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Avian magnetoreception is assumed to occur in the retina. Although its molecular mechanism is unclear, magnetic field-dependent formation and the stability of radical-containing photointermediate(s) are suggested to play key roles in a hypothesis called the radical pair mechanism. Chicken cryptochrome4 (cCRY4) has been identified as a candidate magnetoreceptive molecule due to its expression in the retina and its ability to form stable flavin neutral radicals (FADH●) upon blue light absorption. Herein, we used millisecond flash photolysis to investigate the cCRY4 photocycle, in both the presence and absence of dithiothreitol (DTT); detecting the anion radical form of FAD (FAD●-) under both conditions. Using spectral data obtained during flash photolysis and UV-visible photospectroscopy, we estimated the absolute absorbance spectra of the photointermediates, thus allowing us to decompose each spectrum into its individual components. Notably, in the absence of DTT, approximately 37% and 63% of FAD●- was oxidized to FADOX and protonated to form FADH●, respectively. Singular value decomposition analysis suggested the presence of two FAD●- molecular species, each of which was destined to be oxidized to FADOX or protonated to FADH●. A tyrosine neutral radical was also detected; however, it likely decayed concomitantly with the oxidation of FAD●-. On the basis of these results, we considered the occurrence of bifurcation prior to FAD●- generation, or during FAD●- oxidization, and discussed the potential role played by the tyrosine radical in the radical pair mechanism.
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Affiliation(s)
- Hiroaki Otsuka
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Hiromasa Mitsui
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Kota Miura
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Keiko Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
| | - Yasushi Imamoto
- Department of Biophysics, Division of Biological Sciences, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshiyuki Okano
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, Waseda University, TWIns, Wakamatsucho 2-2, Shinjuku-Ku, Tokyo 162-8480, Japan
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67
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Goett-Zink L, Klocke JL, Bögeholz LAK, Kottke T. In-cell infrared difference spectroscopy of LOV photoreceptors reveals structural responses to light altered in living cells. J Biol Chem 2020; 295:11729-11741. [PMID: 32580943 PMCID: PMC7450117 DOI: 10.1074/jbc.ra120.013091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/21/2020] [Indexed: 12/19/2022] Open
Abstract
Proteins are usually studied in well-defined buffer conditions, which differ substantially from those within a host cell. In some cases, the intracellular environment has an impact on the mechanism, which might be missed by in vitro experiments. IR difference spectroscopy previously has been applied to study the light-induced response of photoreceptors and photoenzymes in vitro Here, we established the in-cell IR difference (ICIRD) spectroscopy in the transmission and attenuated total reflection configuration to investigate the light-induced response of soluble proteins in living bacterial cells. ICIRD spectroscopy on the light, oxygen, or voltage (LOV) domains of the blue light receptors aureochrome and phototropin revealed a suppression of the response of specific secondary structure elements, indicating that the intracellular environment affects LOV photoreceptor mechanisms in general. Moreover, in-cell fluorescence spectroscopy disclosed that the intracellular environment slows down the recovery of the light-induced flavin adduct. Segment-resolved ICIRD spectroscopy on basic-region leucine zipper (bZIP)-LOV of aureochrome 1a from the diatom Phaeodactylum tricornutum indicated a signal progression from the LOV sensor to the bZIP effector independent of unfolding of the connecting A'α-helix, an observation that stood in contrast to in vitro results. This deviation was recapitulated in vitro by emulating the intracellular environment through the addition of the crowding agent BSA, but not by sucrose polymers. We conclude that ICIRD spectroscopy is a noninvasive, label-free approach for assessing conformational changes in receptors in living cells at ambient conditions. As demonstrated, these near-native responses may deviate from the mechanisms established under in vitro conditions.
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Affiliation(s)
- Lukas Goett-Zink
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Jessica L Klocke
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Lena A K Bögeholz
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Tilman Kottke
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany
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68
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Ma L, Wang X, Guan Z, Wang L, Wang Y, Zheng L, Gong Z, Shen C, Wang J, Zhang D, Liu Z, Yin P. Structural insights into BIC-mediated inactivation of Arabidopsis cryptochrome 2. Nat Struct Mol Biol 2020; 27:472-479. [PMID: 32398826 DOI: 10.1038/s41594-020-0410-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 03/09/2020] [Indexed: 02/04/2023]
Abstract
Cryptochromes (CRYs) are blue-light receptors in plants that harbor FAD as a cofactor and regulate various physiological responses. Photoactivated CRYs undergo oligomerization, which increases the binding affinity to downstream signaling partners. Despite decades of research on the activation of CRYs, little is known about how they are inactivated. Binding of blue-light inhibitors of cryptochromes (BICs) to CRY2 suppresses its photoactivation, but the underlying mechanism remains unknown. Here, we report crystal structures of CRY2N (CRY2 PHR domain) and the BIC2-CRY2N complex with resolutions of 2.7 and 2.5 Å, respectively. In the BIC2-CRY2N complex, BIC2 exhibits an extremely extended structure that sinuously winds around CRY2N. In this way, BIC2 not only restrains the transfer of electrons and protons from CRY2 to FAD during photoreduction but also interacts with the CRY2 oligomer to return it to the monomer form. Uncovering the mechanism of CRY2 inactivation lays a solid foundation for the investigation of cryptochrome protein function.
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Affiliation(s)
- Ling Ma
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Xiang Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Zeyuan Guan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Lixia Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Yidong Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Le Zheng
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Zhou Gong
- Laboratory of Magnetic Resonance and Atomic Molecular Physics, Wuhan Institute of Physics and Mathematics of the Chinese Academy of Sciences, Wuhan, China
| | - Cuicui Shen
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Jing Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Delin Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Zhu Liu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China
| | - Ping Yin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, China.
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69
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Matthews JSA, Vialet-Chabrand S, Lawson T. Role of blue and red light in stomatal dynamic behaviour. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2253-2269. [PMID: 31872212 PMCID: PMC7134916 DOI: 10.1093/jxb/erz563] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/19/2019] [Indexed: 05/20/2023]
Abstract
Plants experience changes in light intensity and quality due to variations in solar angle and shading from clouds and overlapping leaves. Stomatal opening to increasing irradiance is often an order of magnitude slower than photosynthetic responses, which can result in CO2 diffusional limitations on leaf photosynthesis, as well as unnecessary water loss when stomata continue to open after photosynthesis has reached saturation. Stomatal opening to light is driven by two distinct pathways; the 'red' or photosynthetic response that occurs at high fluence rates and saturates with photosynthesis, and is thought to be the main mechanism that coordinates stomatal behaviour with photosynthesis; and the guard cell-specific 'blue' light response that saturates at low fluence rates, and is often considered independent of photosynthesis, and important for early morning stomatal opening. Here we review the literature on these complicated signal transduction pathways and osmoregulatory processes in guard cells that are influenced by the light environment. We discuss the possibility of tuning the sensitivity and magnitude of stomatal response to blue light which potentially represents a novel target to develop ideotypes with the 'ideal' balance between carbon gain, evaporative cooling, and maintenance of hydraulic status that is crucial for maximizing crop performance and productivity.
