scholarly journals Xylans of Red and Green Algae: What Is Known about Their Structures and How They Are Synthesised?

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 354 ◽  
Author(s):  
Yves Hsieh ◽  
Philip Harris
Keyword(s):  
Cell Wall ◽  
Green Algae ◽  
Red Algae ◽  
Cell Walls ◽  
Orthologous Gene ◽  
Land Plant ◽  
Land Plants ◽  
Triple Helices ◽  
Cell Wall Matrix ◽  
Klebsormidium Flaccidum

Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced orders of charophyte green algae. Small proportions of 1,4-β-d-xylans have also been found in the cell walls of some chlorophyte green algae and red algae but have not been well characterised. 1,3-β-d-Xylans occur as triple helices in microfibrils in the cell walls of chlorophyte algae in the order Bryopsidales and of red algae in the order Bangiales. 1,3;1,4-β-d-Xylans occur in the cell wall matrix of red algae in the orders Palmariales and Nemaliales. In the angiosperm Arabidopsis thaliana, the gene IRX10 encodes a xylan 1,4-β-d-xylosyltranferase (xylan synthase), and, when heterologously expressed, this protein catalysed the production of the backbone of 1,4-β-d-xylans. An orthologous gene from the charophyte green alga Klebsormidium flaccidum, when heterologously expressed, produced a similar protein that was also able to catalyse the production of the backbone of 1,4-β-d-xylans. Indeed, it is considered that land plant xylans evolved from xylans in ancestral charophyte green algae. However, nothing is known about the biosynthesis of the different xylans found in chlorophyte green algae and red algae. There is, thus, an urgent need to identify the genes and enzymes involved.

scholarly journals Ancient origin of fucosylated xyloglucan in charophycean green algae

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Maria Dalgaard Mikkelsen ◽  
Jesper Harholt ◽  
Bjørge Westereng ◽  
David Domozych ◽  
Stephen C. Fry ◽  
...  
Keyword(s):  
Green Algae ◽  
Structural Component ◽  
Cell Walls ◽  
Uronic Acid ◽  
Structural Elucidation ◽  
Land Plants ◽  
Evolutionary Significance ◽  
Biosynthetic Enzymes ◽  
Major Structural Component ◽  
Mesotaenium Caldariorum

AbstractThe charophycean green algae (CGA or basal streptophytes) are of particular evolutionary significance because their ancestors gave rise to land plants. One outstanding feature of these algae is that their cell walls exhibit remarkable similarities to those of land plants. Xyloglucan (XyG) is a major structural component of the cell walls of most land plants and was originally thought to be absent in CGA. This study presents evidence that XyG evolved in the CGA. This is based on a) the identification of orthologs of the genetic machinery to produce XyG, b) the identification of XyG in a range of CGA and, c) the structural elucidation of XyG, including uronic acid-containing XyG, in selected CGA. Most notably, XyG fucosylation, a feature considered as a late evolutionary elaboration of the basic XyG structure and orthologs to the corresponding biosynthetic enzymes are shown to be present in Mesotaenium caldariorum.

scholarly journals ELECTRON-OPAQUE FIBRILS AND GRANULES IN AND BETWEEN THE CELL WALLS OF HIGHER PLANTS

1972 ◽  
Vol 53 (3) ◽  
pp. 695-703 ◽  
Author(s):  
Gary G. Leppard ◽  
J. Ross Colvin
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cultured Cells ◽  
Higher Plants ◽  
Middle Lamella ◽  
Woody Species ◽  
Morning Glory ◽  
Plant Cell Walls ◽  
Higher Plant ◽  
Cell Wall Matrix

The components of higher-plant cell walls which become electron-opaque after staining with ruthenium-osmium were studied by electron microscopy. A fibrillar material which absorbs this stain is a major wall constituent in the root epidermal cells of carrot and morning glory. In both form and size, these fibrils resemble those found on the surface of suspension-cultured cells of the same species Some cells of woody species show an irregular distribution of electron-opaque material in the cell wall matrix and middle lamella. This material, which has an amorphous appearance with many electron stains, is shown by ruthenium-osmium staining to be an aggregate of discrete granules, 150–220 A in diameter. These observations are not consistent with the concept of the cell wall matrix and middle lamella as an amorphous, uniform gel

scholarly journals The Charophycean green algae as model systems to study plant cell walls and other evolutionary adaptations that gave rise to land plants

