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1.
Advances in Cell Wall Matrix Research with a Focus on Mixed-Linkage Glucan.
Kim, SJ, Brandizzi, F
Plant & cell physiology. 2021;(12):1839-1846
Abstract
Mixed β(1,3;1,4)-linkage glucan (MLG) is commonly found in the monocot lineage, at particularly high levels in the Poaceae family, but also in the evolutionally distant genus, Equisetum. MLG has several properties that make it unique from other plant cell wall polysaccharides. It consists of β1,4-linked polymers of glucose interspersed with β1,3-linkages, but the presence of β1,3-linkages provides quite different physical properties compared to its closest form of the cell wall component, cellulose. The mechanisms of MLG biosynthesis have been investigated to understand whether single or multiple enzymes are required to build mixed linkages in the glucan chain. Currently, MLG synthesis by a single enzyme is supported by mutagenesis analyses of cellulose synthase-like F6, the major MLG synthase, but further investigation is needed to gather mechanistic insights. Because of transient accumulation of MLG in elongating cells and vegetative tissues, several hypotheses have been proposed to explain the role of MLG in the plant cell wall. Studies have been carried out to identify gene expression regulators during development and light cycles as well as enzymes involved in MLG organization in the cell wall. A role of MLG as a storage molecule in grains is evident, but the role of MLG in vegetative tissues is still not well understood. Characterization of a cell wall component is difficult due to the complex heterogeneity of the plant cell wall. However, as detailed in this review, recent exciting research has made significant impacts in the understanding of MLG biology in plants.
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2.
Regulation and Function of Defense-Related Callose Deposition in Plants.
Wang, Y, Li, X, Fan, B, Zhu, C, Chen, Z
International journal of molecular sciences. 2021;(5)
Abstract
Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms. Callose is a β-(1,3)-D-glucan that is widely distributed in higher plants. In addition to its role in normal growth and development, callose plays an important role in plant defense. Callose is deposited between the plasma membrane and the cell wall at the site of pathogen attack, at the plasmodesmata, and on other plant tissues to slow pathogen invasion and spread. Since it was first reported more than a century ago, defense-related callose deposition has been extensively studied in a wide-spectrum of plant-pathogen systems. Over the past 20 years or so, a large number of studies have been published that address the dynamic nature of pathogen-induced callose deposition, the complex regulation of synthesis and transport of defense-related callose and associated callose synthases, and its important roles in plant defense responses. In this review, we summarize our current understanding of the regulation and function of defense-related callose deposition in plants and discuss both the progresses and future challenges in addressing this complex defense mechanism as a critical component of a plant immune system.
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3.
RBCK1-related disease: A rare multisystem disorder with polyglucosan storage, auto-inflammation, recurrent infections, skeletal, and cardiac myopathy-Four additional patients and a review of the current literature.
Phadke, R, Hedberg-Oldfors, C, Scalco, RS, Lowe, DM, Ashworth, M, Novelli, M, Vara, R, Merwick, A, Amer, H, Sofat, R, et al
Journal of inherited metabolic disease. 2020;(5):1002-1013
Abstract
In this article, we report four new patients, from three kindreds, with pathogenic variants in RBCK1 and a multisystem disorder characterised by widespread polyglucosan storage. We describe the clinical presentation of progressive skeletal and cardiac myopathy, combined immunodeficiencies and auto-inflammation, illustrate in detail the histopathological findings in multiple tissue types, and report muscle MRI findings.
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4.
Glucanases and Chitinases.
Roncero, C, Vázquez de Aldana, CR
Current topics in microbiology and immunology. 2020;:131-166
Abstract
In many yeast and fungi, β-(1,3)-glucan and chitin are essential components of the cell wall, an important structure that surrounds cells and which is responsible for their mechanical protection and necessary for maintaining the cellular shape. In addition, the cell wall is a dynamic structure that needs to be remodelled along with the different phases of the fungal life cycle or in response to extracellular stimuli. Since β-(1,3)-glucan and chitin perform a central structural role in the assembly of the cell wall, it has been postulated that β-(1,3)-glucanases and chitinases should perform an important function in cell wall softening and remodelling. This review focusses on fungal glucanases and chitinases and their role during fungal morphogenesis.
