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Robin M, Djediat C, Bardouil A, Baccile N, Chareyron C, Zizak I, Fratzl P, Selmane M, Haye B, Genois I, Krafft J, Costentin G, Azaïs T, Artzner F, Giraud‐Guille M, Zaslansky P, Nassif N. Acidic Osteoid Templates the Plywood Structure of Bone Tissue. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2304454. [PMID: 38115757 PMCID: PMC10916609 DOI: 10.1002/advs.202304454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/18/2023] [Indexed: 12/21/2023]
Abstract
Bone is created by osteoblasts that secrete osteoid after which an ordered texture emerges, followed by mineralization. Plywood geometries are a hallmark of many trabecular and cortical bones, yet the origin of this texturing in vivo has never been shown. Nevertheless, extensive in vitro work revealed how plywood textures of fibrils can emerge from acidic molecular cholesteric collagen mesophases. This study demonstrates in sheep, which is the preferred model for skeletal orthopaedic research, that the deeper non-fibrillar osteoid is organized in a liquid-crystal cholesteric geometry. This basophilic domain, rich in acidic glycosaminoglycans, exhibits low pH which presumably fosters mesoscale collagen molecule ordering in vivo. The results suggest that the collagen fibril motif of twisted plywood matures slowly through self-assembly thermodynamically driven processes as proposed by the Bouligand theory of biological analogues of liquid crystals. Understanding the steps of collagen patterning in osteoid-maturation processes may shed new light on bone pathologies that emerge from collagen physico-chemical maturation imbalances.
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Affiliation(s)
- Marc Robin
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Chakib Djediat
- Muséum National d'Histoire NaturelleUMR CNRS 7245, Bâtiment 39, CP 39, 57 rue CuvierParis75231France
| | - Arnaud Bardouil
- Université de Rennes, CNRSInstitut de Physique de Rennes (IPR)RennesF‐35000France
| | - Niki Baccile
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Camille Chareyron
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Ivo Zizak
- Helmholtz‐Zentrum Berlin für Materialien und Energie – Speicherring BESSY IIAlbert‐Einstein Str. 15D‐12349BerlinGermany
| | - Peter Fratzl
- Department of BiomaterialsMax Planck Institute of Colloids and Interfacesam Mühlenberg 114476PotsdamGermany
| | - Mohamed Selmane
- Institut des Matériaux de Paris CentreSorbonne UniversitéParisF‐75005France
| | - Bernard Haye
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Isabelle Genois
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Jean‐Marc Krafft
- Sorbonne Université, CNRSLaboratoire Réactivité de Surface (LRS)ParisF‐75005France
| | - Guylène Costentin
- Sorbonne Université, CNRSLaboratoire Réactivité de Surface (LRS)ParisF‐75005France
| | - Thierry Azaïs
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Franck Artzner
- Université de Rennes, CNRSInstitut de Physique de Rennes (IPR)RennesF‐35000France
| | - Marie‐Madeleine Giraud‐Guille
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
| | - Paul Zaslansky
- Department for OperativePreventive and Pediatric DentistryCharité – Universitätsmedizin BerlinAßmannshauser Str. 4–614197BerlinGermany
| | - Nadine Nassif
- CNRS, Sorbonne Université, Collège de FranceLaboratoire Chimie de la Matière Condensée de Paris (LCMCP)ParisF‐75005France
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2
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Sasaki Y, Yoshikuni Y. Metabolic engineering for valorization of macroalgae biomass. Metab Eng 2022; 71:42-61. [PMID: 35077903 DOI: 10.1016/j.ymben.2022.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/18/2022]
Abstract
Marine macroalgae have huge potential as feedstocks for production of a wide spectrum of chemicals used in biofuels, biomaterials, and bioactive compounds. Harnessing macroalgae in these ways could promote wellbeing for people while mitigating climate change and environmental destruction linked to use of fossil fuels. Microorganisms play pivotal roles in converting macroalgae into valuable products, and metabolic engineering technologies have been developed to extend their native capabilities. This review showcases current achievements in engineering the metabolisms of various microbial chassis to convert red, green, and brown macroalgae into bioproducts. Unique features of macroalgae, such as seasonal variation in carbohydrate content and salinity, provide the next challenges to advancing macroalgae-based biorefineries. Three emerging engineering strategies are discussed here: (1) designing dynamic control of metabolic pathways, (2) engineering strains of halophilic (salt-tolerant) microbes, and (3) developing microbial consortia for conversion. This review illuminates opportunities for future research communities by elucidating current approaches to engineering microbes so they can become cell factories for the utilization of macroalgae feedstocks.
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Affiliation(s)
- Yusuke Sasaki
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Global Institution for Collaborative Research and Education, Hokkaido University, Hokkaido, 060-8589, Japan.
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3
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Middleton R, Moyroud E, Rudall PJ, Prychid CJ, Conejero M, Glover BJ, Vignolini S. Using structural colour to track length scale of cell-wall layers in developing Pollia japonica fruits. THE NEW PHYTOLOGIST 2021; 230:2327-2336. [PMID: 33720398 DOI: 10.1111/nph.17346] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
Helicoidally arranged layers of cellulose microfibrils in plant cell walls can produce strong and vivid coloration in a wide range of species. Despite its significance, the morphogenesis of cell walls, whether reflective or not, is not fully understood. Here we show that by optically monitoring the reflectance of Pollia japonica fruits during development we can directly map structural changes of the cell wall on a scale of tens of nanometres. Visible-light reflectance spectra from individual living cells were measured throughout the fruit maturation process and compared with numerical models. Our analysis reveals that periodic spacing of the helicoidal architecture remains unchanged throughout fruit development, suggesting that interactions in the cell-wall polysaccharides lead to a fixed twisting angle of cellulose helicoids in the cell wall. By contrast with conventional electron microscopy, which requires analysis of different fixed specimens at different stages of development, the noninvasive optical technique we present allowed us to directly monitor live structural changes in biological photonic systems as they develop. This method therefore is applicable to investigations of photonic tissues in other organisms.
