Chlorophyll fluorescence induction: an indicator of photosynthetic activity in marine algae undergoing desiccation

1978 ◽  
Vol 56 (21) ◽  
pp. 2787-2794 ◽  
Author(s):  
James Wiltens ◽  
Ulrich Schreiber ◽  
William Vidaver
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Photosystem Ii ◽  
Water Content ◽  
High Tide ◽  
Net Photosynthesis ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Physiological Basis ◽  
Value Analysis

Algae of higher intertidal regions tend to be tolerant of extended periods of desiccation, while many lower tidal or subtidal species do not withstand even mild water loss. (Tidal regions can be characterized as high (regularly immersed at high tide and exposed at low tide), low (emergence only during minus tides (lower than mean low tide)), or subtidal (never exposed at low tide and extending to the maximum depth at which net photosynthesis can occur).) The ecological necessity for tolerance in frequently emerged species is obvious, but the physiological basis of it is not well understood. Changes of photosynthetic partial reactions upon desiccation and rehydration of tolerant and sensitive algae were studied by measurements of chlorophyll fluorescence induction kinetics (Kautsky effect). With progressive decrease in water content the gradual disappearance of the characteristic fluorescence transients was observed in both tolerant and sensitive species. The water content ranges where typical changes occurred were species dependent. Rehydration in tolerant plants resulted in rapid recovery from severe desiccation; there was no such recovery in sensitive plants when water content was decreased below a critical value. Analysis of the fluorescence changes upon desiccation and rehydration suggests: (1) electron transport between photosystem II and photosystem I, as well as H2O splitting are the partial reactions sensitive to desiccation; (2) in the resistant Porphyra sanjuanensis, intersystem electron transport is blocked at around 25% water content; (3) further desiccation leads to loss of water-splitting activity and eventually to the complete loss of variable fluorescence photosystem II reaction centers; and (4) on rehydration intersystem electron transport begins almost immediately while recovery of H2O splitting requires several minutes.

The Inhibition of Photosynthetic Electron Transport by DBMIB and its Restoration by p-Phenylenediamines; Studied by Means of Prompt and Delayed Chlorophyll Fluorescence of Green Algae

1974 ◽  
Vol 29 (11-12) ◽  
pp. 725-732 ◽  
Author(s):  
Robert Bauer ◽  
Mathijs J. G. Wijnands
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Photosystem Ii ◽  
Photosynthetic Electron Transport ◽  
Primary Electron ◽  
Delayed Fluorescence ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Exchange Reactions ◽  
Redox Systems

Abstract The effect of the plastohydroquinone antagonist dibromothym oquinone (DBMIB) on photosynthetic electron transport reactions was studied in the presence and absence of p-phenylene-diamines by means of measurements of prompt and delayed chlorophyll fluorescence induction of the green alga Scenedesm us obliquus. Prompt and delayed chlorophyll fluorescence induction phenomena are valid indicators for the native presence of and cooperation between the two photosynthetic light reactions. Their kinetics reflect the balancing of electron exchange reactions in the chain of coupled redox-systems between the two photosystems upon sudden illumination. From distinct alterations of the short-term (sec) light induced changes in the yield of prom pt and delayed chlorophyll fluorescence it is concluded that DBMIB inhibits the photosynthetic electron transport in the chain of redox-systems between the two light reactions. There is evidence to show that upon illumination of DBMIB treated cells only the reduction of primary electron ac­ceptor pools of photosystem II (i. e. Q and PQ) is still possible. After their reduction the further electron transport through photosystem II is blocked. The addition of p-phenylenediamines to DBM IB-treated cells abolishes the typical DBMIB-affected prom pt and delayed fluorescence inhibition curves and the normal induction curves re­ appear qualitatively in all their important features. From these measurements it is suggested that the redox properties of p-phenylenediamines allow an electron transport bypass of the DBMIB inhibition site which results in a fully restored photosynthetic electron transport from water to NADP.

Humidity-sensitive Degreening and Regreening of Leaves of Borya nitida Labill. As Followed by Changes in Chlorophyll Fluorescence

1982 ◽  
Vol 9 (5) ◽  
pp. 587 ◽  
Author(s):  
SE Hethzerington ◽  
RM Smillie
Keyword(s):  
Chlorophyll Fluorescence ◽  
Relative Humidity ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Fluorescence Induction ◽  
Physiological Age ◽  
Chlorophyll Fluorescence Induction ◽  
Induction Kinetics ◽  
Mediated Electron Transfer

