The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
David S. Domozych - One of the best experts on this subject based on the ideXlab platform.
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The effects of osmotic stress on the cell wall-plasma membrane domains of the unicellular streptophyte, Penium margaritaceum
Protoplasma, 2021Co-Authors: David S. Domozych, Li Kozel, Kattia Palacio-lopezAbstract:Penium margaritaceum is a unicellular zygnematophyte (basal Streptophyteor Charophyte) that has been used as a model organism for the study of cell walls of Streptophytes and for elucidating organismal adaptations that were key in the evolution of land plants.. When Penium is incubated in sorbitol-enhance medium, i.e., hyperosmotic medium, 1000–1500 Hechtian strands form within minutes and connect the plasma membrane to the cell wall. As cells acclimate to this osmotic stress over time, further significant changes occur at the cell wall and plasma membrane domains. The homogalacturonan lattice of the outer cell wall layer is significantly reduced and is accompanied by the formation of a highly elongate, “filamentous” phenotype. Distinct peripheral thickenings appear between the CW and plasma membrane and contain membranous components and a branched granular matrix. Monoclonal antibody labeling of these thickenings indicates the presence of rhamnogalacturonan-I epitopes. Acclimatization also results in the proliferation of the cell’s vacuolar networks and macroautophagy. Penium ’s ability to acclimatize to osmotic stress offers insight into the transition of ancient zygnematophytes from an aquatic to terrestrial existence.
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experimental manipulation of pectin architecture in the cell wall of the unicellular charophyte Penium margaritaceum
Frontiers in Plant Science, 2020Co-Authors: Kattia Palaciolopez, Reagan Reed, Iben Sørensen, Jocelyn K C Rose, Li Sun, Eric Kang, David S. DomozychAbstract:Pectins represent one of the main components of the plant primary cell wall. These polymers have critical roles in cell expansion, cell-cell adhesion and response to biotic stress. We present a comprehensive screening of pectin architecture of the unicellular streptophyte, Penium margaritaceum. Penium possesses a distinct cell wall whose outer layer consists of a lattice of pectin-rich fibers and projections. In this study, cells were exposed to a variety of physical, chemical and enzymatic treatments that directly affect the cell wall, especially the pectin lattice. Correlative analyses of pectin lattice perturbation using field emission scanning electron microscopy, confocal laser scanning microscopy, and transmission electron microscopy demonstrate that pectin lattice microarchitecture is both highly sensitive and malleable.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Li Sun, Zhangjun Fei, Jocelyn K C RoseAbstract:The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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callose deposition is essential for the completion of cytokinesis in the unicellular alga Penium margaritaceum
bioRxiv, 2020Co-Authors: Destiny J. Davis, David S. Domozych, Iben Sørensen, Jocelyn K C Rose, Minmin Wang, Georgia DrakakakiAbstract:Abstract Cytokinesis in land plants involves the formation of a cell plate that develops into the new cell wall. Callose is a β-1,3 glucan that transiently accumulates at later stages of cell plate development and is thought to stabilize the delicate membrane network of the cell plate as it expands. Cytokinetic callose deposition is currently considered specific to multicellular plant species as it has not been detected in unicellular algae. Here we present callose at the cytokinesis junction of the unicellular charophyte, Penium margaritaceum. Notably, callose deposition at the division plane of P. margaritaceum showed distinct, spatiotemporal patterns that could represent distinct roles of this polymer in cytokinesis and cell wall assembly. Pharmacological inhibition of cytokinetic callose deposition by Endosidin 7 treatment resulted in cytokinesis defects, consistent with the essential role for this polymer in P. margaritaceum cell division. Cell wall deposition and assembly at the isthmus zone was also affected by the absence of callose, demonstrating the dynamic nature of new wall assembly in P. margaritaceum. The identification of candidate callose synthase genes provides molecular evidence for callose biosynthesis in P. margaritaceum. The evolutionary implications of cytokinetic callose in this unicellular Zygnematopycean alga is discussed in the context of the conquest of land by plants. Summary Statement Evolutionarily conserved callose in Penium margaritaceum is essential for the completion of cytokinesis.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Mingjia Li, Jocelyn K C RoseAbstract:: The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. EPS production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
Iben Sørensen - One of the best experts on this subject based on the ideXlab platform.
