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Foissner I, Hoeftberger M, Hoepflinger MC, Sommer A, Bulychev AA. Brefeldin A inhibits clathrin-dependent endocytosis and ion transport in Chara internodal cells. Biol Cell 2020; 112:317-334. [PMID: 32648585 DOI: 10.1111/boc.202000031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND The Characeae are multicellular green algae, which are closely related to higher plants. Their internodal cells are a convenient model to study membrane transport and organelle interactions. RESULTS In this study, we report on the effect of brefeldin A (BFA), an inhibitor of vesicle trafficking, on internodal cells of Chara australis. BFA induced the commonly observed agglomeration of Golgi bodies and trans Golgi network into 'brefeldin compartments' at concentrations between 6 and 500 μM and within 30-120 min treatment. In contrast to most other cells, however, BFA inhibited endocytosis and significantly decreased the number of clathrin-coated pits and clathrin-coated vesicles at the plasma membrane. BFA did not inhibit secretion of organelles at wounds induced by puncturing or local light damage but prevented the formation of cellulosic wound walls probably because of insufficient membrane recycling. We also found that BFA inhibited the formation of alkaline and acid regions along the cell surface ('pH banding pattern') which facilitates carbon uptake required for photosynthesis; we hypothesise that this is due to insufficient recycling of ion transporters. During long-term treatments over several days, BFA delayed the formation of complex 3D plasma membranes (charasomes). Interestingly, BFA had no detectable effect on clathrin-dependent charasome degradation. Protein sequence analysis suggests that the peculiar effects of BFA in Chara internodal cells are due to a mutation in the guanine-nucleotide exchange factor GNOM required for recruitment of membrane coats via activation of ADP-ribosylation factor proteins. CONCLUSIONS AND SIGNIFICANCE This work provides an overview on the effects of BFA on different processes in C. australis. It revealed similarities but also distinct differences in vesicle trafficking between higher plant and algal cells. It shows that characean internodal cells are a promising model to study interactions between seemingly distant metabolic pathways.
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Affiliation(s)
- Ilse Foissner
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | | | | | - Aniela Sommer
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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Bulychev AA, Foissner I. Inhibition of endosomal trafficking by brefeldin A interferes with long-distance interaction between chloroplasts and plasma membrane transporters. PHYSIOLOGIA PLANTARUM 2020; 169:122-134. [PMID: 31816092 PMCID: PMC7216902 DOI: 10.1111/ppl.13058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 06/01/2023]
Abstract
The huge internodal cells of the characean green algae are a convenient model to study long-range interactions between organelles via cytoplasmic streaming. It has been shown previously that photometabolites and reactive oxygen species released by illuminated chloroplasts are transmitted to remote shaded regions where they interfere with photosynthetic electron transport and the differential activity of plasma membrane transporters, and recent findings indicated the involvement of organelle trafficking pathways. In the present study, we applied pulse amplitude-modulated microscopy and pH-sensitive electrodes to study the effect of brefeldin A (BFA), an inhibitor of vesicle trafficking, on long-distance interactions in Chara australis internodal cells. These data were compared with BFA-induced changes in organelle number, size and distribution using fluorescent dyes and confocal laser scanning microscopy. We found that BFA completely and immediately inhibited endocytosis in internodal cells and induced the aggregation of organelles into BFA compartments within 30-120 min of treatment. The comparison with the physiological data suggests that the early response, the arrest of endocytosis, is related to the attenuation of differences in surface pH, whereas the longer lasting formation of BFA compartments is probably responsible for the acceleration of the cyclosis-mediated interaction between chloroplasts. These data indicate that intracellular turnover of membrane material might be important for the circulation of electric currents between functionally distinct regions in illuminated characean internodes and that translational movement of metabolites is delayed by transient binding of the transported substances to organelles.