Fast and slow chlorophyll fluorescence induction kinetics were used to follow changes in photosynthetic activity during humidity-sensitive degreening and regreening of leaves of Borya nidita Labill. During dry periods the leaves of this desiccation-tolerant plant lose chlorophyll, becoming yellow-brown and upon rehydration turn green again. This degreening process can be simulated in detached leaves by slow dehydration at 96% relative humidity. Under these conditions changes in chlorophyll fluorescence in vivo and the activities of photosystems I and II in chloroplasts isolated from dehydrated leaves indicated that degreening was accompanied initially by a stimulation of photosystem II activity and a gradual decrease in photosystem I-mediated electron transfer, while at advanced stages of degreening both photosystems were lost. Control leaves detached and kept at 100% relative humidity remained green and showed little change in chlorophyll fluorescence kinetics. During the rehydration and subsequent regreening of dry yellow leaves, photosystem I activity appeared to recover faster than photosystem II. The ability of the leaves to recover and regreen from the dried state, either on the plant or after detachment, depended upon the physiological age of the leaves at the time of dehydration.

scholarly journals Some special features of the water regime and the photosynthetic apparatus activity in Feijoa sellowiana (O. Berg) O. Berg plants under the water stress

2021 ◽  
Vol 38 ◽  
pp. 00117
Author(s):  
Elena Shishkina ◽  
Tatiyna Gubanova ◽  
Valerii Titov
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Drought Tolerance ◽  
Water Content ◽  
Water Regime ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Ps Ii ◽  
Water Stress Tolerance ◽  
Leaf Tissues

When assessing the drought tolerance of Feijoa sellowiana cultivars and forms, the total water content in leaf tissues and their waterretaining and regenerative capacity were determined, and the parameters of chlorophyll fluorescence induction were measured at different water content in leaves. Current-year leaves were characterized by a higher sensitivity to drought. According to the complex of water regime parameters and characteristics of the chlorophyll fluorescence induction (CFI), it was found that the cultivar Aromatnaya Fantazia and the form 3/1 are characterized by a relatively high drought tolerance. It has been demonstrated that the common method for assessing plant tolerance by the index of their water-retaining forces, in relation to Feijoa sellowiana genotypes, does not allow determining the critical level of water deficit. It has been found that in the cultivars and forms with low water stress tolerance, with the water loss of 20-25% from the leaf tissues complete hydration, irreversible irregularities in the PS II structures occurred. The most sensitive to the lack of water in the leaves were such parameters as variable fluorescence, rate constants of the photochemical and non-photochemical deactivation of the excitation, as well as the processes of Qa reduction in the reaction centers of PS II.

Effects of Atrazine, Cyanazine, and Procyazine on the Photochemical Reactions of Isolated Chloroplasts

Weed Science ◽  
1979 ◽  
Vol 27 (3) ◽  
pp. 300-308 ◽  
Author(s):  
P. E. Brewer ◽  
C. J. Arntzen ◽  
F. W. Slife
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Primary Electron ◽  
Fluorescence Induction ◽  
Photochemical Reactions ◽  
Time Dependent ◽  
Chlorophyll Fluorescence Induction ◽  
Transport Assay ◽  
Highly Hydrophobic ◽  
Isolated Chloroplasts

The effects of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl] amino]-2-methylpropionitrile}, and procyazine {2-[[4-chloro-6-(cyclopropylamino)-1,3,5-triazine-2-yl] amino]-2-methylpropanenitrile} on the photochemical reactions of isolated pea (Pisum sativum L. ‘Progress #9 Dwarf’) chloroplasts were studied. Atrazine, cyanazine, and procyazine inhibited electron transport but did not uncouple photophosphorylation. The primary site of inhibition for all three herbicides was on the reducing side of photosystem II; the electron transfer step between the primary electron acceptor (Q) and the plastoquinone pool of the electron transport chain is suggested as the site of action of all three herbicides. The amount of inhibition of electron transport observed after addition of herbicide to isolated chloroplasts was time-dependent for cyanazine and procyazine but not for atrazine. This was apparently due to a slower partitioning of cyanazine and procyazine from the aqueous phase of the reaction solution into the highly hydrophobic environment within the chloroplast membrane. Treatment of the thylakoid membranes with detergent reduced the time-dependent inhibitory nature of cyanazine and procyazine, and the ability of atrazine to block electron transport. A photosystem II-dependent electron transport assay and a chlorophyll fluorescence induction assay were used to determine the inhibitory potentials of atrazine, cyanazine, and procyazine. After allowing for differences in the rate of membrane penetration, I50 values of approximately 2 × 10−7 M were determined for each of the three herbicides.

scholarly journals Methyl Jasmonate Protects the PS II System by Maintaining the Stability of Chloroplast D1 Protein and Accelerating Enzymatic Antioxidants in Heat-Stressed Wheat Plants

