scholarly journals Comparative transcriptomics reveals the molecular toolkit used by an algivorous protist for cell wall perforation

2021 ◽  
Author(s):  
Jennifer V. Gerbracht ◽  
Tommy Harding ◽  
Alastair G. B. Simpson ◽  
Andrew J. Roger ◽  
Sebastian Hess
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cell Biology ◽  
Algal Cell ◽  
Feeding Strategies ◽  
Generalist Predators ◽  
Related Factors ◽  
Prey Cell ◽  
Complex Behaviour ◽  
Green Algal

Microbial eukaryotes display a stunning diversity of feeding strategies, ranging from generalist predators to highly specialised parasites. The unicellular protoplast feeders represent a fascinating mechanistic intermediate, as they penetrate other eukaryotic cells (algae, fungi) like some parasites, but then devour their cell contents by phagocytosis. Besides prey recognition and attachment, this complex behaviour involves the local, pre-phagocytotic dissolution of the prey cell wall, which results in well-defined perforations of species-specific size and structure. Yet, the molecular processes that enable protoplast feeders to overcome cell walls of diverse biochemical composition remain unknown. We used the flagellate Orciraptor agilis (Viridiraptoridae, Rhizaria) as a model protoplast feeder, and applied differential gene expression analysis to examine its penetration of green algal cell walls. Besides distinct expression changes that reflect major cellular processes (e.g. locomotion, cell division), we found lytic carbohydrate-active enzymes that are highly expressed and upregulated during the attack on the alga. A putative endocellulase (family GH5_5) with a secretion signal is most prominent, and a potential key factor for cell wall dissolution. Other candidate enzymes (e.g. lytic polysaccharide monooxygenases) belong to families that are largely uncharacterised, emphasising the potential of non-fungal micro-eukaryotes for enzyme exploration. Unexpectedly, we discovered various chitin-related factors that point to an unknown chitin metabolism in Orciraptor, potentially also involved in the feeding process. Our findings provide first molecular insights into an important microbial feeding behaviour, and new directions for cell biology research on non-model eukaryotes.

Root hair cell walls: filling in the frameworkThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.

2006 ◽  
Vol 84 (4) ◽  
pp. 613-621 ◽  
Author(s):  
M.E. Galway
Keyword(s):  
Cell Wall ◽  
Hair Cell ◽  
Plant Cell ◽  
Root Hair ◽  
Cell Walls ◽  
Cell Biology ◽  
High Speed ◽  
Root Hairs ◽  
Experimental System ◽  
Plant Cell Walls

Rapid progress is being made in determining the composition, synthesis, and mechanical properties of plant cell walls. Although tip-growing root hairs provide an excellent example of high-speed cell wall assembly, they have been relatively neglected by researchers interested in cell walls and those interested in tip growth. This review aims to present the root hair as an experimental system for future cell wall studies by assembling recent discoveries about the walls onto the existing framework based on older information. Most recent data come from arabidopsis ( Arabidopsis thaliana (L.) Heynh) and model legumes. Evidence supporting the turgor-mediated expansion of hair cell walls is considered, along with a survey of three components needed for cell wall expansion without rupture: cellulose (the role of CesA cellulose synthases is also addressed), Csld3, a cellulose synthase-like protein, and Lrx1, a cell wall protein. Further clues about hair cell wall composition have been obtained from gene expression studies and the use of monoclonal antibodies. Finally, there is a review of the experimental evidence that (i) hairs near the hypocotyl differ developmentally and structurally from other hairs and (ii) biosynthesis of wall components in hairs may differ significantly from the epidermal cells that they grew from. All of these recent advances suggest that root hairs could provide valuable data to augment models of plant cell walls based on more conventional cell types.

scholarly journals Current and future advances in fluorescence-based visualization of plant cell wall components and cell wall biosynthetic machineries

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Brian T DeVree ◽  
Lisa M Steiner ◽  
Sylwia Głazowska ◽  
Felix Ruhnow ◽  
Klaus Herburger ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Plant Cell Wall ◽  
Imaging Techniques ◽  
Molecular Probes ◽  
Comprehensive Overview ◽  
Biotechnology Research ◽  
High Level

AbstractPlant cell wall-derived biomass serves as a renewable source of energy and materials with increasing importance. The cell walls are biomacromolecular assemblies defined by a fine arrangement of different classes of polysaccharides, proteoglycans, and aromatic polymers and are one of the most complex structures in Nature. One of the most challenging tasks of cell biology and biomass biotechnology research is to image the structure and organization of this complex matrix, as well as to visualize the compartmentalized, multiplayer biosynthetic machineries that build the elaborate cell wall architecture. Better knowledge of the plant cells, cell walls, and whole tissue is essential for bioengineering efforts and for designing efficient strategies of industrial deconstruction of the cell wall-derived biomass and its saccharification. Cell wall-directed molecular probes and analysis by light microscopy, which is capable of imaging with a high level of specificity, little sample processing, and often in real time, are important tools to understand cell wall assemblies. This review provides a comprehensive overview about the possibilities for fluorescence label-based imaging techniques and a variety of probing methods, discussing both well-established and emerging tools. Examples of applications of these tools are provided. We also list and discuss the advantages and limitations of the methods. Specifically, we elaborate on what are the most important considerations when applying a particular technique for plants, the potential for future development, and how the plant cell wall field might be inspired by advances in the biomedical and general cell biology fields.

