Comparative thermoluminescence study of autotrophically and photoheterotrophically cultivated Chlamydobotrys stellata

Wießner, Wolfgang; Demeter, S.

doi:10.1007/bf00034839

Cited by 12 publications

(7 citation statements)

References 43 publications

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“…TL was measured using a custom-made TL apparatus described by Wiessner and Demeter (1988). Leaf discs were placed on a copper sample holder, connected to a cold finger immersed in liquid nitrogen.…”

Section: Tl Measurementsmentioning

confidence: 99%

The Physiological Role of Ascorbate as Photosystem II Electron Donor: Protection against Photoinactivation in Heat-Stressed Leaves

et al. 2011

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Previously, we showed that ascorbate (Asc), by donating electrons to photosystem II (PSII), supports a sustained electron transport activity in leaves in which the oxygen-evolving complexes were inactivated with a heat pulse (49°C, 40 s). Here, by using wild-type, Asc-overproducing, and -deficient Arabidopsis (Arabidopsis thaliana) mutants (miox4 and vtc2-3, respectively), we investigated the physiological role of Asc as PSII electron donor in heat-stressed leaves (40°C, 15 min), lacking active oxygen-evolving complexes. Chlorophyll-a fluorescence transients show that in leaves excited with trains of saturating singleturnover flashes spaced 200 ms apart, allowing continual electron donation from Asc to PSII, the reaction centers remained functional even after thousands of turnovers. Higher flash frequencies or continuous illumination (300 mmol photons m 22 s 21 ) gradually inactivated them, a process that appeared to be initiated by a dramatic deceleration of the electron transfer from Tyr Z to P680 + , followed by the complete loss of charge separation activity. These processes occurred with half-times of 1.2 and 10 min, 2.8 and 23 min, and 4.1 and 51 min in vtc2-3, the wild type, and miox4, respectively, indicating that the rate of inactivation strongly depended on the Asc content of the leaves. The recovery of PSII activity, following the degradation of PSII proteins (D1, CP43, and PsbO), in moderate light (100 mmol photons m 22 s 21 , comparable to growth light), was also retarded in the Ascdeficient mutant. These data show that high Asc content of leaves contributes significantly to the ability of plants to withstand heat-stress conditions.

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Section: Tl Measurementsmentioning

confidence: 99%

The Physiological Role of Ascorbate as Photosystem II Electron Donor: Protection against Photoinactivation in Heat-Stressed Leaves

et al. 2011

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“…Thermoluminescence was measured in a home-built apparatus as described by Wiessner and Demeter (1988). 0.4 cm 3 aliquots of algal sample [10 g(Chl) m -3 ] taken directly from the culture vessel were excited by continuous "white light" (50 μmol m -2 s -1 ) at -80 o C. The emitted thermoluminescence was measured during heating the sample in the dark at a heating rate of 20 ºC per min by a Hamamatsu end-window photomultiplier.…”

Section: Measurement Of Photosynthetic Activitiesmentioning

confidence: 99%

Effect of chromium on photosystem 2 in the unicellular green alga, Chlorella pyrenoidosa

Hörcsik¹,

Kovács

Láposi³

et al. 2007

Photosynt.

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We investigated the effect of chromium (20-40 g m -3 , 8-72 h) on the photosystem 2 (PS2) activities of Chlorella pyrenoidosa cells. By using chlorophyll fluorescence transients, thermoluminescence, oxygen polarography, and Western blot analysis for D1 protein we found that inhibition of PS2 can be accounted for by the enhanced photodestruction of the reaction centres in the cells cultivated in the presence of Cr(VI) at 25 o C in "white light" (18 W m -2 ). Hence photodestruction of D1 is caused by an enhanced oxidative stress and lipid peroxidation, as indicated by the appearance of a high-temperature thermoluminescence band.

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“…Thermoluminescence was measured using a custom-made TL apparatus described by Wiessner and Demeter (1988). For TL measurements, thylakoid suspension (0.3 ml, 50 mg Chl (a+b) ml À1 ) was placed on a copper sample holder.…”

Section: Thermoluminescence Measurementsmentioning

confidence: 99%

Biophysical studies of photosystem II-related recovery processes after a heat pulse in barley seedlings (Hordeum vulgare L.)

Tóth

Schansker

Kissimon

et al. 2005

Journal of Plant Physiology

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Comparative thermoluminescence study of autotrophically and photoheterotrophically cultivated Chlamydobotrys stellata

Cited by 12 publications

References 43 publications

The Physiological Role of Ascorbate as Photosystem II Electron Donor: Protection against Photoinactivation in Heat-Stressed Leaves

The Physiological Role of Ascorbate as Photosystem II Electron Donor: Protection against Photoinactivation in Heat-Stressed Leaves

Effect of chromium on photosystem 2 in the unicellular green alga, Chlorella pyrenoidosa

Biophysical studies of photosystem II-related recovery processes after a heat pulse in barley seedlings (Hordeum vulgare L.)

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