Die Wirkung von Phytochrom auf die Bildung von Einzelcarotinoiden in etiolierten Horde um -Keimlingen / The Influence of Phytochrome on the Formation of Individual Carotenoids in Etiolated Hordeum Seedlings

Abstract Short time red pulses, given 6 times for 5 min within 36 h, induce in etiolated barley seedlings an enhanced synthesis of the main chloroplast carotenoids β-carotene, violaxanthine, lutein and neoxanthine. The level of antheraxanthine and zeaxanthine decreases by red light treatment. These red light effects are reverted by subsequent short time far-red pulses. The results show that the white light induced change in the accumulation rate of individual carotenoids is initiated and regulated by active phytochrome Pfr . In the case of neoxanthin and zeaxanthin the red light effects cannot be fully reverted by far-red; this points to very fast phytochrome reaction.

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Light Gradient-Based Screening of Arabidopsis thaliana on a 384-Well Type Plant Array Chip

Micromachines ◽

10.3390/mi11020191 ◽

2020 ◽

Vol 11 (2) ◽

pp. 191

Author(s):

Youn-Hee Park ◽

Je-Kyun Park

Keyword(s):

Arabidopsis Thaliana ◽

White Light ◽

Solid Medium ◽

Red Light ◽

Phytochrome B ◽

Wild Type ◽

Light Gradient ◽

Gradient Based ◽

Light Effects ◽

Germination And Growth

Arabidopsis thaliana (Arabidopsis), as a model for plant research, is widely used for various aspects of plant science. To provide a more sophisticated and microscopic environment for the germination and growth of Arabidopsis, we report a 384-well type plant array chip in which each Arabidopsis seed is independently seeded in a solid medium. The plant array chip is made of a poly(methyl methacrylate) (PMMA) acrylic material and is assembled with a home-made light gradient module to investigate the light effects that significantly affect the germination and growth of Arabidopsis. The light gradient module was used to observe the growth pattern of seedlings according to the intensity of the white light and to efficiently screen for the influence of the white light. To investigate the response to red light (600 nm), which stimulates seed germination, the light gradient module was also applied to the germination test. As a result, the germination results showed that the plant array chip can be used to simultaneously screen wild type seeds and phytochrome B mutant seeds on a single array chip according to the eight red light intensities.

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Photosynthesis of the Cyanidioschyzon merolae cells in blue, red, and white light

Photosynthesis Research ◽

10.1007/s11120-020-00796-x ◽

2020 ◽

Vol 147 (1) ◽

pp. 61-73

Author(s):

Eugeniusz Parys ◽

Tomasz Krupnik ◽

Ilona Kułak ◽

Kinga Kania ◽

Elżbieta Romanowska

Keyword(s):

Blue Light ◽

White Light ◽

Red Light ◽

Carbonic Anhydrase Activity ◽

Compensation Point ◽

Cyanidioschyzon Merolae ◽

Rate Of Photosynthesis ◽

White Control ◽

Β Carotene

AbstractPhotosynthesis and respiration rates, pigment contents, CO2 compensation point, and carbonic anhydrase activity in Cyanidioschizon merolae cultivated in blue, red, and white light were measured. At the same light quality as during the growth, the photosynthesis of cells in blue light was significantly lowered, while under red light only slightly decreased as compared with white control. In white light, the quality of light during growth had no effect on the rate of photosynthesis at low O2 and high CO2 concentration, whereas their atmospheric level caused only slight decrease. Blue light reduced markedly photosynthesis rate of cells grown in white and red light, whereas the effect of red light was not so great. Only cells grown in the blue light showed increased respiration rate following the period of both the darkness and illumination. Cells grown in red light had the greatest amount of chlorophyll a, zeaxanthin, and β-carotene, while those in blue light had more phycocyanin. The dependence on O2 concentration of the CO2 compensation point and the rate of photosynthesis indicate that this alga possessed photorespiration. Differences in the rate of photosynthesis at different light qualities are discussed in relation to the content of pigments and transferred light energy together with the possible influence of related processes. Our data showed that blue and red light regulate photosynthesis in C. merolae for adjusting its metabolism to unfavorable for photosynthesis light conditions.

