A synthetic switch based on orange carotenoid protein to control blue light responses in chloroplasts

ABSTRACTSynthetic biology approaches to engineer light‐responsive system are widely used, but their applications in plants are still limited, due to the interference with endogenous photoreceptors. Cyanobacteria, such as Synechocystis spp., possess a soluble carotenoid associated protein named Orange Carotenoid binding Protein (OCP) that, when activated by blue‐green light, undergoes reversible conformational changes that enable photoprotection of the phycobilisomes. Exploiting this system, we developed a new chloroplast‐localized synthetic photoswitch based on a photoreceptor‐associated protein‐fragment complementation assay (PCA). Since Arabidopsis thaliana does not possess the prosthetic group needed for the assembly of the OCP2 protein, we implemented the carotenoid biosynthetic pathway with a bacterial β‐carotene ketolase enzyme (crtW), to generate keto‐carotenoids producing plants. The novel photoswitch was tested and characterized in Arabidopsis protoplasts with experiments aimed to uncover its regulation by light intensity, wavelength, and its conversion dynamics. We believe that this pioneer study establishes the basis for future implementation of plastid optogenetics to regulate organelle responses, such as gene transcription or enzymatic activity, upon exposure to specific light spectra.One-sentence summaryInspired by the light-driven conformational transitions of orange carotenoid proteins of cyanobacteria, we generated a molecular device able to switch its dimeric state in response to blue light.

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Transcriptomic and Metabolomic Profiling Reveals the Effect of LED Light Quality on Fruit Ripening and Anthocyanin Accumulation in Cabernet Sauvignon Grape

Frontiers in Nutrition ◽

10.3389/fnut.2021.790697 ◽

2021 ◽

Vol 8 ◽

Author(s):

Peian Zhang ◽

Suwen Lu ◽

Zhongjie Liu ◽

Ting Zheng ◽

Tianyu Dong ◽

...

Keyword(s):

Blue Light ◽

White Light ◽

Plant Traits ◽

Soluble Sugars ◽

Red Light ◽

Green Light ◽

Grape Berries ◽

Light Spectra ◽

Metabolomic Profiling ◽

Highly Expressed Genes

Different light qualities have various impacts on the formation of fruit quality. The present study explored the influence of different visible light spectra (red, green, blue, and white) on the formation of quality traits and their metabolic pathways in grape berries. We found that blue light and red light had different effects on the berries. Compared with white light, blue light significantly increased the anthocyanins (malvidin-3-O-glucoside and peonidin-3-O-glucoside), volatile substances (alcohols and phenols), and soluble sugars (glucose and fructose), reduced the organic acids (citric acid and malic acid), whereas red light achieved the opposite effect. Transcriptomics and metabolomics analyses revealed that 2707, 2547, 2145, and 2583 differentially expressed genes (DEGs) and (221, 19), (254, 22), (189, 17), and (234, 80) significantly changed metabolites (SCMs) were filtered in the dark vs. blue light, green light, red light, and white light, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, most of the DEGs identified were involved in photosynthesis and biosynthesis of flavonoids and flavonols. Using weighted gene co-expression network analysis (WGCNA) of 23410 highly expressed genes, two modules significantly related to anthocyanins and soluble sugars were screened out. The anthocyanins accumulation is significantly associated with increased expression of transcription factors (VvHY5, VvMYB90, VvMYB86) and anthocyanin structural genes (VvC4H, Vv4CL, VvCHS3, VvCHI1, VvCHI2, VvDFR), while significantly negatively correlated with VvPIF4. VvISA1, VvISA2, VvAMY1, VvCWINV, VvβGLU12, and VvFK12 were all related to starch and sucrose metabolism. These findings help elucidate the characteristics of different light qualities on the formation of plant traits and can inform the use of supplemental light in the field and after harvest to improve the overall quality of fruit.