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Affiliation(s)
- Jack S A Matthews
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, UK
| | | | - Tracy Lawson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, UK
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70
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Kusuma P, Pattison PM, Bugbee B. From physics to fixtures to food: current and potential LED efficacy. HORTICULTURE RESEARCH 2020; 7:56. [PMID: 32257242 PMCID: PMC7105460 DOI: 10.1038/s41438-020-0283-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 03/05/2020] [Accepted: 03/09/2020] [Indexed: 05/21/2023]
Affiliation(s)
- Paul Kusuma
- Crop Physiology Laboratory, Utah State University, Logan, 84341 UT USA
| | | | - Bruce Bugbee
- Crop Physiology Laboratory, Utah State University, Logan, 84341 UT USA
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71
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Laser Irradiation Effects at Different Wavelengths on Phenology and Yield Components of Pretreated Maize Seed. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10031189] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study aims to compare the effects of different laser wavelengths, exposure times, and low-power-intensity laser irradiation on maize seeds. Seeds were exposed to He–Ne (632.8 nm) red laser, Nd:YAG second-harmonic-generation (532 nm) green laser, and diode (410 nm) blue laser. Four different exposure times (45, 65, 85, and 105 s) with different intensity (2 and 4 mW/cm2), for each laser were tested. Phenology and yield components (plant height, leaf area, number of rows per ear, seed yield, harvest index, yield efficiency, and grain weight) were determined. The experiment was conducted in a randomized complete block design with three replications. Plant height was found comparatively high in blue laser light—211 cm at 85 s. Blue and green laser lights showed significant increases in the number of rows per ear to 39.1 at 85 s and 45 at 65 s, respectively, compared to the control of 36 rows/ear. The order of seed yield was blue (7003.4 kg/ha) > green (6667.8 kg/ha) > red (6568.01 t/ha) based on different exposure times of 85 s, 85 s, and 105 s, respectively, compared to the control of 6.9 kg/ha. The findings indicate the possibility of using blue laser light to manipulate the growth and yield of maize.
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72
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Hammad M, Albaqami M, Pooam M, Kernevez E, Witczak J, Ritz T, Martino C, Ahmad M. Cryptochrome mediated magnetic sensitivity in Arabidopsis occurs independently of light-induced electron transfer to the flavin. Photochem Photobiol Sci 2020; 19:341-352. [DOI: 10.1039/c9pp00469f] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Arabidopsis cryptochrome-dependent magnetosensitivity occurs via a reaction that does not require light. This excludes radical pairs formed during light-triggered electron transfer to the flavin.
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Affiliation(s)
- M. Hammad
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
| | - M. Albaqami
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
| | - M. Pooam
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
| | - E. Kernevez
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
| | - J. Witczak
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
| | - T. Ritz
- Department of Physics and Astronomy
- University of California at Irvine
- USA
| | - C. Martino
- Department of Biomedical and Chemical Engineering and Science
- Florida Institute of Technology
- Melbourne
- USA
| | - M. Ahmad
- Sorbonne Universités – UPMC Paris 6 – CNRS
- UMR8256 - IBPS
- Photobiology Research Group
- 75005 Paris
- France
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73
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Battle MW, Jones MA. Cryptochromes integrate green light signals into the circadian system. PLANT, CELL & ENVIRONMENT 2020; 43:16-27. [PMID: 31410859 PMCID: PMC6973147 DOI: 10.1111/pce.13643] [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: 02/08/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 05/04/2023]
Abstract
Plants are acutely sensitive of their light environment, adapting their growth habit and prioritizing developmental decisions to maximize fecundity. In addition to providing an energy source and directional information, light quality also contributes to entrainment of the circadian system, an endogenous timing mechanism that integrates endogenous and environmental signalling cues to promote growth. Whereas plants' perception of red and blue portions of the spectrum are well defined, green light sensitivity remains enigmatic. In this study, we show that low fluence rates of green light are sufficient to entrain and maintain circadian rhythms in Arabidopsis and that cryptochromes contribute to this response. Importantly, green light responses are distinguishable from low blue light-induced phenotypes. These data suggest a distinct signalling mechanism enables entrainment of the circadian system in green light-enriched environments, such as those found in undergrowth and in densely planted monoculture.
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Affiliation(s)
| | - Matthew Alan Jones
- School of Life SciencesUniversity of EssexColchesterCO4 3SQUK
- Institute of Molecular, Cell and Systems BiologyUniversity of GlasgowGlasgowG12 8QQUK
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74
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Thoma F, Somborn-Schulz A, Schlehuber D, Keuter V, Deerberg G. Effects of Light on Secondary Metabolites in Selected Leafy Greens: A Review. FRONTIERS IN PLANT SCIENCE 2020; 11:497. [PMID: 32391040 PMCID: PMC7193822 DOI: 10.3389/fpls.2020.00497] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 04/02/2020] [Indexed: 05/05/2023]
Abstract
In contrast to the primary metabolism, responsible for essential synthesis mechanisms and mass balance in plants, the secondary metabolism is not of particular importance for each cell but for the plant organism as its whole. Most of these metabolites show antioxidant properties and are beneficial for human health. In order to affect accumulation of those metabolites, light is an essential factor. It is possible to select various combinations of light intensity and light quality to address corresponding photoreceptors and synthesis. However, the plethora of additional variables considering environmental conditions such as temperature, relative humidity or cultivation method complicate defining specific "light recipes". This review summarizes experiments dealing with consumable leafy greens such as lettuce or basil and the enhancement of three selected metabolites - anthocyanins, carotenoids and flavonols.
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75
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Toldi D, Gyugos M, Darkó É, Szalai G, Gulyás Z, Gierczik K, Székely A, Boldizsár Á, Galiba G, Müller M, Simon-Sarkadi L, Kocsy G. Light intensity and spectrum affect metabolism of glutathione and amino acids at transcriptional level. PLoS One 2019; 14:e0227271. [PMID: 31891631 PMCID: PMC6938384 DOI: 10.1371/journal.pone.0227271] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/16/2019] [Indexed: 11/19/2022] Open
Abstract
The effects of various light intensities and spectral compositions on glutathione and amino acid metabolism were compared in wheat. Increase of light intensity (low-normal-high) was accompanied by a simultaneous increase in the shoot fresh weight, photosynthetic activity and glutathione content. These parameters were also affected by the modification of the ratios of blue, red and far-red components (referred to as blue, pink and far-red lights) compared to normal white light. The photosynthetic activity and the glutathione content decreased to 50% and the percentage of glutathione disulfide (characterising the redox state of the tissues) in the total glutathione pool doubled in far-red light. The alterations in the level and redox state of the antioxidant glutathione resulted from the effect of light on its synthesis as it could be concluded from the changes in the transcription of the related genes. Modification of the light conditions also greatly affected both the amount and the ratio of free amino acids. The total free amino acid content was greatly induced by the increase of light intensity and was greatly reduced in pink light compared to the normal intensity white light. The concentrations of most amino acids were similarly affected by the light conditions as described for the total free amino acid content but Pro, Met, Thr, ornithine and cystathionine showed unique response to light. As observed for the amino acid levels, the expression of several genes involved in their metabolism also enhanced due to increased light intensity. Interestingly, the modification of the spectrum greatly inhibited the expression of most of these genes. Correlation analysis of the investigated parameters indicates that changes in the light conditions may affect growth through the adjustment of photosynthesis and the glutathione-dependent redox state of the tissues. This process modifies the metabolism of glutathione and amino acids at transcriptional level.
