The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Lukas Schreiber - One of the best experts on this subject based on the ideXlab platform.
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root endodermal barrier system contributes to defence against plant parasitic cyst and root knot nematodes
Plant Journal, 2019Co-Authors: Julia Holbein, Rochus Franke, Lukas Schreiber, Peter Marhavý, Satoshi Fujita, M Gorecka, Miroslaw Sobczak, Niko Geldner, Florian M W Grundler, Shahid SiddiqueAbstract:Plant-parasitic nematodes (PPNs) cause tremendous yield losses worldwide in almost all economically important crops. The agriculturally most important PPNs belong to a small group of root-infecting sedentary endoparasites that includes cyst and root-knot nematodes. Both cyst and root-knot nematodes induce specialized long-term feeding structures in root vasculature from which they obtain their nutrients. A specialized cell layer in roots called the endodermis, which has cell walls reinforced with Suberin deposits and a lignin-based Casparian strip (CS), protects the vascular cylinder against abiotic and biotic threats. To date, the role of the endodermis, and especially of Suberin and the CS, during plant-nematode interactions was largely unknown. Here, we analyzed the role of Suberin and CS during interaction between Arabidopsis plants and two sedentary root-parasitic nematode species, the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. We found that nematode infection damages the endodermis leading to the activation of Suberin biosynthesis genes at nematode infection sites. Although feeding sites induced by both cyst and root-knot nematodes are surrounded by endodermis during early stages of infection, the endodermis is degraded during later stages of feeding site development, indicating periderm formation or ectopic suberization of adjacent tissue. Chemical Suberin analysis showed a characteristic Suberin composition resembling peridermal Suberin in nematode-infected tissue. Notably, infection assays using Arabidopsis lines with CS defects and impaired compensatory suberization, revealed that the CS and suberization impact nematode infectivity and feeding site size. Taken together, our work establishes the role of the endodermal barrier system in defence against a soil-borne pathogen.
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partial depolymerization of genetically modified potato tuber periderm reveals intermolecular linkages in Suberin polyester
Phytochemistry, 2015Co-Authors: José Graça, Lukas Schreiber, Vanessa Cabral, Sara Santos, Pedro Lamosa, Olga Serra, Marisa Molinas, Friedrich Kauder, Rochus FrankeAbstract:Suberin is a biopolyester found in specialized plant tissues, both internal and external, with key frontier physiological functions. The information gathered so far from its monomer and oligomer composition, and in situ studies made by solid state techniques, haven't solved the enigma of how the Suberin polyester is assembled as a macromolecule. To investigate how monomers are linked in Suberin, we analyzed oligomer fragments solubilized by the partial depolymerization of Suberin from potato (Solanum tuberosum) tuber periderms. The structure of the Suberin oligomers, namely which monomers they included, and the type and frequency of the inter-monomer ester linkages, was assessed by ESI-MS/MS and high resolution NMR analysis. The analyzed potato periderms included the one from wild type (cv. Desiree) and from plants where Suberin-biosynthesis genes were downregulated in chain elongation (StKCS6), ω-hydroxylation (CYP86A33) and feruloylation (FHT). Two building blocks were identified as possible key structures in the macromolecular development of the potato periderm Suberin: glycerol - α,ω-diacid - glycerol, as the core of a continuous Suberin aliphatic polyester; and glycerol - ω-hydroxyacid - ferulic acid, anchoring this polyaliphatic matrix at its periphery to the vicinal polyaromatics, through linking to ferulic acid. The silencing of the StKCS6 gene led to non-significant alterations in Suberin structure, showing the relatively minor role of the very-long chain (>C28) fatty acids in potato Suberin composition. The silencing of CYP86A33 gene impaired significantly Suberin production and disrupted the biosynthesis of acylglycerol structures, proving the relevance of the latter and thus of the glycerol - α,ω-diacid - glycerol unit for the typical Suberin lamellar organization. The silencing of the FHT gene led to a lower frequency of ferulate linkages in Suberin polyester but to more polyphenolic guaiacyl units as seen by FTIR analyses in the intact polymer.