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Affiliation(s)
| | - Ilse Foissner
- Department of BiosciencesUniversity of SalzburgSalzburgAustria
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Bulychev AA, Alova AV, Krupenina NA, Rubin AB. Cytoplasmic Streaming as an Intracellular Conveyer: Effect on Photosynthesis and H+ Fluxes in Chara Cells. Biophysics (Nagoya-shi) 2020. [DOI: 10.1134/s0006350920020037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kuznetsov M, Polezhaev A. Widening the criteria for emergence of Turing patterns. CHAOS (WOODBURY, N.Y.) 2020; 30:033106. [PMID: 32237770 DOI: 10.1063/1.5140520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/17/2020] [Indexed: 06/11/2023]
Abstract
The classical concept for emergence of Turing patterns in reaction-diffusion systems requires that a system should be composed of complementary subsystems, one of which is unstable and diffuses sufficiently slowly while the other one is stable and diffuses sufficiently rapidly. In this work, the phenomena of emergence of Turing patterns are studied and do not fit into this concept, yielding the following results. (1) The criteria are derived, under which a reaction-diffusion system with immobile species should spontaneously produce Turing patterns under any diffusion coefficients of its mobile species. It is shown for such systems that under certain sets of types of interactions between their species, Turing patterns should be produced under any parameter values, at least provided that the corresponding spatially non-distributed system is stable. (2) It is demonstrated that in a reaction-diffusion system, which contains more than two species and is stable in absence of diffusion, the presence of a sufficiently slowly diffusing unstable subsystem is already sufficient for diffusion instability (i.e., Turing or wave instability), while its complementary subsystem can also be unstable. (3) It is shown that the presence of an immobile unstable subsystem, which leads to destabilization of waves within an infinite range of wavenumbers, in a spatially discrete case can result in the generation of large-scale stationary or oscillatory patterns. (4) It is demonstrated that under the presence of subcritical Turing and supercritical wave bifurcations, the interaction of two diffusion instabilities can result in the spontaneous formation of Turing structures outside the region of Turing instability.
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Affiliation(s)
- Maxim Kuznetsov
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow119991, Russian Federation
| | - Andrey Polezhaev
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow119991, Russian Federation
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Eremin A, Bulychev AA, Kluge C, Harbinson J, Foissner I. PH-dependent cell-cell interactions in the green alga Chara. PROTOPLASMA 2019; 256:1737-1751. [PMID: 31367920 PMCID: PMC6820879 DOI: 10.1007/s00709-019-01392-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/29/2019] [Indexed: 06/10/2023]
Abstract
Characean internodal cells develop alternating patterns of acid and alkaline zones along their surface in order to facilitate uptake of carbon required for photosynthesis. In this study, we used a pH-indicating membrane dye, 4-heptadecylumbiliferone, to study the kinetics of alkaline band formation and decomposition. The differences in growth/decay kinetics suggested that growth occurred as an active, autocatalytic process, whereas decomposition was due to diffusion. We further investigated mutual interactions between internodal cells and found that their alignment parallel to each other induced matching of the pH banding patterns, which was mirrored by chloroplast activity. In non-aligned cells, the lowered photosynthetic activity was noted upon a rise of the external pH, suggesting that the matching of pH bands was due to a local elevation of membrane conductance by the high pH of the alkaline zones of neighboured cells. Finally, we show that the altered pH banding pattern caused the reorganization of the cortical cytoplasm. Complex plasma membrane elaborations (charasomes) were degraded via endocytosis, and mitochondria were moved away from the cortex when a previously acid region became alkaline and vice versa. Our data show that characean internodal cells react flexibly to environmental cues, including those originating from neighboured cells.
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Affiliation(s)
- Alexey Eremin
- Institute of Physics, Otto von Guericke University of Magdeburg, 39016, Magdeburg, Germany
| | - Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow, 119991, Russia
| | - Christopher Kluge
- Institute of Physics, Otto von Guericke University of Magdeburg, 39016, Magdeburg, Germany
| | - Jeremy Harbinson
- Department of Plant Sciences, University of Wageningen, 6708 PB, Wageningen, The Netherlands
| | - Ilse Foissner
- Department of Biosciences, University of Salzburg, 5020, Salzburg, Austria.