2012 ◽  
Vol 7 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Iben Sørensen ◽  
Jocelyn K.C. Rose ◽  
Jeff J. Doyle ◽  
David S. Domozych ◽  
William G.T. Willats
Keyword(s):  
Green Algae ◽  
Plant Cell ◽  
Cell Walls ◽  
Model Systems ◽  
Land Plants ◽  
Plant Cell Walls

scholarly journals From morphogenesis to pathogenesis: A cellulose loosening protein is one of the most widely distributed tools in nature

2019 ◽  
Author(s):  
William R. Chase ◽  
Olga Zhaxybayeva ◽  
Jorge Rocha ◽  
Daniel J. Cosgrove ◽  
Lori R. Shapiro
Keyword(s):  
Cell Wall ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Cell Walls ◽  
Growth And Development ◽  
Land Plants ◽  
Cellulose Microfibrils ◽  
Plant Cell Walls ◽  
Phylogenetic Distribution ◽  
Bacteria And Fungi

AbstractPlants must rearrange the network of complex carbohydrates in their cell walls during normal growth and development. To accomplish this, all plants depend on proteins called expansins that non-enzymatically loosen hydrogen bonds between cellulose microfibrils. Because of their key role in cell wall extension during growth, expansin genes are ubiquitous, diverse, and abundant throughout all land plants. Surprisingly, expansin genes have more recently been found in some bacteria and microbial eukaryotes, where their biological functions are largely unknown. Here, we reconstruct the phylogeny of microbial expansin genes. We find these genes in all eukaryotic microorganisms that have structural cellulose in their cell walls, suggesting expansins evolved in ancient marine microorganisms long before the evolution of land plants. We also find expansins in an unexpectedly high phylogenetic diversity of bacteria and fungi that do not have cellulosic cell walls. These bacteria and fungi with expansin genes inhabit varied ecological contexts mirroring the diversity of terrestrial and aquatic niches where plant and/or algal cellulosic cell walls are present. The microbial expansin phylogeny shows evidence of multiple horizontal gene transfer events within and between bacterial and eukaryotic microbial lineages, which may in part underlie their unusually broad phylogenetic distribution. Taken together, we find expansins to be unexpectedly widespread in both bacterial and eukaryotic genetic backgrounds, and that the contribution of these genes to bacterial and fungal ecological interactions with plants and algae has likely been underappreciated.ImportanceCellulose is the most abundant biopolymer on earth. In plant cell walls, where most global cellulose biomass is found, cellulose microfibrils occur intertwined with hemicelluloses and pectins. The rigidity of this polysaccharide matrix provides plant cell walls with structural support, but this rigidity also restricts cellular growth and development. Irreversible, non-enzymatic loosening of structural carbohydrates by expansin proteins is key to successful cell wall growth in plants and green algae. Here, we find that expansin genes are distributed far more broadly throughout diverse bacterial and fungal lineages lacking cellulosic cell walls than previously known. Multiple horizontal gene transfer events are in part responsible for their unusually wide phylogenetic distribution. Together, these results suggest that in addition to being the key evolutionary innovation by which eukaryotes remodel structural cellulose in their cell walls, expansins likely have remarkably broad and under-recognized utility for microbial species that interact with plant and algal structural cellulose in diverse ecological contexts.

scholarly journals The Role of Cutinsomes in Plant Cuticle Formation

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1778 ◽  
Author(s):  
Dariusz Stępiński ◽  
Maria Kwiatkowska ◽  
Agnieszka Wojtczak ◽  
Justyna Teresa Polit ◽  
Eva Domínguez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Cell Walls ◽  
The Other ◽  
Land Plants ◽  
Plant Cuticle ◽  
Cuticle Formation ◽  
Linear Chains ◽  
Main Components

