Afterglow Thermoluminescence Measured in Isolated Chloroplasts

Belatik, Ahmed; Essemine, Jemâa; Hotchandani, Surat; Carpentier, Robert

doi:10.1111/j.1751-1097.2011.01016.x

Cited by 7 publications

(4 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5A, Ctrl) attained its maximal intensity at the temperature of 38uC, characteristic of the temperature optimum for the B band appearing in the range between 30 and 40uC, as previously reported for this type of material (46)(47). The B band is attributed to the charge recombination of S 2 /S 3 Q B 2 pairs produced by linear electron transport in PSII (48)(49)(50)(51). The intensity of the B band progressively diminished as the concentration of PbCl 2 increased (Fig.…”

Section: Thermoluminescencesupporting

confidence: 79%

See 1 more Smart Citation

Inhibition of the Water Oxidizing Complex of Photosystem II and the Reoxidation of the Quinone Acceptor QA− by Pb2+

2013

Self Cite

View full text Add to dashboard Cite

The action of the environmental toxic Pb2+ on photosynthetic electron transport was studied in thylakoid membranes isolated from spinach leaves. Fluorescence and thermoluminescence techniques were performed in order to determine the mode of Pb2+ action in photosystem II (PSII). The invariance of fluorescence characteristics of chlorophyll a (Chl a) and magnesium tetraphenylporphyrin (MgTPP), a molecule structurally analogous to Chl a, in the presence of Pb2+ confirms that Pb cation does not interact directly with chlorophyll molecules in PSII. The results show that Pb interacts with the water oxidation complex thus perturbing charge recombination between the quinone acceptors of PSII and the S2 state of the Mn4Ca cluster. Electron transfer between the quinone acceptors QA and QB is also greatly retarded in the presence of Pb2+. This is proposed to be owing to a transmembrane modification of the acceptor side of the photosystem.

show abstract

Section: Thermoluminescencesupporting

confidence: 79%

“…5B). The reason for the absence of B band is that since DCMU stops the electron flow past Q A , the formation of Q B 2 and state S 3 is not realized (49). The addition of 20 mM PbCl 2 already suppressed 12% of the Q band intensity.…”

Section: Thermoluminescencementioning

confidence: 99%

Inhibition of the Water Oxidizing Complex of Photosystem II and the Reoxidation of the Quinone Acceptor QA− by Pb2+

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, the AG emission can be observed only in intact systems, including intact chloroplasts, but not in isolated thylakoids (Belatik et al, 2012; Cerović et al, 1991). The reason for that can be found in the requirement of a proton gradient and in the role of soluble molecules in stroma (NADPH, ATP, and ferredoxin) and also the phosphoglycerate/dihydroxyacetone phosphate system that determines the NADPH+ATP assimilatory potential (Gerst et al, 1994; Krieger et al, 1998).…”

Section: The Origin Of the Afterglow Light Emissionmentioning

confidence: 99%

“…The AG emission has been used as a tool to characterize the effect of thermal stress on intact photosynthetic systems and to understand the mechanisms of constitutive or induced tolerance to this stress (Ducruet et al, 1997; Ducruet et al, 2007). The TL AG band reflects the integrity of the chloroplast (Belatik et al, 2012) and is also a good indicator of the assimilatory potential (NADPH+ATP), thus being very sensitive to temperature stress. Besides, AG band seems to be more sensitive to temperature stress than B band (Janda et al, 2000; Miranda & Ducruet, 1995b).…”

Section: Ag Emission As a Sensitive Indicator Of Stress In Chloroplastsmentioning

confidence: 99%

The afterglow photosynthetic luminescence

Ortega

Roncel

2020

Physiologia Plantarum

View full text Add to dashboard Cite

The afterglow (AG) photosynthetic luminescence is a long‐lived chlorophyll fluorescence emitted from PSII after the illumination of photosynthetic materials by FR or white light and placed in darkness. The AG emission corresponds to the fraction of PSII centers in the S2/3QB non‐radiative state immediately after pre‐illumination, in which the arrival of an electron transferred from stroma along cyclic/chlororespiratory pathway(s) produces the S2/3QB− radiative state that emits luminescence. This emission can be optimally recorded by a linear temperature gradient as sharp thermoluminescence (TL) band peaking at about 45°C. The AG emission recorded by TL technique has been proposed as a simple non‐invasive tool to investigate the chloroplast energetic state and some of its metabolism processes as cyclic transport of electrons around PSI, chlororespiration or photorespiration. On the other hand, this emission has demonstrated to be a useful probe to study the effect of various stress conditions in photosynthetic materials.

show abstract

Re-evaluation of the side effects of cytochrome b6f inhibitor dibromothymoquinone on photosystem II excitation and electron transfer

et al. 2013

View full text Add to dashboard Cite

Dibromothymoquinone (DBMIB) has been used as a specific inhibitor of plastoquinol oxidation at the Q0 binding site of the cytochrome b6f complex for 40 years. It is thought to suppress electron transfer between photosystem (PS) II and I, as well as cyclic electron transfer around PSI. However, DBMIB has also been reported to act as a quencher of chlorophyll excited states. In this study, we have re-evaluated the effects of DBMIB on chlorophyll excited states and PSII photochemistry. The results show that DBMIB significantly quenches the chlorophyll excited states of PSII antenna even at low concentration (from 0.1 μM), lowering the effective excitation rate of the actinic light. It also acts as a potent PSII electron acceptor retarding the reduction of the plastoquinone pool with almost maximal potency at 2 μM. Altogether, these results suggest that experiments using DBMIB can easily be misinterpreted and stress on the importance of taking into account all these side effects that occur in the same range of DBMIB concentration used for inhibition of plastoquinol oxidation (1 μM).

show abstract

Afterglow Thermoluminescence Measured in Isolated Chloroplasts

Cited by 7 publications

References 46 publications

Inhibition of the Water Oxidizing Complex of Photosystem II and the Reoxidation of the Quinone Acceptor QA− by Pb2+

Inhibition of the Water Oxidizing Complex of Photosystem II and the Reoxidation of the Quinone Acceptor QA− by Pb2+

The afterglow photosynthetic luminescence

Re-evaluation of the side effects of cytochrome b6f inhibitor dibromothymoquinone on photosystem II excitation and electron transfer

Contact Info

Product

Resources

About