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Affiliation(s)
- Rox Middleton
- Chemistry Department, University of Cambridge, Cambridge, CB2 1EW, UK
- Department of Life Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Edwige Moyroud
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | - Paula J Rudall
- Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3AB, UK
| | | | - Maria Conejero
- Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3AB, UK
| | - Beverley J Glover
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Silvia Vignolini
- Chemistry Department, University of Cambridge, Cambridge, CB2 1EW, UK
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4
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Williams GT, Kedge JL, Fossey JS. Molecular Boronic Acid-Based Saccharide Sensors. ACS Sens 2021; 6:1508-1528. [PMID: 33844515 PMCID: PMC8155662 DOI: 10.1021/acssensors.1c00462] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 03/30/2021] [Indexed: 12/13/2022]
Abstract
Boronic acids can reversibly bind diols, a molecular feature that is ubiquitous within saccharides, leading to their use in the design and implementation of sensors for numerous saccharide species. There is a growing understanding of the importance of saccharides in many biological processes and systems; while saccharide or carbohydrate sensing in medicine is most often associated with detection of glucose in diabetes patients, saccharides have proven to be relevant in a range of disease states. Herein the relevance of carbohydrate sensing for biomedical applications is explored, and this review seeks to outline how the complexity of saccharides presents a challenge for the development of selective sensors and describes efforts that have been made to understand the underpinning fluorescence and binding mechanisms of these systems, before outlining examples of how researchers have used this knowledge to develop ever more selective receptors.
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Affiliation(s)
- George T. Williams
- School of Chemistry, University
of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, United Kingdom
| | - Jonathan L. Kedge
- School of Chemistry, University
of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, United Kingdom
| | - John S. Fossey
- School of Chemistry, University
of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, United Kingdom
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5
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Abstract
The Embden–Meyerhof–Parnas (EMP) and Entner–Doudoroff (ED) pathways are considered the most abundant catabolic pathways found in microorganisms, and ED enzymes have been shown to also be widespread in cyanobacteria, algae and plants. In a large number of organisms, especially common strains used in molecular biology, these pathways account for the catabolism of glucose. The existence of pathways for other carbohydrates that are relevant to biomass utilization has been recognized as new strains have been characterized among thermophilic bacteria and Archaea that are able to transform simple polysaccharides from biomass to more complex and potentially valuable precursors for industrial microbiology. Many of the variants of the ED pathway have the key dehydratase enzyme involved in the oxidation of sugar derived from different families such as the enolase, IlvD/EDD and xylose-isomerase-like superfamilies. There are the variations in structure of proteins that have the same specificity and generally greater-than-expected substrate promiscuity. Typical biomass lignocellulose has an abundance of xylan, and four different pathways have been described, which include the Weimberg and Dahms pathways initially oxidizing xylose to xylono-gamma-lactone/xylonic acid, as well as the major xylose isomerase pathway. The recent realization that xylan constitutes a large proportion of biomass has generated interest in exploiting the compound for value-added precursors, but few chassis microorganisms can grow on xylose. Arabinose is part of lignocellulose biomass and can be metabolized with similar pathways to xylose, as well as an oxidative pathway. Like enzymes in many non-phosphorylative carbohydrate pathways, enzymes involved in L-arabinose pathways from bacteria and Archaea show metabolic and substrate promiscuity. A similar multiplicity of pathways was observed for other biomass-derived sugars such as L-rhamnose and L-fucose, but D-mannose appears to be distinct in that a non-phosphorylative version of the ED pathway has not been reported. Many bacteria and Archaea are able to grow on mannose but, as with other minor sugars, much of the information has been derived from whole cell studies with additional enzyme proteins being incorporated, and so far, only one synthetic pathway has been described. There appears to be a need for further discovery studies to clarify the general ability of many microorganisms to grow on the rarer sugars, as well as evaluation of the many gene copies displayed by marine bacteria.
