Plant Cell Wall (Campbell Biology)
The cell wall is an extracellular structure of plant cells. This is one of the features that distinguishes plant cells from animal cells. The wall protects the plant cell, maintains its shape, and prevents excessive uptake of water. On the level of the whole plant, the strong walls of specialized cells hold the plant up against the force of gravity. Prokaryotes, fungi, and some unicellular eukaryotes also have cell walls.
Plant cell walls are much thicker than the plasma membrane, ranging from 0.1 µm to several micrometers. The exact chemical composition of the wall varies from species to species and even from one cell type to another in the same plant, but the basic design of the wall is consistent. Microfibrils made of the polysaccharide cellulose are synthesized by an enzyme called cellulose synthase and secreted to the extracellular space, where they become embedded in a matrix of other polysaccharides and proteins. This combination of materials, strong fibers in a “ground substance” (matrix), is the same basic architectural design found in steel-reinforced concrete and in fiberglass.
A young plant cell first secretes a relatively thin and flexible wall called the primary cell wall. Between primary walls of adjacent cells is the middle lamella, a thin layer rich in sticky polysaccharides called pectins. The middle lamella glues adjacent cells together. (Pectin is used in cooking as a thickening agent in jams and jellies.) When the cell matures and stops growing, it strengthens its wall. Some plant cells do this simply by secreting hardening substances into the primary wall. Other cells add a secondary cell wall between the plasma membrane and the primary wall. The secondary wall, often deposited in several laminated layers, has a strong and durable matrix that affords the cell protection and support. Wood, for example, consists mainly of secondary walls. Plant cell walls are usually perforated by channels between adjacent cells called plasmodesmata.
Urry, Lisa A.. Campbell Biology. Pearson Education. Kindle Edition. https://www.pearson.com/us/higher-education/series/Campbell-Biology-Series/2244849.html
Date Published: September 18, 2014 Publisher: Public Library of Science Author(s): Lisbeth G. Thygesen, Emil E. Thybring, Katja S. Johansen, Claus Felby, Tobias Isaac Baskin. http://doi.org/10.1371/journal.pone.0108313 Abstract: Mechanical agitation during enzymatic hydrolysis of insoluble plant biomass at high dry matter contents is indispensable for the initial liquefaction step in biorefining. It is known that particle … Continue reading
Research Article: Cell Wall Assembly and Intracellular Trafficking in Plant Cells Are Directly Affected by Changes in the Magnitude of Gravitational Acceleration
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Research Article: Two new gene clusters involved in the degradation of plant cell wall from the fecal microbiota of Tunisian dromedary
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Research Article: Plant cell wall glycosyltransferases: High-throughput recombinant expression screening and general requirements for these challenging enzymes
Date Published: June 9, 2017 Publisher: Public Library of Science Author(s): Ditte Hededam Welner, David Shin, Giovani P. Tomaleri, Andy M. DeGiovanni, Alex Yi-Lin Tsai, Huu M. Tran, Sara Fasmer Hansen, Derek T. Green, Henrik V. Scheller, Paul D. Adams, Andreas Hofmann. http://doi.org/10.1371/journal.pone.0177591 Abstract: Molecular characterization of plant cell wall glycosyltransferases is a critical step … Continue reading
Research Article: The signal peptide-like segment of hpaXm is required for its association to the cell wall in transgenic tobacco plants
Date Published: January 31, 2017 Publisher: Public Library of Science Author(s): Le Li, Weiguo Miao, Wenbo Liu, Shujian Zhang, Leandro Peña. http://doi.org/10.1371/journal.pone.0170931 Abstract: Harpins, encoded by hrp (hypersensitive response and pathogenicity) genes of Gram-negative plant pathogens, are elicitors of hypersensitive response (HR). HpaXm is a novel harpin-like protein described from cotton leaf blight bacteria, Xanthomonas … Continue reading
Research Article: A method for extracting high-quality total RNA from plant rich in polysaccharides and polyphenols using Dendrobium huoshanense
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Date Published: February 12, 2016 Publisher: Public Library of Science Author(s): Marcel G. A. van der Heijden, Martin Hartmann Abstract: Almost all higher organisms, including plants, insects, and mammals, are colonized by complex microbial communities and harbor a microbiome. Emerging studies with plants reveal that these microbiomes are structured and form complex, interconnected microbial networks. … Continue reading