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5.
Synthesis of novel α-glucans with potential health benefits through controlled glucose release in the human gastrointestinal tract.
Gangoiti, J, Corwin, SF, Lamothe, LM, Vafiadi, C, Hamaker, BR, Dijkhuizen, L
Critical reviews in food science and nutrition. 2020;(1):123-146
Abstract
The glycemic carbohydrates we consume are currently viewed in an unfavorable light in both the consumer and medical research worlds. In significant part, these carbohydrates, mainly starch and sucrose, are looked upon negatively due to their rapid and abrupt glucose delivery to the body which causes a high glycemic response. However, dietary carbohydrates which are digested and release glucose in a slow manner are recognized as providing health benefits. Slow digestion of glycemic carbohydrates can be caused by several factors, including food matrix effect which impedes α-amylase access to substrate, or partial inhibition by plant secondary metabolites such as phenolic compounds. Differences in digestion rate of these carbohydrates may also be due to their specific structures (e.g. variations in degree of branching and/or glycosidic linkages present). In recent years, much has been learned about the synthesis and digestion kinetics of novel α-glucans (i.e. small oligosaccharides or larger polysaccharides based on glucose units linked in different positions by α-bonds). It is the synthesis and digestion of such structures that is the subject of this review.
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6.
A Report on Fungal (1→3)-α-d-glucans: Properties, Functions and Application.
Złotko, K, Wiater, A, Waśko, A, Pleszczyńska, M, Paduch, R, Jaroszuk-Ściseł, J, Bieganowski, A
Molecules (Basel, Switzerland). 2019;(21)
Abstract
The cell walls of fungi are composed of glycoproteins, chitin, and α- and β-glucans. Although there are many reports on β-glucans, α-glucan polysaccharides are not yet fully understood. This review characterizes the physicochemical properties and functions of (1→3)-α-d-glucans. Particular attention has been paid to practical application and the effect of glucans in various respects, taking into account unfavourable effects and potential use. The role of α-glucans in plant infection has been proven, and collected facts have confirmed the characteristics of Aspergillus fumigatus infection associated with the presence of glucan in fungal cell wall. Like β-glucans, there are now evidence that α-glucans can also stimulate the immune system. Moreover, α-d-glucans have the ability to induce mutanases and can thus decompose plaque.
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7.
Pullulan production from agro-industrial waste and its applications in food industry: A review.
Singh, RS, Kaur, N, Kennedy, JF
Carbohydrate polymers. 2019;:46-57
Abstract
Pullulan is a microbial exopolysaccharide produced from Aureobasidium pullulans by submerged fermentation of a medium supplemented with carbon, nitrogen and other essential nutrients. These nutrients are expensive which increase the cost of pullulan production. The requirement of alternative cost-effective substrates for pullulan production is a prerequisite. Agro-based industries generate a large volume of solid/liquid waste and its accumulation generates a severe environmental impact. These wastes are composed of carbohydrates, proteins and other constituents, and can be used as substrates for the development of low-cost processes for the production of various microbial products. This could be a good environmental friendly waste management system. Pullulan production from agro-industrial wastes can be carried out by both submerged and solid-state fermentation by A. pullulans. Owing to its unique properties, pullulan has wide applications in many food-based industries. This review highlights pullulan production from agro-industrial wastes and potential applications of pullulan in various food industries.
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8.
Bulking for stress urinary incontinence in men: A systematic review.