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Blue as an Underrated Alternative to Green: Photoplethysmographic Heartbeat Intervals Estimation under Two Temperature Conditions

Sensors ◽

10.3390/s21124241 ◽

2021 ◽

Vol 21 (12) ◽

pp. 4241

Author(s):

Evgeniia Shchelkanova ◽

Liia Shchapova ◽

Alexander Shchelkanov ◽

Tomohiro Shibata

Keyword(s):

Blue Light ◽

Characteristic Point ◽

Biological Effects ◽

Green Light ◽

Estimation Accuracy ◽

Lower Sensitivity ◽

Light Spectrum ◽

Cardiovascular Parameter ◽

Temperature Conditions ◽

Characteristic Points

Since photoplethysmography (PPG) sensors are usually placed on open skin areas, temperature interference can be an issue. Currently, green light is the most widely used in the reflectance PPG for its relatively low artifact susceptibility. However, it has been known that hemoglobin absorption peaks at the blue part of the spectrum. Despite this fact, blue light has received little attention in the PPG field. Blue wavelengths are commonly used in phototherapy. Combining blue light-based treatments with simultaneous blue PPG acquisition could be potentially used in patients monitoring and studying the biological effects of light. Previous studies examining the PPG in blue light compared to other wavelengths employed photodetectors with inherently lower sensitivity to blue, thereby biasing the results. The present study assessed the accuracy of heartbeat intervals (HBIs) estimation from blue and green PPG signals, acquired under baseline and cold temperature conditions. Our PPG system is based on TCS3472 Color Sensor with equal sensitivity to both parts of the light spectrum to ensure unbiased comparison. The accuracy of the HBIs estimates, calculated with five characteristic points (PPG systolic peak, maximum of the first PPG derivative, maximum of the second PPG derivative, minimum of the second PPG derivative, and intersecting tangents) on both PPG signal types, was evaluated based on the electrocardiographic values. The statistical analyses demonstrated that in all cases, the HBIs estimation accuracy of blue PPG was nearly equivalent to the G PPG irrespective of the characteristic point and measurement condition. Therefore, blue PPG can be used for cardiovascular parameter acquisition. This paper is an extension of work originally presented at the 42nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

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Green-blue light-emitting platinum(ii) complexes of cyclometallated 4,6-difluoro-1,3-dipyridylbenzenes showing mesophase organisation

Journal of Materials Chemistry C ◽

10.1039/c5tc02077h ◽

2015 ◽

Vol 3 (39) ◽

pp. 10177-10187 ◽

Cited By ~ 12

Author(s):

Valery N. Kozhevnikov ◽

Bertrand Donnio ◽

Benoît Heinrich ◽

J. A. Gareth Williams ◽

Duncan W. Bruce

Keyword(s):

Blue Light ◽

Green Light ◽

Light Emitting

Blue-green light-emitting phosphorescent PtII complexes of 1,3-bis(2-pyridyl)benzene are reported that incorporate hexadecyl-containing fragments in the 5-position of the pyridine rings.

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Operando direct observation of spin-states and charge-trappings of blue light-emitting-diode materials in thin-film devices

Scientific Reports ◽

10.1038/s41598-020-75668-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Fumiya Osawa ◽

Kazuhiro Marumoto

Keyword(s):

Blue Light ◽

High Performance ◽

Density Functional ◽

Light Emitting Diode ◽

Green Light ◽

Spin States ◽

Light Emitting ◽

Full Color ◽

Color Displays ◽

Materials Used

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

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Blue and green are frequently seen: responses of seeds to short- and mid-wavelength light

Seed Science Research ◽

10.1017/s0960258511000444 ◽

2011 ◽

Vol 22 (1) ◽

pp. 27-35 ◽

Cited By ~ 9

Author(s):

Danica E. Goggin ◽

Kathryn J. Steadman

Keyword(s):

Blue Light ◽

Seedling Establishment ◽

Native Species ◽

Green Light ◽

Model System ◽

Light Perception ◽

Vegetative Tissues ◽

Wavelength Light

AbstractSeeds have long been a model system for studying the intricacies of phytochrome-mediated light perception and signalling. However, very little is known about how they perceive blue and green light. Cryptochromes and phototropins, the major blue-light receptors in plants, are increasingly well-studied in vegetative tissues, but their role in light perception in seeds largely remains a mystery. Green light elicits a number of responses in plants that cannot be explained by the action of any of the known photoreceptors, and some seeds are apparently also capable of perceiving green light. Here, the responses of seeds to blue and green light are collated from a thorough examination of the literature and considered from the perspective of the potential photoreceptor(s) mediating them. Knowledge of how seeds perceive wavelengths that are suboptimal for phytochrome activation could help to improve germination and seedling establishment for both crop and native species.

