Micro-electrode Measurements of the Transmembrane Potential of Chloroplasts and its Photoinduced Changes

Булычев, А. А.; Андрианов, В. К.; Kurella, G. A.; Litvin, F. F.

doi:10.1038/236175a0

Cited by 103 publications

(18 citation statements)

References 6 publications

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“…Following this initial contraction chloroplasts continue to decrease in volume, but at a much slower rate. The half-time for the first phase of chloroplast flattening is much shorter than that found in previously examined tissues (Nobel 1968;Nobel et al 1969;Miller and Nobel 1972), where it varied between 0·5 and 5 min and approached that found for the photo-induced changes of the transmembrane electric potential of chloroplasts in Peperomia metallica (Bulychev et al 1972). The initial phase of the photoelectric response was attributed to the transfer of hydrogen ions, while the slow phase was thought to be due to changes in the activity of cations in chloroplasts and the cytoplasm.…”

Section: (B) Effect Of Illuminationmentioning

confidence: 74%

Effect of Light on the Volume and Ion Relations of Chloroplasts in Detached Leaves of Elodea Densa

Fillippis¹,

Pallaghy²

1973

Aust. Jnl. Of Bio. Sci.

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Light-induced changes in chloroplasts of detached leaves of E. densa were investigated either by fixing leaves in 6% glutaraldehyde or by snap-freezing leaves and isolating chloroplasts after freeze-substitution in acetone. Individual chloroplasts were examined by electron probe analysis.Upon illumination (450 lux green light) chloroplasts in detached leaves flattened, with a reduction in volume of about 30% within the first second. During this initial phase of chloroplast contraction the calculated osmotic potential of chloroplasts fell from about -17 bars in the dark to -21 bars after 1 s of illumination, suggesting that the rapid contraction was not the result of an osmotic mechanism of water efflux brought about by an efflux of chloride, potassium, sodium, or calcium ions from chloroplasts. During the next hour of illumination chloroplast volume was reduced by only a further 5%, but the chloroplasts lost approximately 50% of their original ion content. The calculated osmotic potential of the chloroplasts rose to approximately -11 bars.During the first hour of illumination the average net efflux of ions (± standard error of the mean) across the chloroplast envelope was 32·6 ± 3·5 for chloride, 8·7 ± 0·8 for potassium, and 21·24 ± 1·4 p-equiv.cm-2 s-1 for sodium. The estimated efflux for calcium was approximately 8 p-equiv. cm-2 S-1. Typical concentrations of chloride, potassium, and sodium respectively in chloroplasts were 0·53, 0'24, and 0·31 equiv/l of chloroplast volume in dark-treated leaves and 0·32, 0·20, and 0·17 equiv/l in light-treated leaves. The chloride content of chloroplasts represents at least 20% of the total chloride content of dark-treated leaves. In the light the corresponding proportion is approximately 8%. The effects of CO2, ammonia, brucine, ouabain, and 3-p-chlorophenyl-1,I-dimethylurea on the in vivo ion and volume relations of E. densa chloroplasts are described.

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Section: (B) Effect Of Illuminationmentioning

confidence: 74%

Effect of Light on the Volume and Ion Relations of Chloroplasts in Detached Leaves of Elodea Densa

Fillippis¹,

Pallaghy²

1973

Aust. Jnl. Of Bio. Sci.

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“…by the redox-active tyrosine Y Z (Pokorny et al 1994;Mamedov et al 1995;Haumann et al 1997). The sign of the DW (negative charge of the proteoliposome interior) suggests that OEC faces the outer surface of the membrane, i.e., the polarity of the signal from PS II core particles is opposite to that in thylakoid membranes (Schliephake et al 1968;Witt et al 1968;Bulychev et al 1972). The slow decay of the photovoltage is due to the back reaction from the S 2 Q A -state (curve 1); typical lifetimes are in the order of a few seconds at room temperature (Robinson and Crofts 1983;Rappaport et al 2002).…”

Section: Electrogenic Events Associated With Early Stages Of Photocyclementioning

confidence: 96%

Electrogenic reactions and dielectric properties of photosystem II

2008

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This review is focused on the mechanism of photovoltage generation involving the photosystem II turnover. This large integral membrane enzyme catalyzes the light-driven oxidation of water and reduction of plastoquinone. The data discussed in this work show that there are four main electrogenic steps in native complexes: (i) light-induced charge separation between special pair chlorophylls P(680) and primary quinone acceptor Q(A); (ii) P(680)(+) reduction by the redox-active tyrosine Y(Z) of polypeptide D1; (iii) oxidation of Mn cluster by Y(Z)(ox) followed by proton release, and (iv) protonation of double reduced secondary quinone acceptor Q(B). The electrogenicity related to (i) proton-coupled electron transfer between Q(A)(-) and preoxidized non-heme iron (Fe(3+)) in native and (ii) electron transfer between protein-water boundary and Y(Z)(ox) in the presence of redox-dye(s) in Mn-depleted samples, respectively, were also considered. Evaluation of the dielectric properties using the electrometric data and the polarity profiles of reaction center from purple bacteria Blastochloris viridis and photosystem II are presented. The knowledge of the profile of dielectric permittivity along the photosynthetic reaction center is important for understanding of the mechanism of electron transfer between redox cofactors.

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“…A well-known species in the genus is Peperomia metallica which was reported to contain giant chloroplasts in its palisade parenchyma cells (Schürhoff 1908, Neumann 1973. Because of this unique feature, P. metallica chloroplasts have been a preferred model of electrophysiological studies (Bulche et al 1972). The large size of the chloroplasts is compensated by a small chloroplast number, which is in the range of only 2 to 6 per palisade cell (Bartels 1965).…”

Section: Introductionmentioning

confidence: 98%

Plastid division and morphology in the genus Peperomia

Ahmadabadi¹,

Bock²

2012

Biol. plant.

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We have investigated several factors determining plastid size and number in Peperomia, a genus in the Piperaceae family whose species naturally display great interspecific variation in chloroplast size and number per cell. Using microscopic techniques, we show that chloroplast size and number are differently regulated in the palisade parenchyma and the spongy parenchyma, suggesting that chloroplast division in these cell types is controlled in different ways. Microscopic studies of iodine-stained root cells revealed a correlation between amyloplast size in root cells and chloroplast size in palisade parenchyma cells. However, despite substantial variation in chloroplast number in leaf mesophyll cells, amyloplast number in root cells was very similar in all species. The results suggest that organelle size and number are regulated in a tissue-specific manner rather than in dependency on the plastid type. We also demonstrate that plastid size determines the size but not the number of starch grains in root amyloplasts.Additional key words: amyloplast, chloroplast, plastid number, plastid size.

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Micro-electrode Measurements of the Transmembrane Potential of Chloroplasts and its Photoinduced Changes

Cited by 103 publications

References 6 publications

Effect of Light on the Volume and Ion Relations of Chloroplasts in Detached Leaves of Elodea Densa

Effect of Light on the Volume and Ion Relations of Chloroplasts in Detached Leaves of Elodea Densa

Electrogenic reactions and dielectric properties of photosystem II

Plastid division and morphology in the genus Peperomia

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