Effect of adaptation to high light intensity on the kinetics of energy transfer from phycobilisomes to photosystem II in Anabaena cylindrica

1988 ◽  
Vol 16 (5) ◽  
Author(s):  
E. Kaiseva ◽  
L. Zim�nyi ◽  
I. Laczk�
Keyword(s):  
Energy Transfer ◽  
Photosystem Ii ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Anabaena Cylindrica ◽  
Kinetics Of

scholarly journals Photosystem II core quenching in desiccated Leptolyngbya ohadii

2019 ◽  
Vol 143 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Reza Ranjbar Choubeh ◽  
Leeat Bar-Eyal ◽  
Yossi Paltiel ◽  
Nir Keren ◽  
Paul C. Struik ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Light Intensity ◽  
Photosynthetic Activity ◽  
High Light Intensity ◽  
Primary Electron ◽  
High Light ◽  
Harsh Environment ◽  
Primary Electron Donor ◽  
Protection Mechanism ◽  
The Core

Abstract Cyanobacteria living in the harsh environment of the desert have to protect themselves against high light intensity and prevent photodamage. These cyanobacteria are in a desiccated state during the largest part of the day when both temperature and light intensity are high. In the desiccated state, their photosynthetic activity is stopped, whereas upon rehydration the ability to perform photosynthesis is regained. Earlier reports indicate that light-induced excitations in Leptolyngbya ohadii are heavily quenched in the desiccated state, because of a loss of structural order of the light-harvesting phycobilisome structures (Bar Eyal et al. in Proc Natl Acad Sci 114:9481, 2017) and via the stably oxidized primary electron donor in photosystem I, namely P700+ (Bar Eyal et al. in Biochim Biophys Acta Bioenergy 1847:1267–1273, 2015). In this study, we use picosecond fluorescence experiments to demonstrate that a third protection mechanism exists, in which the core of photosystem II is quenched independently.

scholarly journals Heterocyst differentiation and cell division in the cyanobacterium Anabaena cylindrica: effect of high light intensity

1981 ◽  
Vol 49 (1) ◽  
pp. 341-352
Author(s):  
D.G. Adams ◽  
N.G. Carr
Keyword(s):  
Cell Division ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Anabaena Cylindrica ◽  
Fixed Nitrogen ◽  
Heterocyst Differentiation ◽  
Short Period ◽  
Cyanobacterium Anabaena ◽  
Normal Light

Heterocyst differentiation in the cyanobacterium Anabaena cylindrica is initiated by the removal of fixed nitrogen from the medium. These specialized cells occur singly at regular intervals within filaments of vegetative cells. Incubation of cultures for periods of up to 12 h immediately prior to or following removal of fixed nitrogen, at a light intensity (500 mi Einsteins cm-2 s-1) approximately 10-fold higher than that required for optimum growth, resulted in the differentiation of pairs of adjacent (double) heterocysts. The frequency of double heterocysts was proportional to the length of the period of high light intensity. During growth at normal light intensity approximately 5% of cell divisions were symmetrical, but this increased more than 3-fold during 10-h incubation at high light intensity. The frequency of dividing cells remained constant during this period, but increased rapidly on return to normal light. The frequency of double heterocysts was reduced if a period of incubation at normal light intensity was interposed between the 12-h period at high light intensity and transfer to nitrogen-free medium. A period of 8 h normal light was required to reduce the frequency of double heterocysts to control values, and this corresponded to the length of time needed for the frequency of symmetrical divisions to return to control levels following 12 h at high light intensity. We confirm that cell division in Anabaena cylindrica is asymmetrical and conclude that the presence of double heterocysts results from an increase in the symmetry of cell division during incubation at high light intensity. The results also support the finding of previous workers that a cell is only susceptible to differentiation during a short period following its formation. During the period of high light the rate of doubling of the absorbance of the culture at 750 mn increased from 24 h to approximately 10 h and decreased to more than 100 h on return to normal light. The very high rate could be explained by increases in the volume and granular content of cells during incubation at high light intensity and did not represent an equivalent increase in the rate of cell division.