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experimental manipulation of pectin architecture in the cell wall of the unicellular charophyte Penium margaritaceum
Frontiers in Plant Science, 2020Co-Authors: Kattia Palaciolopez, Reagan Reed, Iben Sørensen, Jocelyn K C Rose, Li Sun, Eric Kang, David S. DomozychAbstract:Pectins represent one of the main components of the plant primary cell wall. These polymers have critical roles in cell expansion, cell-cell adhesion and response to biotic stress. We present a comprehensive screening of pectin architecture of the unicellular streptophyte, Penium margaritaceum. Penium possesses a distinct cell wall whose outer layer consists of a lattice of pectin-rich fibers and projections. In this study, cells were exposed to a variety of physical, chemical and enzymatic treatments that directly affect the cell wall, especially the pectin lattice. Correlative analyses of pectin lattice perturbation using field emission scanning electron microscopy, confocal laser scanning microscopy, and transmission electron microscopy demonstrate that pectin lattice microarchitecture is both highly sensitive and malleable.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Li Sun, Zhangjun Fei, Jocelyn K C RoseAbstract:The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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callose deposition is essential for the completion of cytokinesis in the unicellular alga Penium margaritaceum
bioRxiv, 2020Co-Authors: Destiny J. Davis, David S. Domozych, Iben Sørensen, Jocelyn K C Rose, Minmin Wang, Georgia DrakakakiAbstract:Abstract Cytokinesis in land plants involves the formation of a cell plate that develops into the new cell wall. Callose is a β-1,3 glucan that transiently accumulates at later stages of cell plate development and is thought to stabilize the delicate membrane network of the cell plate as it expands. Cytokinetic callose deposition is currently considered specific to multicellular plant species as it has not been detected in unicellular algae. Here we present callose at the cytokinesis junction of the unicellular charophyte, Penium margaritaceum. Notably, callose deposition at the division plane of P. margaritaceum showed distinct, spatiotemporal patterns that could represent distinct roles of this polymer in cytokinesis and cell wall assembly. Pharmacological inhibition of cytokinetic callose deposition by Endosidin 7 treatment resulted in cytokinesis defects, consistent with the essential role for this polymer in P. margaritaceum cell division. Cell wall deposition and assembly at the isthmus zone was also affected by the absence of callose, demonstrating the dynamic nature of new wall assembly in P. margaritaceum. The identification of candidate callose synthase genes provides molecular evidence for callose biosynthesis in P. margaritaceum. The evolutionary implications of cytokinetic callose in this unicellular Zygnematopycean alga is discussed in the context of the conquest of land by plants. Summary Statement Evolutionarily conserved callose in Penium margaritaceum is essential for the completion of cytokinesis.
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the Penium margaritaceum genome hallmarks of the origins of land plants
Cell, 2020Co-Authors: Chen Jiao, Iben Sørensen, Hila Behar, Saleh Alseekh, Glenn Philippe, Kattia Palacio Lopez, Li Sun, Xuepeng Sun, Honghe Sun, Reagan ReedAbstract:Summary The evolutionary features and molecular innovations that enabled plants to first colonize land are not well understood. Here, insights are provided through our report of the genome sequence of the unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The genome has a high proportion of repeat sequences that are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with representatives of earlier diverging algal lineages, P. margaritaceum has expanded repertoires of gene families, signaling networks, and adaptive responses that highlight the evolutionary trajectory toward terrestrialization. These encompass a broad range of physiological processes and protective cellular features, such as flavonoid compounds and large families of modifying enzymes involved in cell wall biosynthesis, assembly, and remodeling. Transcriptome profiling further elucidated adaptations, responses, and selective pressures associated with the semi-terrestrial ecosystems of P. margaritaceum, where a simple body plan would be an advantage.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Mingjia Li, Jocelyn K C RoseAbstract:: The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. EPS production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
Jocelyn K C Rose - One of the best experts on this subject based on the ideXlab platform.