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Affiliation(s)
- Dávid Toldi
- Department of Food Chemistry and Nutrition, Szent István University, Budapest, Hungary
- Doctoral School for Food Sciences, Szent István University, Budapest, Hungary
| | - Mónika Gyugos
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Éva Darkó
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Gabriella Szalai
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Zsolt Gulyás
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Krisztián Gierczik
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
- Festetics Doctoral School, Georgikon Faculty, University of Pannonia, Keszthely, Hungary
| | - András Székely
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Ákos Boldizsár
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Gábor Galiba
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
- Festetics Doctoral School, Georgikon Faculty, University of Pannonia, Keszthely, Hungary
| | - Maria Müller
- Institute of Biology, Department of Plant Sciences, University of Graz, Graz, Austria
| | - Livia Simon-Sarkadi
- Department of Food Chemistry and Nutrition, Szent István University, Budapest, Hungary
- Doctoral School for Food Sciences, Szent István University, Budapest, Hungary
| | - Gábor Kocsy
- Agricultural Institute, Centre for Agricultural Research, Martonvásár, Hungary
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76
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Oldemeyer S, Haddad AZ, Fleming GR. Interconnection of the Antenna Pigment 8-HDF and Flavin Facilitates Red-Light Reception in a Bifunctional Animal-like Cryptochrome. Biochemistry 2019; 59:594-604. [PMID: 31846308 DOI: 10.1021/acs.biochem.9b00875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cryptochromes are ubiquitous flavin-binding light sensors closely related to DNA-repairing photolyases. The animal-like cryptochrome CraCRY from the green alga Chlamydomonas reinhardtii challenges the paradigm of cryptochromes as pure blue-light receptors by acting as a (6-4) photolyase, using 8-hydroxy-5-deazaflavin (8-HDF) as a light-harvesting antenna with a 17.4 Å distance to flavin and showing spectral sensitivity up to 680 nm. The expanded action spectrum is attributed to the presence of the flavin neutral radical (FADH•) in the dark, despite a rapid FADH• decay observed in vitro in samples exclusively carrying flavin. Herein, the red-light response of CraCRY carrying flavin and 8-HDF was studied, revealing a 3-fold prolongation of the FADH• lifetime in the presence of 8-HDF. Millisecond time-resolved ultraviolet-visible spectroscopy showed the red-light-induced formation and decay of an absorbance band at 458 nm concomitant with flavin reduction. Time-resolved Fourier transform infrared (FTIR) spectroscopy and density functional theory attributed these changes to the deprotonation of 8-HDF, challenging the paradigm of 8-HDF being permanently deprotonated in photolyases. FTIR spectra showed changes in the hydrogen bonding network of asparagine 395, a residue suggested to indirectly control flavin protonation, indicating the involvement of N395 in the stabilization of FADH•. Fluorescence spectroscopy revealed a decrease in the energy transfer efficiency of 8-HDF upon flavin reduction, possibly linked to 8-HDF deprotonation. The discovery of the interdependence of flavin and 8-HDF beyond energy transfer processes highlights the essential role of the antenna, introducing a new concept enabling CraCRY and possibly other bifunctional cryptochromes to fulfill their dual function.
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Affiliation(s)
- Sabine Oldemeyer
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Molecular Biophysics and Integrated Bioimaging Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Andrew Z Haddad
- Energy Technologies Area , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Graham R Fleming
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Molecular Biophysics and Integrated Bioimaging Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Kavli Energy Nanoscience Institute , Berkeley , California 94720 , United States
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77
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Araguirang GE, Niemann N, Kiontke S, Eckel M, Dionisio-Sese ML, Batschauer A. The Arabidopsis cryptochrome 2 I404F mutant is hypersensitive and shows flavin reduction even in the absence of light. PLANTA 2019; 251:33. [PMID: 31832774 DOI: 10.1007/s00425-019-03323-y] [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: 08/30/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
The cryptochrome photoreceptor mutant cry2I404F exhibits hyperactivity in the dark, hypersensitivity in different light conditions, and in contrast to the wild-type protein, its flavin chromophore is reducible even in the absence of light. Plant cryptochromes (cry) are blue-light photoreceptors involved in multiple signaling pathways and various photomorphogenic responses. One biologically hyperactive mutant of a plant cryptochrome that was previously characterized is Arabidopsis cry1L407F (Exner et al. in Plant Physiol 154:1633-1645, 2010). Protein sequence alignments of different cryptochromes revealed that L407 in cry1 corresponds to I404 in cry2. Point mutation of Ile to Phe in cry2 in this position created a novel mutant. The present study provided a baseline data on the elucidation of the properties of cry2I404F. This mutant was still able to bind ATP-triggering conformational changes, as confirmed by partial tryptic digestion and thermo-FAD assays. Surprisingly, the FAD cofactor of cry2I404F was reduced by the addition of reductant even in the absence of light. In vivo, cry2I404F exhibited a cop phenotype in the dark and hypersensitivity to various light conditions compared to cry2 wild type. Overall, these data suggest that the hypersensitivity to red and blue light and hyperactivity of this novel mutant in the dark can be mostly accounted to structural alterations brought forth by the Ile to Phe mutation at position 404 that allows reduction of the flavin chromophore even in the absence of light.
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Affiliation(s)
- Galileo Estopare Araguirang
- Graduate School, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
- Department of Plant Adaptation, Leibniz-Institut für Gemüse- und Zierpflanzenbau (IGZ), Großbeeren, 14979, Germany
| | - Nils Niemann
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Stephan Kiontke
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Maike Eckel
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany
| | - Maribel L Dionisio-Sese
- Graduate School, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
- Plant Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, 4031, Laguna, Philippines
| | - Alfred Batschauer
- Department of Plant Physiology and Photobiology, Faculty of Biology, Philipps-University Marburg, 35032, Marburg, Germany.
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78
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Landi M, Zivcak M, Sytar O, Brestic M, Allakhverdiev SI. Plasticity of photosynthetic processes and the accumulation of secondary metabolites in plants in response to monochromatic light environments: A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148131. [PMID: 31816291 DOI: 10.1016/j.bbabio.2019.148131] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/17/2019] [Accepted: 11/28/2019] [Indexed: 01/08/2023]
Abstract
Light spectra significantly influence plant metabolism, growth and development. Here, we review the effects of monochromatic blue, red and green light compared to those of multispectral light sources on the morpho-anatomical, photosynthetic and molecular traits of herbaceous plants. Emphasis is given to the effect of light spectra on the accumulation of secondary metabolites, which are important bioactive phytochemicals that determine the nutritional quality of vegetables. Overall, blue light may promote the accumulation of phenylpropanoid-based compounds without substantially affecting plant morpho-anatomical traits compared to the effects of white light. Red light, conversely, strongly alters plant morphology and physiology compared to that under white light without showing a consistent positive effect on secondary metabolism. Due to species-specific effects and the small shifts in the spectral band within the same color that can substantially affect plant growth and metabolism, it is conceivable that monochromatic light significantly affects not only plant photosynthetic performance but also the "quality" of plants by modulating the biosynthesis of photoprotective compounds.
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Affiliation(s)
- Marco Landi
- Department of Agriculture, Food and Environment, University of Pisa, Italy
| | - Marek Zivcak
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovak Republic.
| | - Oksana Sytar
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovak Republic
| | - Marian Brestic
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovak Republic; Department of Botany and Plant Physiology, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 16500 Prague, Czech Republic
| | - Suleyman I Allakhverdiev
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia; Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, Russia; Department of Plant Physiology, M.V. Lomonosov Moscow State University, Moscow, Russia; Department of Molecular and Cell Biology, Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow Region, Russia; Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Baku, Azerbaijan; King Saud University, Riyadh, Saudi Arabia.
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79
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Hoshino R, Yoshida Y, Tsukaya H. Multiple steps of leaf thickening during sun-leaf formation in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:738-753. [PMID: 31350790 PMCID: PMC6900135 DOI: 10.1111/tpj.14467] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 05/20/2023]
Abstract
Plant morphological and physiological traits exhibit plasticity in response to light intensity. Leaf thickness is enhanced under high light (HL) conditions compared with low light (LL) conditions through increases in both cell number and size in the dorsoventral direction; however, the regulation of such phenotypic plasticity in leaf thickness (namely, sun- or shade-leaf formation) during the developmental process remains largely unclear. By modifying observation techniques for tiny leaf primordia in Arabidopsis thaliana, we analysed sun- and shade-leaf development in a time-course manner and found that the process of leaf thickening can be divided into early and late phases. In the early phase, anisotropic cell elongation and periclinal cell division on the adaxial side of mesophyll tissue occurred under the HL conditions used, which resulted in the dorsoventral growth of sun leaves. Anisotropic cell elongation in the palisade tissue is triggered by blue-light irradiation. We discovered that anisotropic cell elongation processes before or after periclinal cell division were differentially regulated independent of or dependent upon signalling through blue-light receptors. In contrast, during the late phase, isotropic cell expansion associated with the endocycle, which determined the final leaf thickness, occurred irrespective of the light conditions. Sucrose production was high under HL conditions, and we found that sucrose promoted isotropic cell expansion and the endocycle even under LL conditions. Our analyses based on this method of time-course observation addressed the developmental framework of sun- and shade-leaf formation.