Toia, B, Gresty, H, Pakzad, M, Hamid, R, Ockrim, J, Greenwell, T
Neurourology and urodynamics. 2019;(7):1804-1811
Abstract
AIMS: An updated literature review on outcomes in men treated with currently commercially available bulking agents was performed to determine whether this is a reasonable option in selected patients. METHODS The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework of systematic reviews. A comprehensive search of PubMed, Medline, and Embase was undertaken. Abstracts were independently screened by two investigators to include men with stress urinary incontinence treated with a peri-urethral injection of bulking agents currently available in the market. RESULTS Only eight original articles met the inclusion criteria. The bulking agents used were Macroplastique in five studies (total 123 patients), Opsys, Durasphere, and Urolastic in one study each (10, 7, and 2 patients, respectively). Only one study was randomized; Macroplastique vs AUS in men with mild or total incontinence. The included populations were heterogeneous and encompassed endoscopic, perineal, abdominal and laparoscopic prostate surgery as well as spinal cord injuries and urethral sphincter insufficiency. Significant dissimilarity was evident for the duration of incontinence (9-108 months), mean volume of bulking agent used (2.3-13.5 mL), number of cushions (1-5), depth and position of the cushions. The outcomes varied significantly, with reported dry rates between 0% and 83%. Outcomes were limited by relatively short follow-up in most studies. CONCLUSION Following initial enthusiasm and then dismay with collagen-based compounds, sparse and heterogeneous literature data were produced on newer non-migrating and nonabsorbable bulking agents. Some studies have suggested encouraging, if short term outcomes, however, future studies are needed in this field to support recommendations for widespread use.
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9.
Callose balancing at plasmodesmata.
Wu, SW, Kumar, R, Iswanto, ABB, Kim, JY
Journal of experimental botany. 2018;(22):5325-5339
Abstract
In plants, communication and molecular exchanges between different cells and tissues are dependent on the apoplastic and symplastic pathways. Symplastic molecular exchanges take place through the plasmodesmata, which connect the cytoplasm of neighboring cells in a highly controlled manner. Callose, a β-1,3-glucan polysaccharide, is a plasmodesmal marker molecule that is deposited in cell walls near the neck zone of plasmodesmata and controls their permeability. During cell differentiation and plant development, and in response to diverse stresses, the level of callose in plasmodesmata is highly regulated by two antagonistic enzymes, callose synthase or glucan synthase-like and β-1,3-glucanase. The diverse modes of regulation by callose synthase and β-1,3-glucanase have been uncovered in the past decades through biochemical, molecular, genetic, and omics methods. This review highlights recent findings regarding the function of plasmodesmal callose and the molecular players involved in callose metabolism, and provides new insight into the mechanisms maintaining plasmodesmal callose homeostasis.
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10.
A review on versatile applications of blends and composites of pullulan with natural and synthetic polymers.
Tabasum, S, Noreen, A, Maqsood, MF, Umar, H, Akram, N, Nazli, ZI, Chatha, SAS, Zia, KM
International journal of biological macromolecules. 2018;(Pt A):603-632
Abstract
Pullulan is a non-ionic, linear, water-soluble and a neutral polysaccharide. It is composed of α-(1,6) repeated maltotriose units via α-(1,4) glycosidic bond having chemical formula (C6H10O5)n. It shows non-immunogenic, non-toxic, non-carcinogenic and non-mutagenic properties. It is used in food edible coatings, films, as flocculant, foaming agent and adhesive. It may also be used as a carrier for bioactive compounds and a protective packaging for food and pharmaceutical products. Therefore, it is blended with different polymers such as carrageenan, mucilages, chitosan, cellulose, sodium alginate, starch, polyethyleneimine, whey-protein, polyisopropylacrylamide, histone, jeffamine, polyamidoamine, pemulen, hyaluronic acid, polyvinyl alcohol and caboxymethyl cellulose. In this article, a comprehensive overview of combination of pullulan with natural and synthetic polymers and their applications in biomedical field involving drug delivery system, tissue engineering, wound healing and gene therapy, is presented. It also describes the utilization of pullulan based materials in food industry, water treatment and pharmaceutical industry. All the technical scientific issues have been addressed; highlighting the recent advancements.