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experimental manipulation of pectin architecture in the cell wall of the unicellular charophyte Penium margaritaceum
Frontiers in Plant Science, 2020Co-Authors: Kattia Palaciolopez, Reagan Reed, Iben Sørensen, Jocelyn K C Rose, Li Sun, Eric Kang, David S. DomozychAbstract:Pectins represent one of the main components of the plant primary cell wall. These polymers have critical roles in cell expansion, cell-cell adhesion and response to biotic stress. We present a comprehensive screening of pectin architecture of the unicellular streptophyte, Penium margaritaceum. Penium possesses a distinct cell wall whose outer layer consists of a lattice of pectin-rich fibers and projections. In this study, cells were exposed to a variety of physical, chemical and enzymatic treatments that directly affect the cell wall, especially the pectin lattice. Correlative analyses of pectin lattice perturbation using field emission scanning electron microscopy, confocal laser scanning microscopy, and transmission electron microscopy demonstrate that pectin lattice microarchitecture is both highly sensitive and malleable.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Li Sun, Zhangjun Fei, Jocelyn K C RoseAbstract:The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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callose deposition is essential for the completion of cytokinesis in the unicellular alga Penium margaritaceum
bioRxiv, 2020Co-Authors: Destiny J. Davis, David S. Domozych, Iben Sørensen, Jocelyn K C Rose, Minmin Wang, Georgia DrakakakiAbstract:Abstract Cytokinesis in land plants involves the formation of a cell plate that develops into the new cell wall. Callose is a β-1,3 glucan that transiently accumulates at later stages of cell plate development and is thought to stabilize the delicate membrane network of the cell plate as it expands. Cytokinetic callose deposition is currently considered specific to multicellular plant species as it has not been detected in unicellular algae. Here we present callose at the cytokinesis junction of the unicellular charophyte, Penium margaritaceum. Notably, callose deposition at the division plane of P. margaritaceum showed distinct, spatiotemporal patterns that could represent distinct roles of this polymer in cytokinesis and cell wall assembly. Pharmacological inhibition of cytokinetic callose deposition by Endosidin 7 treatment resulted in cytokinesis defects, consistent with the essential role for this polymer in P. margaritaceum cell division. Cell wall deposition and assembly at the isthmus zone was also affected by the absence of callose, demonstrating the dynamic nature of new wall assembly in P. margaritaceum. The identification of candidate callose synthase genes provides molecular evidence for callose biosynthesis in P. margaritaceum. The evolutionary implications of cytokinetic callose in this unicellular Zygnematopycean alga is discussed in the context of the conquest of land by plants. Summary Statement Evolutionarily conserved callose in Penium margaritaceum is essential for the completion of cytokinesis.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Mingjia Li, Jocelyn K C RoseAbstract:: The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. EPS production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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callose deposition is essential for the completion of cytokinesis in the unicellular alga Penium margaritaceum
Journal of Cell Science, 2020Co-Authors: Destiny J. Davis, David S. Domozych, Iben Sørensen, Jocelyn K C Rose, Minmin Wang, Georgia DrakakakiAbstract:Cytokinesis in land plants involves the formation of a cell plate that develops into the new cell wall. Callose, a β-1,3 glucan accumulates at later stages of cell plate development presumably to stabilize this delicate membrane network during expansion. Cytokinetic callose is considered specific to multicellular plant species, as it has not been detected in unicellular algae. Here we present callose at the cytokinesis junction of the unicellular charophyte, P. margaritaceum. Callose deposition at the division plane of P. margaritaceum showed distinct, spatiotemporal patterns likely representing distinct roles of this polymer in cytokinesis. Pharmacological inhibition by Endosidin 7 resulted in cytokinesis defects, consistent with the essential role for this polymer in P. margaritaceum cell division. Cell wall deposition at the isthmus zone was also affected by the absence of callose, demonstrating the dynamic nature of new wall assembly in P. margaritaceum. The identification of candidate callose synthase genes provides molecular evidence for callose biosynthesis in P. margaritaceum. The evolutionary implications of cytokinetic callose in this unicellular Zygnematopycean alga is discussed in the context of the conquest of land by plants.