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Affiliation(s)
- Rina Hoshino
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
| | - Yuki Yoshida
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
| | - Hirokazu Tsukaya
- Department of Biological SciencesGraduate School of ScienceThe University of TokyoBunkyo‐kuTokyo113‐0033Japan
- Exploratory Research Center on Life and Living SystemsNational Institutes of Natural SciencesOkazakiAichi444‐8787Japan
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80
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Distinct mechanisms of Drosophila CRYPTOCHROME-mediated light-evoked membrane depolarization and in vivo clock resetting. Proc Natl Acad Sci U S A 2019; 116:23339-23344. [PMID: 31659046 PMCID: PMC6859314 DOI: 10.1073/pnas.1905023116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Drosophila CRYPTOCHROME (dCRY) mediates electrophysiological depolarization and circadian clock resetting in response to blue or ultraviolet (UV) light. These light-evoked biological responses operate at different timescales and possibly through different mechanisms. Whether electron transfer down a conserved chain of tryptophan residues underlies biological responses following dCRY light activation has been controversial. To examine these issues in in vivo and in ex vivo whole-brain preparations, we generated transgenic flies expressing tryptophan mutant dCRYs in the conserved electron transfer chain and then measured neuronal electrophysiological phototransduction and behavioral responses to light. Electrophysiological-evoked potential analysis shows that dCRY mediates UV and blue-light-evoked depolarizations that are long lasting, persisting for nearly a minute. Surprisingly, dCRY appears to mediate red-light-evoked depolarization in wild-type flies, absent in both cry-null flies, and following acute treatment with the flavin-specific inhibitor diphenyleneiodonium in wild-type flies. This suggests a previously unsuspected functional signaling role for a neutral semiquinone flavin state (FADH•) for dCRY. The W420 tryptophan residue located closest to the FAD-dCRY interaction site is critical for blue- and UV-light-evoked electrophysiological responses, while other tryptophan residues within electron transfer distance to W420 do not appear to be required for light-evoked electrophysiological responses. Mutation of the dCRY tryptophan residue W342, more distant from the FAD interaction site, mimics the cry-null behavioral light response to constant light exposure. These data indicate that light-evoked dCRY electrical depolarization and clock resetting are mediated by distinct mechanisms.
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81
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Zoltowski BD, Chelliah Y, Wickramaratne A, Jarocha L, Karki N, Xu W, Mouritsen H, Hore PJ, Hibbs RE, Green CB, Takahashi JS. Chemical and structural analysis of a photoactive vertebrate cryptochrome from pigeon. Proc Natl Acad Sci U S A 2019; 116:19449-19457. [PMID: 31484780 PMCID: PMC6765304 DOI: 10.1073/pnas.1907875116] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Computational and biochemical studies implicate the blue-light sensor cryptochrome (CRY) as an endogenous light-dependent magnetosensor enabling migratory birds to navigate using the Earth's magnetic field. Validation of such a mechanism has been hampered by the absence of structures of vertebrate CRYs that have functional photochemistry. Here we present crystal structures of Columba livia (pigeon) CRY4 that reveal evolutionarily conserved modifications to a sequence of Trp residues (Trp-triad) required for CRY photoreduction. In ClCRY4, the Trp-triad chain is extended to include a fourth Trp (W369) and a Tyr (Y319) residue at the protein surface that imparts an unusually high quantum yield of photoreduction. These results are consistent with observations of night migratory behavior in animals at low light levels and could have implications for photochemical pathways allowing magnetosensing.
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Affiliation(s)
- Brian D Zoltowski
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275
- Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275
| | - Yogarany Chelliah
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Anushka Wickramaratne
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lauren Jarocha
- Department of Chemistry, University of Oxford, OX1 3QZ Oxford, United Kingdom
| | - Nischal Karki
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275
- Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275
| | - Wei Xu
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, DE-26111 Oldenburg, Germany
- Research Center for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
| | - Peter J Hore
- Department of Chemistry, University of Oxford, OX1 3QZ Oxford, United Kingdom
| | - Ryan E Hibbs
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Carla B Green
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Joseph S Takahashi
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390;
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
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82
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Abstract
Birds can use two kinds of information from the geomagnetic field for navigation: the direction of the field lines as a compass and probably magnetic intensity as a component of the navigational ‘map’. The direction of the magnetic field appears to be sensed via radical pair processes in the eyes, with the crucial radical pairs formed by cryptochrome. It is transmitted by the optic nerve to the brain, where parts of the visual system seem to process the respective information. Magnetic intensity appears to be perceived by magnetite-based receptors in the beak region; the information is transmitted by the ophthalmic branch of the trigeminal nerve to the trigeminal ganglion and the trigeminal brainstem nuclei. Yet in spite of considerable progress in recent years, many details are still unclear, among them details of the radical pair processes and their transformation into a nervous signal, the precise location of the magnetite-based receptors and the centres in the brain where magnetic information is combined with other navigational information for the navigational processes.
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Affiliation(s)
- Roswitha Wiltschko
- FB Biowissenschaften, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Wolfgang Wiltschko
- FB Biowissenschaften, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
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83
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Serrage H, Heiskanen V, Palin WM, Cooper PR, Milward MR, Hadis M, Hamblin MR. Under the spotlight: mechanisms of photobiomodulation concentrating on blue and green light. Photochem Photobiol Sci 2019; 18:1877-1909. [PMID: 31183484 PMCID: PMC6685747 DOI: 10.1039/c9pp00089e] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/30/2019] [Indexed: 12/31/2022]
Abstract
Photobiomodulation (PBM) describes the application of light at wavelengths ranging from 400-1100 nm to promote tissue healing, reduce inflammation and promote analgesia. Traditionally, red and near-infra red (NIR) light have been used therapeutically, however recent studies indicate that other wavelengths within the visible spectrum could prove beneficial including blue and green light. This review aims to evaluate the literature surrounding the potential therapeutic effects of PBM with particular emphasis on the effects of blue and green light. In particular focus is on the possible primary and secondary molecular mechanisms of PBM and also evaluation of the potential effective parameters for application both in vitro and in vivo. Studies have reported that PBM affects an array of molecular targets, including chromophores such as signalling molecules containing flavins and porphyrins as well as components of the electron transport chain. However, secondary mechanisms tend to converge on pathways induced by increases in reactive oxygen species (ROS) production. Systematic evaluation of the literature indicated 72% of publications reported beneficial effects of blue light and 75% reported therapeutic effects of green light. However, of the publications evaluating the effects of green light, reporting of treatment parameters was uneven with 41% failing to report irradiance (mW cm-2) and 44% failing to report radiant exposure (J cm-2). This review highlights the potential of PBM to exert broad effects on a range of different chromophores within the body, dependent upon the wavelength of light applied. Emphasis still remains on the need to report exposure and treatment parameters, as this will enable direct comparison between different studies and hence enable the determination of the full potential of PBM.
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Affiliation(s)
- Hannah Serrage
- College of Medical and Dental Sciences, University of Birmingham, UK.
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84
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Time-Resolved Infrared and Visible Spectroscopy on Cryptochrome aCRY: Basis for Red Light Reception. Biophys J 2019; 117:490-499. [PMID: 31326107 DOI: 10.1016/j.bpj.2019.06.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 12/18/2022] Open
Abstract
Cryptochromes function as flavin-binding photoreceptors in bacteria, fungi, algae, land plants, and insects. The discovery of an animal-like cryptochrome in the green alga Chlamydomonas reinhardtii has expanded the spectral range of sensitivity of these receptors from ultraviolet A/blue light to almost the complete visible spectrum. The broadened light response has been explained by the presence of the flavin neutral radical as a chromophore in the dark. Concomitant with photoconversion of the flavin, an unusually long-lived tyrosyl radical with a red-shifted ultraviolet-visible spectrum is formed, which is essential for the function of the receptor. In this study, the microenvironment of this key residue, tyrosine 373, was scrutinized using time-resolved Fourier transform infrared spectroscopy on several variants of animal-like cryptochrome and density functional theory for band assignment. The reduced tyrosine takes on distinct hydrogen bond scenarios depending on the presence of the C-terminal extension and of a neighboring cysteine. Upon radical formation, all variants showed a signal at 1400 cm-1, which we assigned to the ν7'a marker band of the CO stretching mode. The exceptionally strong downshift of this band cannot be attributed to a loss of hydrogen bonding only. Time-resolved ultraviolet-visible spectroscopy on W322F, a mutant of the neighboring tryptophan residue, revealed a decrease of the tyrosyl radical lifetime by almost two orders of magnitude, along with a shift of the absorbance maximum from 416 to 398 nm. These findings strongly support the concept of a π-π stacking as an apolar interaction between Y373 and W322 to be responsible for the characteristics of the tyrosyl radical. This concept of radical stabilization has been unknown to cryptochromes so far but might be highly relevant for other homologs with a tetrad of tryptophans and tyrosines as electron donors.