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Species-Specific Responses of Submerged Macrophytes to Simulated Extreme Precipitation: A Mesocosm Study. WATER 2019. [DOI: 10.3390/w11061160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
More frequent extreme climate events (e.g., extreme precipitation) are to be expected in the future, and such events may potentially have significant effects on freshwater ecosystems. In the present mesocosm study, the effects of simulated extreme precipitation on submerged macrophytes were evaluated for three different macrophyte community (MC) treatments (MC1, MC2 and MC3). MC1 consisted of only Vallisneria denseserrulata, while MC2 and MC3 included three and six species of various growth forms. Two treatments of extreme precipitation (EP) were simulated—an extreme treatment (E) simulating a sudden increase of water level from 75 cm to 150 cm within one day and a gradual treatment (G) simulating an increase to the same water level within 3 months, combined with two control treatments. Total macrophyte community biomass was resilient to the EP and MC treatments, while species-specific variations in responses, in terms of biomass, maximum height, and sexual reproduction, were found. For instance, E led to earlier flowering of Potamogeton lucens and production of more flowers, while it had adverse effects on the flowering of Ottelia alismoides. We conclude that freshwater ecosystems with high coverage of submerged macrophytes may be overall resilient to extreme precipitation under nutrient-limited conditions, especially communities with diverse growth forms.
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Bulychev AA, Krupenina NA. Interchloroplast communications in Chara are suppressed under the alkaline bands and are relieved after the plasma membrane excitation. Bioelectrochemistry 2019; 129:62-69. [PMID: 31103848 DOI: 10.1016/j.bioelechem.2019.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/10/2019] [Accepted: 05/10/2019] [Indexed: 12/25/2022]
Abstract
Immobile chloroplasts in Chara internodal cells release photometabolites into the streaming cytoplasm that distributes the exported solutes and provides metabolic connectivity between spatially remote plastids. The metabolite transmission by fluid flow is evident from chlorophyll fluorescence changes in shaded chloroplasts upon local illumination applied upstream of the analyzed area. The connectivity correlates with the pH pattern on cell surface: it is strong in cell regions with high H+-pump activity and is low in regions featuring large passive H+ influx (OH- efflux). One explanation for low connectivity under the alkaline bands is that H+ influx lowers the cytoplasmic pH, thus retarding metabolic conversions of solutes carried by the microfluidic transporter. The cessation of H+ influx across the plasma membrane by eliciting the action potential and by adding NH4Cl into the medium greatly enhanced the amplitude of cyclosis-mediated fluorescence transients. The transition from latent to the transmissive state after the dark pretreatment was paralleled by the temporary increase in chlorophyll fluorescence, reflecting changes in photosynthetic electron transport. It is proposed that the connectivity between distant chloroplasts is controlled by cytoplasmic pH.
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Affiliation(s)
- Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Moscow State University, 119991 Moscow, Russia.
| | - Natalia A Krupenina
- Department of Biophysics, Faculty of Biology, Moscow State University, 119991 Moscow, Russia
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Absolonova M, Beilby MJ, Sommer A, Hoepflinger MC, Foissner I. Surface pH changes suggest a role for H +/OH - channels in salinity response of Chara australis. PROTOPLASMA 2018; 255:851-862. [PMID: 29247277 PMCID: PMC5904247 DOI: 10.1007/s00709-017-1191-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/27/2017] [Indexed: 05/16/2023]
Abstract
To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H+/OH- channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl2, the main known blocker of animal H+ channels. The cells were imaged with confocal microscopy, using fluorescein isothiocyanate (FITC) coupled to dextran 70 to illuminate the pH changes outside the cell wall in artificial fresh water (AFW) and in saline medium. In the early saline exposure, we observed alkaline patches (bright fluorescent spots) appearing transiently in random spatial distribution. After longer exposure, some of the spots became fixed in space. Saline also abolished or diminished the pH banding pattern observed in the untreated control cells. ZnCl2 suppressed the alkaline spot formation in saline and the pH banding pattern in AFW. The osmotic component of the saline stress did not produce transient bright spots or affect banding. The displacement of H+ from the cell wall charges, the H+/OH- channel conductance/density, and self-organization are discussed. No homologies to animal H+ channels were found. Salinity activation of the H+/OH- channels might contribute to saline response in roots of land plants and leaves of aquatic angiosperms.
