Photochemical and Non-Photochemical Quenching of Chlorophyll Fluorescence Induced by Hydrogen Peroxide

1989 ◽  
Vol 44 (3-4) ◽  
pp. 262-270 ◽  
Author(s):  
Christian Neubauer ◽  
Ulrich Schreiber
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorophyll Fluorescence ◽  
Fluorescence Quenching ◽  
Ascorbate Peroxidase ◽  
Photochemical Quenching ◽  
Maximal Rate ◽  
Saturation Pulse ◽  
Non Photochemical Quenching ◽  
H 20

Abstract Chlorophyll Fluorescence. Fluorescence Quenching, Hydrogen Peroxide. Active Oxygen. Ascorbate Peroxidase Chlorophyll fluorescence quenching induced by H 20 2 in intact spinach chloroplasts was investi­gated with a modulation fluorometer which allows to distinguish between photochemical and non­ photochemical quenching components by the so-called saturation pulse method. Residual catalase activity was removed by washing and percoll gradient centrifugation. H2O2 was found to induce pronounced photochem ical and non-photochemical quenching, characteristic for the action of a Hill reagent, with a half-maximal rate already observed at 5 × 10-6 m . The saturation characteris­tics and maximal rate of H2O2-reduction were very similar to those of methylviologen reduction. H2O2-dependent quenching was stimulated by ascorbate and inhibited by cyanide and azide in agreement with previous findings by other researchers that H2O2-reduction involves the ascorbate peroxidase scavenging system and that the actual “Hill acceptor” is an oxidation product of ascorbate, i.e. monodehydroascorbate or dehydroascorbate. With well-coupled intact chloro­plasts reducing CO2 at 150 (μmol (mg Chl)-1h-1, iodoacetamide stopped CO2-dependent O2-evolution and consequent addition of 10″3 m H2O2 produced an O2-Solution rate of 240 (μmol (mg Chl)-1h-1 .It is concluded that light-dependent H 20 2 reduction is a very efficient reaction in intact chloroplasts. As H2O2 formation and consequent reduction also occur in vivo, the corre­sponding quenching should be considered when assimilatory electron flow is estimated from quenching coefficients. It is suggested that proton flux associated with H2O2-formation and reduc­tion may be important for the adjustment of appropriate ATP /NADPH ratios required for CO2-fixation in vivo. Furthermore, H2O2-reduction may serve as a valve reaction whenever Calvin cycle activity is limited by factors different from NADPH supply, thus protecting against photo-inhibitory damage.

Contrasting pH-Optima of Light-Driven O2-and H2O2-Reduction in Spinach Chloroplasts as Measured via Chlorophyll Fluorescence Quenching

1991 ◽  
Vol 46 (7-8) ◽  
pp. 635-643 ◽  
Author(s):  
Ulrich Schreiber ◽  
Heinz Reising ◽  
Christian Neubauer
Keyword(s):  
Chlorophyll Fluorescence ◽  
Ascorbate Peroxidase ◽  
Electron Flow ◽  
Chlorophyll Fluorescence Induction ◽  
Monodehydroascorbate Reductase ◽  
Photochemical Quenching ◽  
Illumination Time ◽  
Saturation Pulse ◽  
Spinach Chloroplasts ◽  
Non Photochemical Quenching

Abstract Quenching analysis of chlorophyll fluorescence by the saturation pulse method is used to investigate the pH-dependency of O2-dependent electron flow in intact spinach chloroplasts with high ascorbate peroxidase activity. When carboxylase/oxygenase activity is blocked, pho­tochemical and non-photochemical quenching are initially low and increase with illumination time. Quenching shows a pH-optimum around pH 6.5, but only when ΔpH-formation is al­ lowed. It is suggested that overall O2-dependent electron flow involves two major components, namely O2-reduction (Mehlerreaction) and reduction of the H2O2 formed in the Mehlerreaction, involving enzymic activity of ascorbate peroxidase and monodehydroascorbate reductase. The separated pH-dependencies of light driven O2-reduction (presence of KCN) and of H2O2-reduction (anaerobic conditions) reveal contrasting pH-optima around pH 5 and 8.5, respectively. Energy-dependent, dark relaxable non-photochemical quenching is not observed with O2-reduction but with H2O2-reduction, and only at pH-values above 6.5. The relevance of these findings with respect to regulation of photosynthetic electron flow is discussed. It is suggested that upon limitation of assimilatory electron flow O2-dependent non-assimilatory flow is responsible for ΔpH-formation, by which it is autocatalytically stimulated. It is proposed that this autocatalytical reaction sequence is the basis of the so-called “Kautsky effect” of chlorophyll fluorescence induction.

Modulation of Millisecond Chlorophyll Luminescence by Non-Photochemical Fluorescence Quenching

1989 ◽  
Vol 44 (11-12) ◽  
pp. 966-970 ◽  
Author(s):  
W. Bilger ◽  
U. Schreiber
Keyword(s):  
Photosystem Ii ◽  
Fluorescence Quenching ◽  
High Frequency ◽  
Reaction Centers ◽  
Photochemical Quenching ◽  
Saturation Pulse ◽  
Induction Kinetics ◽  
Non Photochemical Quenching ◽  
Energy Dependent

Abstract By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring sys­tems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenching at photosystem II reaction centers, thus allowing determination of the non-photochemical quenching component. The saturation pulse induction curves of luminescence are well correlated with the corresponding curves of fluorescence, suggesting that luminescence yield is lowered by the same type of non-photochemical quenching (mostly “energy dependent quenching”) as fluorescence. Hence, in order to evaluate luminescence signals in terms of the rate of charge recombination at photosystem II reaction centers, knowledge of fluorescence quenching is required.