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Gleuwitz FR, Sivasankarapillai G, Chen Y, Friedrich C, Laborie MPG. Lignin-Assisted Stabilization of an Oriented Liquid Crystalline Cellulosic Mesophase, Part B: Toward the Molecular Origin and Mechanism. Biomacromolecules 2020; 21:2276-2284. [DOI: 10.1021/acs.biomac.0c00220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- F. Robert Gleuwitz
- Institute of Earth and Environmental Science, Chair of Forest Biomaterials, University of Freiburg, Freiburg, Germany
- Freiburg Materials Research Centre (FMF), University of Freiburg, Freiburg, Germany
| | - Gopakumar Sivasankarapillai
- Institute of Earth and Environmental Science, Chair of Forest Biomaterials, University of Freiburg, Freiburg, Germany
- Freiburg Materials Research Centre (FMF), University of Freiburg, Freiburg, Germany
| | - Yian Chen
- Institute of Earth and Environmental Science, Chair of Forest Biomaterials, University of Freiburg, Freiburg, Germany
| | - Christian Friedrich
- Freiburg Materials Research Centre (FMF), University of Freiburg, Freiburg, Germany
- Institute for Macromolecular Chemistry, University of Freiburg, Freiburg, Germany
| | - Marie-Pierre G. Laborie
- Institute of Earth and Environmental Science, Chair of Forest Biomaterials, University of Freiburg, Freiburg, Germany
- Freiburg Materials Research Centre (FMF), University of Freiburg, Freiburg, Germany
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7
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Nikolić N, Squartini A, Concheri G, Stevanato P, Zanin G, Masin R. Weed Seed Decay in No-Till Field and Planted Riparian Buffer Zone. PLANTS 2020; 9:plants9030293. [PMID: 32121486 PMCID: PMC7154824 DOI: 10.3390/plants9030293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 11/16/2022]
Abstract
Field management practices can alter the physical and chemical properties of the soil, also causing changes to the seed bank. Alterations can also occur to the soil microbial community, which in turn can increase or diminish the process of weed seed decay. In this research, the issue of seed degradation was studied in an undisturbed and a no-till soil, trying not only to uncover where seeds are more degraded, but also to investigate the microbial activities that could be involved in this process. Six different weed species, commonly found in northern Italy, were used: Abutilon theopharsti, Alopecurus myosuroides, Amaranthus retroflexus, Digitaria sanguinalis, Portulaca oleracea and Sorghum halepense. Seed decay was tested in two different sites, a no-till field and the adjacent buffer zone. Soil microbial activity was also measured using the Fertimetro, an approach based on the degradation of cotton and silk threads buried in the soil for one week. Degradation of the buried seeds was higher in the no-till field soil than in the buffer strip for all the studied species as was the microbial cellulolytic activity. Even though the buffer strip soil is an undisturbed habitat and resulted as having higher organic matter, the no-till soil conditions appeared more unfavourable to seed viability. Our findings suggest that no-till management can improve weed seed suppression in the soil. Moreover, cellulolytic microorganisms play an important role in seedbank longevity, so cellulolytic activity surveys could be used as an early monitoring bioindicator for weed seed suppression in soil.
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8
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Gleuwitz FR, Friedrich C, Laborie MPG. Lignin-Assisted Stabilization of an Oriented Liquid Crystalline Cellulosic Mesophase, Part A: Observation of Microstructural and Mechanical Behavior. Biomacromolecules 2020; 21:1069-1077. [DOI: 10.1021/acs.biomac.9b01352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F. Robert Gleuwitz
- Institute of Earth and Environmental Science, Faculty of Environment and Natural Resources, Chair of Forest Biomaterials, University of Freiburg, 79085 Freiburg Germany
- Freiburg Materials Research Centre (FMF), University of Freiburg, 79104 Freiburg, Germany
| | - Christian Friedrich
- Freiburg Materials Research Centre (FMF), University of Freiburg, 79104 Freiburg, Germany
- Institute for Macromolecular Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Marie-Pierre G. Laborie
- Institute of Earth and Environmental Science, Faculty of Environment and Natural Resources, Chair of Forest Biomaterials, University of Freiburg, 79085 Freiburg Germany
- Freiburg Materials Research Centre (FMF), University of Freiburg, 79104 Freiburg, Germany
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9
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Characterisation of the First Archaeal Mannonate Dehydratase from Thermoplasma acidophilum and Its Potential Role in the Catabolism of D-Mannose. Catalysts 2019. [DOI: 10.3390/catal9030234] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mannonate dehydratases catalyse the dehydration reaction from mannonate to 2-keto-3-deoxygluconate as part of the hexuronic acid metabolism in bacteria. Bacterial mannonate dehydratases present in this gene cluster usually belong to the xylose isomerase-like superfamily, which have been the focus of structural, biochemical and physiological studies. Mannonate dehydratases from archaea have not been studied in detail. Here, we identified and characterised the first archaeal mannonate dehydratase (TaManD) from the thermoacidophilic archaeon Thermoplasma acidophilum. The recombinant TaManD enzyme was optimally active at 65 °C and showed high specificity towards D-mannonate and its lactone, D-mannono-1,4-lactone. The gene encoding for TaManD is located adjacent to a previously studied mannose-specific aldohexose dehydrogenase (AldT) in the genome of T. acidophilum. Using nuclear magnetic resonance (NMR) spectroscopy, we showed that the mannose-specific AldT produces the substrates for TaManD, demonstrating the possibility for an oxidative metabolism of mannose in T. acidophilum. Among previously studied mannonate dehydratases, TaManD showed closest homology to enzymes belonging to the xylose isomerase-like superfamily. Genetic analysis revealed that closely related mannonate dehydratases among archaea are not located in a hexuronate gene cluster like in bacteria, but next to putative aldohexose dehydrogenases, implying a different physiological role of mannonate dehydratases in those archaeal species.
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Sykes D, Hartwell R, Bradley RS, Burnett TL, Hornberger B, Garwood RJ, Withers PJ. Time-lapse three-dimensional imaging of crack propagation in beetle cuticle. Acta Biomater 2019; 86:109-116. [PMID: 30660007 DOI: 10.1016/j.actbio.2019.01.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/09/2019] [Accepted: 01/14/2019] [Indexed: 11/17/2022]
Abstract
Arthropod cuticle has extraordinary properties. It is very stiff and tough whilst being lightweight, yet it is made of rather ordinary constituents. This desirable combination of properties results from a hierarchical structure, but we currently have a poor understanding of how this impedes damage propagation. Here we use non-destructive, time-lapse in situ tensile testing within an X-ray nanotomography (nCT) system to visualise crack progression through dry beetle elytron (wing case) cuticle in 3D. We find that its hierarchical pseudo-orthogonal laminated microstructure exploits many extrinsic toughening mechanisms, including crack deflection, fibre and laminate pull-out and crack bridging. We highlight lessons to be learned in the design of engineering structures from the toughening methods employed. STATEMENT OF SIGNIFICANCE: We present the first comprehensive study of the damage and toughening mechanisms within arthropod cuticle in a 3D time-lapse manner, using X-ray nanotomography during crack growth. This technique allows lamina to be isolated despite being convex, which limits 2D analysis of microstructure. We report toughening mechanisms previously unobserved in unmineralised cuticle such as crack deflection, fibre and laminate pull-out and crack bridging; and provide insights into the effects of hierarchical microstructure on crack propagation. Ultimately the benefits of the hierarchical microstructure found here can not only be used to improve biomimetic design, but also helps us to understand the remarkable success of arthropods on Earth.