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Affiliation(s)
- Marketa Absolonova
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Mary J Beilby
- School of Physics, The University of NSW, Sydney, NSW, 2052, Australia.
| | - Aniela Sommer
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Marion C Hoepflinger
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Ilse Foissner
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
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Cherkashin AA, Vanag VK. Self-Organization Induced by Self-Assembly in Microheterogeneous Reaction-Diffusion System. J Phys Chem B 2017; 121:2127-2131. [DOI: 10.1021/acs.jpcb.6b12089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander A. Cherkashin
- Department
of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119899, Russia
| | - Vladimir K. Vanag
- Centre
for Nonlinear Chemistry, Immanuel Kant Baltic Federal University, 14 A. Nevskogo str., Kaliningrad 236016, Russia
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Foissner I, Sommer A, Hoeftberger M, Hoepflinger MC, Absolonova M. Is Wortmannin-Induced Reorganization of the trans-Golgi Network the Key to Explain Charasome Formation? FRONTIERS IN PLANT SCIENCE 2016; 7:756. [PMID: 27375631 PMCID: PMC4891338 DOI: 10.3389/fpls.2016.00756] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/17/2016] [Indexed: 05/18/2023]
Abstract
Wortmannin, a fungal metabolite and an inhibitor of phosphatidylinositol-3 (PI3) and phosphatidylinositol-4 (PI4) kinases, is widely used for the investigation and dissection of vacuolar trafficking routes and for the identification of proteins located at multivesicular bodies (MVBs). In this study, we applied wortmannin on internodal cells of the characean green alga Chara australis. Wortmannin was used at concentrations of 25 and 50 μM which, unlike in other cells, arrested neither constitutive, nor wounding-induced endocytosis via coated vesicles. Wortmannin caused the formation of "mixed compartments" consisting of MVBs and membranous tubules which were probably derived from the trans-Golgi network (TGN) and within these compartments MVBs fused into larger organelles. Most interestingly, wortmannin also caused pronounced changes in the morphology of the TGNs. After transient hypertrophy, the TGNs lost their coat and formed compact, three-dimensional meshworks of anastomosing tubules containing a central core. These meshworks had a size of up to 4 μm and a striking resemblance to charasomes, which are convoluted plasma membrane domains, and which serve to increase the area available for transporters. Our findings indicate that similar mechanisms are responsible for the formation of charasomes and the wortmannin-induced reorganization of the TGN. We hypothesize that both organelles grow because of a disturbance of clathrin-dependent membrane retrieval due to inhibition of PI3 and/or PI4 kinases. This leads to local inhibition of clathrin-mediated endocytosis during charasome formation in untreated cells and to inhibition of vesicle release from the TGN in wortmannin-treated cells, respectively. The morphological resemblance between charasomes and wortmannin-modified TGN compartments suggests that homologous proteins are involved in membrane curvature and organelle architecture.
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Sommer A, Hoeftberger M, Hoepflinger MC, Schmalbrock S, Bulychev A, Foissner I. Convoluted Plasma Membrane Domains in the Green Alga Chara are Depleted of Microtubules and Actin Filaments. PLANT & CELL PHYSIOLOGY 2015; 56:1981-1996. [PMID: 26272553 PMCID: PMC4684100 DOI: 10.1093/pcp/pcv119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/09/2015] [Indexed: 05/29/2023]
Abstract
Charasomes are convoluted plasma membrane domains in the green alga Chara australis. They harbor H(+)-ATPases involved in acidification of the medium, which facilitates carbon uptake required for photosynthesis. In this study we investigated the distribution of cortical microtubules and cortical actin filaments in relation to the distribution of charasomes. We found that microtubules and actin filaments were largely lacking beneath the charasomes, suggesting the absence of nucleating and/or anchoring complexes or an inhibitory effect on polymerization. We also investigated the influence of cytoskeleton inhibitors on the light-dependent growth and the darkness-induced degradation of charasomes. Inhibition of cytoplasmic streaming by cytochalasin D significantly inhibited charasome growth and delayed charasome degradation, whereas depolymerization of microtubules by oryzalin or stabilization of microtubules by paclitaxel had no effect. Our data indicate that the membrane at the cytoplasmic surface of charasomes has different properties in comparison with the smooth plasma membrane. We show further that the actin cytoskeleton is necessary for charasome growth and facilitates charasome degradation presumably via trafficking of secretory and endocytic vesicles, respectively. However, microtubules are required neither for charasome growth nor for charasome degradation.