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Effect of Red Light Treatment of Seedlings of Pepper, Pumpkin, and Tomato on the Occurrence of Phytophthora Damping-off

HortScience ◽

10.21273/hortsci.37.4.678 ◽

2002 ◽

Vol 37 (4) ◽

pp. 678-681 ◽

Cited By ~ 16

Author(s):

S.Z. Islam ◽

M. Babadoost ◽

Y. Honda

Keyword(s):

White Light ◽

Phytophthora Capsici ◽

Red Light ◽

Dry Weight ◽

Light Treatment ◽

Bell Pepper ◽

Infested Soil ◽

Damping Off ◽

Soil Mix ◽

Seedling Infection

A study was conducted in the greenhouse to investigate the effects of red light (600-700 nm) on the subsequent occurrence of seedling infection of bell pepper, pumpkin, and tomato caused by Phytophthora capsici. Three- or 4-week-old seedlings were inoculated with zoospores or transplanted into pots filled with artificially infested soil mix. Red light treatment of seedlings reduced Phytophthora damping-off by up to 79%. Only 21% to 36% of red light-treated seedlings became infected, whereas 78% to 100% of the control seedlings, grown either in natural daylight (NDL) or under white light (WL), became infected and died. The height, and fresh and dry weight of seedlings treated with red light were significantly higher than those grown under NDL or WL.

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INTENSITY DISCRIMINATION IN THE HUMAN EYE

The Journal of General Physiology ◽

10.1085/jgp.22.1.7 ◽

1938 ◽

Vol 22 (1) ◽

pp. 7-19 ◽

Cited By ~ 48

Author(s):

Selig Hecht ◽

James C. Peskin ◽

Marjorie Patt

Keyword(s):

White Light ◽

Red Light ◽

Numerical Data ◽

Published Data ◽

Intensity Discrimination ◽

Abrupt Transition ◽

Rods And Cones ◽

New Apparatus ◽

Chemical Events ◽

Short Time

1. A new apparatus is described for measuring visual intensity discrimination over a large range of intensities, with white light and with selected portions of the spectrum. With it measurements were made of the intensity ΔI which is just perceptible when it is added for a short time to a portion of a field of intensity I to which the eye has been adapted. 2. For white and for all colors the fraction ΔI/I decreases as I increases and reaches an asymptotic minimum value at high values of I. In addition, with white light the relation between ΔI/I and I shows two sections, one at low intensities and the other at high intensities, the two being separated by an abrupt transition. These findings are contrary to the generally accepted measurements of Koenig and Brodhun; however, they confirm the recent work of Steinhardt, as well as the older work of Blanchard and of Aubert. The abrupt transition is in keeping with the Duplicity theory which attributes the two sections to the functions of the rods and cones respectively. 3. Measurements with five parts of the spectrum amplify these relationships in terms of the different spectral sensibilities of the rods and cones. With extreme red light the relation of ΔI/I to I shows only a high intensity section corresponding to cone function, while with other colors the low intensity rod section appears and increases in extent as the light used moves toward the violet end of the spectrum. 4. Like most of the previously published data from various sources, the present numerical data are all described with precision by the theory which supposes that intensity discrimination is determined by the initial photochemical and chemical events in the rods and cones.

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Stable Reference Gene Selection for qRT-PCR Normalization in Strawberry (Fragaria × ananassa) Leaves under Different Stress and Light-Quality Conditions

Horticulturae ◽

10.3390/horticulturae7110452 ◽

2021 ◽

Vol 7 (11) ◽

pp. 452

Author(s):

Yuntian Ye ◽

Yang Lu ◽

Guangyi Wang ◽

Yongqiang Liu ◽

Yunting Zhang ◽

...

Keyword(s):