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Affiliation(s)
- Dan Sykes
- Henry Moseley X-ray Imaging Facility, The Royce Institute, School of Materials, The University of Manchester, Manchester M13 9PL, UK.
| | - Rebecca Hartwell
- Henry Moseley X-ray Imaging Facility, The Royce Institute, School of Materials, The University of Manchester, Manchester M13 9PL, UK
| | - Rob S Bradley
- Henry Moseley X-ray Imaging Facility, The Royce Institute, School of Materials, The University of Manchester, Manchester M13 9PL, UK
| | - Timothy L Burnett
- Henry Moseley X-ray Imaging Facility, The Royce Institute, School of Materials, The University of Manchester, Manchester M13 9PL, UK
| | | | - Russell J Garwood
- School of Earth and Environmental Science, The University of Manchester, Manchester M13 9PL, UK; Earth Sciences Department, Natural History Museum, London SW7 5BD, UK
| | - Philip J Withers
- Henry Moseley X-ray Imaging Facility, The Royce Institute, School of Materials, The University of Manchester, Manchester M13 9PL, UK
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11
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Kuivanen J, Biz A, Richard P. Microbial hexuronate catabolism in biotechnology. AMB Express 2019; 9:16. [PMID: 30701402 PMCID: PMC6353982 DOI: 10.1186/s13568-019-0737-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/23/2019] [Indexed: 01/11/2023] Open
Abstract
The most abundant hexuronate in plant biomass is D-galacturonate. D-Galacturonate is the main constituent of pectin. Pectin-rich biomass is abundantly available as sugar beet pulp or citrus processing waste and is currently mainly used as cattle feed. Other naturally occurring hexuronates are D-glucuronate, L-guluronate, D-mannuronate and L-iduronate. D-Glucuronate is a constituent of the plant cell wall polysaccharide glucuronoxylan and of the algal polysaccharide ulvan. Ulvan also contains L-iduronate. L-Guluronate and D-mannuronate are the monomers of alginate. These raw materials have the potential to be used as raw material in biotechnology-based production of fuels or chemicals. In this communication, we will review the microbial pathways related to these hexuronates and their potential use in biotechnology.
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12
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Kuivanen J, Richard P. NADPH-dependent 5-keto-D-gluconate reductase is a part of the fungal pathway for D-glucuronate catabolism. FEBS Lett 2017; 592:71-77. [PMID: 29265364 PMCID: PMC5814732 DOI: 10.1002/1873-3468.12946] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/28/2017] [Accepted: 12/09/2017] [Indexed: 11/18/2022]
Abstract
NADPH‐dependent 5‐keto‐D‐gluconate reductase was identified as a missing element in the pathway for D‐glucuronate catabolism in fungi. The disruption of the gene, gluF, by CRISPR/Cas9 in the filamentous fungus Aspergillus niger resulted in a strain unable to catabolise D‐glucuronate. The purified GluF protein was characterized and kcat and Km values of 23.7 ± 1.8 s−1 and 3.2 ± 0.1 mm for 5‐keto‐D‐gluconate, respectively, were determined. The enzyme is reversible and is active with NADP+ and D‐gluconate. We suggest a pathway for D‐glucuronate catabolism with the intermediates L‐gulonate, 2‐keto‐L‐gulonate, L‐idonate, 5‐keto‐D‐gluconate, D‐gluconate and D‐gluconate‐6‐phosphate which is a part of the pentose phosphate pathway. A fungal enzyme activity for the conversion of L‐gulonate to 2‐keto‐L‐gulonate remains to be identified.
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Affiliation(s)
- Joosu Kuivanen
- VTT Technical Research Centre of Finland Ltd, Espoo, Finland
| | - Peter Richard
- VTT Technical Research Centre of Finland Ltd, Espoo, Finland
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13
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Kuivanen J, Arvas M, Richard P. Clustered Genes Encoding 2-Keto-l-Gulonate Reductase and l-Idonate 5-Dehydrogenase in the Novel Fungal d-Glucuronic Acid Pathway. Front Microbiol 2017; 8:225. [PMID: 28261181 PMCID: PMC5306355 DOI: 10.3389/fmicb.2017.00225] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/31/2017] [Indexed: 12/03/2022] Open
Abstract
D-Glucuronic acid is a biomass component that occurs in plant cell wall polysaccharides and is catabolized by saprotrophic microorganisms including fungi. A pathway for D-glucuronic acid catabolism in fungal microorganisms is only partly known. In the filamentous fungus Aspergillus niger, the enzymes that are known to be part of the pathway are the NADPH requiring D-glucuronic acid reductase forming L-gulonate and the NADH requiring 2-keto-L-gulonate reductase that forms L-idonate. With the aid of RNA sequencing we identified two more enzymes of the pathway. The first is a NADPH requiring 2-keto-L-gulonate reductase that forms L-idonate, GluD. The second is a NAD+ requiring L-idonate 5-dehydrogenase forming 5-keto-gluconate, GluE. The genes coding for these two enzymes are clustered and share the same bidirectional promoter. The GluD is an enzyme with a strict requirement for NADP+/NADPH as cofactors. The kcat for 2-keto-L-gulonate and L-idonate is 21.4 and 1.1 s-1, and the Km 25.3 and 12.6 mM, respectively, when using the purified protein. In contrast, the GluE has a strict requirement for NAD+/NADH. The kcat for L-idonate and 5-keto-D-gluconate is 5.5 and 7.2 s-1, and the Km 30.9 and 8.4 mM, respectively. These values also refer to the purified protein. The gluD deletion resulted in accumulation of 2-keto-L-gulonate in the liquid cultivation while the gluE deletion resulted in reduced growth and cessation of the D-glucuronic acid catabolism.
