scholarly journals Quantum Requirement for Photosynthesis in Chlorophyll-Deficient Plants with Unusual Lamellar Structures

1967 ◽  
Vol 50 (9) ◽  
pp. 2131-2144 ◽  
Author(s):  
Georg H. Schmid ◽  
Hans Gaffron
Keyword(s):  
Quantum Number ◽  
Blue Light ◽  
Lamellar Structure ◽  
Higher Plants ◽  
Red Light ◽  
Blue Region ◽  
Lamellar Structures ◽  
Quantum Requirement ◽  
Optimal Efficiency ◽  
Red Radiation

Neither an over-all deficiency of chlorophyll, nor an increased enzymatic capacity for maximal rates, nor an unusual lamellar structure was found to change the number of quanta required for the evolution of one molecule of oxygen in healthy aurea mutants of tobacco. The average minimal quantum number remains 10 (efficiency 0.1) as in many algae and typical higher plants. Most of the time the optimal efficiency depends on the availability of some far-red radiation, particularly in the blue region of the spectrum where blue light alone is rather inefficient. These results fit an explanation offered earlier in connection with the hydrogen or acetate photometabolism of algae in far-red light.

THE EFFECT OF SUBLETHAL DOSES OF ARTIFICIAL SUNLIGHT ON ADAPTIVE ENZYME SYNTHESIS BY ESCHERICHIA COLI

1963 ◽  
Vol 41 (1) ◽  
pp. 859-866
Author(s):  
S. J. Webb
Keyword(s):  
Escherichia Coli ◽  
Blue Light ◽  
Red Light ◽  
Enzyme Synthesis ◽  
Blue Dye ◽  
Direct Sunlight ◽  
Yellow Light ◽  
Blue Region ◽  
Sublethal Doses ◽  
Inhibited Enzyme

The effect of sublethal doses of artificial sunlight and individual wavebands of light on the ability of Escherichia coli to synthesize the enzymes concerned in lactose oxidation have been studied. It was found that direct sunlight completely inhibited enzyme synthesis but did not affect the action of preformed enzymes. Blue and yellow light were both active in preventing enzyme synthesis but the blue region of the spectrum was by far the most effective. No effect of red light could be demonstrated. Staining cells with yellow or red dyes reduced the action of blue light whereas staining the cells with a blue dye increased the effectiveness of yellow light.

Smallseed Dodder (Cuscuta planiflora) Phototropism toward Far-red When in White Light

Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Gregory L. Orr ◽  
Mustapha A. Haidar ◽  
Deborah A. Orr
Keyword(s):  
Blue Light ◽  
Potassium Iodide ◽  
White Light ◽  
Host Location ◽  
Red Light ◽  
Infra Red ◽  
Red Radiation

White light-grown seedlings of smallseed dodder were (a) provided with unilateral far-red (700 to 800 nm) at photon irradiances ranging from 20 to 110 μmol m−2s−1against a background of cool white light (400 to 700 nm) from above at 77 μmol m−2s−1, or (b) transferred to darkness and provided with unilateral white light at 20 μmol m−2s−1, unilateral blue light (400 to 500 nm) at 10 μmol m−2s−1, unilateral red light (600 to 700 nm) at 10 μmol m−2s−1, unilateral far-red at 50 μmol m−2s−1, or (c) in experiments utilizing bilateral irradiations, provided with unilateral far-red perpendicular to unilateral white light. Positive phototropic curvature was induced by unilateral white light and by unilateral blue light in otherwise darkness and by unilateral far-red in a background of cool white light. Seedling vines were also phototropic toward unilateral far-red when provided with unilateral white light perpendicular to unilateral far-red. Phototropism to unilateral white light was inhibited in seedlings treated with 200 μM norflurazon and 50 mM potassium iodide. Norflurazon- and potassium iodide-treated seedlings remained phototropic toward unilateral far-red when provided with unilateral white light perpendicular to unilateral far-red. Seedling vines were not phototropic to unilateral red or to unilateral far-red in otherwise darkness, and seedlings in cool white light were neither skototropic (i.e., tropic toward unilateral darkness) nor tropic to or from infra-red (radiation with wavelengths greater than 900 nm). Phototropism toward regions of lowered red:far-red may aid smallseed dodder in chlorophyllous host location and attachment.

The effects of prolonged darkness and light on the fine structure of Ceratodon purpureus

1971 ◽  
Vol 49 (4) ◽  
pp. 547-554 ◽  
Author(s):  
Niina Valanne
Keyword(s):  
Blue Light ◽  
Structural Changes ◽  
Red Light ◽  
Monochromatic Light ◽  
Fibrillar Material ◽  
Lamellar Structures ◽  
Long Duration ◽  
Inorganic Medium ◽  
Effective Use ◽  
Subsequent Disappearance

A description is given of the ultrastructure of moss spores incubated in darkness and posttreated with monochromatic light. Fine structural changes occur in darkness, especially in the chloroplasts, and are also noted with inorganic medium, in spite of the lack of germination. The most conspicuous is the increase of starch grains in the chloroplasts at the beginning of the dark-incubation, and their subsequent disappearance, which coincides with an increase in the number of grana lamellae. A synthesis of chlorophyll is correlated with the decrease of the starch. The incubation of sporelings in a 0.1% solution of sucrose results in the degeneration of the chloroplasts to amyloplast-like with concentrated lamellae and the accumulation of fibrillar material in the cytoplasm. When exposed to blue and red light, the chloroplasts of both inorganic and sucrose cultures develop into normal chloroplasts. A comparison of the effects of different wavelengths of light shows that the chloroplasts of sporelings exposed to blue light remain richer in starch and have a denser stroma than red-light chloroplasts. Red light allows more effective use of reserve lipids, but there are more mitochondria after blue light. No great differences in the lamellar structures of the chloroplasts can be noted between sporelings exposed to blue and red light, unless the illumination is of very long duration.