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Suberin goes genomics use of a short living plant to investigate a long lasting polymer
Frontiers in Plant Science, 2012Co-Authors: Rochus Franke, Isabel Dombrink, Lukas SchreiberAbstract:Suberin is a highly persistent cell wall polymer, predominantly composed of long-chain hydroxylated fatty acids. Apoplastic Suberin depositions occur in internal and peripheral dermal tissues where they generate lipophilic barriers preventing uncontrolled flow of water, gases and ions. In addition, suberization provides resistance to environmental stress conditions. Despite this physiological importance the knowledge about Suberin formation has increased slowly for decades. Lately, the chemical characterization of Suberin in Arabidopsis enabled the proposal of genes required for Suberin biosynthesis such as β-ketoacyl-CoA synthases (KCS) for fatty acid elongation and cytochrome P450 oxygenases (CYP) for fatty acid hydroxylation. Advantaged by the Arabidopsis moleculargenetic resources the in silico expression pattern of candidate genes, concerted with the tissue-specific distribution of Suberin in Arabidopsis, led to the identification of Suberin involved genes including KCS2, CYP86A1 and CYP86B1. The isolation of mutants with a modified Suberin composition facilitated physiological studies revealing that the strong reduction in Suberin in cyp86a1 mutants results in increased root water and solute permeabilities. The enhanced Suberin 1 mutant, characterized by two-fold increased root Suberin content, has increased water-use efficiency and is affected in mineral ion uptake and transport. In this review the most recent findings on the biosynthesis and physiological importance of Suberin in Arabidopsis are summarized and discussed.
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endodermis and exodermis in roots
eLS, 2011Co-Authors: Lukas Schreiber, Rochus FrankeAbstract:Roots of terrestrial plants are designed to take up water and nutrients. At the same time, uptake of unwanted compounds, for example toxic, and infection by soil borne pathogens must be avoided. Specific unicellular tissues, the endodermis and the exodermis, allow roots to establish and maintain this selectivity. The endodermis represents an unicellular cell layer separating the central cylinder of the root from the cortex. The exodermis represents an unicellular cell layer located at the outer surface of the root directly below the root epidermis. Both tissues are characterised by specific cell wall modifications. In early developmental stages the anticlinal radial walls exhibit Casparian bands, composed of the polymers Suberin and lignin. In a subsequent developmental state a Suberin lamella is deposited on the inner surface of endo- and exodermal cell walls. These apoplastic barriers, mainly composed of Suberin, significantly affect radial uptake of water and dissolved nutrients and radial loss of oxygen. Key Concepts: Casparian bands, composed of lignin and Suberin, form characteristic cell wall modifications in radial walls of endodermal and exodermal cells. Suberin lamellae are deposited onto the inner surface of endodermal and exodermal cell walls. Apoplastic barriers in roots are established by the deposition of Suberin into and onto the cell wall. Suberised apoplastic barriers in roots help to establish root selectivity in nutrient uptake. The endodermis, forming an ‘inner’ apoplastic barrier in the root, is important in preventing nutrients actively concentrated in the xylem from passively diffusing back to the soil. The exodermis, forming an ‘outer’ apoplastic barrier at the root surface, mainly establishes the root/soil interface between the root and the soil environment surrounding the root. As an adaptation to various environmental stress factors (e.g. drought, salt, heavy metal stress, oxygen deficiency, etc.) suberisation of apoplastic barriers is significantly modified. Fatty acid elongases and cytochrome P450 hydroxylases represent important key enzymes in Suberin biosynthesis. Keywords: apoplastic barrier; Casparian band; endodermis; exodermis; hypodermis; nutrient uptake; plant root; Suberin; transport
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water and solute permeabilities of arabidopsis roots in relation to the amount and composition of aliphatic Suberin
Journal of Experimental Botany, 2011Co-Authors: Kosala Ranathunge, Lukas SchreiberAbstract:Although it is implied that suberized apoplastic barriers of roots negatively correlate with water and solute permeabilities, direct transport measurements across roots with altered amounts and compositions of aliphatic Suberin are scarce. In the present study, hydroponically grown Arabidopsis wild types (Col8 and Col0) and different Suberin mutants with altered amounts and/or compositions (horst, esb1-1, and esb1-2) were used to test this hypothesis. Detailed histochemical studies revealed late development of Casparian bands and Suberin lamellae in the horst mutant compared with wild types and esb mutants. Suberin analysis with gas chromatography and mass spectrometry (GC-MS) showed that the horst mutant had ;33% lower amounts of aliphatic monomers than Col8 and Col0. In contrast, enhanced Suberin mutants (esb1-1 and esb1-2) had twice the amount of Suberin as the wild types. Correlative permeability measurements, which were carried out for the first time with a root pressure probe for Arabidopsis, revealed that the hydraulic conductivity (Lpr) and NaCl permeability (Psr) of the whole root system of the horst mutant were markedly greater than in the respective wild types. This was reflected by the total amounts of aliphatic Suberin determined in the roots. However, increased levels of aliphatic Suberin in esb mutants failed to reduce either water or NaCl permeabilities below those of the wild types. It was concluded that the simple view and the conventional assumption that the amount of root Suberin negatively correlates with permeability may not always be true. The aliphatic monomer arrangement in the Suberin biopolymer and its microstructure also play a role in apoplastic barrier formation.
