Energetics of Photosystem II Charge Recombination in Acaryochloris marina Studied by Thermoluminescence and Flash Induced Chlorophyll Fluorescence Measurements

2008 ◽  
pp. 231-234
Author(s):  
Imre Vass ◽  
Krisztián Cser ◽  
Alison Telfer ◽  
Samuel L. Benson ◽  
James Barber ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Charge Recombination ◽  
Fluorescence Measurements ◽  
Acaryochloris Marina

scholarly journals Limitation of photosynthetic processes in photosystem II in alpine mosses exposed to low temperatures: Response of chlorophyll fluorescence parameters

2018 ◽  
Vol 8 (2) ◽  
pp. 218-229 ◽  
Author(s):  
Yeray Folgar Cameán ◽  
Miloš Barták
Keyword(s):  
Chlorophyll Fluorescence ◽  
Low Temperature ◽  
Photosystem Ii ◽  
Temperature Stress ◽  
Low Temperature Stress ◽  
Ps Ii ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Fluorescence Measurements ◽  
Sphagnum Girgensohnii

In this study, we evaluated the effects of low and sub-zero temperature on the fast chlorophyll fluorescence transient (OJIP) and OJIP-derived parameters in 4 different mosses: Sphagnum girgensohnii, Polytrichum formosum, Hylocomium splendens and Pleurozium schreberi. The low temperature stress was applied on the mosses for 90 min. at 3 different temperatures (5°C, -1°C and -10°C). To investigate the effects of this stress on the functioning of photosystem II (PS II), the chlorophyll fluorescence measurements were taken at control temperature (22°C) and, after a 90 min. acclimation period, at each experimental temperature. The shape of OJIP curves and chlorophyll fluorescence parameters were found temperature-dependent in all the species. The mosses differed in their sensitivity to the stress but general trends in response to low temperature were similar. The results support the idea that S. girgensohnii is less resistant to low temperature stress than the other species. We were also interested in the K and L steps in OJIPs, representing different disorders caused by low temperature. The K-step was seen in P. formosum and P. schreberi and the L-step in H. splendens and S. girgensohnii.

SO2 Injury in Intact Leaves, as Detected by Chlorophyll Fluorescence

1988 ◽  
Vol 43 (3-4) ◽  
pp. 269-274 ◽  
Author(s):  
Wolfgang Schmidt ◽  
Ulrich Schreiber ◽  
Wolfgang Urbach
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Calvin Cycle ◽  
Photosynthetic Apparatus ◽  
Enzymatic Reactions ◽  
Decay Kinetics ◽  
Saturation Pulse ◽  
Induction Kinetics ◽  
Fluorescence Measurements

The effects of short-time fumigation (0-60 min) of intact spinach leaves with SO2 (2 ppm) on the photosynthetic apparatus were investigated. A rather high SO2 concentration was applied to monitor immediate effects on the fluorescence behaviour with the influence of repair processes or secondary types of damage being minimized. Three different types of in vivo chlorophyll fluorescence measurements were used: Rapid induction kinetics (Kautsky effect), slow induction kinetics with repetitive application of saturation pulses (saturation pulse method), and decay kinetics following a single turnover saturating flash. The slow induction kinetics with repetitive application of saturation pulses reacts in the most sensitive way indicating a primary damage at the level of the enzymatic reactions of the Calvin cycle. It is suggested that stromal acidification upon SO2 uptake interferes with light activation of Calvin cycle enzymes. With longer fumigation times also damage at the level of photosystem II becomes apparent: A decrease in variable fluorescence yield reflects a lowering of photosystem II quantum yield, and the slowing down of fluorescence relaxation kinetics reveals an effect on the secondary electron transport from Qᴀ to Qв. The detrimental effects of SO2 depend to a great extent on the application of light during fumigation. Besides a light requirement for SO2 uptake by stomata opening also the possibility of photoinhibitory damage is discussed. The susceptibility of leaves to photoinhibition may increase with a lowering of Calvin cycle activity by SO2.

Multiple Effects of Cadmium on the Photosynthetic Apparatus of Avicennia germinans L. as Probed by OJIP Chlorophyll Fluorescence Measurements

2007 ◽  
Vol 62 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
Daniel Gonzalez-Mendoza ◽  
Francisco Espadas y Gil ◽  
Jorge M. Santamaría ◽  
Omar Zapata-Perez
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Water Splitting ◽  
Performance Index ◽  
Photosynthetic Apparatus ◽  
Reaction Centers ◽  
Avicennia Germinans ◽  
Fluorescence Measurements ◽  
Active Reaction ◽  
Primary Photochemistry

Abstract The toxic effects of cadmium on the photosynthetic apparatus of Avicennia germinans were evaluated by means of the chlorophyll fluorescence transient O-J-I-P. The chlorophyll fluorescence transients were recorded in vivo with high time resolution and analyzed according to the OJIP-test that can quantify the performance of photosystem II. Cadmium-treated plants showed a decrease in yield for primary photochemistry, TR0/ABS. The performance index of photosystem II (PSII), PIABS, decreased due to cadmium treatment. This performance index is the combination of the indexes of three independent parameters: (1) total number of active reaction centers per absorption (RC/ABS), (2) yield of primary photochemistry (TR0/ABS), and (3) efficiency with which a trapped exciton can move an electron into the electron transport chain (ET0/TR0). Additionally, the F0/Fv registered the highest sensitivity to the metal, thus indicating that the water-splitting apparatus of the oxidizing side of PSII is the primary site of action of cadmium. In summary, cadmium affects several targets of photosystem II. More specifically the main targets of cadmium, according to the OJIPtest, can be listed as a decrease in the number of active reaction centers and damage to the activity of the water-splitting complex.

Kinetics of Action of Different Photosystem II Herbicides on Thylakoids

1990 ◽  
Vol 45 (5) ◽  
pp. 348-352 ◽  
Author(s):  
Jean-Marc Ducruet ◽  
Sophie Creuzet ◽  
Josiane Viénot
Keyword(s):  
Electron Transfer ◽  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Temperature Dependent ◽  
Binding Process ◽  
Uracil Derivatives ◽  
Fluorescence Measurements ◽  
Kinetics Of

The kinctics of inhibition of photosystem II electron transfer by different diuron-like herbicides (ureas, triazines, triazinoncs, biscarbamates. uraciles) were studied, mainly by chlorophyll fluorescence measurements. Uracil derivatives and cyanazine, a particular triazinc. were the slowest acting compounds. The half-times of action were strongly temperature-dependent and were of the order of tens of seconds at 5 °C for urea or triazine inhibitors. The role of different limiting steps in the binding process is discussed.

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