Digitonin-sensitive LHCII enlarges the antenna of Photosystem I in stroma lamellae of Arabidopsis thaliana after far-red and blue-light treatment

Light, one of the most important natural resources for plant species, significantly influences the biomass yield and nutrient uptake capacity in plants. However, the impacts of light treatment on the toxicity of metals in soils has rarely been reported. Light irradiation treatments were performed to evaluate the influence of red, yellow, and blue lights on the concentrations and fractions of dissolved organic matter (DOM) in the rhizosphere soils of Arabidopsis thaliana. The results showed that monochromatic red light significantly raised the levels of DOM and proportions of hydrophilic fractionations in the rhizosphere of A. thaliana relative to the control, while monochromatic blue light had the opposite effect. Moreover, the proportions of hydrophobic acid, which can mobilize Cd effectively, also raised with increasing doses of red light, which stimulated Cd mobilization. The application of yellow light not only increased the levels of hydrophobic acid in monochromatic red light treatment, but also decreased the proportion of hydrophobic fractions in monochromatic blue light treatment, partially weakening the negative impacts of pure blue light on soil Cd activation. Moreover, DOM from the combined red, yellow, and blue lights resulted in a significantly stronger Cd extraction efficiency compared with the other light irradiation treatments, consequently enhancing the Cd phytoextraction efficiency of A. thaliana. The findings of this study demonstrated that a suitable light combination can enhance the phytoremediation effect of A. thaliana by activating soil Cd, and this method can be extrapolated to the real field, where light irradiation can be easily applied.

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Identification of a single-copy gene encoding a Type I chlorophyll a/b-binding polypeptide of photosystem I in Arabidopsis thaliana

Physiologia Plantarum ◽

10.1034/j.1399-3054.1992.840410.x ◽

1992 ◽

Vol 84 (4) ◽

pp. 561-567 ◽

Cited By ~ 1

Author(s):

Poul E. Jensen ◽

Michael Kristensen ◽

Tine Hoff ◽

Jan Lehmbeck ◽

Bjarne M. Stummann ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Chlorophyll A ◽

Photosystem I ◽

Single Copy ◽

Type I ◽

Single Copy Gene ◽

Gene Encoding ◽

Copy Gene

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Single Wavelengths of LED Light Supplement Promote the Biosynthesis of Major Cyclic Monoterpenes in Japanese Mint

Plants ◽

10.3390/plants10071420 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1420

Author(s):

Takahiro Ueda ◽

Miki Murata ◽

Ken Yokawa

Keyword(s):

Blue Light ◽

Solid Phase ◽

Glandular Trichomes ◽

Red Light ◽

Glandular Trichome ◽

Pulse Amplitude ◽

Light Treatment ◽

Led Light ◽

Trichome Formation ◽

Japanese Mint

Environmental light conditions influence the biosynthesis of monoterpenes in the mint plant. Cyclic terpenes, such as menthol, menthone, pulegone, and menthofuran, are major odor components synthesized in mint leaves. However, it is unclear how light for cultivation affects the contents of these compounds. Artificial lighting using light-emitting diodes (LEDs) for plant cultivation has the advantage of preferential wavelength control. Here, we monitored monoterpene contents in hydroponically cultivated Japanese mint leaves under blue, red, or far-red wavelengths of LED light supplements. Volatile cyclic monoterpenes, pulegone, menthone, menthol, and menthofuran were quantified using the head-space solid phase microextraction method. As a result, all light wavelengths promoted the biosynthesis of the compounds. Remarkably, two weeks of blue-light supplement increased all compounds: pulegone (362% increase compared to the control), menthofuran (285%), menthone (223%), and menthol (389%). Red light slightly promoted pulegone (256%), menthofuran (178%), and menthol (197%). Interestingly, the accumulation of menthone (229%) or menthofuran (339%) was observed with far-red light treatment. The quantification of glandular trichomes density revealed that no increase under light supplement was confirmed. Blue light treatment even suppressed the glandular trichome formation. No promotion of photosynthesis was observed by pulse-amplitude-modulation (PAM) fluorometry. The present result indicates that light supplements directly promoted the biosynthetic pathways of cyclic monoterpenes.