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Affiliation(s)
- Aniela Sommer
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, 5020 Salzburg, Austria
| | - Margit Hoeftberger
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, 5020 Salzburg, Austria
| | - Marion C Hoepflinger
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, 5020 Salzburg, Austria
| | - Sarah Schmalbrock
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, 5020 Salzburg, Austria
| | - Alexander Bulychev
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow 119991, Russia
| | - Ilse Foissner
- Department of Cell Biology, Division of Plant Physiology, University of Salzburg, 5020 Salzburg, Austria
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Bulychev AA, Komarova AV. Long-distance signal transmission and regulation of photosynthesis in characean cells. BIOCHEMISTRY (MOSCOW) 2014; 79:273-81. [DOI: 10.1134/s0006297914030134] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Foissner I, Wasteneys GO. Characean internodal cells as a model system for the study of cell organization. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 311:307-64. [PMID: 24952921 DOI: 10.1016/b978-0-12-800179-0.00006-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Giant internodal cells of characean green algae have been widely used for studying cellular physiology. This review emphasizes their significance for understanding cytoarchitecture and cytoplasmic reorganization. The cytoarchitecture of internodal cells undergoes pronounced, cytoskeleton-dependent changes during development and in response to environmental cues. Under bright light, internodes develop alternating bands of acid and alkaline pH at their surface that correlate with the differential size and abundance of cortical organelles and, in the genus Chara, with the size and distribution of convoluted plasma membrane domains known as charasomes. Wounding induces responses ranging from chloroplast detachment to deposition of wound walls. These properties and the possibility for mechanical manipulation make the internodal cell ideal for exploring plasma membrane domains, organelle interactions, vesicle trafficking, and local cell wall deposition. The significance of this model system will further increase with the application of molecular biological methods in combination with metabolomics and proteomics.
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Affiliation(s)
- Ilse Foissner
- Division of Plant Physiology, Department of Cell Biology, University of Salzburg, Salzburg, Austria.
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Eremin A, Bulychev A, Hauser MJB. Cyclosis-mediated transfer of H2O 2 elicited by localized illumination of Chara cells and its relevance to the formation of pH bands. PROTOPLASMA 2013; 250:1339-49. [PMID: 23760663 DOI: 10.1007/s00709-013-0517-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 05/27/2013] [Indexed: 05/09/2023]
Abstract
Cytoplasmic streaming occurs in most plant cells and is vitally important for large cells as a means of long-distance intracellular transport of metabolites and messengers. In internodal cells of characean algae, cyclosis participates in formation of light-dependent patterns of surface pH and photosynthetic activity, but lateral transport of regulatory metabolites has not been visualized yet. Hydrogen peroxide, being a signaling molecule and a stress factor, is known to accumulate under excessive irradiance. This study was aimed to examine whether H2O2 produced in chloroplasts under high light conditions is released into streaming fluid and transported downstream by cytoplasmic flow. To this end, internodes of Chara corallina were loaded with the fluorogenic probe dihydrodichlorofluorescein diacetate and illuminated locally by a narrow light beam through a thin optic fiber. Fluorescence of dihydrodichlorofluorescein (DCF), produced upon oxidation of the probe by H2O2, was measured within and around the illuminated cell region. In cells exhibiting active streaming, H2O2 first accumulated in the illuminated region and then entered into the streaming cytoplasm, giving rise to the expansion of DCF fluorescence downstream of the illuminated area. Inhibition of cyclosis by cytochalasin B prevented the spreading of DCF fluorescence along the internode. The results suggest that H2O2 released from chloroplasts under high light is transported along the cell with the cytoplasmic flow. It is proposed that the shift of cytoplasmic redox poise and light-induced elevation of cytoplasmic pH facilitate the opening of H(+)/OH(-)-permeable channels in the plasma membrane.