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Microwave synthesis, photophysical properties of novel fluorescent iminocoumarins and their application in textile printing

Pigment & Resin Technology ◽

10.1108/prt-04-2014-0029 ◽

2015 ◽

Vol 44 (2) ◽

pp. 87-93 ◽

Cited By ~ 5

Author(s):

G.H. Elgemeie ◽

K.A. Ahmed ◽

E.A. ahmed ◽

M.H. helal ◽

D.M. Masoud

Keyword(s):

Blue Light ◽

Microwave Synthesis ◽

Photophysical Properties ◽

Ethyl Cyanoacetate ◽

High Yield ◽

The Novel ◽

Dioxane Solution ◽

Content Type ◽

Textile Printing ◽

Short Time

Purpose – This paper aims to synthesise coumarine flourescent dyes from a cheap material in a very short time with a very high yield, and by using a clean green chemistry. Design/methodology/approach – Efficient microwave synthesis for some novel iminocoumarins starts from the reaction of p-phenyl-enediamine and ethyl cyanoacetate followed by cyclocondensation with salicylaldehyde derivatives. Findings – The synthesized iminocoumarine compounds were characterized by spectroscopic methods. Absorption and fluorescence spectra of the compounds were also recorded. All compounds were fluorescent in 1,4-dioxane solution, they all emitted blue light (440-460 nm). The printing properties were studied, and their applications on printing polyester and polyamide fabrics were studied by silk screen printing. Originality/value – The authors designed efficient microwavel synthesis for some novel iminocoumarine derivatives; The novel procedure features short-reaction time, moderate yields and simple workup; All compounds were fluorescent in 1,4-dioxane solution, and they all emitted blue light; The authors studied their application in printing polyester and polyamide fabrics.

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The Unique Protein-To-Protein Carotenoid Transfer Mechanism

10.1101/127183 ◽

2017 ◽

Author(s):

Eugene G. Maksimov ◽

Nikolai N. Sluchanko ◽

Yury B. Slonimskiy ◽

Kirill S. Mironov ◽

Konstantin E. Klementiev ◽

...

Keyword(s):

Transfer Process ◽

Targeted Delivery ◽

Green Light ◽

Water Soluble ◽

Uncharacterized Protein ◽

Water Soluble Protein ◽

Orange Carotenoid Protein ◽

Highly Hydrophobic

Orange Carotenoid Protein (OCP) is known to be an effector and regulator of cyanobacterial photoprotection. This 35 kDa water-soluble protein provides specific environment for keto-carotenoids, the excitation of which induced by the absorption of blue-green light causes dramatic but fully reversible rearrangements of the OCP structure, including carotenoid translocation and separation of C- and N-terminal domains upon transition from the basic orange to photoactivated red OCP form. While recent studies significantly improved our understanding of the OCP photocycle and interaction with phycobilisomes and the fluorescence recovery protein, the mechanism of OCP assembly remains unclear. Apparently, this process requires targeted delivery and incorporation of a highly hydrophobic carotenoid molecule into the water-soluble apoprotein of OCP. Recently, we introduced a novel carotenoid carrier protein, COCP, which consists of dimerized C-domain(s) of OCP and can combine with the isolated N-domain to form transient OCP-like species. Here, we demonstrate that in vitro COCP efficiently transfers otherwise tightly bound carotenoid to the full-length OCP apoprotein, resulting in formation of the photoactive OCP from completely photoinactive species. We accurately analyze peculiarities of this carotenoid transfer process which, to the best of our knowledge, seems unique, previously uncharacterized protein-to-protein carotenoid transfer process. We hypothesize that a similar OCP assembly can occur in vivo, substantiating specific roles of the COCP carotenoid carrier in cyanobacterial photoprotection.