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Complete Inactivation of Blood Borne Pathogen Trypanosoma cruzi in Stored Human Platelet Concentrates and Plasma Treated With 405 nm Violet-Blue Light

Frontiers in Medicine ◽

10.3389/fmed.2020.617373 ◽

2020 ◽

Vol 7 ◽

Author(s):

Katarzyna I. Jankowska ◽

Rana Nagarkatti ◽

Nirmallya Acharyya ◽

Neetu Dahiya ◽

Caitlin F. Stewart ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Human Plasma ◽

Blue Light ◽

Chagas Disease ◽

Light Treatment ◽

Platelet Concentrates ◽

Complete Inactivation ◽

Pathogen Reduction ◽

Biochemical Indices

The introduction of pathogen reduction technologies (PRTs) to inactivate bacteria, viruses and parasites in donated blood components stored for transfusion adds to the existing arsenal toward reducing the risk of transfusion-transmitted infectious diseases (TTIDs). We have previously demonstrated that 405 nm violet-blue light effectively reduces blood-borne bacteria in stored human plasma and platelet concentrates. In this report, we investigated the microbicidal effect of 405 nm light on one important bloodborne parasite Trypanosoma cruzi that causes Chagas disease in humans. Our results demonstrated that a light irradiance at 15 mWcm−2 for 5 h, equivalent to 270 Jcm−2, effectively inactivated T. cruzi by over 9.0 Log10, in plasma and platelets that were evaluated by a MK2 cell infectivity assay. Giemsa stained T. cruzi infected MK2 cells showed that the light-treated parasites in plasma and platelets were deficient in infecting MK2 cells and did not differentiate further into intracellular amastigotes unlike the untreated parasites. The light-treated and untreated parasite samples were then evaluated for any residual infectivity by injecting the treated parasites into Swiss Webster mice, which did not develop infection even after the animals were immunosuppressed, further demonstrating that the light treatment was completely effective for inactivation of the parasite; the light-treated platelets had similar in vitro metabolic and biochemical indices to that of untreated platelets. Overall, these results provide a proof of concept toward developing 405 nm light treatment as a pathogen reduction technology (PRT) to enhance the safety of stored human plasma and platelet concentrates from bloodborne T. cruzi, which causes Chagas disease.

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THE BLUE LIGHT TREATMENT IN DISEASES OF THE SKIN.

JAMA ◽

10.1001/jama.1904.92490540022001e ◽

1904 ◽

Vol XLII (9) ◽

pp. 590

Author(s):

LOUIS E. SCHMIDT

Keyword(s):

Blue Light ◽

Light Treatment

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Lateral distribution and diffusion of plastocyanin in chloroplast thylakoids.

The Journal of Cell Biology ◽

10.1083/jcb.108.4.1397 ◽

1989 ◽

Vol 108 (4) ◽

pp. 1397-1405 ◽

Cited By ~ 51

Author(s):

W Haehnel ◽

R Ratajczak ◽

H Robenek

Keyword(s):

Photosystem I ◽

Laser Flash ◽

Lateral Distribution ◽

High Time Resolution ◽

High Concentration ◽

Long Distance ◽

Kinetic Measurements ◽

Stroma Lamellae ◽

Negative Surface ◽

Negative Surface Charge

The lateral distribution of plastocyanin in the thylakoid lumen of spinach and pea chloroplasts was studied by combining immunocytochemical localization and kinetic measurements of P700+ reduction at high time resolution. In dark-adapted chloroplasts, the concentration of plastocyanin in the photosystem I containing stroma membranes exceeds that in photosystem II containing grana membranes by a factor of about two. Under these conditions, the reduction of P700+ with a halftime of 12 microseconds after a laser flash of saturating intensity indicates that to greater than 95% of total photosystem I a plastocyanin molecule is bound. An analysis of the labeling densities, the length of the different lumenal regions, and the total amounts of plastocyanin and P700 shows that most of the remaining presumable mobile plastocyanin is found in the granal lumen. This distribution of plastocyanin is consistent with a more negative surface charge density in the stromal than in the granal lumen. During illumination the concentration of plastocyanin in grana increases at the expense of that in stroma lamellae, indicating a light-driven diffusion from stroma to grana regions. Our observations provide evidence that a high concentration of plastocyanin in grana in the light favors the lateral electron transport from cytochrome b6/f complexes in appressed grana across the long distance to photosystem I in nonappressed stroma membranes.

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