Observations on crossed lamellar structures in the cell walls of higher plants

1954 ◽  
Vol 2 (2) ◽  
pp. 154 ◽  
Author(s):  
AB Wardrop
Keyword(s):  
Green Algae ◽  
Outer Layer ◽  
Cell Walls ◽  
Lamellar Structure ◽  
Secondary Wall ◽  
Higher Plants ◽  
The Other ◽  
Lamellar Structures ◽  
Wood Fibres ◽  
Vinca Major

Crossed lamellar structures in cell walls have been known to occur with certainty only in some green algae. A number of higher plants in which it was considered this structure might be present have been examined, and it has been demonstrated in the phloem fibres of Vinca major and the tracheidal elements of the aerial root of Alstonia spathulata. In the latter two types of crossed structure are recognized, in one bands of laterally associated microfibrils c. 0.5µ wide intersect at variable angles, whereas in the other lateral association is complete, forming a crossed lamellar structure which approaches most nearly that occurring in the algae. In the outer layer of the secondary wall of wood fibres of Eucalyptus elaeophora and E. regnans there is inconclusive evidence of a crossed structure similar to that observed in the cell walls of some vessels, which consists of a loosely formed meshwork of aggregates of microfibrils. This structure is considered to be distinct from the crossed lamellar and cross-banded structures.

THE EFFECT OF SUBLETHAL DOSES OF ARTIFICIAL SUNLIGHT ON ADAPTIVE ENZYME SYNTHESIS BY ESCHERICHIA COLI

1963 ◽  
Vol 41 (4) ◽  
pp. 859-866 ◽  
Author(s):  
S. J. Webb
Keyword(s):  
Escherichia Coli ◽  
Blue Light ◽  
Red Light ◽  
Enzyme Synthesis ◽  
Blue Dye ◽  
Direct Sunlight ◽  
Yellow Light ◽  
Blue Region ◽  
Sublethal Doses ◽  
Inhibited Enzyme

The effect of sublethal doses of artificial sunlight and individual wavebands of light on the ability of Escherichia coli to synthesize the enzymes concerned in lactose oxidation have been studied. It was found that direct sunlight completely inhibited enzyme synthesis but did not affect the action of preformed enzymes. Blue and yellow light were both active in preventing enzyme synthesis but the blue region of the spectrum was by far the most effective. No effect of red light could be demonstrated. Staining cells with yellow or red dyes reduced the action of blue light whereas staining the cells with a blue dye increased the effectiveness of yellow light.

scholarly journals Effect of blue and red radiation on cycling stomata of bean.

1973 ◽  
Vol 21 (2) ◽  
pp. 117-123
Author(s):  
P.A.M. Hopmans
Keyword(s):  
Blue Light ◽  
Red Light ◽  
Guard Cells ◽  
Radiant Flux ◽  
Stomatal Behaviour ◽  
Blue Radiation ◽  
Quantum Flux ◽  
Permeability For Water ◽  
Red Radiation ◽  
Blue And Red Radiation

Differences in the effect of blue and red radiation of low radiant flux density on sustained stomatal cycling were studied in Phaseolus vulgaris cv. Vroege Wagenaar. Stomatal behaviour in a constant environment was observed indirectly by recording the differences between leaf and air temperature. In radiation with equal radiant flux densities of 1.75 W/m2 and with equal estimated absorbed quantum flux densities of 0.73 nE/cm2 s of both colours, cycling was more rapid and peak-to-trough differences were smaller in red than in blue radiation. Blue radiation from below caused more rapid cycling with larger peak-to-trough differences than radiation from above. In red radiation the direction of radiation had a much smaller influence on period and peak-to-trough difference. To explain these qualitatively different effects of both colours on cycling stomata, the hypothesis is proposed that blue light increases the osmotic pressure in the guard cells more effectively than red light. In blue light the permeability for water transport of the guard cell membranes is lower than in red light. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Phototropin 1 and dim-blue light modulate the red light de-etiolation response

2014 ◽  
Vol 9 (11) ◽  
pp. e976158
Author(s):  
Yihai Wang ◽  
Kevin M Folta
Keyword(s):  
Blue Light ◽  
Red Light

scholarly journals Blue light sensing in higher plants.

2001 ◽  
Vol 276 (20) ◽  
pp. 17620
Author(s):  
John M. Christie ◽  
Winslow R. Briggs
Keyword(s):  
Blue Light ◽  
Higher Plants ◽  
Light Sensing

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

Plants ◽  
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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