Effects of light intensity and CO2 concentration on the kinetics of 1st month growth and nitrogen fixation of alfalfa

1983 ◽  
Vol 61 (3) ◽  
pp. 731-740 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
Plant Growth ◽  
Rhizobium Meliloti ◽  
Net Photosynthesis ◽  
Co2 Concentration ◽  
Shoot Elongation ◽  
High Light Intensity ◽  
High Light ◽  
Low Light ◽  
Kinetics Of

Medicago sativa L. cv. Algonquin seedlings were grown for 28 days in growth rooms at several intensities of light and concentrations of CO2. Optimal or deficient NO3− concentrations were provided, the latter with or without inoculation and nodulation by Rhizobium meliloti str. 102F70 (Burton). All growth coefficients (k1′) were hyperbolically dependent on the intensity of light. Light saturation of plant k1′ was achieved, but the k1′ for nitrogenase development the highest in value, was not light saturated at high CO2 by the highest light intensity (555 μE∙m−2∙s−1). That intensity also did not saturate the photosynthesis of plants grown at that intensity nor the amount (yield) and absolute rate of plant growth. The latter were very much reduced at intensities below the compensation point (100 μE∙m−2∙s−1) of net photosynthesis. The data for k1′ at low light intensity indicated that photosynthate was utilized with equal efficiency for N2 and NO3− reduction. Fourfold enrichment of CO2 concentration did not influence the k1′ of plant growth in optimum NO3− and high light intensity but increased the yield by 78%. In the absence of high NO3− concentration, however, it nearly doubled the nitrogenase growth k1′, to a doubling time of 1.4 days, increased the nodule yield fourfold, the plant (symbiotic) yield threefold, and N content twofold. Sevenfold enrichment of CO2 was inhibitory to yields of N-deficient plants and nodules. The previous conclusion that added (combined) N chiefly limited seedling growth was supported by the lack of effect on plant k1′ of the stimulation of photosynthesis by high light intensity and CO2 concentration. A limitation on the value of the k1′ for shoot elongation in deficient combined N raised CO2 and high light was relieved symbiotically.

Influence of carbon supply on developmental kinetics of symbiotic and nonsymbiotic alfalfa cv. Algonquin through first flowering

1985 ◽  
Vol 63 (4) ◽  
pp. 847-849
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Organic N ◽  
Initial Growth ◽  
Carbon Supply ◽  
N Supply ◽  
N Metabolism ◽  
Light Inhibition ◽  
Kinetics Of

Biphasic first-order growth kinetics of NO3-supported or symbiotic seedlings of Medicago sativa L. cv. Algonquin were followed over a range of light intensities and at two concentrations of CO2. The initial, [Formula: see text]-supported growth coefficients ([Formula: see text] or relative growth rate) decreased with decreasing light intensity, but those for symbiotic growth showed relief from high light inhibition by passing through a maximum [Formula: see text] at an intermediate light intensity. In low light intensity (60 μE∙m−2∙s−1) the low initial growth coefficient persisted to 40 days in Hoagland's solution, or for 58 days symbiotically at which time the corresponding biomass was reached. At high light intensity (550 μE∙m−2∙s−1) the initial values of [Formula: see text] were insensitive to the enrichment of CO2 (1325 μL∙L−1), but after 27 days values of [Formula: see text] were enhanced by the raised CO2 concentration. The initial growth phase, which is N limited at a high C supply, was followed by a phase of growth that was C limited at a high N supply. The symbiotic N supply, unlike the combined N supply, was dependent only on the C supply because when the CO2 concentration was raised the acceleration of symbiotic seedling growth equalled the maximum on [Formula: see text] nutrition. The results support a hypothesis that the change in kinetic phase is controlled by developmental morphogenesis independent of N source and C supply and that a plant pool of organic N metabolites plays a role in the regulation of the N metabolism that is involved in the growth effects.

Characteristics of Photosynthesis in Different Wheat Cultivars under High Light Intensity and High Temperature Stresses

2009 ◽  
Vol 34 (12) ◽  
pp. 2196-2201 ◽  
Author(s):  
Xue-Li QI ◽  
Lin HU ◽  
Hai-Bin DONG ◽  
Lei ZHANG ◽  
Gen-Song WANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Wheat Cultivars ◽  
Temperature Stresses

scholarly journals Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

2017 ◽  
Vol 124 ◽  
pp. 331-337 ◽  
Author(s):  
Amir Abdallah ◽  
Ounsi El Daif ◽  
Brahim Aïssa ◽  
Maulid Kivambe ◽  
Nouar Tabet ◽  
...  
Keyword(s):  
Solar Cell ◽  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Heterojunction Solar Cell ◽  
Cell Configuration ◽  
Silicon Heterojunction Solar Cell
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