The cuticle commonly appears as a continuous lipophilic layer located at the outer epidermal cell walls of land plants. Cutin and waxes are its main components. Two methods for cutin synthesis are considered in plants. One that is based on enzymatic biosynthesis, in which cutin synthase (CUS) is involved, is well-known and commonly accepted. The other assumes the participation of specific nanostructures, cutinsomes, which are formed in physicochemical self-assembly processes from cutin precursors without enzyme involvement. Cutinsomes are formed in ground cytoplasm or, in some species, in specific cytoplasmic domains, lipotubuloid metabolons (LMs), and are most probably translocated via microtubules toward the cuticle-covered cell wall. Cutinsomes may additionally serve as platforms transporting cuticular enzymes. Presumably, cutinsomes enrich the cuticle in branched and cross-linked esterified polyhydroxy fatty acid oligomers, while CUS1 can provide both linear chains and branching cutin oligomers. These two systems of cuticle formation seem to co-operate on the surface of aboveground organs, as well as in the embryo and seed coat epidermis. This review focuses on the role that cutinsomes play in cuticle biosynthesis in S. lycopersicum, O. umbellatum and A. thaliana, which have been studied so far; however, these nanoparticles may be commonly involved in this process in different plants.

scholarly journals Evolution of the cell wall components during terrestrialization

2014 ◽  
Vol 83 (4) ◽  
pp. 349-362 ◽  
Author(s):  
Alicja Banasiak
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Terrestrial Ecosystems ◽  
Land Plants ◽  
Cell Wall Components ◽  
Additional Information ◽  
Evolutionary Context ◽  
Adaptive Processes ◽  
Main Components ◽  
Wall Components

<p>Colonization of terrestrial ecosystems by the first land plants, and their subsequent expansion and diversification, were crucial for the life on the Earth. However, our understanding of these processes is still relatively poor. Recent intensification of studies on various plant organisms have identified the plant cell walls are those structures, which played a key role in adaptive processes during the evolution of land plants. Cell wall as a structure protecting protoplasts and showing a high structural plasticity was one of the primary subjects to changes, giving plants the new properties and capabilities, which undoubtedly contributed to the evolutionary success of land plants.</p><p>In this paper, the current state of knowledge about some main components of the cell walls (cellulose, hemicelluloses, pectins and lignins) and their evolutionary alterations, as preadaptive features for the land colonization and the plant taxa diversification, is summarized. Some aspects related to the biosynthesis and modification of the cell wall components, with particular emphasis on the mechanism of transglycosylation, are also discussed. In addition, new surprising discoveries related to the composition of various cell walls, which change how we perceive their evolution, are presented, such as the presence of lignin in red algae or MLG (1→3),(1→4)-β-D-glucan in horsetails. Currently, several new and promising projects, regarding the cell wall, have started, deciphering its structure, composition and metabolism in the evolutionary context. That additional information will allow us to better understand the processes leading to the terrestrialization and the evolution of extant land plants.</p>

Occurrence of silica in brown and green algae

1969 ◽  
Vol 47 (4) ◽  
pp. 537-540 ◽  
Author(s):  
Bruce C. Parker
Keyword(s):  
Cell Wall ◽  
Green Algae ◽  
Phylogenetic Relationships ◽  
Brown Algae ◽  
Cell Walls ◽  
Organic Substances

Small but significant amounts of silica occur in all brown algae and green Hydrodictyaceae examined. At least in the hydrodictyaceous Pediastrum and Tetraëdron, the silica predominates in the cell wall. This silica is largely isotropic, non-crystalline opal with a small amount of α-quartz. Occurrence of silica in brown algae constitutes yet another feature suggesting phylogenetic relationships with the Chrysophycophyta, and the siliceous cell walls of the Hydrodictyaceae facilitate an understanding of both the nature of organic substances present and the process of zoosporogenesis.

scholarly journals Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae

2014 ◽  
Vol 114 (6) ◽  
pp. 1217-1236 ◽  
Author(s):  
Maria D. Mikkelsen ◽  
Jesper Harholt ◽  
Peter Ulvskov ◽  
Ida E. Johansen ◽  
Jonatan U. Fangel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Green Algae ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Land Plant

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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