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85
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Meng Q, Runkle ES. Regulation of flowering by green light depends on its photon flux density and involves cryptochromes. PHYSIOLOGIA PLANTARUM 2019; 166:762-771. [PMID: 30187495 DOI: 10.1111/ppl.12832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/31/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
Photoperiodic lighting can promote flowering of long-day plants (LDPs) and inhibit flowering of short-day plants (SDPs). Red (R) and far-red (FR) light regulate flowering through phytochromes, whereas blue light does so primarily through cryptochromes. In contrast, the role of green light in photoperiodic regulation of flowering has been inconsistent in previous studies. We grew four LDP species (two petunia cultivars, ageratum, snapdragon and Arabidopsis) and two SDP species (three chrysanthemum cultivars and marigold) in a greenhouse under truncated 9-h short days with or without 7-h day-extension lighting from green light (peak = 521 nm) at 0, 2, 13 or 25 μmol m-2 s-1 or R + white (W) + FR light at 2 μmol m-2 s-1 . Increasing the green photon flux density from 0 to 25 μmol m-2 s-1 accelerated flowering of all LDPs and delayed flowering of all SDPs. Petunia flowered similarly fast under R + W + FR light and moderate green light but was shorter and developed more branches under green light. To be as effective as R + W + FR light, saturation green photon flux densities were 2 μmol m-2 s-1 for LDP ageratum and SDP marigold and 13 μmol m-2 s-1 for LDP petunia. Snapdragon was the least sensitive to green light. In Arabidopsis, cryptochrome 2 mediated promotion of flowering under moderate green light, whereas both phytochrome B and cryptochrome 2 mediated that under R + W + FR light. We conclude that 7-h day-extension lighting from green light-emitting diodes can control flowering of photoperiodic ornamentals and that in Arabidopsis, cryptochrome 2 mediates promotion of flowering under green light.
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Affiliation(s)
- Qingwu Meng
- Department of Horticulture, Michigan State University, East Lansing, MI 48824-1325, USA
| | - Erik S Runkle
- Department of Horticulture, Michigan State University, East Lansing, MI 48824-1325, USA
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86
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Berntsson O, Rodriguez R, Henry L, Panman MR, Hughes AJ, Einholz C, Weber S, Ihalainen JA, Henning R, Kosheleva I, Schleicher E, Westenhoff S. Photoactivation of Drosophila melanogaster cryptochrome through sequential conformational transitions. SCIENCE ADVANCES 2019; 5:eaaw1531. [PMID: 31328161 PMCID: PMC6636987 DOI: 10.1126/sciadv.aaw1531] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 06/13/2019] [Indexed: 05/27/2023]
Abstract
Cryptochromes are blue-light photoreceptor proteins, which provide input to circadian clocks. The cryptochrome from Drosophila melanogaster (DmCry) modulates the degradation of Timeless and itself. It is unclear how light absorption by the chromophore and the subsequent redox reactions trigger these events. Here, we use nano- to millisecond time-resolved x-ray solution scattering to reveal the light-activated conformational changes in DmCry and the related (6-4) photolyase. DmCry undergoes a series of structural changes, culminating in the release of the carboxyl-terminal tail (CTT). The photolyase has a simpler structural response. We find that the CTT release in DmCry depends on pH. Mutation of a conserved histidine, important for the biochemical activity of DmCry, does not affect transduction of the structural signal to the CTT. Instead, molecular dynamics simulations suggest that it stabilizes the CTT in the resting-state conformation. Our structural photocycle unravels the first molecular events of signal transduction in an animal cryptochrome.
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Affiliation(s)
- Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
- MAX IV Laboratory, Lund University, 224 84 Lund, Sweden
| | - Ryan Rodriguez
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Léocadie Henry
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Matthijs R. Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Ashley J. Hughes
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Christopher Einholz
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Stefan Weber
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Janne A. Ihalainen
- Nanoscience Center, Department of Biological and Environmental Sciences, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Robert Henning
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Irina Kosheleva
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Erik Schleicher
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
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87
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Alrifai O, Hao X, Marcone MF, Tsao R. Current Review of the Modulatory Effects of LED Lights on Photosynthesis of Secondary Metabolites and Future Perspectives of Microgreen Vegetables. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:6075-6090. [PMID: 31021630 DOI: 10.1021/acs.jafc.9b00819] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Light-emitting diode (LED) lights have recently been applied in controlled environment agriculture toward growing vegetables of various assortments, including microgreens. Spectral qualities of LED light on photosynthesis in microgreens are currently being studied for their ease of spectral optimization and high photosynthetic efficiency. This review aims to summarize the most recent discoveries and advances in specific phytochemical biosyntheses modulated by LED and other conventional lighting, to identify research gaps, and to provide future perspectives in this emerging multidisciplinary field of research and development. Specific emphasis was made on the effect of light spectral qualities on the biosynthesis of phenolics, carotenoids, and glucosinolates, as these phytochemicals are known for their antioxidant, anti-inflammatory effects, and many health benefits. Future perspectives on enhancing biosynthesis of these bioactives using the rapidly progressing LED light technology are further discussed.
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Affiliation(s)
- Oday Alrifai
- Guelph Research & Development Center , Agriculture and Agri-Food Canada , 93 Stone Road West , Guelph , Ontario N1G 5C9 , Canada
- Department of Food Science, Ontario Agricultural College , University of Guelph , Guelph , Ontario N1G 2W1 , Canada
| | - Xiuming Hao
- Harrow Research & Development Center , Agriculture and Agri-Food Canada , 2585 County Road 20 , Harrow , Ontario N0R 1G0 , Canada
| | - Massimo F Marcone
- Department of Food Science, Ontario Agricultural College , University of Guelph , Guelph , Ontario N1G 2W1 , Canada
| | - Rong Tsao
- Guelph Research & Development Center , Agriculture and Agri-Food Canada , 93 Stone Road West , Guelph , Ontario N1G 5C9 , Canada
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88
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Brelsford CC, Nybakken L, Kotilainen TK, Robson TM. The influence of spectral composition on spring and autumn phenology in trees. TREE PHYSIOLOGY 2019; 39:925-950. [PMID: 30901060 DOI: 10.1093/treephys/tpz026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 01/25/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its spectral composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to spectral composition. Our objective was to explore the natural variation in spectral composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where spectral composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more-southern species and ecotypes to adapt and use spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.
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Affiliation(s)
- Craig C Brelsford
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Line Nybakken
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Titta K Kotilainen
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Natural Resources Institute Finland, Turku, Finland
| | - T Matthew Robson
- Organismal and Evolutionary Biology, Viikki Plant Science Centre, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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89
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Su D, Kabir MP, Orozco-Gonzalez Y, Gozem S, Gadda G. Fluorescence Properties of Flavin Semiquinone Radicals in Nitronate Monooxygenase. Chembiochem 2019; 20:1646-1652. [PMID: 30748074 DOI: 10.1002/cbic.201900016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 11/09/2022]
Abstract
Fluorescent cofactors like flavins can be exploited to probe their local environment with spatial and temporal resolution. Although the fluorescence properties of the oxidized and two-electron-reduced states of flavins have been studied extensively, this is not the case for the one-electron-reduced state. Both the neutral and anionic semiquinones have proven particularly challenging to examine, as they are unstable in solution and are transient, short-lived species in many catalytic cycles. Here, we report that the nitronate monooxygenase (NMO) from Pseudomonas aeruginosa PAO1 is capable of stabilizing both semiquinone forms anaerobically for hours, thus enabling us to study their spectroscopy in a constant protein environment. We found that in the active site of NMO, the anionic semiquinone exhibits no fluorescence, whereas the neutral semiquinone radical shows a relatively strong fluorescence, with a behavior that violates the Kasha-Vavilov rule. These fluorescence properties are discussed in the context of time-dependent density functional theory calculations, which reveal low-lying dark states in both systems.