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Affiliation(s)
- Joosu Kuivanen
- VTT Technical Research Centre of Finland Ltd Espoo, Finland
| | - Mikko Arvas
- VTT Technical Research Centre of Finland Ltd Espoo, Finland
| | - Peter Richard
- VTT Technical Research Centre of Finland Ltd Espoo, Finland
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14
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Kuivanen J, Sugai-Guérios MH, Arvas M, Richard P. A novel pathway for fungal D-glucuronate catabolism contains an L-idonate forming 2-keto-L-gulonate reductase. Sci Rep 2016; 6:26329. [PMID: 27189775 PMCID: PMC4870679 DOI: 10.1038/srep26329] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/29/2016] [Indexed: 11/09/2022] Open
Abstract
For the catabolism of D-glucuronate, different pathways are used by different life forms. The pathways in bacteria and animals are established, however, a fungal pathway has not been described. In this communication, we describe an enzyme that is essential for D-glucuronate catabolism in the filamentous fungus Aspergillus niger. The enzyme has an NADH dependent 2-keto-L-gulonate reductase activity forming L-idonate. The deletion of the corresponding gene, the gluC, results in a phenotype of no growth on D-glucuronate. The open reading frame of the A. niger 2-keto-L-gulonate reductase was expressed as an active protein in the yeast Saccharomyces cerevisiae. A histidine tagged protein was purified and it was demonstrated that the enzyme converts 2-keto-L-gulonate to L-idonate and, in the reverse direction, L-idonate to 2-keto-L-gulonate using the NAD(H) as cofactors. Such an L-idonate forming 2-keto-L-gulonate dehydrogenase has not been described previously. In addition, the finding indicates that the catabolic D-glucuronate pathway in A. niger differs fundamentally from the other known D-glucuronate pathways.
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Affiliation(s)
- Joosu Kuivanen
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Finland
| | - Maura H Sugai-Guérios
- Departamento de Engenharia Química e Engenharia de Alimentos, Universidade Federal de Santa Catarina, Cx.P. 476 Centro Tecnológico, Florianópolis 88040-900, Santa Catarina, Brazil
| | - Mikko Arvas
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Finland
| | - Peter Richard
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, 02044-VTT, Finland
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15
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Vinnitskiy DZ, Ustyuzhanina NE, Nifantiev NE. Natural bacterial and plant biomolecules bearing α-d-glucuronic acid residues. Russ Chem Bull 2016. [DOI: 10.1007/s11172-015-1010-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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16
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Li Z, Chen CH, Hegg EL, Hodge DB. Rapid and effective oxidative pretreatment of woody biomass at mild reaction conditions and low oxidant loadings. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:119. [PMID: 23971902 PMCID: PMC3765420 DOI: 10.1186/1754-6834-6-119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/20/2013] [Indexed: 05/09/2023]
Abstract
BACKGROUND One route for producing cellulosic biofuels is by the fermentation of lignocellulose-derived sugars generated from a pretreatment that can be effectively coupled with an enzymatic hydrolysis of the plant cell wall. While woody biomass exhibits a number of positive agronomic and logistical attributes, these feedstocks are significantly more recalcitrant to chemical pretreatments than herbaceous feedstocks, requiring higher chemical and energy inputs to achieve high sugar yields from enzymatic hydrolysis. We previously discovered that alkaline hydrogen peroxide (AHP) pretreatment catalyzed by copper(II) 2,2΄-bipyridine complexes significantly improves subsequent enzymatic glucose and xylose release from hybrid poplar heartwood and sapwood relative to uncatalyzed AHP pretreatment at modest reaction conditions (room temperature and atmospheric pressure). In the present work, the reaction conditions for this catalyzed AHP pretreatment were investigated in more detail with the aim of better characterizing the relationship between pretreatment conditions and subsequent enzymatic sugar release. RESULTS We found that for a wide range of pretreatment conditions, the catalyzed pretreatment resulted in significantly higher glucose and xylose enzymatic hydrolysis yields (as high as 80% for both glucose and xylose) relative to uncatalyzed pretreatment (up to 40% for glucose and 50% for xylose). We identified that the extent of improvement in glucan and xylan yield using this catalyzed pretreatment approach was a function of pretreatment conditions that included H2O2 loading on biomass, catalyst concentration, solids concentration, and pretreatment duration. Based on these results, several important improvements in pretreatment and hydrolysis conditions were identified that may have a positive economic impact for a process employing a catalyzed oxidative pretreatment. These improvements include identifying that: (1) substantially lower H2O2 loadings can be used that may result in up to a 50-65% decrease in H2O2 application (from 100 mg H2O2/g biomass to 35-50 mg/g) with only minor losses in glucose and xylose yield, (2) a 60% decrease in the catalyst concentration from 5.0 mM to 2.0 mM (corresponding to a catalyst loading of 25 μmol/g biomass to 10 μmol/g biomass) can be achieved without a subsequent loss in glucose yield, (3) an order of magnitude improvement in the time required for pretreatment (minutes versus hours or days) can be realized using the catalyzed pretreatment approach, and (4) enzyme dosage can be reduced to less than 30 mg protein/g glucan and potentially further with only minor losses in glucose and xylose yields. In addition, we established that the reaction rate is improved in both catalyzed and uncatalyzed AHP pretreatment by increased solids concentrations. CONCLUSIONS This work explored the relationship between reaction conditions impacting a catalyzed oxidative pretreatment of woody biomass and identified that significant decreases in the H2O2, catalyst, and enzyme loading on the biomass as well as decreases in the pretreatment time could be realized with only minor losses in the subsequent sugar released enzymatically. Together these changes would have positive implications for the economics of a process based on this pretreatment approach.