The involvement of Microbial Epiphytes in Uptake Measurements with the Giant-celled Alga Chara australis

1988 ◽  
Vol 15 (4) ◽  
pp. 483
Author(s):  
MR Wilson ◽  
JM Hush ◽  
NA Walker
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Algal Cell ◽  
Pond Water ◽  
Substantial Contribution ◽  
Free Paper ◽  
Solute Uptake ◽  
Water Ph ◽  
Chara Australis ◽  
Transport Of Ions

The giant-celled algae Chara and Nitella have been used extensively in studies of the transport of ions and other solutes. Before this report, uptake measurements were made without a detailed consideration of the effects of microbial epiphytes living on the external surface of the algal cell wall. Examination of the cell walls of Chara and Nitella with the scanning electron microscope revealed the presence of an often dense microflora consisting of diatoms, many types of bacteria, and even fungi. The contribution of this microflora to uptake measurements made with radiotracers was estimated by using isolated Chara cell wall cylinders internally filled with a silicone compound. For the Chara tested by us, the microflora was shown to make a substantial contribution to the uptake of urea, uric acid and glycine measured for untreated internodes. It was shown that, by briefly soaking Chara internodes in an artificial pond water, pH 8.5, containing 3 mM EGTA and then wiping their surfaces with a Kimwipe (a lint-free paper tissue), the microbial epiphytes can be quickly and simply removed. This treatment could be very useful in radiotracer studies of giant-celled algae in which the activity of the surface microflora complicates measurements of solute uptake.

A review about brown algal cell walls and fucose-containing sulfated polysaccharides: Cell wall context, biomedical properties and key research challenges

2017 ◽  
Vol 175 ◽  
pp. 395-408 ◽  
Author(s):  
Estelle Deniaud-Bouët ◽  
Kevin Hardouin ◽  
Philippe Potin ◽  
Bernard Kloareg ◽  
Cécile Hervé
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Algal Cell ◽  
Sulfated Polysaccharides ◽  
Research Challenges

scholarly journals Insights into cell wall disintegration of Chlorella vulgaris

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262500
Author(s):  
Sophie Weber ◽  
Philipp M. Grande ◽  
Lars M. Blank ◽  
Holger Klose
Keyword(s):  
Cell Wall ◽  
Chlorella Vulgaris ◽  
Cell Walls ◽  
Algal Cell ◽  
Monosaccharide Composition ◽  
Total Biomass ◽  
Algal Cell Wall ◽  
Wall Structures ◽  
Valuable Compounds ◽  
Hydrolysis Of

With their ability of CO2 fixation using sunlight as an energy source, algae and especially microalgae are moving into the focus for the production of proteins and other valuable compounds. However, the valorization of algal biomass depends on the effective disruption of the recalcitrant microalgal cell wall. Especially cell walls of Chlorella species proved to be very robust. The wall structures that are responsible for this robustness have been studied less so far. Here, we evaluate different common methods to break up the algal cell wall effectively and measure the success by protein and carbohydrate release. Subsequently, we investigate algal cell wall features playing a role in the wall’s recalcitrance towards disruption. Using different mechanical and chemical technologies, alkali catalyzed hydrolysis of the Chlorella vulgaris cells proved to be especially effective in solubilizing up to 56 wt% protein and 14 wt% carbohydrates of the total biomass. The stepwise degradation of C. vulgaris cell walls using a series of chemicals with increasingly strong conditions revealed that each fraction released different ratios of proteins and carbohydrates. A detailed analysis of the monosaccharide composition of the cell wall extracted in each step identified possible factors for the robustness of the cell wall. In particular, the presence of chitin or chitin-like polymers was indicated by glucosamine found in strong alkali extracts. The presence of highly ordered starch or cellulose was indicated by glucose detected in strong acidic extracts. Our results might help to tailor more specific efforts to disrupt Chlorella cell walls and help to valorize microalgae biomass.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

Histological aspects of the cryopreservation of potato

2008 ◽  
Vol 56 (3) ◽  
pp. 341-348
Author(s):  
P. Pepó ◽  
A. Kovács
Keyword(s):  
Cell Wall ◽  
Low Temperatures ◽  
Cell Walls ◽  
Cellular Level ◽  
Adaptive Mechanism ◽  
Epidermal Layer ◽  
Freezing And Thawing ◽  
Meristematic Cells ◽  
Suitable Solution ◽  
Vacuolated Cells

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.

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