Rochus Franke - One of the best experts on this subject based on the ideXlab platform.
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root endodermal barrier system contributes to defence against plant parasitic cyst and root knot nematodes
Plant Journal, 2019Co-Authors: Julia Holbein, Rochus Franke, Lukas Schreiber, Peter Marhavý, Satoshi Fujita, M Gorecka, Miroslaw Sobczak, Niko Geldner, Florian M W Grundler, Shahid SiddiqueAbstract:Plant-parasitic nematodes (PPNs) cause tremendous yield losses worldwide in almost all economically important crops. The agriculturally most important PPNs belong to a small group of root-infecting sedentary endoparasites that includes cyst and root-knot nematodes. Both cyst and root-knot nematodes induce specialized long-term feeding structures in root vasculature from which they obtain their nutrients. A specialized cell layer in roots called the endodermis, which has cell walls reinforced with Suberin deposits and a lignin-based Casparian strip (CS), protects the vascular cylinder against abiotic and biotic threats. To date, the role of the endodermis, and especially of Suberin and the CS, during plant-nematode interactions was largely unknown. Here, we analyzed the role of Suberin and CS during interaction between Arabidopsis plants and two sedentary root-parasitic nematode species, the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. We found that nematode infection damages the endodermis leading to the activation of Suberin biosynthesis genes at nematode infection sites. Although feeding sites induced by both cyst and root-knot nematodes are surrounded by endodermis during early stages of infection, the endodermis is degraded during later stages of feeding site development, indicating periderm formation or ectopic suberization of adjacent tissue. Chemical Suberin analysis showed a characteristic Suberin composition resembling peridermal Suberin in nematode-infected tissue. Notably, infection assays using Arabidopsis lines with CS defects and impaired compensatory suberization, revealed that the CS and suberization impact nematode infectivity and feeding site size. Taken together, our work establishes the role of the endodermal barrier system in defence against a soil-borne pathogen.
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partial depolymerization of genetically modified potato tuber periderm reveals intermolecular linkages in Suberin polyester
Phytochemistry, 2015Co-Authors: José Graça, Lukas Schreiber, Vanessa Cabral, Sara Santos, Pedro Lamosa, Olga Serra, Marisa Molinas, Friedrich Kauder, Rochus FrankeAbstract:Suberin is a biopolyester found in specialized plant tissues, both internal and external, with key frontier physiological functions. The information gathered so far from its monomer and oligomer composition, and in situ studies made by solid state techniques, haven't solved the enigma of how the Suberin polyester is assembled as a macromolecule. To investigate how monomers are linked in Suberin, we analyzed oligomer fragments solubilized by the partial depolymerization of Suberin from potato (Solanum tuberosum) tuber periderms. The structure of the Suberin oligomers, namely which monomers they included, and the type and frequency of the inter-monomer ester linkages, was assessed by ESI-MS/MS and high resolution NMR analysis. The analyzed potato periderms included the one from wild type (cv. Desiree) and from plants where Suberin-biosynthesis genes were downregulated in chain elongation (StKCS6), ω-hydroxylation (CYP86A33) and feruloylation (FHT). Two building blocks were identified as possible key structures in the macromolecular development of the potato periderm Suberin: glycerol - α,ω-diacid - glycerol, as the core of a continuous Suberin aliphatic polyester; and glycerol - ω-hydroxyacid - ferulic acid, anchoring this polyaliphatic matrix at its periphery to the vicinal polyaromatics, through linking to ferulic acid. The silencing of the StKCS6 gene led to non-significant alterations in Suberin structure, showing the relatively minor role of the very-long chain (>C28) fatty acids in potato Suberin composition. The silencing of CYP86A33 gene impaired significantly Suberin production and disrupted the biosynthesis of acylglycerol structures, proving the relevance of the latter and thus of the glycerol - α,ω-diacid - glycerol unit for the typical Suberin lamellar organization. The silencing of the FHT gene led to a lower frequency of ferulate linkages in Suberin polyester but to more polyphenolic guaiacyl units as seen by FTIR analyses in the intact polymer.
