Membrane Excitation and Cytoplasmic Streaming as Modulators of Photosynthesis and Proton Flows in Characean Cells

Булычев, А. А.

doi:10.1007/978-3-642-29119-7_12

Cited by 10 publications

(2 citation statements)

References 76 publications

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“…This differential sensitivity of alkaline zones induced in intact and microwounded cells suggests that these zones result from either activation of different transporters or from operation of different regulatory pathways targeted on identical transporters. We favor the first alternative because the inactivation of high pH channels, manifested as an abrupt increase in membrane resistance concurrent with the decline of alkaline pH o after eliciting the action potential, 20 did not inactivate the transporters responsible for the alkaline shift at the site of microperforation. Moreover, the pH response to microwounding was stimulated after the cell excitation.…”

Section: Discussionmentioning

confidence: 99%

Pathways for external alkalinization in intact and in microwounded Chara cells are differentially sensitive to wortmannin

Булычев

Foissner

2017

Plant Signaling & Behavior

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Proton flows across the plant cell membranes play a major role in electrogenesis and regulation of photosynthesis and ion balance. The profiles of external pH along the illuminated internodal cells of characean algae consist of alternating high- and low-pH zones that are spatially coordinated with the distribution of photosynthetic activity of chloroplasts underlying these zones. The results based on confocal laser scanning fluorescence microscopy, pH microsensors, and pulse-amplitude-modulated chlorophyll microfluorometry revealed that the coordination of H+ transport and photosynthesis is disrupted by the 2 different environmental cues (low light and wounding) and by a chemical, wortmannin interfering with the inositol phospholipid metabolism. On the one hand, the transition from moderate to low irradiance diminished the peaks in the profiles of photosystem II (PSII) quantum efficiency but did not remove the pH bands. On the other hand, the microwounding of the internode with a glass micropipette, impacting primarily the cell wall, resulted in a rapid local alkalinization of the external medium (by 2–2.5 pH units) near the cell surface, thus mimicking the appearance of natural pH bands. Despite their seeming similarity, the alkaline bands of intact cells were eliminated by wortmannin, whereas the wound-induced alkalinization was insensitive to this drug. Furthermore, the attenuation of natural pH bands in wortmannin-treated cells was accompanied by the enhancement in spatial heterogeneity of PSII efficiency and electron transport rates, which indicates the complexity of chloroplast–plasma membrane interactions. The results suggest that the light- and wound-induced alkaline areas on the cell surface are associated with different ion-transport systems.

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Section: Discussionmentioning

confidence: 99%

Pathways for external alkalinization in intact and in microwounded Chara cells are differentially sensitive to wortmannin

Булычев

Foissner

2017

Plant Signaling & Behavior

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“…Characean algae are able to generate under light the contrast patterns of external pH, calcification, CO 2 and O 2 content, as well as the patterns of photosynthetic electron-transport rates, non-photochemical quenching, and probably cytoplasmic pH [14,15]. Although uniform illumination is sufficient for pattern emergence, the spot illumination resembling sunflecks of natural fluctuating daylight was found to promote zonation of photosynthesis and external pH.…”

Section: Introductionmentioning

confidence: 98%

Photoinduction of cyclosis-mediated interactions between distant chloroplasts

Булычев

Комарова

2015

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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Communications between chloroplasts and other organelles based on the exchange of metabolites, including redox active substances, are recognized as a part of intracellular regulation, chlororespiration, and defense against oxidative stress. Similar communications may operate between spatially distant chloroplasts in large cells where photosynthetic and respiratory activities are distributed unevenly under fluctuating patterned illumination. Microfluorometry of chlorophyll fluorescence in vivo in internodal cells of the alga Chara corallina revealed that a 30-s pulse of localized light induces a transient increase (~25%) in F' fluorescence of remote cell parts exposed to dim background light at a 1.5-mm distance on the downstream side from the illuminated spot in the plane of unilateral cytoplasmic streaming but has no effect on F' at equal distance on the upstream side. An abrupt arrest of cytoplasmic streaming for about 30s by triggering the action potential extended either the ascending or descending fronts of the F' fluorescence response, depending on the exact moment of streaming cessation. The response of F' fluorescence to localized illumination of a distant cell region was absent in dark-adapted internodes, when the localized light was applied within the first minute after switching on continuous background illumination of the whole cell, but it appeared in full after longer exposures to continuous background light. These results and the elimination of the F' response by methyl viologen known to redirect electron transport pathways beyond photosystem I indicate the importance of photosynthetic induction and the stromal redox state for long-distance communications of chloroplasts in vivo.

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Biogenic Manganese–Calcium Oxides on the Cell Walls of the Algae Chara Corallina: Elemental Composition, Atomic Structure, and Water‐Oxidation Catalysis

et al. 2013

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Keywords: Bioinorganic chemistry / Manganese / Oxygen / X-ray absorption spectroscopy / X-ray microfocus experiments Chara corallina freshwater algae produce brown deposits of manganese oxides on their cell wall surfaces when growing in manganese-rich media. We report on the formation, topology, composition, atomic structure, and catalytic activities of these biogenic manganese oxides (BMOs). The deposits are volcano shaped and exhibit 3-5 μm craters in their centers. Microfocus X-ray irradiation and detection of characteristic X-ray fluorescence lines allowed elemental mapping at 5 μm spatial resolution and the identification of the volcanoshaped deposits as a Mn-Ca oxide. X-ray absorption spectroscopy (XAS) revealed a high-valent Mn III/IV oxide. The structural analysis involved XAS spectra collected for a single volcano at room temperature and for single cells at 20 K.

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Membrane Excitation and Cytoplasmic Streaming as Modulators of Photosynthesis and Proton Flows in Characean Cells

Cited by 10 publications

References 76 publications

Pathways for external alkalinization in intact and in microwounded Chara cells are differentially sensitive to wortmannin

Pathways for external alkalinization in intact and in microwounded Chara cells are differentially sensitive to wortmannin

Photoinduction of cyclosis-mediated interactions between distant chloroplasts

Biogenic Manganese–Calcium Oxides on the Cell Walls of the Algae Chara Corallina: Elemental Composition, Atomic Structure, and Water‐Oxidation Catalysis

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