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Affiliation(s)
- Zhenglun Li
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
| | - Charles H Chen
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
| | - Eric L Hegg
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, USA
| | - David B Hodge
- Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- Department of Biosystems & Agricultural Engineering, Michigan State University, East Lansing, USA
- Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
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17
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Fernandes SN, Geng Y, Vignolini S, Glover BJ, Trindade AC, Canejo JP, Almeida PL, Brogueira P, Godinho MH. Structural Color and Iridescence in Transparent Sheared Cellulosic Films. MACROMOL CHEM PHYS 2012. [DOI: 10.1002/macp.201200351] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Kim JS, Awano T, Yoshinaga A, Takabe K. Immunolocalization and structural variations of xylan in differentiating earlywood tracheid cell walls of Cryptomeria japonica. PLANTA 2010; 232:817-824. [PMID: 20628757 DOI: 10.1007/s00425-010-1225-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 07/03/2010] [Indexed: 05/29/2023]
Abstract
We investigated the spatial and temporal distribution of xylans in the cell walls of differentiating earlywood tracheids of Cryptomeria japonica using two different types of monoclonal antibodies (LM10 and LM11) combined with immunomicroscopy. Xylans were first deposited in the corner of the S(1) layer in the early stages of S(1) formation in tracheids. Cell corner middle lamella also showed strong xylan labeling from the early stage of cell wall formation. During secondary cell wall formation, the innermost layer and the boundary between the S(1) and S(2) layers (S(1)/S(2) region) showed weaker labeling than other parts of the cell wall. However, mature tracheids had an almost uniform distribution of xylans throughout the entire cell wall. Xylan localization labeled with LM10 antibody was stronger in the outer S(2) layer than in the inner layer, whereas xylans labeled with LM11 antibody were almost uniformly distributed in the S(2) layer. In addition, the LM10 antibody showed almost no xylan labeling in the S(1)/S(2) region, whereas the LM11 antibody revealed strong xylan labeling in the S(1)/S(2) region. These findings suggest that structurally different types of xylans may be deposited in the tracheid cell wall depending on the developmental stage of, or location in, the cell wall. Our study also indicates that deposition of xylans in the early stages of tracheid cell wall formation may be spatially consistent with the early stage of lignin deposition in the tracheid cell wall.
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Affiliation(s)
- Jong Sik Kim
- Laboratory of Tree Cell Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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19
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Elbaum R, Gorb S, Fratzl P. Structures in the cell wall that enable hygroscopic movement of wheat awns. J Struct Biol 2008; 164:101-7. [PMID: 18625323 DOI: 10.1016/j.jsb.2008.06.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 06/17/2008] [Accepted: 06/18/2008] [Indexed: 11/28/2022]
Abstract
The dispersal unit of wild wheat bears two prominent filaments called awns. The awns bend as they dry and straighten in a damp environment. This hygroscopic movement is explained by the orientation of the cellulose fibrils that build the cell wall, as follows. The stiff fibrils are embedded in a soft hygroscopic matrix. When the cell wall dries, the matrix shrinks but the fibrils do not. Therefore, the cell wall contracts in a direction perpendicular to the fibril orientation. Using X-ray scattering we identified a region at the base of the awn that contains fibrils aligned in all directions. This is the active part, which contracts as it dries and pulls the awn to a bent position. Cryo-scanning electron microscopy revealed sequential laminas which are rotated to form a nano-scale plywood construction, implying planar local order within the global isotropy. Water molecules absorbed into the matrix probably cause large microscopic distortions by expanding neighboring layers in perpendicular directions. This is thought to cause opening of tiny gaps between fiber layers, to facilitate the exchange and the transport of water through the cell wall, and thereby to increase the sensitivity of the actuating unit to moderate changes in humidity.
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Affiliation(s)
- Rivka Elbaum
- Department of Plant Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel.
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20
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Mitov M, Dessaud N. Dépassement de la limite de réflexion de la lumière des cristaux liquides cholestériques: de Plusiotis resplendens aux gels à inversion d'hélicité. CR CHIM 2008. [DOI: 10.1016/j.crci.2007.03.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Mitov M, Dessaud N. Going beyond the reflectance limit of cholesteric liquid crystals. NATURE MATERIALS 2006; 5:361-4. [PMID: 16604079 DOI: 10.1038/nmat1619] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 02/22/2006] [Indexed: 05/08/2023]
Abstract
Cholesteric liquid-crystalline states of matter are abundant in nature: atherosclerosis, arthropod cuticles, condensed phases of DNA, plant cell walls, human compact bone osteon, and chiral biopolymers. The self-organized helical structure produces unique optical properties. Light is reflected when the wavelength matches the pitch (twice periodicity); cholesteric liquid crystals are not only coloured filters, but also reflectors and polarizers. But, in theory, the reflectance is limited to 50% of the ambient (unpolarized) light because circularly polarized light of the same handedness as the helix is reflected. Here we give details of a cholesteric medium for which the reflectance limit is exceeded. Photopolymerizable monomers are introduced into a cholesteric medium exhibiting a thermally induced helicity inversion, and the blend is then cured with ultraviolet light when the helix is right-handed. Because of memory effects attributable to the polymer network, the reflectance exceeds 50% when measured at the temperature assigned for a cholesteric helix with the same pitch but a left-handed sense before the reaction. As cholesteric materials are used as tunable bandpass filters, reflectors or polarizers and temperature or pressure sensors, novel opportunities to modulate the reflection over the whole light flux range, instead of only 50%, are offered.