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Suberin goes genomics use of a short living plant to investigate a long lasting polymer
Frontiers in Plant Science, 2012Co-Authors: Rochus Franke, Isabel Dombrink, Lukas SchreiberAbstract:Suberin is a highly persistent cell wall polymer, predominantly composed of long-chain hydroxylated fatty acids. Apoplastic Suberin depositions occur in internal and peripheral dermal tissues where they generate lipophilic barriers preventing uncontrolled flow of water, gases and ions. In addition, suberization provides resistance to environmental stress conditions. Despite this physiological importance the knowledge about Suberin formation has increased slowly for decades. Lately, the chemical characterization of Suberin in Arabidopsis enabled the proposal of genes required for Suberin biosynthesis such as β-ketoacyl-CoA synthases (KCS) for fatty acid elongation and cytochrome P450 oxygenases (CYP) for fatty acid hydroxylation. Advantaged by the Arabidopsis moleculargenetic resources the in silico expression pattern of candidate genes, concerted with the tissue-specific distribution of Suberin in Arabidopsis, led to the identification of Suberin involved genes including KCS2, CYP86A1 and CYP86B1. The isolation of mutants with a modified Suberin composition facilitated physiological studies revealing that the strong reduction in Suberin in cyp86a1 mutants results in increased root water and solute permeabilities. The enhanced Suberin 1 mutant, characterized by two-fold increased root Suberin content, has increased water-use efficiency and is affected in mineral ion uptake and transport. In this review the most recent findings on the biosynthesis and physiological importance of Suberin in Arabidopsis are summarized and discussed.
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endodermis and exodermis in roots
eLS, 2011Co-Authors: Lukas Schreiber, Rochus FrankeAbstract:Roots of terrestrial plants are designed to take up water and nutrients. At the same time, uptake of unwanted compounds, for example toxic, and infection by soil borne pathogens must be avoided. Specific unicellular tissues, the endodermis and the exodermis, allow roots to establish and maintain this selectivity. The endodermis represents an unicellular cell layer separating the central cylinder of the root from the cortex. The exodermis represents an unicellular cell layer located at the outer surface of the root directly below the root epidermis. Both tissues are characterised by specific cell wall modifications. In early developmental stages the anticlinal radial walls exhibit Casparian bands, composed of the polymers Suberin and lignin. In a subsequent developmental state a Suberin lamella is deposited on the inner surface of endo- and exodermal cell walls. These apoplastic barriers, mainly composed of Suberin, significantly affect radial uptake of water and dissolved nutrients and radial loss of oxygen. Key Concepts: Casparian bands, composed of lignin and Suberin, form characteristic cell wall modifications in radial walls of endodermal and exodermal cells. Suberin lamellae are deposited onto the inner surface of endodermal and exodermal cell walls. Apoplastic barriers in roots are established by the deposition of Suberin into and onto the cell wall. Suberised apoplastic barriers in roots help to establish root selectivity in nutrient uptake. The endodermis, forming an ‘inner’ apoplastic barrier in the root, is important in preventing nutrients actively concentrated in the xylem from passively diffusing back to the soil. The exodermis, forming an ‘outer’ apoplastic barrier at the root surface, mainly establishes the root/soil interface between the root and the soil environment surrounding the root. As an adaptation to various environmental stress factors (e.g. drought, salt, heavy metal stress, oxygen deficiency, etc.) suberisation of apoplastic barriers is significantly modified. Fatty acid elongases and cytochrome P450 hydroxylases represent important key enzymes in Suberin biosynthesis. Keywords: apoplastic barrier; Casparian band; endodermis; exodermis; hypodermis; nutrient uptake; plant root; Suberin; transport
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Suberin research in the genomics era new interest for an old polymer
Plant Science, 2011Co-Authors: Kosala Ranathunge, Lukas Schreiber, Rochus FrankeAbstract:Suberin is an apoplastic biopolymer with tissue-specific deposition in the cell walls of the endo- and exodermis of roots, of periderms including wound periderm and other border tissues. Suberised cell walls contain both polyaliphatic and polyaromatic domains which are supposedly cross-linked. The predominant aliphatic components are ω-hydroxyacids, α,ω-diacids, fatty acids and primary alcohols, whereas hydroxycinnamic acids, especially ferulic acid, are the main components of the polyaromatic domain. Although the monomeric composition of Suberin has been known for decades, its biosynthesis and deposition has mainly been a subject of speculation. Only recently, significant progress elucidating Suberin biosynthesis has been achieved using molecular genetic approaches, especially in the model species Arabidopsis. In parallel, the long-standing hypothesis that Suberin functions as an apoplastic barrier has been corroborated by sophisticated, quantitative physiological studies in the past decade. These studies demonstrated that suberised cell walls could act as barriers, minimising the movement of water and nutrients, restricting pathogen invasion and impeding toxic gas diffusion. In addition, suberised cell walls provide a barrier to radial oxygen loss from roots to the anaerobic root substrate in wetland plants. The recent onset of multidisciplinary approaches combining genetic, analytical and physiological studies has begun to deliver further insights into the physiological importance of Suberin depositions in plants.