Mechanism of Non-Photochemical Chlorophyll Fluorescence Quenching. I. The Role of De-Epoxidised Xanthophylls and Sequestered Thylakoid Membrane Protons as Probed by Dibucaine

1995 ◽  
Vol 22 (2) ◽  
pp. 231 ◽  
Author(s):  
N Mohanty ◽  
HY Yamamoto
Keyword(s):  
Chlorophyll Fluorescence ◽  
Fluorescence Quenching ◽  
Xanthophyll Cycle ◽  
Thylakoid Membranes ◽  
Photochemical Quenching ◽  
Chlorophyll Fluorescence Quenching ◽  
Mechanism Of Inhibition ◽  
Non Photochemical Quenching ◽  
Energy Dependent

Dibucaine reportedly inhibits the light-induced transthylakoid proton gradient of chloroplasts without inhibiting energy-dependent non-photochemical chlorophyll fluorescence quenching (Laasch, H. and Weis, E. (1989). Photosynthesis Research 22, 137-146). We show that dibucaine can inhibit fluorescence quenching, depending on the de-epoxidation state of the xanthophyll cycle. Whereas dibucaine (20-40 μM) had little effect on fluorescence quenching in pre-illuminated-type thylakoids (loaded with zeaxanthin and antheraxanthin), it strongly inhibited quenching in dark-adapted-type thylakoids (no preinduction of de-epoxidation). Dibucaine inhibited lumen acidification similarly in both types of thylakoids and also the induction of violaxanthin de-epoxidation in dark-adapted thylakoids. Thus dark-adapted and pre-illuminated thylakoids differed in de-epoxidation states and their suspectibility to dibucaine inhibition of fluorescence quenching corresponded to this difference. The mechanism of inhibition of de-epoxidation by dibucaine is unclear. It could be due to the inhibition of lumen acidification but an inhibition of the violaxanthin available for de-epoxidation is not excluded. High dibucaine concentrations inhibited de-epoxidase activity directly. Dibucaine inhibition of fluorescence quenching, however, is not limited to the inhibition of de-epoxidation. Small but clear effects on fluorescence quenching were present in thylakoids even with de-epoxidation preinduced. Moreover, thylakoids with preinduced de-epoxidation were more resistant to dibucaine inhibition of fluorescene quenching when poised by salt treatments for proton partitioning into membrane-sequestered domains than when poised for proton partitioning into delocalised domains. We conclude that non-photochemical quenching of chlorophyll fluorescence depends on both de-epoxidised xanthophylls and sequestered proton domains in the thylakoid membranes

scholarly journals Identification of parallel pH- and zeaxanthin-dependent quenching of excess energy in LHCSR3 in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Julianne M. Troiano ◽  
Federico Perozeni ◽  
Raymundo Moya ◽  
Luca Zuliani ◽  
Kwangryul Baek ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Complex Stress ◽  
Excess Energy ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

AbstractUnder high light conditions, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating excess absorbed energy, which is called non-photochemical quenching (NPQ). In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via pH and serves as a quenching site. However, the mechanisms by which LHCSR3 functions have not been determined. Using a combined in vivo and in vitro approach, we identify two parallel yet distinct quenching processes, individually controlled by pH and carotenoid composition, and their likely molecular origin within LHCSR3 from Chlamydomonas reinhardtii. The pH-controlled quenching is removed within a mutant LHCSR3 that lacks the protonable residues responsible for sensing pH. Constitutive quenching in zeaxanthin-enriched systems demonstrates zeaxanthin-controlled quenching, which may be shared with other light-harvesting complexes. We show that both quenching processes prevent the formation of damaging reactive oxygen species, and thus provide distinct timescales and mechanisms of protection in a changing environment.

scholarly journals From ecophysiology to phenomics: some implications of photoprotection and shade–sun acclimation in situ for dynamics of thylakoids in vitro

2012 ◽  
Vol 367 (1608) ◽  
pp. 3503-3514 ◽  
Author(s):  
Shizue Matsubara ◽  
Britta Förster ◽  
Melinda Waterman ◽  
Sharon A. Robinson ◽  
Barry J. Pogson ◽  
...  
Keyword(s):  
Membrane Dynamics ◽  
Persea Americana ◽  
Physiological Data ◽  
Photochemical Quenching ◽  
Shade Acclimation ◽  
Non Photochemical Quenching ◽  
Time Frames ◽  
Shade Leaves

Half a century of research into the physiology and biochemistry of sun–shade acclimation in diverse plants has provided reality checks for contemporary understanding of thylakoid membrane dynamics. This paper reviews recent insights into photosynthetic efficiency and photoprotection from studies of two xanthophyll cycles in old shade leaves from the inner canopy of the tropical trees Inga sapindoides and Persea americana (avocado). It then presents new physiological data from avocado on the time frames of the slow coordinated photosynthetic development of sink leaves in sunlight and on the slow renovation of photosynthetic properties in old leaves during sun to shade and shade to sun acclimation. In so doing, it grapples with issues in vivo that seem relevant to our increasingly sophisticated understanding of Δ pH-dependent, xanthophyll-pigment-stabilized non-photochemical quenching in the antenna of PSII in thylakoid membranes in vitro .

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