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Affiliation(s)
- Dan Su
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Mohammad Pabel Kabir
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Yoelvis Orozco-Gonzalez
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Samer Gozem
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, 50 Decatur St. SE, Atlanta, GA, 30302, USA.,Department of Biology, Georgia State University, 100 Piedmond Ave., Atlanta, GA, 30303, USA.,Center for Diagnostics and Therapeutics, Georgia State University, P.O. Box 5090, Atlanta, GA, 30303, USA.,Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA, 30302, USA
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90
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Nohr D, Weber S, Schleicher E. EPR spectroscopy on flavin radicals in flavoproteins. Methods Enzymol 2019; 620:251-275. [PMID: 31072489 DOI: 10.1016/bs.mie.2019.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Flavin semiquinone redox states are important intermediates in a broad variety of reactions catalyzed by flavoproteins. As paramagnetic states they can be favorably probed by EPR spectroscopy in all its flavors. This review summarizes recent results in the characterization of flavin radicals. On the one hand, flavin radical states, e.g., trapped as reaction intermediates, can be characterized using modern pulsed EPR methods to unravel their electronic structure and to gain information about the surrounding environment and its changes on protein action. On the other hand, short-lived intermediate flavin radical states generated, e.g., photochemically, can be followed by time-resolved EPR, which allows a direct tracking of flavin-dependent reactions with a temporal resolution reaching nanoseconds.
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Affiliation(s)
- Daniel Nohr
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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91
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Zheng C, Ma JQ, Ma CL, Shen SY, Liu YF, Chen L. Regulation of Growth and Flavonoid Formation of Tea Plants ( Camellia sinensis) by Blue and Green Light. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:2408-2419. [PMID: 30721059 DOI: 10.1021/acs.jafc.8b07050] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The effects of blue (BL) and green light (GL) treatment during the dark period were examined in Camellia sinensis as a first step to understanding the spectral effects of artificial BL and GL on plant secondary metabolism and light signaling interactions. BL could induce the expression of CRY2/3, SPAs, HY5, and R2R3-MYBs to promote the accumulation of anthocyanins and catechins in tea plants. GL, on the other hand, could stimulate the accumulation of several functional substances (e.g., procyanidin B2/B3 and l-ascorbate) and temper these BL responses via down-regulation of CRY2/3 and PHOT2. Furthermore, the molecular events that triggered by BL and GL signals were partly overlapped with abiotic/biotic stress responses. We indicate the possibility of a targeted use of BL and GL to regulate the amount of functional metabolites to enhance tea quality and taste, and to potentially trigger defense mechanisms of tea plants.
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Affiliation(s)
- Chao Zheng
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
| | - Jian-Qiang Ma
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
| | - Chun-Lei Ma
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
| | - Si-Yan Shen
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
| | - Yu-Fei Liu
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
| | - Liang Chen
- Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs , Tea Research Institute of the Chinese Academy of Agricultural Sciences , Hangzhou , China
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92
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Khudyakova AY, Kreslavski VD, Shmarev AN, Lyubimov VY, Shirshikova GN, Pashkovskiy PP, Kuznetsov VV, Allakhverdiev SI. Impact of UV-B radiation on the photosystem II activity, pro-/antioxidant balance and expression of light-activated genes in Arabidopsis thaliana hy4 mutants grown under light of different spectral composition. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 194:14-20. [PMID: 30897399 DOI: 10.1016/j.jphotobiol.2019.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 11/27/2022]
Abstract
The effect of UV-B irradiation on the photosystem II (PSII) activity, the content of photosynthetic and UV-absorbing pigments (UAPs), activity of antioxidant enzymes such as catalase (CAT) and peroxidase (POD), as well as H2O2 content in 25-day-old wild type (WT) and the cryptochrome 1 (Cry1) mutant hy4 of Arabidopsis thaliana Col-0 plants was studied. In addition, expression of photoreceptor genes Cry1, Cry2 and UVR8, photomorphogenetic gene COP1 and transcription factors genes HY5, HYH, the gene of chlorophyll-binding protein of the PSII CAB1 as well as the flavonoid biosynthesis genes CHS, PAL and thylakoid ascorbate peroxidase gene tAPX was examined. It has been shown that UV-B leads to a decrease in the photochemical activity of PSII (FV/FM) and the PSII performance index (PIABS) of WT plants grown on white (WL) and red (RL) light and also hy4 mutants grown on WL, RL and blue light (BL). In plants grown on BL and WL, the decrease in the PSII photochemical activity was significantly greater in hy4 compared to WT. The PSII of WT plants grown in BL was resistant to UV-B. The UAPs content of hy4 grown on BL and WL was lower than that in WT. The POD and CAT activities of WT grown in BL were significantly higher than in the mutant. In WT and hy4 plants grown in RL, a noticeable difference in these enzymes activity was not found. In both types of plants grown in BL and RL, the expression of photomorphogenetic genes HYH, HY5 markedly increased after UV-B treatment but the expression of the UV-B photoreceptor gene UVR8 was reduced in hy4 grown in BL and RL. It is assumed that reduced resistance of PSII in hy4 plants grown in BL and WL can be associated with low UAPs content as well as lowered POD and CAT activities. In addition, we suggest the lowered expression of UVR8 and COP1 genes caused by Cry1 deficiency leads to a shift of balance of oxidants and antioxidants towards oxidants.
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Affiliation(s)
- Aleksandra Yu Khudyakova
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia
| | - Vladimir D Kreslavski
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia; Russian Academy of Sciences, Timiryazev Institute of Plant Physiology, Botanicheskaya Street 35, Moscow 127276, Russia.
| | - Aleksandr N Shmarev
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia
| | - Valery Yu Lyubimov
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia
| | - Galina N Shirshikova
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia
| | - Pavel P Pashkovskiy
- Russian Academy of Sciences, Timiryazev Institute of Plant Physiology, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Vladimir V Kuznetsov
- Russian Academy of Sciences, Timiryazev Institute of Plant Physiology, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Suleyman I Allakhverdiev
- Russian Academy of Sciences, Institute of Basic Biological Problems, Institutskaya Street 2, Pushchino, Moscow 142290, Russia; Russian Academy of Sciences, Timiryazev Institute of Plant Physiology, Botanicheskaya Street 35, Moscow 127276, Russia; Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow 119991, Russia; Department of Molecular and Cell Biology, Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow 141700, Russia; Bionanotechnology Laboratory, Azerbaijan National Academy of Sciences, Institute of Molecular Biology and Biotechnology, Matbuat Avenue 2a, Baku 1073, Azerbaijan.