Andreia F Sousa - One of the best experts on this subject based on the ideXlab platform.
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unravelling the distinct crystallinity and thermal properties of Suberin compounds from quercus suber and betula pendula outer barks
International Journal of Biological Macromolecules, 2016Co-Authors: Andreia F Sousa, Carlos Pascoal Neto, Alessandro Gandini, Carmen S R Freire, Ana P F Caetano, Teresa M R Maria, Armando J D SilvestreAbstract:Abstract The main purpose of this study was to investigate the potential of Suberin (a naturally occurring aromatic–aliphatic polyester ubiquitous to the vegetable realm) as a renewable source of chemicals and, in particular, to assess their physical properties. A comparison between cork and birch Suberin fragments obtained by conventional depolymerisation processes (hydrolysis or methanolysis) is provided, focusing essentially on their thermal and crystallinity properties. It was found that Suberin fragments obtained by the hydrolysis depolymerisation of birch had a high degree of crystallinity, as indicated by their thermal analysis and corroborated by the corresponding XRD diffractions, as opposed to hydrolysis-depolymerised cork Suberin counterparts, which were essentially amorphous.
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ex situ reconstitution of the plant biopolyester Suberin as a film
Biomacromolecules, 2014Co-Authors: Helga Garcia, Andreia F Sousa, Armando J D Silvestre, Celso Martins, Rui Cruz Ferreira, Carmen S R Freire, Luis Paulo N Rebelo, Werner Kunz, Cristina Silva PereiraAbstract:Biopolymers often have unique properties of considerable interest as a basis for new materials. It is however not evident how to extract them from plants without destroying their chemical skeleton and inherent properties. Here we report the ex situ reconstitution of the biopolyester Suberin as a new waterproof and antimicrobial material. In plant cell walls, Suberin, a cross-linked network of aromatic and aliphatic monomers, builds up a hydrophobic protective and antimicrobial barrier. Recently we succeeded in extracting Suberin from the plant cell wall using the ionic liquid cholinium hexanoate. During extraction the native three-dimensional structure of Suberin was partially preserved. In this study, we demonstrate that this preservation is the key for its ex situ reconstitution. Without any chemical additives or purification, the Suberin composing macromolecules undergo self-association on the casting surface forming a film. Suberin films obtained show barrier properties similar to those of the Suberin...
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isolation of Suberin from birch outer bark and cork using ionic liquids a new source of macromonomers
Industrial Crops and Products, 2013Co-Authors: Rui Cruz Ferreira, Andreia F Sousa, Armando J D Silvestre, Helga Garcia, Carmen S R Freire, Luis Paulo N Rebelo, Cristina Silva PereiraAbstract:Cholinium hexanoate, a biocompatible and biodegradable ionic liquid, was recently demonstrated to efficiently and selectively extract Suberin domains from cork, combining high extraction efficiency with isolation of a partial depolymerised material. In the present paper, we report a comparative study of the characterisation of Suberin extracted from birch outer bark and from cork using cholinium hexanoate. It became apparent that both extracted Suberin samples showed still a cross-linked nature, i.e. likely to be closely related to in situ Suberin. Suberin samples were mainly constituted by oligomeric or polymeric structures in turn essentially composed by long chain hydroxyacids monomers. Their high thermal stability together with the oligomeric/polymeric nature, open new perspectives for Suberin use as macromonomers in the development of bio-based polymeric materials. This also contributes for the valorisation of Suberin rich agro-forest residues.