Berke Tinaz - One of the best experts on this subject based on the ideXlab platform.
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protoplast isolation and manipulation in the unicellular model plant Penium margaritaceum
Methods of Molecular Biology, 2020Co-Authors: David S. Domozych, Berke Tinaz, Anna Lietz, Eleanore Ritter, Sandra C RaimundoAbstract:The unicellular freshwater green alga Penium margaritaceum has become a novel and valuable model organism for elucidating cell wall dynamics in plants. We describe a rapid and simple means for isolating protoplasts using commercial enzymes in a mannitol-based buffer. Protoplasts can be cultured and cell wall recovery can be monitored in sequentially diluted mannitol-based medium. We also describe an optimized protocol to prepare highly pure, organelle-free nuclei fractions from protoplasts using sucrose gradients. This technology provides a new and effective tool in Penium biology that can be used for analysis of cell wall polymer deposition, organelle isolation and characterization, and molecular research including genetic transformation and somatic hybridization.
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Isolation and manipulation of protoplasts from the unicellular green alga Penium margaritaceum
Plant Methods, 2018Co-Authors: Sandra Cristina Raimundo, Berke Tinaz, Iben Sørensen, Jocelyn K C Rose, Eleanore Ritter, David S. DomozychAbstract:Background The unicellular charophycean green alga Penium margaritaceum has emerged as an appealing experimental organism in plant cell wall and cell biology research. Innovative practical approaches in the manipulation and maintenance of this unicellular model alga are needed in order to probe the complexities of its subcellular and molecular machinery. Protoplast isolation and manipulation expedites a new range of experimental possibilities for Penium -based studies. These include enhanced means of isolation of subcellular components and macromolecules, application of intracellular probes for high resolution microscopy of live cells, transformation studies and analysis of the fundamental mechanisms of plant cell expansion and wall polymer deposition. Results We present a methodology for enzyme-based digestion of the Penium cell wall and the isolation of protoplasts. The subcellular events associated with this technology are presented using multiple microscopy-based techniques. We also provide protocols for applying an array of intracellular dyes that can be used as markers for specific organelles and membrane microdomains in live cells. Finally, we present a protocol for the purification of a nuclei-rich fraction from protoplasts, which can be used for the isolation of nuclear DNA. Conclusion Protoplast isolation, culturing and manipulation provide valuable means for molecular and cellular studies of Penium . The protocol described here offers a rapid and effective mechanism for fast and effective production of protoplasts. Subsequently, the protoplasts may be used for microscopy-based studies of specific subcellular components and the isolation of organelles and nuclear DNA. These methods offer a new practical methodology for future studies of this model organism in cell and molecular biology.
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isolation and manipulation of protoplasts from the unicellular green alga Penium margaritaceum
Plant Methods, 2018Co-Authors: Sandra C Raimundo, Berke Tinaz, Iben Sørensen, Jocelyn K C Rose, Eleanore Ritter, David S. DomozychAbstract:The unicellular charophycean green alga Penium margaritaceum has emerged as an appealing experimental organism in plant cell wall and cell biology research. Innovative practical approaches in the manipulation and maintenance of this unicellular model alga are needed in order to probe the complexities of its subcellular and molecular machinery. Protoplast isolation and manipulation expedites a new range of experimental possibilities for Penium-based studies. These include enhanced means of isolation of subcellular components and macromolecules, application of intracellular probes for high resolution microscopy of live cells, transformation studies and analysis of the fundamental mechanisms of plant cell expansion and wall polymer deposition. We present a methodology for enzyme-based digestion of the Penium cell wall and the isolation of protoplasts. The subcellular events associated with this technology are presented using multiple microscopy-based techniques. We also provide protocols for applying an array of intracellular dyes that can be used as markers for specific organelles and membrane microdomains in live cells. Finally, we present a protocol for the purification of a nuclei-rich fraction from protoplasts, which can be used for the isolation of nuclear DNA. Protoplast isolation, culturing and manipulation provide valuable means for molecular and cellular studies of Penium. The protocol described here offers a rapid and effective mechanism for fast and effective production of protoplasts. Subsequently, the protoplasts may be used for microscopy-based studies of specific subcellular components and the isolation of organelles and nuclear DNA. These methods offer a new practical methodology for future studies of this model organism in cell and molecular biology.
