Effects of preillumination with light of different wavelengths on subsequent dark CO2-fixation in Chlorella cells

1970 ◽  
Vol 48 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
Shigetoh Miyachi ◽  
Daisuke Hogetsu
Keyword(s):  
Blue Light ◽  
Co2 Fixation ◽  
Red Light ◽  
Anaerobic Conditions ◽  
Nitrogen Gas ◽  
Pep Carboxylase ◽  
Radioactive Carbon ◽  
Initial Fixation ◽  
Dark Fixation ◽  
Dark Co2 Fixation

The effects of preillumination with monochromatic red or blue light on the subsequent dark 14CO2-fixation in Chlorella cells were studied under aerobic as well as anaerobic conditions. When the cell suspension was made aerobic by bubbling air (CO2-free) throughout the periods of preillumination and the following dark 14CO2-fixation, the initial fixation product was mainly PGA. The radioactive carbon first incorporated in PGA was transferred mostly to aspartate during the later periods of dark 14CO2-fixation. The rate of 14C-incorporation into aspartate after preillumination with blue light was 2 to 3 times as high as that observed after red-light pretreatment. The observations support our previous inference that the activity of PEP carboxylase in Chlorella cells is stimulated by preillumination with blue light. When nitrogen gas was used during preillumination and the subsequent dark fixation, the radioactivity of 14C incorporated during the initial enhanced 14CO2-fixation was eventually transferred to alanine and lactate. The increase in radioactivity of alanine and lactate was more pronounced during dark fixation after preillumination with red light than after preillumination with blue light.

Environmental influences on light and dark CO2 fixation by Kalanchoe daigremontiana

1975 ◽  
Vol 53 (11) ◽  
pp. 1132-1138 ◽  
Author(s):  
E. Nalborczyk ◽  
L. J. Lacroix ◽  
R. D. Hill
Keyword(s):  
Co2 Fixation ◽  
Red Light ◽  
Day Length ◽  
Low Oxygen ◽  
Long Day ◽  
C Value ◽  
Warm Night ◽  
Dark Co2 Fixation ◽  
Kalanchoë Daigremontiana ◽  
Kalanchoe Daigremontiana

The influence of day length, light quality, temperature, drought, and oxygen concentration on gas exchange of Kalanchoe daigremontiana was investigated. The ratio of photosynthesis to dark CO2 fixation with plants under a long-day and short-warm-night regime was 2.0 and under a short-day and long-cool-night regime, 0.2. With drought conditions this value may be less than 0.02. Under low oxygen concentrations high photosynthetic rates of about 20 mg CO2 dm−2 h−1 were observed with a compensation point of about 20 ppm. Restricting CO2 supply to dark periods produced plants with a δ13C value of −10.6‰. Restricting CO2 supply to light periods gave a δ13C value of −25.9‰, whereas no control of CO2 gave δ13C values of −15‰. The data obtained suggest that variations in δ13C values in Kalanchoe result from changes in the proportion of light and dark CO2 fixation.Far-red light and oxygen promoted the release of CO2 from Kalanchoe after the plants had undergone a period of dark CO2 fixation. Maximum release occurred within about 1 h. The effect could be reversed by removal of either far-red light or oxygen. Decreases in the acidity of the plants accompanied CO2 release, which indicated that decarboxylation of a C4 acid was the source of the CO2.

Untersuchungen über die photooxydative Farbstoffzerstörung und Stoffwechselhemmung bei Chlorellamutanten und panaschierten Oenotheren

1956 ◽  
Vol 11 (12) ◽  
pp. 708-718 ◽  
Author(s):  
Otto Kandler ◽  
Franz Schötz
Keyword(s):  
Glucose Uptake ◽  
Blue Light ◽  
Purple Bacteria ◽  
Red Light ◽  
Pigment Content ◽  
Photodynamic Effect ◽  
Anaerobic Conditions ◽  
Plastid Mutation ◽  
Manometric Method

1. The influence of light on respiration, glucose uptake and pigment content was studied in the α- and β-carotin lacking Chlorella mutant 9 a isolated by Claes. The assimilation of glucose is inhibited even by very small amounts of blue light, while the consumption of O2 and the pigment content remain unchanged. The pigments are destroyed only at higher intensities of light; along with it goes an increased consumption of O.,. Red light is much less effective than blue light. Normal photosynthesis could not be observed either by the manometric method or by using 14CO2.2. Under anaerobic conditions there is no destruction of pigments even at high intensities of light. The inhibition of oxidative assimilation, however, is only partly prevented, as shown by experiments on the assimilation of glucose in the dark after illumination under anaerobic conditions.3. Also in variegated Oenothera strains, no matter whether they are the result of plastid mutation 1 or of hybridisation. the bleaching can be prevented by the withdrawal of O2.4. The results correspond to the findings of Griffith and coworkers with blue green mutants of purple bacteria. The fact that in variegated Oenotheras carotin is present speaks against the assumption of these authors that photosensitiveness generally is caused by the deficiency of carotins. The stronger action of blue light indicates that also the carotins may have a photodynamic effect.