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quercus suber and betula pendula outer barks as renewable sources of oleochemicals a comparative study
Industrial Crops and Products, 2009Co-Authors: Paula Pinto, Andreia F Sousa, Armando J D Silvestre, Carlos Pascoal Neto, Alessandro Gandini, Christer Eckerman, Bjarne HolmbomAbstract:Abstract A comparative study on the chemical composition of oak cork ( Quercus suber L.) and corresponding industrial residues and birch ( Betula pendula L.) outer bark is reported. Cork oak samples have lower extractives contents (6–9%) and higher contents of carbohydrates and lignin (23–27 and 33–38%, respectively) than those found for birch outer bark (40, 6 and 9%, respectively); Suberin contents accounted for around 30% of cork, 11% of industrial cork powder and 45% of birch outer bark. Analysis of the Suberin monomeric composition revealed that C18 and C22 ω-hydroxyfatty acids (including mid-chain epoxy- and dihydroxy-derivatives), followed by α,ω-dicarboxylic acids, are the main components in both Suberins, with 9,10-epoxy-18-hydroxyoctadecanoic, 18-hydroxyoctadec-9-enoic, 9,10,18-trihydroxyoctadecanoic and octadec-9-enoic acids as the major components. The differences in the relative amounts of these acids in the Suberin samples and the impact on the potential exploitation of the different industrial by-products are discussed.
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synthesis and characterization of novel biopolyesters from Suberin and model comonomers
Chemsuschem, 2008Co-Authors: Andreia F Sousa, Armando J D Silvestre, Alessandro Gandini, Carlos Pascoal NetoAbstract:The synthesis of novel polyesters from model long-chain aliphatic monomers and from Suberin reactive aliphatic fragments was conducted using mild polycondensation or polytransesterification conditions. The ensuing polyesters were characterized by means of various techniques. When mixtures of simple Suberin-like monomers were used, the ensuing polyesters had very regular structures, with melting temperatures around 80 degrees C and glass transitions below room temperature. This first systematic study of the exploitation of Suberin as a precursor to novel aliphatic polyesters confirmed the huge potential of using this abundant renewable resource to prepare macromolecular materials for promising applications.
Cristina Silva Pereira - One of the best experts on this subject based on the ideXlab platform.
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elucidating how the saprophytic fungus aspergillus nidulans uses the plant polyester Suberin as carbon source
BMC Genomics, 2014Co-Authors: Isabel Martins, Diego O Hartmann, Paula C Alves, Celso Martins, Helga Garcia, Celine C Leclercq, Rui Cruz Ferreira, Jenny Renaut, Jorg D Becker, Cristina Silva PereiraAbstract:Lipid polymers in plant cell walls, such as cutin and Suberin, build recalcitrant hydrophobic protective barriers. Their degradation is of foremost importance for both plant pathogenic and saprophytic fungi. Regardless of numerous reports on fungal degradation of emulsified fatty acids or cutin, and on fungi–plant interactions, the pathways involved in the degradation and utilisation of Suberin remain largely overlooked. As a structural component of the plant cell wall, Suberin isolation, in general, uses harsh depolymerisation methods that destroy its macromolecular structure. We recently overcame this limitation isolating Suberin macromolecules in a near-native state. Suberin macromolecules were used here to analyse the pathways involved in Suberin degradation and utilisation by Aspergillus nidulans. Whole-genome profiling data revealed the complex degrading enzymatic machinery used by this saprophytic fungus. Initial Suberin modification involved ester hydrolysis and ω-hydroxy fatty acid oxidation that released long chain fatty acids. These fatty acids were processed through peroxisomal β-oxidation, leading to up-regulation of genes encoding the major enzymes of these pathways (e.g. faaB and aoxA). The obtained transcriptome data was further complemented by secretome, microscopic and spectroscopic analyses. Data support that during fungal growth on Suberin, cutinase 1 and some lipases (e.g. AN8046) acted as the major Suberin degrading enzymes (regulated by FarA and possibly by some unknown regulatory elements). Suberin also induced the onset of sexual development and the boost of secondary metabolism.