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Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms

Frontiers in Plant Science ◽

10.3389/fpls.2021.619987 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jun Liu ◽

Marc W. van Iersel

Keyword(s):

Blue Light ◽

Interactive Effect ◽

Red Light ◽

Green Light ◽

Photosynthetic Photon Flux Density ◽

Interactive Effects ◽

Photon Flux ◽

Photon Flux Density ◽

Light Spectrum ◽

Response Curves

Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower absorptance, green light can penetrate deeper and excite chlorophyll deeper in leaves. We hypothesized that, at high photosynthetic photon flux density (PPFD), green light may achieve higher QY and net CO2 assimilation rate (An) than red or blue light, because of its more uniform absorption throughtout leaves. To test the interactive effects of PPFD and light spectrum on photosynthesis, we measured leaf An of “Green Tower” lettuce (Lactuca sativa) under red, blue, and green light, and combinations of those at PPFDs from 30 to 1,300 μmol⋅m–2⋅s–1. The electron transport rates (J) and the maximum Rubisco carboxylation rate (Vc,max) at low (200 μmol⋅m–2⋅s–1) and high PPFD (1,000 μmol⋅m–2⋅s–1) were estimated from photosynthetic CO2 response curves. Both QYm,inc (maximum QY on incident PPFD basis) and J at low PPFD were higher under red light than under blue and green light. Factoring in light absorption, QYm,abs (the maximum QY on absorbed PPFD basis) under green and red light were both higher than under blue light, indicating that the low QYm,inc under green light was due to lower absorptance, while absorbed blue photons were used inherently least efficiently. At high PPFD, the QYinc [gross CO2 assimilation (Ag)/incident PPFD] and J under red and green light were similar, and higher than under blue light, confirming our hypothesis. Vc,max may not limit photosynthesis at a PPFD of 200 μmol m–2 s–1 and was largely unaffected by light spectrum at 1,000 μmol⋅m–2⋅s–1. Ag and J under different spectra were positively correlated, suggesting that the interactive effect between light spectrum and PPFD on photosynthesis was due to effects on J. No interaction between the three colors of light was detected. In summary, at low PPFD, green light had the lowest photosynthetic efficiency because of its low absorptance. Contrary, at high PPFD, QYinc under green light was among the highest, likely resulting from more uniform distribution of green light in leaves.

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Role of Short-wavelength Blue Light in the Formation of Cataract and Expression of Caspase-1, -11 and Gasdermin D in rat Lens Epithelium Cells: Insight into the Novel Pathogenesis of Cataract.

10.21203/rs.2.18560/v1 ◽

2019 ◽

Author(s):

Yamin Wang ◽

Min Zhang ◽

Ying Sun ◽

Xiaohui Wang ◽

Zhaowei Song ◽

...

Keyword(s):

Blue Light ◽

Short Wavelength ◽

Light Exposure ◽

The Novel ◽

Blue Led ◽

Caspase 1 ◽

Epithelium Cells ◽

Experimental Group ◽

Insight Into

Abstract Background Cataracts have been verified to be associated with a number of risk factors. The sun and artificial light sources, including light-emitting diode (LED) and fluorescent light tubes, are the primary sources of short-wavelength blue light. With the increasing popularity of blue-rich LED-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to evaluate the role of short-wavelength blue light in the formation of cataract. Additionally, the pathogenesis of cataracts after short-wavelength light exposure was investigated.Methods SD rats were randomly divided into 2 main groups: a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 hours per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 hours, after which a 12-hour light/dark cycle was resumed. The intensity of the lamp was 3000 lux. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) in rat epithelium cells (LECs) were examined in rat epithelial cells (LECs) using qRT-PCR and Western blotting analyses. Results After 6 weeks, cataracts had developed in the experimental rats (4/20 eyes). The clarity of the lens then gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. Then the expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in samples from rats exposed to a short-wavelength blue LED lamp than samples from control rat (p˂0.05). Conclusion The data indicate that pyroptosis play a key role of in cataracts induced by short-wavelength blue light exposure, highlighting caspase-1, caspase-11 and GSDMD as possible therapeutic targets for cataract treatment. This study might provide new insight into the novel pathogenesis of cataracts.

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