Zur photosynthetischen CO2-Fixierung von Synechococcus / Photosynthetic CO2 Fixation of Synechococcus

1980 ◽  
Vol 35 (11-12) ◽  
pp. 978-981 ◽  
Author(s):  
Günter Döhler
Keyword(s):  
Steady State ◽  
White Light ◽  
Co2 Fixation ◽  
Calvin Cycle ◽  
Anacystis Nidulans ◽  
Dark Light ◽  
Radioactive Carbon ◽  
Initial Fixation ◽  
Phosphoglyceric Acid ◽  
Photosynthetic Products

The cyanobacterium Synechococcus (Anacystis nidulans strain L 1402-1) was grown at + 37 °C in 3.0 vol.% CO2. The effect of preillumination with white light on the subsequent dark 14CO2 fixation was studied under aerobic conditions at + 30 °C. The radioactive carbon first incoiporated into 3-phosphoglyceric acid was transferred during the later periods of dark 14CO2 fixation to phosphoenolpyruvate and aspartate. No labelling or a very low label in sugar monophosphates could be observed. During the dark/light transients the initial fixation product was mainly aspartate. The pattern of 14C-incorporation into photosynthetic products under steady state conditions (10 min photosynthesis) varied with the temperature during the experiments. The radioactive carbon was firstly incorporated into 3-phosphoglyceric acid. During the later periods of photosynthetic 14CO2 fixation an increased 14C-incorporation into aspartate and glutamate could be observed. Our findings were interpreted with operating of a phospho­enolpyruvate carboxylation besides the Calvin cycle.

Effect of Oxygen and carbon Diozide Concentrations on Gross Dark CO2 Fixation and Dark Respiration in Bryophyllim diagremontiaum

1977 ◽  
Vol 4 (5) ◽  
pp. 745
Author(s):  
A Kaplan ◽  
J Gale ◽  
A Poljakoff-Mayber
Keyword(s):  
Time Course ◽  
Co2 Fixation ◽  
Dark Period ◽  
Dark Respiration ◽  
Principal Component ◽  
Light Period ◽  
Co2 Uptake ◽  
Dark Fixation ◽  
Effect Of Oxygen ◽  
Dark Co2 Fixation

Effects of O2 and CO2 concentrations on the rates of net and gross dark CO2 fixation in B. daigremontianum were examined. Raising [CO2]i from 60 to 420 �ll-� resulted in a decrease in the rate of dark respiration, increase in the rate of gross dark fixation (GDF) and shortened the time taken to reach maximum rate of GDF. However, cumulative GDF was relatively unaffected by [CO2]i at that range. At 14�C, lowering [O2] from 21 to 1.5 % had little effect on the rates and time course of dark respiration and GDF. However, at 24�C, this caused a drop in the rate of dark respiration, changed the time dependence of GDF and slightly increased cumulative GDF. Consequently, at 24�C cumulative net CO2 uptake was 3 .3 times higher at 1 .5 % versus 21% O2. These data are discussed in view of the suggested hypothesis that the amount of available substrate, at the end of the light period, is a principal component of the regulation of the amount of gross dark fixation and dark respiration in the following dark period.

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 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.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

scholarly journals Guard cells control hypocotyl elongation through HXK1, HY5, and PIF4

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gilor Kelly ◽  
Danja Brandsma ◽  
Aiman Egbaria ◽  
Ofer Stein ◽  
Adi Doron-Faigenboim ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Blue Light ◽  
Opposite Effect ◽  
Red Light ◽  
Guard Cells ◽  
Cell Types ◽  
Hypocotyl Elongation ◽  
Sugar Production ◽  
Effect Of Light

AbstractThe hypocotyls of germinating seedlings elongate in a search for light to enable autotrophic sugar production. Upon exposure to light, photoreceptors that are activated by blue and red light halt elongation by preventing the degradation of the hypocotyl-elongation inhibitor HY5 and by inhibiting the activity of the elongation-promoting transcription factors PIFs. The question of how sugar affects hypocotyl elongation and which cell types stimulate and stop that elongation remains unresolved. We found that overexpression of a sugar sensor, Arabidopsis hexokinase 1 (HXK1), in guard cells promotes hypocotyl elongation under white and blue light through PIF4. Furthermore, expression of PIF4 in guard cells is sufficient to promote hypocotyl elongation in the light, while expression of HY5 in guard cells is sufficient to inhibit the elongation of the hy5 mutant and the elongation stimulated by HXK1. HY5 exits the guard cells and inhibits hypocotyl elongation, but is degraded in the dark. We also show that the inhibition of hypocotyl elongation by guard cells’ HY5 involves auto-activation of HY5 expression in other tissues. It appears that guard cells are capable of coordinating hypocotyl elongation and that sugar and HXK1 have the opposite effect of light on hypocotyl elongation, converging at PIF4.

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