Reference Gene ◽

White Light ◽

Reference Genes ◽

Light Quality ◽

Red Light ◽

Light Treatment ◽

Data Normalization ◽

Fragaria Ananassa ◽

Expression Stability ◽

Qrt Pcr

Selecting an appropriate reference gene is of crucial importance for improving the accuracy of qRT-PCR analyses. In this study, strawberry (Fragaria ananassa) seedlings were subjected to different environmental conditions including heat, cold, drought, salt, white-light, blue-light, and red-light treatments. The expression levels of seven candidate reference genes, including Fa18S, FaGAPDH, FaPIRUV, FaDBP, FaHISTH4, FaACTIN1, and FaACTIN2, in the strawberry leaves were measured by qRT-PCR. Then, four programs (geNorm, NormFinder, BestKeeper, and RefFinder) were employed as tools to evaluate the expression stability of the candidate reference genes. The results showed that the expression stability of the reference genes varied under different conditions. For the cold stress and white-light treatments, FaACTIN2 was evaluated to be the most stable reference gene. FaGAPDH should be used as the reference gene under salt-stress condition and red-light treatment. For the data normalization under drought-stress treatment, FaDBP is the recommended reference gene with the highest expression stability. FaHISTH4 was observed to be the best reference gene for data normalization under heat stress and blue-light treatment. This work provides information on selecting reference genes for accurate gene expression analyses of target genes in strawberry leaves under various abiotic stress and light-quality conditions.

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Participation of labile and stabile phytochrome in the control of chlorophyll accumulation during the deetiolation of oat seedlings

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1988.013 ◽

2014 ◽

Vol 57 (1) ◽

pp. 137-147

Author(s):

Mariusz Cymerski ◽

Jan Kopcewicz

Keyword(s):

Chlorophyll A ◽

White Light ◽

Dark Period ◽

Accumulation Rate ◽

Red Light ◽

Phytochrome A ◽

Etiolated Seedlings ◽

Chlorophyll Accumulation ◽

Phytochrome System ◽

Chlorophyll A And B

The effect of the phytochrome system on the accumulation rate of chlorophyll-a and b in 96-hour-old oat seedlings during the first 3 hours of white light action was investigated. It was established that initial irradiation with red light stimulated the accumulation rate of both forms of chlorophyll. This effect depended on the level of the PFR form of phytochrome obtained during the initial irradiation and it reached the treshold value in the case of about 20% of PFR in relation to PR in etiolated seedlings. Far red light stimulated only the accumulation of chlorophyll-a. The effect of red light was reversible if far red light was applied directly after red light. The reversibility diminished gradually together with the extension of the dark period between red and far red light, disappearing completely after 6 hours. The results suggest the participation of two pools of phytochrome - a labile and a stabile one - in the reaction stimulating chlorophyll accumulation. A model of labile phytochrome action through the destruction products of phytochrome is proposed.

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Carbon dioxide exchange and phytochrome control of flowering in Xanthium pennsylvanicum

Canadian Journal of Botany ◽

10.1139/b76-309 ◽

1976 ◽

Vol 54 (24) ◽

pp. 2881-2887 ◽

Cited By ~ 3

Author(s):

P. K. Bassi ◽

E. B. Tregunna ◽

P. A. Jolliffe

Keyword(s):

Carbon Dioxide ◽

Red Light ◽

Light Treatment ◽

Carbon Dioxide Exchange ◽

Low Intensity ◽

Apparent Relationship ◽

Light Effects ◽

High Concentrations ◽

Subsequent Flowering ◽

Bud Morphology

The presence of CO2 at sufficiently high concentrations is necessary for red light night interruptions to affect flowering in Xanthium pennsylvanicum L. The present study investigated the involvement of CO2 exchange in the effects of night interruptions on flowering. Brief red or far-red treatments were applied to Xanthium plants under inductive night conditions, and flowering response was assessed according to bud morphology 10 days after light treatment. The occurrence of flowering depended on the timing, wavelength, and intensity of the light treatments and on the CO2 concentration during the treatments. During the night interruptions CO2 exchange was measured in single attached leaves. CO2 exchange was influenced by the conditions during the night interruptions, but there was no apparent relationship between the patterns of CO2 exchange observed and the subsequent flowering responses to the night interruptions. Brief (10–60 s) high-intensity red light interruptions at 350 ppm CO2 had much less effect on CO2 exchange than did 5 min of low-intensity red light interruptions given at 20 ppm CO2. The brief light interruptions inhibited flowering, while the longer interruptions at low CO2 concentrations were ineffective. Moreover, far-red reversal of red light effects was not accompanied by alterations in CO2 exchange. It appears that the action of CO2 in night interruptions is not associated with CO2 exchange during the interruptions.

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Alternative light colors in suckling piglet creep area: preference and validation tests in swine maternity

Ciência Rural ◽

10.1590/0103-8478cr20190328 ◽

2020 ◽

Vol 50 (11) ◽

Author(s):

Ana Caroline Paggi ◽

Taciana Aparecida Diesel ◽

Paulo Armando Victoria de Oliveira ◽

Arlei Coldebella ◽

Diovani Paiano ◽

...

