Light-Activated H<sup>+</sup>Transport into the Vacuole of<i>Valonia ventricosa</i>

Gyenes, M.; Булычев, А. А.; Kurella, G. A.; Alvarez, P. Perez

doi:10.1093/jxb/32.6.1273

Cited by 6 publications

(4 citation statements)

References 14 publications

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“…Light-dependent pH changes in the chloroplast stroma can be measured in leaves by a rapid gas-exchange technique ( Fig. A much smaller light-dependent vacuolar pH shift has been observed in the alga Valonia by Gyenes et al (1981). Methods to measure the light-dependent acidifica-tion of the intrathylakoid space in intact leaves are indirect.…”

Section: Light-dependent Ph Changes In Leavesmentioning

confidence: 99%

Light-dependent pH changes in leaves of C3 plants

Yin

Neimanis

Wagner

et al. 1990

Planta

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Chloroplasts, mesophyll protoplasts, cytoplasts, vacuoplasts, vacuoles and leaves were stained with pH-indicating fluorescent dyes of differing pK values. Fluorescence microscopy was used to obtain information on the intracellular and intercellular distribution of the probes. The kinetics of blue or green fluorescence emitted from chloroplasts, protoplasts, cytoplasts and leaves was measured during illumination with red light. The intensity of light used for fluorescence excitation was so low that it had little effect on photosynthesis. In leaves, fluorescence signals emitted from chloroplasts were small and usually insignificant compared to signals originating from the cytosol. Both indicated light-dependent alkalization and reversal of alkalization on darkening. Vacuolar signals were opposite in sign to cytosolic signals. They indicated acidification of the vacuole in the light-dark transient and reversal of this effect on darkening.

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Section: Light-dependent Ph Changes In Leavesmentioning

confidence: 99%

Light-dependent pH changes in leaves of C3 plants

Yin

Neimanis

Wagner

et al. 1990

Planta

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“…The vacuolar pH is under metabolic control. When the cells of Valonia, Phaeoceros, and Nitellopsis were illuminated, the cell sap became more acid with concomitant changes in the vacuolar potential or the tonoplast potential (1,4,5). In isolated vacuoles of Tulipa, Hevea, and Saccharomyces, both the H+ accumulation and the membrane potential depend on MgATP (6,12,13,16,26).…”

mentioning

confidence: 99%

Electric characteristics of the vacuolar membrane of Chara in relation to pH regulation.

Moriyasu

Shimmen

Tazawa

1984

Cell Struct. Funct.

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ABSTRACT. The vacuolar pH of Chara internodal cells was modified by vacuolar perfusion, and changes in membrane potential and membrane resistance of the tonoplast in response to the vacuolar pH (pHv) change were studied by anesthetizing the cell with 110 mM KCl in the external medium. Under this condition the responses of the vacuolar potential (Ev o) and resistance (Rvo) are assumed to reflect the responses of the tonoplast. E, o showed scarcely any sensitivity to the pHv when the KCl concentration of the vacuole ([KCl]v) was high (100 mM), but it changed by 30 mV in response to changes in the pHv from 5.5 to 7.5 when the [KCl]v was as low as 0.1 mM. This pHv sensitivity of Ev o was suppressed by DCCD, an inhibitor of H+-ATPase.Tonoplast vesicles were prepared from an internodal cell, and the effect of MgATP on their internal pHs was studied by estimating the accumulation of neutral red. A high accumulation of the pigment was found when MgATP was present in the external medium, but the color faded away when ATP was absent. These results together with the effect of DCCD on the Evo. indicate that there is an ATP-dependent electrogenic H+-pump in the tonoplasts of Chara internodal cells and that this electrogenicity is very small under normal conditions in which the natural cell sap contains about 100 mM KCl.Membrane characteristics of the tonoplast were compared with those of the plasmalemma with respect to their passive permeabilities to K+ and H+ and to the pump conductance.

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“…The vacuolar pH of the spherical green alga Valonia ventricosa was measured by Gyenes et al (1981) with a pH microelectrode. The authors measured an acidification in the range of 0.05~).1 pH units upon illumination.…”

Section: Discussionmentioning

confidence: 99%

Light-dependent proton transport into mesophyll vacuoles of leaves of C3 plants as revealed by pH-indicating fluorescent dyes: a reappraisal

Yin

Hüve

Heber

1996

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Abstract. Esculin, a pH-sensitive fluorescent dye, was used to indicate light-dependent pH changes in leaves of Spinacia oleracea L. and Pelargonium zonale L. Shortly after its introduction into the leaves via the transpiration stream, esculin was localized mainly in the symplasm. An increase in its blue fluorescence on illumination with red actinic light indicated that the cytosolic pH had increased. A similar light-dependent alkalinization was seen when the green fluorescence of pyranine was used to monitor changes in the cytosolic pH. After esculin had been transferred into the vacuoles, a light-dependent vacuolar acidification was indicated by a decrease in its blue fluorescence. Since the pK of esculin is close to neutrality, it is suitable as an indicator of proton transport into vacuoles provided the vacuolar sap is only moderately acidic. In leaf cells with very acidic vacuoles, esculin therefore responds only to cytosolic pH changes as long as it remains in the cytosol. The observations made with esculin after it had entered the vacuoles confirmed earlier conclusions on light-dependent proton transport into the vacuoles of mesophyll cells. Previous measurements had been made with 5-carboxy-2',7'-dichlorofluoresceine (CDCF), which has a pK of 4.8. In contrast to esculin, CDCF can, in principle, record pH changes in very acidic vacuoles. However, earlier conclusions made on the basis of observed CDCF fluorescence are now recognized to have no unambiguous basis because new measurements, reported here, show that CDCF fluorescence is influenced not only by pH changes but also by changes in light scattering. The latter are, like pH changes, light-dependent and originate from the thylakoid system of chloroplasts. They indicate both the formation of a large transthylakoid proton gradient and the dissipation of * Present address: Department of Biological Sciences, University of Dundee, Dundee, DD1 4HN, UK Abbreviations: CDCF=5-(and 6-)carboxy-2',7'-dichlorofluoresceine; PT00 = primary donor of PS I; PFD = photon flux density; QA = primary quinone acceptor of PS II; Qp, QN = photochemical, non-photochemical quenching of chlorophyll fluorescence, respectively Correspondence to: K. Hiive; FAX: 49 (931) 888 6158 excess light energy as heat. Decreased green fluorescence of leaves which had been fed CDCF may therefore, depending on conditions, indicate vacuolar acidification or the dissipation of excess light energy absorbed by the pigment system of chloroplasts, or both. Pyranine fluorescence was found to be much less influenced by light scattering than CDCF fluorescence.

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Light-Activated H⁺Transport into the Vacuole ofValonia ventricosa

Cited by 6 publications

References 14 publications

Light-dependent pH changes in leaves of C3 plants

Light-dependent pH changes in leaves of C3 plants

Electric characteristics of the vacuolar membrane of Chara in relation to pH regulation.

Light-dependent proton transport into mesophyll vacuoles of leaves of C3 plants as revealed by pH-indicating fluorescent dyes: a reappraisal

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Light-Activated H+Transport into the Vacuole ofValonia ventricosa

Cited by 6 publications

References 14 publications

Light-dependent pH changes in leaves of C3 plants

Light-dependent pH changes in leaves of C3 plants

Electric characteristics of the vacuolar membrane of Chara in relation to pH regulation.

Light-dependent proton transport into mesophyll vacuoles of leaves of C3 plants as revealed by pH-indicating fluorescent dyes: a reappraisal

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Light-Activated H⁺Transport into the Vacuole ofValonia ventricosa