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Affiliation(s)
- Michel Mitov
- Centre d'Elaboration de Matériaux et d'Etudes Structurales, CEMES, CNRS, BP 94347, 29 rue Jeanne-Marvig, F-31055 Toulouse cedex 4, France.
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22
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Beaugrand J, Paës G, Reis D, Takahashi M, Debeire P, O'donohue M, Chabbert B. Probing the cell wall heterogeneity of micro-dissected wheat caryopsis using both active and inactive forms of a GH11 xylanase. PLANTA 2005; 222:246-57. [PMID: 15965663 DOI: 10.1007/s00425-005-1538-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Accepted: 02/21/2005] [Indexed: 05/03/2023]
Abstract
The external envelope of wheat grain (Triticum aestivum L. cv. Isengrain) is a natural composite whose tissular and cellular heterogeneity constitute a significant barrier for enzymatic cell wall disassembly. To better understand the way in which the cell wall network and tissular organization hamper enzyme penetration, we have devised a strategy based on in situ visualization of an active and an inactive form of a xylanase in whole-wheat bran and in three micro-dissected layers (the outer bran, the inner bran and the aleurone layer). The main aims of this study were to (1) evaluate the role of cuticular layers as obstacles to enzyme diffusion, (2) assess the impact of the cell wall network on xylanase penetration, (3) highlight wall heterogeneity. To conduct this study, we created by in vitro mutagenesis a hydrolytically inactive xylanase that displayed full substrate binding ability, as demonstrated by the calculation of dissociation constants (K(d)) using fluorescence titration. To examine enzyme penetration and action, immunocytochemical localization of the xylanases and of feebly substituted arabinoxylans (AXs) was performed following incubation of the bran layers, or whole bran with active and inactive isoforms of the enzyme for different time periods. The data obtained showed that the micro-dissected layers provided an increased accessible surface for the xylanase and that the enzyme-targeted cell walls were penetrated more quickly than those in intact bran. Examination of immunolabelling of xylanase indicated that the cuticle layers constitute a barrier for enzyme penetration in bran. Moreover, our data indicated that the cell wall network by itself physically restricts enzyme penetration. Inactive xylanase penetration was much lower than that of the active form, whose penetration was facilitated by the concomitant depletion of AXs in enzyme-sensitive cell walls.
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Affiliation(s)
- Johnny Beaugrand
- Institut National de la Recherche Agronomique, UMR614 FARE, 2, esplanade Roland Garros, BP 224, 51686 Reims Cedex 02, France
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23
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Carafa A, Duckett JG, Knox JP, Ligrone R. Distribution of cell-wall xylans in bryophytes and tracheophytes: new insights into basal interrelationships of land plants. THE NEW PHYTOLOGIST 2005; 168:231-40. [PMID: 16159336 DOI: 10.1111/j.1469-8137.2005.01483.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Xylans are known to be major cellulose-linking polysaccharides in secondary cell walls in higher plants. We used two monoclonal antibodies (LM10 and LM11) for a comparative immunocytochemical analysis of tissue and cell distribution of xylans in a number of taxa representative of all major tracheophyte and bryophyte lineages. The results show that xylans containing the epitopes recognized by LM10 and LM11 are ubiquitous components of secondary cell walls in vascular and mechanical tissues in all present-living tracheophytes. In contrast, among the three bryophyte lineages, LM11 binding was detected in specific cell-wall layers in pseudoelaters and spores in the sporophyte of hornworts, while no binding was observed with either antibody in the gametophyte or sporophyte of liverworts and mosses. The ubiquitous occurrence of xylans containing LM10 and LM11 epitopes in tracheophytes suggests that the appearance of these polysaccharides has been a pivotal event for the evolution of highly efficient vascular and mechanical tissues. LM11 binding in the sporophyte of hornworts, indicating the presence of relatively highly substituted xylans (possibly arabinoxylans), separates these from the other bryophytes and is consistent with recent molecular data indicating a sister relationship of the hornworts with tracheophytes.
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Affiliation(s)
- Anna Carafa
- Dipartimento di Scienze ambientali, Seconda Università di Napoli, via A. Vivaldi 43, 81100 Caserta, Italy
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24
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Reis D, Vian B. Helicoidal pattern in secondary cell walls and possible role of xylans in their construction. C R Biol 2004; 327:785-90. [PMID: 15587069 DOI: 10.1016/j.crvi.2004.04.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The helicoidal organization of secondary cell walls is overviewed from several examples. Both the plywood texture and the occurrence of characteristic defects strongly suggest that the wall ordering is relevant of a cholesteric liquid-crystal assembly that is rapidly and strongly consolidated by lignification. A preferential localization of glucuronoxylans, major matrix components, and in vitro re-association experiments emphasize their preeminent role: (1) during the construction of the composite as directing the cellulose microfibrils in a helicoidal array; (2) during the lignification of the composite as a host structure for lignin precursors.
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Affiliation(s)
- Danièle Reis
- Laboratoire de pathologie végétale, UMR 217, INA P-G , 16, rue Claude-Bernard, 75231 Paris cedex 05, France.
