The influence of red and blue light on the rate of photosynthesis and the CO2 compensation point at various oxygen concentrations

1970 ◽  
Vol 48 (6) ◽  
pp. 1251-1257 ◽  
Author(s):  
N. P. Voskresenskaya ◽  
G. S. Grishina ◽  
S. N. Chmora ◽  
N. M. Poyarkova

Apparent photosynthesis of attached leaves of Phaseolus vulgaris, Vicia faba, Pisum sativum, and Nicotiana tabacum at various intensities of blue and red light was measured by infrared CO2 gas analyzer in a closed system. Simultaneously the CO2 compensation point was measured.It was found that light-limited photosynthetic rate in blue light was equal to or more than that in red light. Inhibition of photosynthesis, which sometimes occurred at light-saturated intensities of blue light, could be avoided by addition of red light, prolonged exposure of the plants to blue light, or by lowering the O2 concentration. Accordingly, the increase of photosynthetic rate due to change of O2 concentration from 21 to 3% O2 is higher in blue light only when photosynthesis is inhibited by blue light at 21% O2. The data on the action of blue and red light on the CO2 compensation point seems to exclude the activation of photorespiration by blue light.The possible effects of blue light on apparent photosynthesis are discussed on the basis of the results presented.

2020 ◽  
Vol 147 (1) ◽  
pp. 61-73
Author(s):  
Eugeniusz Parys ◽  
Tomasz Krupnik ◽  
Ilona Kułak ◽  
Kinga Kania ◽  
Elżbieta Romanowska

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.


1967 ◽  
Vol 18 (2) ◽  
pp. 123 ◽  
Author(s):  
GF Humphrey ◽  
DV Subba Rao

Photosynthesis in Cylindrotheca closterium was greatest in 1-day-old cells (2-4 � O2 per 106 cells per hour), declining to about 50% of this at 3 days and to about 10 % at 14 days. Due mainly to a decrease in the intensity of photosynthesis the ratio of photosynthesis to respiration fell from 6-8 at 1 day to 34 at 3 days, and to 0.6-1.6 at 14 days. The decline in photosynthesis started before phosphate or nitrate in the culture medium was exhausted, but was accompanied by a pH change from 7.4 before inoculation to 8.4 at 1 day and 9.2 at 3 days and thereafter. White light of 1000-1500f.c. (6.4-9.6 mW/cm2) saturated photosynthesis, the compensation point varying from 50 to 100 f.c. (0.3-0.6 mW/cm2). In blue light similar in spectral composition to that found at 10m below the surface of the ocean, the compensation point was 0.5-0.6 mW/cm2.


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1017
Author(s):  
Guem-Jae Chung ◽  
Jin-Hui Lee ◽  
Myung-Min Oh

This study aimed to explore the suitable light quality condition for ex vitro acclimation of M9 apple plantlets. Light quality treatments were set as followed; monochromatic LEDs (red (R), green (G), blue (B)) and polychromatic LEDs (R:B = 7:3, 8:2 and 9:1; R:G:B = 6:1:3, 7:1:2 and 8:1:1). Plant height of R, R9B1, and R8G1B1 treatments were significantly higher than the other treatments. The number of leaves and SPAD value of B were significantly higher than the other treatments. Root fresh weights of R9B1 and R7G1B2 treatments showed an increase of at least 1.7-times compared to R, G and R8B2. R8G1B1 accumulated higher starch contents than the other treatments. Photosynthetic rate of R9B1 and R8B2 were significantly higher than the other treatments. In terms of stomatal conductance and transpiration rate, treatments with high blue ratio such as B, R7B3 had higher values. Rubisco concentration was high in R and B among monochromatic treatments. In conclusion, red light was effective to increase photosynthetic rate and biomass and blue light increased chlorophyll content and stomatal conductance. Therefore, for R9B1 and R8G1B1, a mixture of high ratio of red light with a little blue light would be proper for the acclimation of in vitro-propagated apple rootstock M9 plantlets to an ex vitro environment.


1986 ◽  
Vol 64 (5) ◽  
pp. 1016-1017 ◽  
Author(s):  
Demetrios J. Vakalounakis ◽  
Christos Christias

Prolonged exposure to blue light was necessary for almost complete inhibition of sporulation in Alternaria cichorii Nattrass. When a 24-h blue light exposure was followed by darkness, the inhibition of sporulation decreased gradually.


1970 ◽  
Vol 48 (6) ◽  
pp. 1271-1276 ◽  
Author(s):  
N. R. Bulley ◽  
E. B. Tregunna

Attached soybean leaves in a closed system were fed high specific activity 14CO2 at four CO2 compensation points (30, 53, 110, 204 μl/l CO2) which were produced by different O2 concentrations (10, 21, 44, 80% O2). Rates of CO2 uptake and evolution were measured simultaneously using an infrared CO2 gas analyzer and a Geiger tube. The CO2 compensation point was proportional to O2 concentration but did not change for the two light intensities used. The rates of CO2 exchange at the compensation point did increase with light intensity. These rates of CO2 exchange also increased with the increasing CO2 concentration of the compensation point (for increasing O2 concentrations) but tended to saturate for compensation points greater than 110 μl/l CO2.