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93
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Pooam M, Arthaut LD, Burdick D, Link J, Martino CF, Ahmad M. Magnetic sensitivity mediated by the Arabidopsis blue-light receptor cryptochrome occurs during flavin reoxidation in the dark. PLANTA 2019; 249:319-332. [PMID: 30194534 DOI: 10.1007/s00425-018-3002-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Arabidopsis cryptochrome mediates responses to magnetic fields that have been applied in the absence of light, consistent with flavin reoxidation as the primary detection mechanism. Cryptochromes are highly conserved blue-light-absorbing flavoproteins which have been linked to the perception of electromagnetic stimuli in numerous organisms. These include sensing the direction of the earth's magnetic field in migratory birds and the intensity of magnetic fields in insects and plants. When exposed to light, cryptochromes undergo flavin reduction/reoxidation redox cycles leading to biological activation which generate radical pairs thought to be the basis for magnetic sensitivity. However, the nature of the magnetically sensitive radical pairs and the steps at which they act during the cryptochrome redox cycle are currently a matter of debate. Here, we investigate the response of Arabidopsis cryptochrome-1 in vivo to a static magnetic field of 500 μT (10 × earth's field) using both plant growth and light-dependent phosphorylation as an assay. Cryptochrome responses to light were enhanced by the magnetic field, as indicated by increased inhibition of hypocotyl elongation and increased cryptochrome phosphorylation. However, when light and dark intervals were given intermittently, a plant response to the magnetic field was observed even when the magnetic field was given exclusively during the dark intervals between light exposures. This indicates that the magnetically sensitive reaction step in the cryptochrome photocycle must occur during flavin reoxidation, and likely involves the formation of reactive oxygen species.
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Affiliation(s)
- Marootpong Pooam
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Louis-David Arthaut
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Derek Burdick
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Justin Link
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Carlos F Martino
- Department of Biomedical Engineering, Florida Institute of Technology, 150W University Blvd, Melbourne, FL, 32901, USA
| | - Margaret Ahmad
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France.
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA.
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94
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Dhiman SK, Galland P. Effects of weak static magnetic fields on the gene expression of seedlings of Arabidopsis thaliana. JOURNAL OF PLANT PHYSIOLOGY 2018; 231:9-18. [PMID: 30199755 DOI: 10.1016/j.jplph.2018.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 08/26/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Magnetic-field reception of animals and plants is currently discussed in the framework of a cryptochrome-based radical-pair mechanism. Efforts to unravel magnetoreception in plants suffered historically from several shortcomings, most prominently, the conspicuous absence of detailed stimulus-response relationships. To determine the sensitivity of seedlings of Arabidopsis thaliana to weak static magnetic fields we generated stimulus-response curves between near zero and 188 μT for the transcript levels of the genes rbcl, cab4, pal4 and ef1. The moderate magneto-responsiveness of dark-grown seedlings was greatly enhanced under blue light, and for rbcl and pal4 also under red light. The stimulus-response curves obtained under blue light of constant photon-fluence rate displayed multiple maxima and thus a pattern fundamentally different from that prevalent in plant and animal physiology. A double mutant lacking cryptochromes 1 and 2 displayed altered stimulus-response curves without losing, however, magneto-responsiveness completely. A reversal of the magnetic field direction substantially affected the gene expression and the quantity of CAB-protein (chlorophyll a,b-binding protein). The majority of our results are at variance with the notion of cryptochromes acting as the only magnetic-field sensors. They do not, however, exclude the possibility that cryptochromes participate in the magnetic field reception of Arabidopsis. The findings have the unexpected implication that cryptochrome- and phytochrome-mediated plant responses can be modulated by the strength and the orientation of the local geomagnetic field.
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Affiliation(s)
- Sunil K Dhiman
- Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany; Kirori Mal College, Delhi University (North Campus), Delhi-110007, India.
| | - Paul Galland
- Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany.
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95
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Rostas A, Einholz C, Illarionov B, Heidinger L, Said TA, Bauss A, Fischer M, Bacher A, Weber S, Schleicher E. Long-Lived Hydrated FMN Radicals: EPR Characterization and Implications for Catalytic Variability in Flavoproteins. J Am Chem Soc 2018; 140:16521-16527. [PMID: 30412389 DOI: 10.1021/jacs.8b07544] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Until now, FMN/FAD radicals could not be stabilized in aqueous solution or other protic solvents because of rapid and efficient dismutation reactions. In this contribution, a novel system for stabilizing flavin radicals in aqueous solution is reported. Subsequent to trapping FMN in an agarose matrix, light-generated FMN radicals could be produced that were stable for days even under aerobic conditions, and their concentrations were high enough for extensive EPR characterization. All large hyperfine couplings could be extracted by using a combination of continuous-wave EPR and low-temperature ENDOR spectroscopy. To map differences in the electronic structure of flavin radicals, two exemplary proton hyperfine couplings were compared with published values from various neutral and anionic flavoprotein radicals: C(6)H and C(8α)H 3. It turned out that FMN•- in an aqueous environment shows the largest hyperfine couplings, whereas for FMNH• under similar conditions, hyperfine couplings are at the lower end and the values of both vary by up to 30%. This finding demonstrates that protein-cofactor interactions in neutral and anionic flavoprotein radicals can alter their electron spin density in different directions. With this aqueous system that allows the characterization of flavin radicals without protein interactions and that can be extended by using selective isotope labeling, a powerful tool is now at hand to quantify interactions in flavin radicals that modulate the reactivity in different flavoproteins.
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Affiliation(s)
- Arpad Rostas
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Christopher Einholz
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Boris Illarionov
- Hamburg School of Food Science , Institut für Lebensmittelchemie, Universität Hamburg , Grindelallee 117 , 20146 Hamburg , Germany
| | - Lorenz Heidinger
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Tarek Al Said
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Anna Bauss
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Markus Fischer
- Hamburg School of Food Science , Institut für Lebensmittelchemie, Universität Hamburg , Grindelallee 117 , 20146 Hamburg , Germany
| | - Adelbert Bacher
- Department of Chemistry , Technical University of Munich , Lichtenbergstr. 4 , 85747 Garching , Germany
| | - Stefan Weber
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie , Albert-Ludwigs-Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
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96
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Yang LW, Wen XH, Fu JX, Dai SL. ClCRY2 facilitates floral transition in Chrysanthemum lavandulifolium by affecting the transcription of circadian clock-related genes under short-day photoperiods. HORTICULTURE RESEARCH 2018; 5:58. [PMID: 30393540 PMCID: PMC6210193 DOI: 10.1038/s41438-018-0063-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/26/2018] [Accepted: 06/04/2018] [Indexed: 05/23/2023]
Abstract
Plants sense photoperiod signals to confirm the optimal flowering time. Previous studies have shown that Cryptochrome2 (CRY2) functions to promote floral transition in the long-day plant (LDP) Arabidopsis; however, the function and molecular mechanism by which CRY2 regulates floral transition in short-day plants (SDPs) is still unclear. In this study, we identified a CRY2 homologous gene, ClCRY2, from Chrysanthemum lavandulifolium, a typical SDP. The morphological changes in the C. lavandulifolium shoot apex and ClFTs expression analysis under SD conditions showed that adult C. lavandulifolium completed the developmental transition from vegetative growth to reproductive growth after eight SDs. Meanwhile, ClCRY2 mRNA exhibited an increasing trend from 0 to 8 d of SD treatment. ClCRY2 overexpression in wild-type (WT) Arabidopsis and C. lavandulifolium resulted in early flowering. The transcript levels of the CONSTANS-like (COL) genes ClCOL1, ClCOL4, and ClCOL5, and FLOWERING LOCUS T (FT) homologous gene ClFT1 were upregulated in ClCRY2 overexpression (ClCRY2-OE) C. lavandulifolium under SD conditions. The transcript levels of some circadian clock-related genes, including PSEUDO-REPONSE REGULATOR 5 (PRR5), ZEITLUPE (ZTL), FLAVIN-BINDING KELCH REPEAT F-BOX 1 (FKF1), and GIGANTEA (GI-1 and GI-2), were upregulated in ClCRY2-OE C. lavandulifolium, while the expression levels of other circadian clock-related genes, such as EARLY FLOWERING 3 (ELF3), ELF4, LATE ELONGATED HYPOCOTYL (LHY), PRR73, and REVEILLE8 (RVE8), were downregulated in ClCRY2-OE C. lavandulifolium under SD conditions. Taken together, the results suggest that ClCRY2 promotes floral transition by fine-tuning the expression of circadian clock-related gene, ClCOLs and ClFT1 in C. lavandulifolium under SD conditions.