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Affiliation(s)
- Alexey Eremin
- Institute of Experimental Physics, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39016, Magdeburg, Germany
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Propagation of photoinduced signals with the cytoplasmic flow along Characean internodes: evidence from changes in chloroplast fluorescence and surface pH. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:441-53. [DOI: 10.1007/s00249-013-0895-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/03/2012] [Accepted: 02/19/2013] [Indexed: 10/27/2022]
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Dodonova SO, Bulychev AA. Cyclosis-related asymmetry of chloroplast-plasma membrane interactions at the margins of illuminated area in Chara corallina cells. PROTOPLASMA 2011; 248:737-749. [PMID: 21103897 DOI: 10.1007/s00709-010-0241-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 11/03/2010] [Indexed: 05/30/2023]
Abstract
Cytoplasmic streaming in plant cells is an effective means of intracellular transport. The cycling of ions and metabolites between the cytosol and chloroplasts in illuminated cell regions may alter the cytoplasm composition, while directional flow of this modified cytoplasm may affect the plasma membrane and chloroplast activities in cell regions residing downstream of the illumination area. The impact of local illumination is predicted to be asymmetric because the cell regions located downstream and upstream in the cytoplasmic flow with respect to illumination area would be exposed to flowing cytoplasm whose solute composition was influenced by photosynthetic or dark metabolism. This hypothesis was checked by measuring H(+)-transporting activity of plasmalemma and chlorophyll fluorescence of chloroplasts in shaded regions of Chara corallina internodal cells near opposite borders of illuminated region (white light, beam width 2 mm). Both the apoplastic pH and chlorophyll fluorescence, recorded in shade regions at equal distances from illuminated area, exhibited asymmetric light-on responses depending on orientation of cytoplasmic streaming at the light-shade boundary. In the region where the cytoplasm flowed from illuminated area to the measurement area, the alkaline zone (a zone with high plasma membrane conductance) was formed within 4-min illumination, whereas no alkaline zone was observed in the area where cytoplasm approached the boundary from darkened regions. The results emphasize significance of cyclosis in lateral distribution of a functionally active intermediate capable of affecting the membrane transport across the plasmalemma, the functional activity of chloroplasts, and pattern formation in the plant cell.
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Affiliation(s)
- Svetlana O Dodonova
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow, 119991, Russia
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Schmölzer PM, Höftberger M, Foissner I. Plasma membrane domains participate in pH banding of Chara internodal cells. PLANT & CELL PHYSIOLOGY 2011; 52:1274-88. [PMID: 21659328 PMCID: PMC3153728 DOI: 10.1093/pcp/pcr074] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We investigated the identity and distribution of cortical domains, stained by the endocytic marker FM 1-43, in branchlet internodal cells of the characean green algae Chara corallina and Chara braunii. Co-labeling with NBD C(6)-sphingomyelin, a plasma membrane dye, which is not internalized, confirmed their location in the plasma membrane, and co-labelling with the fluorescent pH indicator Lysotracker red indicated an acidic environment. The plasma membrane domains co-localized with the distribution of an antibody against a proton-translocating ATPase, and electron microscopic data confirmed their identity with elaborate plasma membrane invaginations known as charasomes. The average size and the distribution pattern of charasomes correlated with the pH banding pattern of the cell. Charasomes were larger and more frequent at the acidic regions than at the alkaline bands, indicating that they are involved in outward-directed proton transport. Inhibition of photosynthesis by DCMU prevented charasome formation, and incubation in pH buffers resulted in smaller, homogenously distributed charasomes irrespective of whether the pH was clamped at 5.5 or 8.5. These data indicate that the differential size and distribution of charasomes is not due to differences in external pH but reflects active, photosynthesis-dependent pH banding. The fact that pH banding recovered within several minutes in unbuffered medium, however, confirms that pH banding is also possible in cells with evenly distributed charasomes or without charasomes. Cortical mitochondria were also larger and more abundant at the acid bands, and their intimate association with charasomes and chloroplasts suggests an involvement in carbon uptake and photorespiration.