2005 ◽  
Vol 0 (0) ◽  
pp. 050922094851001-??? ◽  
Author(s):  
Catherine D. Campbell ◽  
Rowan F. Sage ◽  
Ferit Kocacinar ◽  
Danielle A. Way

2000 ◽  
Vol 55 (5-6) ◽  
pp. 361-372 ◽  
Author(s):  
Lutz Schäfer ◽  
Jürgen Feierabend

Glycolate oxidase that was partially purified from pea leaves was inactivated in vitro by blue light in the presence of FMN. Inactivation was greatly retarded in the absence of O2. Under aerobic conditions H2O2 was formed. The presence of catalase, GSH or dithiothreitol protected glycolate oxidase against photoinactivation. Less efficient protection was provided by ascorbate, histidine, tryptophan or EDTA. The presence of superoxide dismutase or of hydroxyl radical scavengers had no, or only minor, effects. Glutathione suppressed H2O2 accumulation and was oxidized in the presence of glycolate oxidase in blue light. Glycolate oxidase was also inactivated in the presence of a superoxide-generating system or by H2O2 in darkness. In intact leaves photoinactivation of glycolate oxidase was not observed. However, when catalase was inactivated by the application of 3-amino-1,2,4-triazole or depleted by prolonged exposure to cycloheximide a strong photoinactivation of glycolate oxidase was also seen in leaves. In vivo blue and red light were similarly effective. Furthermore, glycolate oxidase was photoinactivated in leaves when the endogenous GSH was depleted by the application of buthionine sulfoximine. Both catalase and antioxidants, in particular GSH, appear to be essential for the protection of glycolate oxidase in the peroxisomes in vivo.


Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2073-2082 ◽  
Author(s):  
T.C. Mockler ◽  
H. Guo ◽  
H. Yang ◽  
H. Duong ◽  
C. Lin

The Arabidopsis photoreceptors cry1, cry2 and phyB are known to play roles in the regulation of flowering time, for which the molecular mechanisms remain unclear. We have previously hypothesized that phyB mediates a red-light inhibition of floral initiation and cry2 mediates a blue-light inhibition of the phyB function. Studies of the cry2/phyB double mutant provide direct evidence in support of this hypothesis. The function of cryptochromes in floral induction was further investigated using the cry2/cry1 double mutants. The cry2/cry1 double mutants showed delayed flowering in monochromatic blue light, whereas neither monogenic cry1 nor cry2 mutant exhibited late flowering in blue light. This result suggests that, in addition to the phyB-dependent function, cry2 also acts redundantly with cry1 to promote floral initiation in a phyB-independent manner. To understand how photoreceptors regulate the transition from vegetative growth to reproductive development, we examined the effect of sequential illumination by blue light and red light on the flowering time of plants. We found that there was a light-quality-sensitive phase of plant development, during which the quality of light exerts a profound influence on flowering time. After this developmental stage, which is between approximately day-1 to day-7 post germination, plants are committed to floral initiation and the quality of light has little effect on the flowering time. Mutations in either the PHYB gene or both the CRY1 and CRY2 genes resulted in the loss of the light-quality-sensitive phase manifested during floral development. The commitment time of floral transition, defined by a plant's sensitivity to light quality, coincides with the commitment time of inflorescence development revealed previously by a plant's sensitivity to light quantity - the photoperiod. Therefore, the developmental mechanism resulting in the commitment to flowering appears to be the direct target of the antagonistic actions of the photoreceptors.


1962 ◽  
Vol 40 (1) ◽  
pp. 179-189 ◽  
Author(s):  
A. H. W. Hauschild ◽  
C. D. Nelson ◽  
G. Krotkov

Suspensions of Chlorella vulgaris, grown in synchronous culture, were pretreated in darkness for 45 to 225 minutes and illuminated in the presence of C14-bicarbonate with red, with red plus 4% of blue, and with blue light alone. The light intensities were so adjusted that the rate of photosynthesis (fixation of C14) was the same under the different conditions of illumination. The distribution of C14 among the various compounds of the ethanol-soluble fraction was obtained using paper chromatography and autoradiography.After 5 minutes of photosynthesis, the incorporation of C14 into aspartic acid was higher in the presence of red with supplementary blue light than in red light alone. At the same time the total radioactivity in glycine plus serine and in glycolic acid decreased. After 30 minutes of photosynthesis, blue light supplementary to red and blue light alone increased the total incorporation of C14 into the amino acid plus organic acid fraction as compared with incorporation in red light. This was due mainly to an increase in the radioactivity of aspartic and glutamic acids, while at the same time the radioactivity in glycine and glycolic acid was reduced.The duration of dark pretreatment was an important factor in the 30-minute experiments. The effect of increased dark pretreatment was to lower the incorporation of C14 into aspartic and glutamic acids when photosynthesis was carried out in red light, but the incorporation of C14 into these acids was increased in the presence of supplementary blue light.It is concluded that the distribution of carbon among the products of photosynthesis is affected by the quality of light.


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

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