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ex situ reconstitution of the plant biopolyester Suberin as a film
Biomacromolecules, 2014Co-Authors: Helga Garcia, Andreia F Sousa, Armando J D Silvestre, Celso Martins, Rui Cruz Ferreira, Carmen S R Freire, Luis Paulo N Rebelo, Werner Kunz, Cristina Silva PereiraAbstract:Biopolymers often have unique properties of considerable interest as a basis for new materials. It is however not evident how to extract them from plants without destroying their chemical skeleton and inherent properties. Here we report the ex situ reconstitution of the biopolyester Suberin as a new waterproof and antimicrobial material. In plant cell walls, Suberin, a cross-linked network of aromatic and aliphatic monomers, builds up a hydrophobic protective and antimicrobial barrier. Recently we succeeded in extracting Suberin from the plant cell wall using the ionic liquid cholinium hexanoate. During extraction the native three-dimensional structure of Suberin was partially preserved. In this study, we demonstrate that this preservation is the key for its ex situ reconstitution. Without any chemical additives or purification, the Suberin composing macromolecules undergo self-association on the casting surface forming a film. Suberin films obtained show barrier properties similar to those of the Suberin...
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isolation of Suberin from birch outer bark and cork using ionic liquids a new source of macromonomers
Industrial Crops and Products, 2013Co-Authors: Rui Cruz Ferreira, Andreia F Sousa, Armando J D Silvestre, Helga Garcia, Carmen S R Freire, Luis Paulo N Rebelo, Cristina Silva PereiraAbstract:Cholinium hexanoate, a biocompatible and biodegradable ionic liquid, was recently demonstrated to efficiently and selectively extract Suberin domains from cork, combining high extraction efficiency with isolation of a partial depolymerised material. In the present paper, we report a comparative study of the characterisation of Suberin extracted from birch outer bark and from cork using cholinium hexanoate. It became apparent that both extracted Suberin samples showed still a cross-linked nature, i.e. likely to be closely related to in situ Suberin. Suberin samples were mainly constituted by oligomeric or polymeric structures in turn essentially composed by long chain hydroxyacids monomers. Their high thermal stability together with the oligomeric/polymeric nature, open new perspectives for Suberin use as macromonomers in the development of bio-based polymeric materials. This also contributes for the valorisation of Suberin rich agro-forest residues.
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dissolution of cork biopolymers in biocompatible ionic liquids
Green Chemistry, 2010Co-Authors: Helga Garcia, Rui Cruz Ferreira, Luis Paulo N Rebelo, Marija Petkovic, Jamie L Ferguson, Maria C Leitao, H Nimal Q Gunaratne, Kenneth R Seddon, Cristina Silva PereiraAbstract:Classically, the best attempts to separate Suberin from cork biopolymers have resulted in low efficiency; here, we report a class of biocompatible and biodegradable cholinium-based ionic liquids, the cholinium alkanoates, which show a highly efficient and specific dissolution of the Suberin domains from cork biopolymers.
Armando J D Silvestre - One of the best experts on this subject based on the ideXlab platform.
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unravelling the distinct crystallinity and thermal properties of Suberin compounds from quercus suber and betula pendula outer barks
International Journal of Biological Macromolecules, 2016Co-Authors: Andreia F Sousa, Carlos Pascoal Neto, Alessandro Gandini, Carmen S R Freire, Ana P F Caetano, Teresa M R Maria, Armando J D SilvestreAbstract:Abstract The main purpose of this study was to investigate the potential of Suberin (a naturally occurring aromatic–aliphatic polyester ubiquitous to the vegetable realm) as a renewable source of chemicals and, in particular, to assess their physical properties. A comparison between cork and birch Suberin fragments obtained by conventional depolymerisation processes (hydrolysis or methanolysis) is provided, focusing essentially on their thermal and crystallinity properties. It was found that Suberin fragments obtained by the hydrolysis depolymerisation of birch had a high degree of crystallinity, as indicated by their thermal analysis and corroborated by the corresponding XRD diffractions, as opposed to hydrolysis-depolymerised cork Suberin counterparts, which were essentially amorphous.