Keyword(s):

White Light ◽

Red Light ◽

Green Light ◽

Light Treatment ◽

Large White ◽

Led Light ◽

Validation Test ◽

Suckling Piglets ◽

Light Color ◽

Validation Tests

ABSTRACT: We performed a two-stage experiment: a preference and a validation test in swine litters, to determine whether suckling piglets preferred alternative light colors in their creep area over white light; we also determined whether the preferred color affected piglet behavior. In the first stage, five trials of two consecutive days were performed, each at 21-day intervals. In each trial, 40 piglets, from three to five days old, from four F1 sows (Large White x Landrace), were distributed in four treatments, in a paired scheme, receiving the following treatments: Treatment GR: white light vs. green light ; Treatment BL: white light vs. blue light; Treatment YE: yellow light vs. white light; Treatment RD: white light vs. red light. For the validation test, three consecutive lots of eight F1 sows (Large White x Landrace) and their corresponding maternity were used, remaining from birth under the influence of treatments T_Gr and T_Wh, totaling three replicates. T_Gr corresponded to four creep areaswith green LED light and T_Wh to four nurseries with white LED light. The piglets showed a significant preference only for white over blue. Among the alternative colors, piglets significantly preferred green. In the validation stage, there was no significant effect of colors on the mean percentage of permanence of the piglets inside the creep areas over all evaluated periods. Piglets between two and five days of age prefer green lighting;however,in the creep area, the light color used did not influence piglet behavior.

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Preliminary study of the production of metabolites from in vitro cultures of C. ensiformis

BMC Biotechnology ◽

10.1186/s12896-020-00642-x ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Juan F. Saldarriaga ◽

Yuby Cruz ◽

Julián E. López

Keyword(s):

Antioxidant Activity ◽

Bioactive Compounds ◽

Culture Medium ◽

Red Light ◽

Light Treatment ◽

Different Types ◽

Light Effects ◽

Preliminary Study ◽

The Ideal

Abstract Background Canavalia ensiformis is a legume native to Central and South America that has historically been a source of protein. Its main proteins, urease, and lectin have been extensively studied and are examples of bioactive compounds. In this work, the effect of pH and light effects on the growth of C. ensiformis were analyzed. Also, the bioactive compounds such as phenols, carotenoids, chlorophyll a/b, and the growth of callus biomass of C. ensiformis from the effect of different types of light treatments (red, blue and mixture) were evaluated. Likewise, the antioxidative activity of C. ensiformis extracts were studied and related to the production of bioactive compounds. For this, a culture of calluses obtained from seeds were carried out. For the light experiments, polypropylene boxes with red, blue, combination (1/3, 3/1 and 1/1 R-B, respectively) lights and white LED were used as control. In each treatment, three glass containers with 25 ml of MS salts containing 0.25 g of fresh callus were seeded. Results The results have shown that the pH of the culture medium notably affects the increase in callogenic biomass. It shows that the pH of 5.5 shows better results in the callogenic growth of C. ensiformis with an average increase of 1.3051 g (198.04%), regarding the initial weight. It was found that the pH 5.5 and the 1/3 R-B LED combination had higher production of bioactive compounds and better antioxidant activity. At the same time, the red-light treatment was least effective. Conclusions It was possible to find the ideal conditions of important growth under conditions of pH and light of C. ensiformis. Likewise, it is evaluated whether the production of compounds of interest, such as phenolic compounds and carotenoids, occurs under these conditions. The highest production of calluses occurs in the 1/3 R-B LED combined light treatment, which showed a significant increase in biomass, followed by B. From this study, it could be demonstrated that C. ensiformis produces compounds such as phenols and carotenoids in vitro culture that are essential for the antioxidant activity of the plant.

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Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

International Astronomical Union Colloquium ◽

10.1017/s0252921100064484 ◽

2000 ◽

Vol 179 ◽

pp. 197-200

Author(s):

Milan Minarovjech ◽

Milan Rybanský ◽

Vojtech Rušin

Keyword(s):

Time Resolution ◽

White Light ◽

Short Time Scale ◽

High Time Resolution ◽

Green Line ◽

Periodic Intensity ◽

Coronal Green Line ◽

Significant Intensity ◽

Short Time ◽

Coronal Structures

AbstractWe present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of white-light coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

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