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Affiliation(s)
| | | | - Ilse Foissner
- *Corresponding author: E-mail, ; Fax, +43-662-8044-619
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Bulychev AA, Krupenina NA. Transient removal of alkaline zones after excitation of Chara cells is associated with inactivation of high conductance in the plasmalemma. PLANT SIGNALING & BEHAVIOR 2009; 4:727-34. [PMID: 19820298 PMCID: PMC2801383 DOI: 10.4161/psb.4.8.9306] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The action potential (AP) of excitable plant cells is a multifunctional physiological signal. Its generation in characean algae suppresses the pH banding for 15-30 min and enhances the heterogeneity of spatial distribution of photosynthetic activity. This suppression is largely due to the cessation of H(+) influx (OH(-) efflux) in the alkaline cell regions. Measurements of local pH and membrane conductance in individual space-clamped alkaline zones (small cell areas bathed in an isolated pool of external medium) showed that the AP generation is followed by the transient disappearance of alkaline zone in parallel with a large decrease in membrane conductance. These changes, specific to alkaline zones, were only observed under continuous illumination following a relaxation period of at least 15 min after previous excitation. The excitation of dark-adapted cells produced no conductance changes in the post-excitation period. The results indicate that the origin of alkaline zones in characean cells is not due to operation of electroneutral H(+)/HCO(3)(-) symport or OH(-)/HCO(3)(-) antiport. It is concluded that the membrane excitation is associated with inactivation of plasmalemma high conductance in the alkaline cell regions.
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Affiliation(s)
- Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow, Russia.
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Eremin A, Bulychev A, Krupenina NA, Mair T, Hauser MJB, Stannarius R, Müller SC, Rubin AB. Excitation-induced dynamics of external pH pattern in Chara corallina cells and its dependence on external calcium concentration. Photochem Photobiol Sci 2006; 6:103-9. [PMID: 17200745 DOI: 10.1039/b607602e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of cell excitation and external calcium level on the dynamics of light-induced pH bands along the length of Chara corallina cells is studied in the present paper. Generation of an action potential (AP) transiently quenched these pH patterns, which was more pronounced at 0.05-0.1 mM Ca2+ than at higher concentrations of Ca2+ (0.6-2 mM) in the medium. After transient smoothing of the pH bands, some alkaline peaks reemerged at slightly shifted positions in media with low Ca2+ concentrations, while at high Ca2+ concentrations, the alkaline spots reappeared exactly at their initial positions. This Ca2+ dependency has been revealed by both digital imaging and pH microelectrodes. The stabilizing effect of external Ca2+ on the locations of recovering alkaline peaks is supposedly due to formation of a physically heterogeneous environment around the cell owing to precipitation of CaCO3 in the alkaline zones at high Ca2+ during illumination. The elevation of local pH by dissolving CaCO3 facilitates the reappearance of alkaline spots at their initial locations after temporal suppression caused by cell excitation. At low Ca2+ concentrations, when the solubility product of CaCO3 is not attained, the alkaline peaks are not stabilized by CaCO3 dissolution and may appear at random locations.