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Affiliation(s)
- Li-wen Yang
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 P. R. China
| | - Xiao-hui Wen
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 P. R. China
| | - Jian-xin Fu
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 P. R. China
| | - Si-lan Dai
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 P. R. China
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97
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Eckel M, Steinchen W, Batschauer A. ATP boosts lit state formation and activity of Arabidopsis cryptochrome 2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:389-403. [PMID: 30044014 DOI: 10.1111/tpj.14039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 06/27/2018] [Accepted: 07/04/2018] [Indexed: 05/21/2023]
Abstract
Cryptochrome (cry) blue light photoreceptors have important roles in the regulation of plant development. Their photocycle includes redox changes of their flavin adenine dinucleotide (FAD) chromophore, which is fully oxidised in the dark state and semi-reduced in the signalling-active lit state. The two Arabidopsis thaliana cryptochromes, cry1 and cry2, and the plant-type cryptochrome CPH1 from Chlamydomonas rheinhardtii bind ATP and other nucleotides. Binding of ATP affects the photocycle of these photoreceptors and causes structural alterations. However, the exact regions that undergo structural changes have not been defined, and most importantly it is not known whether ATP binding affects the biological activity of these photoreceptors in planta. Here we present studies on the effect of ATP on Arabidopsis cry2. Recombinant cry2 protein showed a high affinity for ATP (KD of 1.09 ± 0.48 μm). Binding of ATP and other adenines promoted photoreduction of the FAD chromophore in vitro and caused structural changes, particularly in α-helix 21 which links the photosensory domain with the C-terminal extension. The constructed cry2Y399A mutant was unable to bind ATP and did not show enhancement of photoreduction by ATP. When this mutant gene was expressed in Arabidopsis null cry2 mutant plants it retained some biological activity, which was, however, lower than that of the wild type. Our results indicate that binding of ATP to cry2, and most likely to other plant-type cryptochromes, is not essential but boosts the formation of the signalling state and biological activity.
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Affiliation(s)
- Maike Eckel
- Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-Universität Marburg, 35032, Marburg, Germany
| | - Wieland Steinchen
- Faculty of Chemistry and LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, 35032, Marburg, Germany
| | - Alfred Batschauer
- Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-Universität Marburg, 35032, Marburg, Germany
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98
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Park Y, Runkle ES. Spectral effects of light-emitting diodes on plant growth, visual color quality, and photosynthetic photon efficacy: White versus blue plus red radiation. PLoS One 2018; 13:e0202386. [PMID: 30114282 PMCID: PMC6095554 DOI: 10.1371/journal.pone.0202386] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/02/2018] [Indexed: 11/23/2022] Open
Abstract
Arrays of blue (B, 400−500 nm) and red (R, 600−700 nm) light-emitting diodes (LEDs) used for plant growth applications make visual assessment of plants difficult compared to a broad (white, W) spectrum. Although W LEDs are sometimes used in horticultural lighting fixtures, little research has been published using them for sole-source lighting. We grew seedlings of begonia (Begonia ×semperflorens), geranium (Pelargonium ×horturum), petunia (Petunia ×hybrida), and snapdragon (Antirrhinum majus) at 20°C under six sole-source LED lighting treatments with a photosynthetic photon flux density (PPFD) of 160 μmol∙m–2∙s–1 using B (peak = 447 nm), green (G, peak = 531 nm), R (peak = 660 nm), and/or mint W (MW, peak = 558 nm) LEDs that emitted 15% B, 59% G, and 26% R plus 6 μmol∙m−2∙s−1 of far-red radiation. The lighting treatments (with percentage from each LED in subscript) were MW100, MW75R25, MW45R55, MW25R75, B15R85, and B20G40R40. At the transplant stage, total leaf area, and fresh and dry weight were similar among treatments in all species. Surprisingly, when petunia seedlings were grown longer (beyond the transplant stage) under sole-source lighting treatments, the primary stem elongated and had flower buds earlier under MW100 and MW75R25 compared to under B15R85. The color rendering index of MW75R25 and MW45R55 were 72, and 77, respectively, which was higher than those of other treatments, which were ≤64. While photosynthetic photon efficacy of B15R85 (2.25 μmol∙J–1) was higher than the W light treatments (1.51−2.13 μmol∙J–1), the dry weight gain per unit electric energy consumption (in g∙kWh–1) of B15R85 was similar to those of MW25R75, MW45R55, and MW75R25 in three species. We conclude that compared to B+R radiation, W radiation had generally similar effects on seedling growth at the same PPFD with similar electric energy consumption, and improved the visual color quality of sole-source lighting.
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Affiliation(s)
- Yujin Park
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
| | - Erik S. Runkle
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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99
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Baik LS, Recinos Y, Chevez JA, Holmes TC. Circadian modulation of light-evoked avoidance/attraction behavior in Drosophila. PLoS One 2018; 13:e0201927. [PMID: 30106957 PMCID: PMC6091921 DOI: 10.1371/journal.pone.0201927] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/24/2018] [Indexed: 12/20/2022] Open
Abstract
Many insects show strong behavioral responses to short wavelength light. Drosophila melanogaster exhibit Cryptochrome- and Hyperkinetic-dependent blue and ultraviolet (UV) light avoidance responses that vary by time-of-day, suggesting that these key sensory behaviors are circadian regulated. Here we show mutant flies lacking core clock genes exhibit defects in both time-of-day responses and valence of UV light avoidance/attraction behavior. Non-genetic environmental disruption of the circadian clock by constant UV light exposure leads to complete loss of rhythmic UV light avoidance/attraction behavior. Flies with ablated or electrically silenced circadian lateral ventral neurons have attenuated avoidance response to UV light. We conclude that circadian clock proteins and the circadian lateral ventral neurons regulate both the timing and the valence of UV light avoidance/attraction. These results provide mechanistic support for Pittendrigh's "escape from light" hypothesis regarding the co-evolution of phototransduction and circadian systems.
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Affiliation(s)
- Lisa Soyeon Baik
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California, United States of America
| | - Yocelyn Recinos
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California, United States of America
| | - Joshua A. Chevez
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California, United States of America
| | - Todd C. Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California, United States of America
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Abstract
Sensory photoreceptors underpin light-dependent adaptations of organismal physiology, development, and behavior in nature. Adapted for optogenetics, sensory photoreceptors become genetically encoded actuators and reporters to enable the noninvasive, spatiotemporally accurate and reversible control by light of cellular processes. Rooted in a mechanistic understanding of natural photoreceptors, artificial photoreceptors with customized light-gated function have been engineered that greatly expand the scope of optogenetics beyond the original application of light-controlled ion flow. As we survey presently, UV/blue-light-sensitive photoreceptors have particularly allowed optogenetics to transcend its initial neuroscience applications by unlocking numerous additional cellular processes and parameters for optogenetic intervention, including gene expression, DNA recombination, subcellular localization, cytoskeleton dynamics, intracellular protein stability, signal transduction cascades, apoptosis, and enzyme activity. The engineering of novel photoreceptors benefits from powerful and reusable design strategies, most importantly light-dependent protein association and (un)folding reactions. Additionally, modified versions of these same sensory photoreceptors serve as fluorescent proteins and generators of singlet oxygen, thereby further enriching the optogenetic toolkit. The available and upcoming UV/blue-light-sensitive actuators and reporters enable the detailed and quantitative interrogation of cellular signal networks and processes in increasingly more precise and illuminating manners.
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Affiliation(s)
- Aba Losi
- Department of Mathematical, Physical and Computer Sciences , University of Parma , Parco Area delle Scienze 7/A-43124 Parma , Italy
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center , New York , New York 10031 , United States.,Department of Chemistry and Biochemistry, City College of New York , New York , New York 10031 , United States.,Ph.D. Programs in Biochemistry, Chemistry, and Biology , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Andreas Möglich
- Lehrstuhl für Biochemie , Universität Bayreuth , 95447 Bayreuth , Germany.,Research Center for Bio-Macromolecules , Universität Bayreuth , 95447 Bayreuth , Germany.,Bayreuth Center for Biochemistry & Molecular Biology , Universität Bayreuth , 95447 Bayreuth , Germany
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