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imaging the dynamics of cell wall polymer deposition in the unicellular model plant Penium margaritaceum
Methods of Molecular Biology, 2017Co-Authors: David S. Domozych, Berke Tinaz, Anna Lietz, Molly Patten, Emily Singer, Sandra C RaimundoAbstract:The unicellular green alga, Penium margaritaceum, represents a novel and valuable model organism for elucidating cell wall dynamics in plants. This organism's cell wall contains several polymers that are highly similar to those found in the primary cell walls of land plants. Penium is easily grown in laboratory culture and is effectively manipulated in various experimental protocols including microplate assays and correlative microscopy. Most importantly, Penium can be live labeled with cell wall-specific antibodies or other probes and returned to culture where specific cell wall developmental events can be monitored. Additionally, live cells can be rapidly cryo-fixed and cell wall surface microarchitecture can be observed with variable pressure scanning electron microscopy. Here, we describe the methodology for maintaining Penium for experimental cell wall enzyme studies.
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The cortical cytoskeletal network and cell-wall dynamics in the unicellular charophycean green alga Penium margaritaceum
Annals of Botany, 2014Co-Authors: Julie Ochs, Therese La Rue, Berke Tinaz, Camille Yongue, David S. DomozychAbstract:BACKGROUND AND AIMS: Penium margaritaceum is a unicellular charophycean green alga with a unique bi-directional polar expansion mechanism that occurs at the central isthmus zone prior to cell division. This entails the focused deposition of cell-wall polymers coordinated by the activities of components of the endomembrane system and cytoskeletal networks. The goal of this study was to elucidate the structural organization of the cortical cytoskeletal network during the cell cycle and identify its specific functional roles during key cell-wall developmental events: pre-division expansion and cell division.\n\nMETHODS: Microtubules and actin filaments were labelled during various cell cycle phases with an anti-tubulin antibody and rhodamine phalloidin, respectively. Chemically induced disruption of the cytoskeleton was used to elucidate specific functional roles of microtubules and actin during cell expansion and division. Correlation of cytoskeletal dynamics with cell-wall development included live cell labelling with wall polymer-specific antibodies and electron microscopy.\n\nKEY RESULTS: The cortical cytoplasm of Penium is highlighted by a band of microtubules found at the cell isthmus, i.e. the site of pre-division wall expansion. This band, along with an associated, transient band of actin filaments, probably acts to direct the deposition of new wall material and to mark the plane of the future cell division. Two additional bands of microtubules, which we identify as satellite bands, arise from the isthmus microtubular band at the onset of expansion and displace toward the poles during expansion, ultimately marking the isthmus of future daughter cells. Treatment with microtubule and actin perturbation agents reversibly stops cell division.\n\nCONCLUSIONS: The cortical cytoplasm of Penium contains distinct bands of microtubules and actin filaments that persist through the cell cycle. One of these bands, termed the isthmus microtubule band, or IMB, marks the site of both pre-division wall expansion and the zone where a cross wall will form during cytokinesis. This suggests that prior to the evolution of land plants, a dynamic, cortical cytoskeletal array similar to a pre-prophase band had evolved in the charophytes. However, an interesting variation on the cortical band theme is present in Penium, where two satellite microtubule bands are produced at the onset of cell expansion, each of which is destined to become an IMB in the two daughter cells after cytokinesis. These unique cytoskeletal components demonstrate the close temporal control and highly coordinated cytoskeletal dynamics of cellular development in Penium.
Reagan Reed - One of the best experts on this subject based on the ideXlab platform.