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Affiliation(s)
- Alexey Eremin
- Otto-von-Guericke-Universität, Institute of Experimental Physics, Universitätsplatz 2, 39016, Magdeburg, Germany
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Bulychev AA, Wijngaard PWJ, Boer AH. Spatial Coordination of Chloroplast and Plasma Membrane Activities in Chara Cells and Its Disruption through Inactivation of 14-3-3 Proteins. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/s10541-005-0005-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Spatial coordination of chloroplast and plasma membrane activities in chara cells and its disruption through inactivation of 14-3-3 proteins. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/s10541-005-0051-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bulychev AA, Kamzolkina NA, Luengviriya J, Rubin AB, Müller SC. Effect of a Single Excitation Stimulus on Photosynthetic Activity and Light-dependent pH Banding in Chara Cells. J Membr Biol 2004; 202:11-9. [PMID: 15702376 DOI: 10.1007/s00232-004-0716-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2004] [Revised: 09/17/2004] [Indexed: 10/25/2022]
Abstract
Using pH microelectrodes and a Microscopy PAM (pulse-amplitude modulated) chlorophyll fluorometer, it is shown that a propagation of an action potential in Chara corallina leads to transient suppression of spatially periodic pH profiles along the illuminated cell. The suppression was manifested as a large pH decrease in the alkaline zones and a slight pH increase in the acid zones. The propagating action potential diminished the maximum yield of chlorophyll fluorescence (F(m)') in the alkaline cell regions, as well as the quantum yield of photosystem II photochemistry, without affecting F(m)' in the acid cell regions. The results indicate an interference of membrane excitation in the mechanisms responsible for pH banding patterns in Characean algae. Apparently, the electrical excitation of the plasma membrane in the alkaline cell regions initiates a pathway that can modulate membrane events at the thylakoid membrane.
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Affiliation(s)
- A A Bulychev
- Biophysics Department, Faculty of Biology, Moscow State University, Moscow, 119899, Russia
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Bulychev AA, Kamzolkina NA, Müller S, Cherkashin AA, Rubin AB. Temporal suppression of periodic pH profile along a charophyte cell after the generation of action potential. DOKL BIOCHEM BIOPHYS 2004; 396:128-31. [PMID: 15378907 DOI: 10.1023/b:dobi.0000033509.85211.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bulychev AA, Zykov SV, Rubin AB, Müller SC. Transitions from alkaline spots to regular bands during pH pattern formation at the plasmalemma of Chara cells. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2003; 32:144-53. [PMID: 12734703 DOI: 10.1007/s00249-003-0280-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2002] [Revised: 12/12/2002] [Accepted: 12/13/2002] [Indexed: 10/25/2022]
Abstract
A scanning pH-microprobe was used to study pH patterns near the surface of Chara corallina cells at various light intensities and during light-induced transitions from homogeneous pH distribution to alternating pH bands. In the irradiance (PAR) range 4-400 micromol quanta m(-2) s(-1), the sustained pH profiles consisted of alternating acid and alkaline bands with a characteristic length of 7-10 mm and pH shifts as large as 2-3 units. At lower irradiance, the number of alkaline bands decreased while the amplitude of remaining peaks stayed high. On cyclic changes in light intensity, a hysteresis of pH banding was observed: the pH bands tolerated low irradiance in weakening light, but higher irradiance was required for their emergence after dark adaptation of the cell. The pH profiles measured for different paths of electrode scanning suggest that the pH pattern at low light level represents patches coexisting with bands. The exposure of the cell to high-intensity light led to formation of radially symmetrical bands. Transformations of the pH pattern induced by lowering the light intensity were similar to those induced by transcellular electric current (1.5-3 microA). The data suggest that band formation at the plasmalemma of Chara cells proceeds through the initial appearance of multiple patches with a localized H(+)-transporting activity and subsequent spot rearrangements (fusion, deletions, widening), leading to establishment of alternating bands.
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Affiliation(s)
- A A Bulychev
- Biophysics Department, Faculty of Biology, Moscow State University, 119899 Moscow, Russia
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Cherkashin AA, Bulychev AA, Rubin AB. The time course of the photosynthetic activity in the forming transport domains of the Chara corallina plasmalemma. DOKL BIOCHEM BIOPHYS 2002; 386:287-9. [PMID: 12469510 DOI: 10.1023/a:1020776031562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A A Cherkashin
- Department of Biology, Moscow State University, Vorob'evy gory, Moscow, 119899 Russia
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