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25
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Mellerowicz EJ, Baucher M, Sundberg B, Boerjan W. Unravelling cell wall formation in the woody dicot stem. PLANT MOLECULAR BIOLOGY 2001; 47:239-274. [PMID: 11554475 DOI: 10.1007/978-94-010-0668-2_15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Populus is presented as a model system for the study of wood formation (xylogenesis). The formation of wood (secondary xylem) is an ordered developmental process involving cell division, cell expansion, secondary wall deposition, lignification and programmed cell death. Because wood is formed in a variable environment and subject to developmental control, xylem cells are produced that differ in size, shape, cell wall structure, texture and composition. Hormones mediate some of the variability observed and control the process of xylogenesis. High-resolution analysis of auxin distribution across cambial region tissues, combined with the analysis of transgenic plants with modified auxin distribution, suggests that auxin provides positional information for the exit of cells from the meristem and probably also for the duration of cell expansion. Poplar sequencing projects have provided access to genes involved in cell wall formation. Genes involved in the biosynthesis of the carbohydrate skeleton of the cell wall are briefly reviewed. Most progress has been made in characterizing pectin methyl esterases that modify pectins in the cambial region. Specific expression patterns have also been found for expansins, xyloglucan endotransglycosylases and cellulose synthases, pointing to their role in wood cell wall formation and modification. Finally, by studying transgenic plants modified in various steps of the monolignol biosynthetic pathway and by localizing the expression of various enzymes, new insight into the lignin biosynthesis in planta has been gained.
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Affiliation(s)
- E J Mellerowicz
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå
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26
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Briggs CL, Ashford AE. Structure and composition of the thick wall in hair root epidermal cells of Woollsia pungens. THE NEW PHYTOLOGIST 2001; 149:219-232. [PMID: 33874622 DOI: 10.1046/j.1469-8137.2001.00031.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
• Hair roots of Woollsia pungens are shown to have thick-walled epidermal cells, a feature found in a small number of other species within the Epacridaceae. Hair roots otherwise had a structure typical of the Ericales. • Ultrastructural, immunocytochemical and histochemical techniques were used to investigate the structure and composition of these thick-walled epidermal cells. • The thick walls were multilamellate with a helicoidal arrangement of microfibrils typical of a secondary cellulosic wall. Staining techniques revealed a relatively high abundance of β-glucans; these were not β 1-3 linked and there was no detectable protein. Galactose side-chains were abundant but not mannose or glucose side-chains. The wall contained a pH-dependent net negative charge. Although apparently rich in COOH groups the thick wall did not react, or only minimally, with the monoclonal antibodies JIM5 and JIM7, testing for nonesterified and methyl-esterified pectins, respectively; this contrasted with the strong positive reaction in the cortical and stelar cells. In epidermal cells colonized by mycorrhizal fungi the thick wall had additional layers of spongy appearance with many interconnected, irregular patches containing dispersed material. Colonized cells retained their integrity longer than noncolonized cells. • The thick wall might be important in long-term survival of infected cells and the low levels of pectin might control mycorrhizal endophyte infection.
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Affiliation(s)
- C L Briggs
- present address: Faculty of Science and Technology, Science Precinct, UWS Hawkesbury, Locked Bag 1, Richmond NSW 2753, Australia
| | - A E Ashford
- School of Biological Science, Faculty of Life Science, UNSW, Sydney, Australia 2052
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27
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Whitney SE, Gothard MG, Mitchell JT, Gidley MJ. Roles of cellulose and xyloglucan in determining the mechanical properties of primary plant cell walls. PLANT PHYSIOLOGY 1999; 121:657-64. [PMID: 10517858 PMCID: PMC59429 DOI: 10.1104/pp.121.2.657] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/1999] [Accepted: 06/28/1999] [Indexed: 05/19/2023]
Abstract
The primary cell walls of growing and fleshy plant tissue mostly share a common set of molecular components, cellulose, xyloglucan (XyG), and pectin, that are required for both inherent strength and the ability to respond to cell expansion during growth. To probe molecular mechanisms underlying material properties, cell walls and analog composites from Acetobacter xylinus have been measured under small deformation and uniaxial extension conditions as a function of molecular composition. Small deformation oscillatory rheology shows a common frequency response for homogenized native cell walls, their sequential extraction residues, and bacterial cellulose alone. This behavior is characteristic of structuring via entanglement of cellulosic rods and is more important than cross-linking with XyG in determining shear moduli. Compared with cellulose alone, composites with XyG have lower stiffness and greater extensibility in uniaxial tension, despite being highly cross-linked at the molecular level. It is proposed that this is due to domains of cross-linked cellulose behaving as mechanical elements, whereas cellulose alone behaves as a mat of individual fibrils. The implication from this work is that XyG/cellulose networks provide a balance of extensibility and strength required by primary cell walls, which is not achievable with cellulose alone.
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Affiliation(s)
- SE Whitney
- Unilever Research Colworth, Colworth House, Sharnbrook, Bedford MK 44 1LQ, United Kingdom
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29
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Giraud-Guille MM. Twisted liquid crystalline supramolecular arrangements in morphogenesis. INTERNATIONAL REVIEW OF CYTOLOGY 1996; 166:59-101. [PMID: 8881773 DOI: 10.1016/s0074-7696(08)62506-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Supramolecular assemblies following liquid crystalline cholesteric geometries have been described in biological systems from optical properties observed in polarized-light microscopy and structural data obtained in electron microscopy. Major biological macromolecules are discussed, including structural polymers of the extracellular matrix, genetic material in nuclei and chromosomes, and proteins of the cytoplasm. The liquid crystalline assembly properties of biological polymers have been demonstrated by experiments in vitro with molecules at basic structural levels, such as molecular chains of cellulose and chitin, triple helices of collagen, and double helices of DNA, and also with entities at higher states of organization as they appear in cells and tissues, such as cellulose and chitin crystallites, and collagen fibrils. It appears that the building of cellular and extracellular edifices implies self-ordering processes of the liquid crystalline type and that the study of these mesomorphic states will help resolve basic questions about the structure and morphogenesis of densely packed biological structures.
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Affiliation(s)
- M M Giraud-Guille
- Histophysique et Cytophysique, Université P. et M. Curie and CNRS, Banyuls-sur-Mer, France
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