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ex situ reconstitution of the plant biopolyester Suberin as a film
Biomacromolecules, 2014Co-Authors: Helga Garcia, Andreia F Sousa, Armando J D Silvestre, Celso Martins, Rui Cruz Ferreira, Carmen S R Freire, Luis Paulo N Rebelo, Werner Kunz, Cristina Silva PereiraAbstract:Biopolymers often have unique properties of considerable interest as a basis for new materials. It is however not evident how to extract them from plants without destroying their chemical skeleton and inherent properties. Here we report the ex situ reconstitution of the biopolyester Suberin as a new waterproof and antimicrobial material. In plant cell walls, Suberin, a cross-linked network of aromatic and aliphatic monomers, builds up a hydrophobic protective and antimicrobial barrier. Recently we succeeded in extracting Suberin from the plant cell wall using the ionic liquid cholinium hexanoate. During extraction the native three-dimensional structure of Suberin was partially preserved. In this study, we demonstrate that this preservation is the key for its ex situ reconstitution. Without any chemical additives or purification, the Suberin composing macromolecules undergo self-association on the casting surface forming a film. Suberin films obtained show barrier properties similar to those of the Suberin...
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isolation of Suberin from birch outer bark and cork using ionic liquids a new source of macromonomers
Industrial Crops and Products, 2013Co-Authors: Rui Cruz Ferreira, Andreia F Sousa, Armando J D Silvestre, Helga Garcia, Carmen S R Freire, Luis Paulo N Rebelo, Cristina Silva PereiraAbstract:Cholinium hexanoate, a biocompatible and biodegradable ionic liquid, was recently demonstrated to efficiently and selectively extract Suberin domains from cork, combining high extraction efficiency with isolation of a partial depolymerised material. In the present paper, we report a comparative study of the characterisation of Suberin extracted from birch outer bark and from cork using cholinium hexanoate. It became apparent that both extracted Suberin samples showed still a cross-linked nature, i.e. likely to be closely related to in situ Suberin. Suberin samples were mainly constituted by oligomeric or polymeric structures in turn essentially composed by long chain hydroxyacids monomers. Their high thermal stability together with the oligomeric/polymeric nature, open new perspectives for Suberin use as macromonomers in the development of bio-based polymeric materials. This also contributes for the valorisation of Suberin rich agro-forest residues.
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quercus suber and betula pendula outer barks as renewable sources of oleochemicals a comparative study
Industrial Crops and Products, 2009Co-Authors: Paula Pinto, Andreia F Sousa, Armando J D Silvestre, Carlos Pascoal Neto, Alessandro Gandini, Christer Eckerman, Bjarne HolmbomAbstract:Abstract A comparative study on the chemical composition of oak cork ( Quercus suber L.) and corresponding industrial residues and birch ( Betula pendula L.) outer bark is reported. Cork oak samples have lower extractives contents (6–9%) and higher contents of carbohydrates and lignin (23–27 and 33–38%, respectively) than those found for birch outer bark (40, 6 and 9%, respectively); Suberin contents accounted for around 30% of cork, 11% of industrial cork powder and 45% of birch outer bark. Analysis of the Suberin monomeric composition revealed that C18 and C22 ω-hydroxyfatty acids (including mid-chain epoxy- and dihydroxy-derivatives), followed by α,ω-dicarboxylic acids, are the main components in both Suberins, with 9,10-epoxy-18-hydroxyoctadecanoic, 18-hydroxyoctadec-9-enoic, 9,10,18-trihydroxyoctadecanoic and octadec-9-enoic acids as the major components. The differences in the relative amounts of these acids in the Suberin samples and the impact on the potential exploitation of the different industrial by-products are discussed.
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synthesis and characterization of novel biopolyesters from Suberin and model comonomers
Chemsuschem, 2008Co-Authors: Andreia F Sousa, Armando J D Silvestre, Alessandro Gandini, Carlos Pascoal NetoAbstract:The synthesis of novel polyesters from model long-chain aliphatic monomers and from Suberin reactive aliphatic fragments was conducted using mild polycondensation or polytransesterification conditions. The ensuing polyesters were characterized by means of various techniques. When mixtures of simple Suberin-like monomers were used, the ensuing polyesters had very regular structures, with melting temperatures around 80 degrees C and glass transitions below room temperature. This first systematic study of the exploitation of Suberin as a precursor to novel aliphatic polyesters confirmed the huge potential of using this abundant renewable resource to prepare macromolecular materials for promising applications.