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experimental manipulation of pectin architecture in the cell wall of the unicellular charophyte Penium margaritaceum
Frontiers in Plant Science, 2020Co-Authors: Kattia Palaciolopez, Reagan Reed, Iben Sørensen, Jocelyn K C Rose, Li Sun, Eric Kang, David S. DomozychAbstract:Pectins represent one of the main components of the plant primary cell wall. These polymers have critical roles in cell expansion, cell-cell adhesion and response to biotic stress. We present a comprehensive screening of pectin architecture of the unicellular streptophyte, Penium margaritaceum. Penium possesses a distinct cell wall whose outer layer consists of a lattice of pectin-rich fibers and projections. In this study, cells were exposed to a variety of physical, chemical and enzymatic treatments that directly affect the cell wall, especially the pectin lattice. Correlative analyses of pectin lattice perturbation using field emission scanning electron microscopy, confocal laser scanning microscopy, and transmission electron microscopy demonstrate that pectin lattice microarchitecture is both highly sensitive and malleable.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Li Sun, Zhangjun Fei, Jocelyn K C RoseAbstract:The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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the Penium margaritaceum genome hallmarks of the origins of land plants
Cell, 2020Co-Authors: Chen Jiao, Iben Sørensen, Hila Behar, Saleh Alseekh, Glenn Philippe, Kattia Palacio Lopez, Li Sun, Xuepeng Sun, Honghe Sun, Reagan ReedAbstract:Summary The evolutionary features and molecular innovations that enabled plants to first colonize land are not well understood. Here, insights are provided through our report of the genome sequence of the unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The genome has a high proportion of repeat sequences that are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with representatives of earlier diverging algal lineages, P. margaritaceum has expanded repertoires of gene families, signaling networks, and adaptive responses that highlight the evolutionary trajectory toward terrestrialization. These encompass a broad range of physiological processes and protective cellular features, such as flavonoid compounds and large families of modifying enzymes involved in cell wall biosynthesis, assembly, and remodeling. Transcriptome profiling further elucidated adaptations, responses, and selective pressures associated with the semi-terrestrial ecosystems of P. margaritaceum, where a simple body plan would be an advantage.
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endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte Penium margaritaceum
Journal of Experimental Botany, 2020Co-Authors: David S. Domozych, Kattia Palaciolopez, Reagan Reed, Susan Jeon, Iben Sørensen, Chen Jiao, Mingjia Li, Jocelyn K C RoseAbstract:: The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. EPS production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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the genome of the charophyte alga Penium margaritaceum bears footprints of the evolutionary origins of land plants
bioRxiv, 2019Co-Authors: Chen Jiao, Reagan Reed, Susan Jeon, Iben Sørensen, Hila Behar, Saleh Alseekh, Glenn Philippe, Kattia Palacio Lopez, Reiko Kiyonami, Sheng ZhangAbstract:ABSTRACT The colonization of land by plants was a pivotal event in the history of the biosphere, and yet the underlying evolutionary features and innovations of the first land plant ancestors are not well understood. Here we present the genome sequence of the unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The P. margaritaceum genome has a high proportion of repeat sequences, which are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with earlier diverging plant lineages, P. margaritaceum has uniquely expanded repertoires of gene families, signaling networks and adaptive responses, supporting its phylogenetic placement and highlighting the evolutionary trajectory towards terrestrialization. These encompass a broad range of physiological processes and cellular structures, such as large families of extracellular polymer biosynthetic and modifying enzymes involved in cell wall assembly and remodeling. Transcriptome profiling of cells exposed to conditions that are common in terrestrial habitats, namely high light and desiccation, further elucidated key adaptations to the semi-aquatic ecosystems that are home to the Zygnematophyceae. Such habitats, in which a simpler body plan would be advantageous, likely provided the evolutionary crucible in which selective pressures shaped the transition to land. Earlier diverging charophyte lineages that are characterized by more complex land plant-like anatomies have either remained exclusively aquatic, or developed alternative life styles that allow periods of desiccation.