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1216
Author(s):  
Mehar Fatma ◽  
Noushina Iqbal ◽  
Zebus Sehar ◽  
Mohammed Nasser Alyemeni ◽  
Prashant Kaushik ◽  
...  
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Methyl Jasmonate ◽  
Reaction Center ◽  
D1 Protein ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Enzymatic Antioxidants ◽  
Ps Ii

The application of 10 µM methyl jasmonate (MeJA) for the protection of wheat (Triticum aestivum L.) photosystem II (PS II) against heat stress (HS) was studied. Heat stress was induced at 42 °C to established plants, which were then recovered at 25 °C and monitored during their growth for the study duration. Application of MeJA resulted in increased enzymatic antioxidant activity that reduced the content of hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) and enhanced the photosynthetic efficiency. Exogenous MeJA had a beneficial effect on chlorophyll fluorescence under HS and enhanced the pigment system (PS) II system, as observed in a JIP-test, a new tool for chlorophyll fluorescence induction curve. Exogenous MeJA improved the quantum yield of electron transport (ETo/CS) as well as electron transport flux for each reaction center (ET0/RC). However, the specific energy fluxes per reaction center (RC), i.e., TR0/RC (trapping) and DI0/RC (dissipation), were reduced by MeJA. These results indicate that MeJA affects the efficiency of PS II by stabilizing the D1 protein, increasing its abundance, and enhancing the expression of the psbA and psbB genes under HS, which encode proteins of the PS II core RC complex. Thus, MeJA is a potential tool to protect PS II and D1 protein in wheat plants under HS and to accelerate the recovery of the photosynthetic capacity.

scholarly journals Respiration Interacts With Photosynthesis Through the Acceptor Side of Photosystem I, Reflected in the Dark-to-Light Induction Kinetics of Chlorophyll Fluorescence in the Cyanobacterium Synechocystis sp. PCC 6803

2021 ◽  
Vol 12 ◽  
Author(s):  
Takako Ogawa ◽  
Kenta Suzuki ◽  
Kintake Sonoike
Keyword(s):  
Chlorophyll Fluorescence ◽  
Electron Transport ◽  
Photosystem I ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Light Induction ◽  
Acceptor Side ◽  
Induction Kinetics ◽  
Electron Transport Chains ◽  
Kinetics Of

In cyanobacteria, the photosynthetic prokaryotes, direct interaction between photosynthesis and respiration exists at plastoquinone (PQ) pool, which is shared by the two electron transport chains. Another possible point of intersection of the two electron transport chains is NADPH, which is the major electron donor to the respiratory chain as well as the final product of the photosynthetic chain. Here, we showed that the redox state of NADPH in the dark affected chlorophyll fluorescence induction in the cyanobacterium Synechocystis sp. PCC 6803 in a quantitative manner. Accumulation of the reduced NADPH in the dark due to the defect in type 1 NAD(P)H dehydrogenase complex in the respiratory chain resulted in the faster rise to the peak in the dark-to-light induction of chlorophyll fluorescence, while depletion of NADPH due to the defect in pentose phosphate pathway resulted in the delayed appearance of the initial peak in the induction kinetics. There was a strong correlation between the dark level of NADPH determined by its fluorescence and the peak position of the induction kinetics of chlorophyll fluorescence. These results indicate that photosynthesis interacts with respiration through NADPH, which enable us to monitor the redox condition of the acceptor side of photosystem I by simple measurements of chlorophyll fluorescence induction in cyanobacteria.

scholarly journals OJIP chlorophyll fluorescence induction profiles and plastoquinone binding affinity of the Photosystem II assembly intermediate PSII-I from Thermosynechococcus elongatus

2021 ◽  
Author(s):  
Jure Zabret ◽  
Marc M Nowaczyk
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Binding Affinity ◽  
Conformational Changes ◽  
Charge Recombination ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Acceptor Side ◽  
Assembly Intermediate

Binding of Psb28 to the photosystem II assembly intermediate PSII-I induces conformational changes to the PSII acceptor side that impact charge recombination and reduce the in situ production of singlet oxygen (Zabret et al. 2021, Nat. Plants 7, 524-538). A detailed fluorometric analysis of the PSII-I assembly intermediate compared with OEC-disrupted and Mn-depleted PSII complexes showed differences between their variable (OJIP) chlorophyll fluorescence induction profiles. These revealed a distinct destabilisation of the QA- state in the PSII-I assembly intermediate and inactivated PSII samples related to an increased rate of direct and safe charge recombination. Furthermore, inactivation or removal of the OEC increases the binding affinity for plastoquinone analogues like DCBQ to the different PSII complexes. These results might indicate a mechanism that further contributes to the protection of PSII during biogenesis or repair.

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