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Sample records for cell wall glycoside

  1. Glycoside Hydrolase MoGls2 Controls Asexual/Sexual Development, Cell Wall Integrity and Infectious Growth in the Rice Blast Fungus

    Science.gov (United States)

    Li, Mengying; Liu, Xinyu; Liu, Zhixi; Sun, Yi; Liu, Muxing; Wang, Xiaoli; Zhang, Haifeng; Zheng, Xiaobo; Zhang, Zhengguang

    2016-01-01

    N-linked glycosylation is a way of glycosylation for newly synthesized protein, which plays a key role in the maturation and transport of proteins. Glycoside hydrolases (GHs) are essential in this process, and are involved in processing of N-linked glycoproteins or degradation of carbohydrate structures. Here, we identified and characterized MoGls2 in Magnaporthe oryzae, which is a yeast glucosidase II homolog Gls2 and is required for trimming the final glucose in N-linked glycans and normal cell wall synthesis. Target deletion of MoGLS2 in M. oryzae resulted in a reduced mycelial growth, an increased conidial production, delayed conidial germination and loss the ability of sexual reproduction. Pathogenicity assays revealed that the ΔMogls2 mutant showed significantly decreased in virulence and infectious growth. Further studies showed that the mutant was less sensitive to salt and osmotic stress, and increased sensitivity to cell wall stresses. Additionally, the ΔMogls2 mutant showed a defect in cell wall integrity. Our results indicate that MoGls2 is a key protein for the growth and development of M. oryzae, involving in the regulation of asexual/sexual development, stress response, cell wall integrity and infectious growth. PMID:27607237

  2. Cell Wall Proteome

    OpenAIRE

    Boudart, Georges; Minic, Zoran; Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth; Pont-Lezica, Rafael F

    2007-01-01

    In this chapter, we will focus on the contribution of proteomics to the identification and determination of the structure and function of CWPs as well as discussing new perspectives in this area. The great variety of proteins found in the plant cell wall is described. Some families, such as glycoside hydrolases, proteases, lectins, and inhibitors of cell wall modifying enzymes, are discussed in detail. Examples of the use of proteomic techniques to elucidate the structure of various cell wall...

  3. Metabolism of [3-{sup 3}H]oleanolic acid in the isolated ``Calendula officinalis`` leaf cells and transport of the synthesized glycosides, to the cell wall and the extracellular space

    Energy Technology Data Exchange (ETDEWEB)

    Szakiel, A.; Wasiukiewicz, I.; Janiszowska, W. [Warsaw Univ. (Poland). Katedra Biochemii

    1995-12-31

    It has been shown for the first time that [3-{sup 3}H]oleanolic acid glycosides formed in the cytosol of ``C. officinalis`` leaf cells are transported to the extracellular space in the form of pentaglucoside VI (44%), whereas glucuronides derived from [3-{sup 3}H]oleanolic acid 3-O-monoglucuronide (29%) as well as a part of glucosides (24%) were transported into the cell walls. (author). 15 refs, 2 figs, 1 tab.

  4. Growth of Chitinophaga pinensis on Plant Cell Wall Glycans and Characterisation of a Glycoside Hydrolase Family 27 β-l-Arabinopyranosidase Implicated in Arabinogalactan Utilisation.

    Directory of Open Access Journals (Sweden)

    Lauren S McKee

    Full Text Available The genome of the soil bacterium Chitinophaga pinensis encodes a diverse array of carbohydrate active enzymes, including nearly 200 representatives from over 50 glycoside hydrolase (GH families, the enzymology of which is essentially unexplored. In light of this genetic potential, we reveal that C. pinensis has a broader saprophytic capacity to thrive on plant cell wall polysaccharides than previously reported, and specifically that secretion of β-l-arabinopyranosidase activity is induced during growth on arabinogalactan. We subsequently correlated this activity with the product of the Cpin_5740 gene, which encodes the sole member of glycoside hydrolase family 27 (GH27 in C. pinensis, CpArap27. Historically, GH27 is most commonly associated with α-d-galactopyranosidase and α-d-N-acetylgalactosaminidase activity. A new phylogenetic analysis of GH27 highlighted the likely importance of several conserved secondary structural features in determining substrate specificity and provides a predictive framework for identifying enzymes with the less common β-l-arabinopyranosidase activity.

  5. Identifying the ionically bound cell wall and intracellular glycoside hydrolases in late growth stage Arabidopsis stems: implications for the genetic engineering of bioenergy crops

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    Hui eWEI

    2015-05-01

    Full Text Available Identifying the cell wall-ionically bound glycoside hydrolases (GHs in Arabidopsis stems is important for understanding the regulation of cell wall integrity. For cell wall proteomics studies, the preparation of clean cell wall fractions is a challenge since cell walls constitute an open compartment, which is more likely to contain a mixture of intracellular and extracellular proteins due to cell leakage at the late growth stage. Here, we utilize a CaCl2-extraction procedure to isolate non-structural proteins from Arabidopsis whole stems, followed by the in-solution and in-gel digestion methods coupled with Nano-LC-MS/MS, bioinformatics and literature analyses. This has led to the identification of 75 proteins identified using the in-solution method and 236 proteins identified by the in-gel method, among which about 10% of proteins predicted to be secreted. Together, eight cell wall proteins, namely AT1G75040, AT5G26000, AT3G57260, AT4G21650, AT3G52960, AT3G49120, AT5G49360 and AT3G14067, were identified by the in-solution method; among them, three were the GHs (AT5G26000, myrosinase 1, GH1; AT3G57260, β-1,3-glucanase 2, GH17; AT5G49360, bifunctional XYL 1/α-L-arabinofuranosidase, GH3. Moreover, four more GHs: AT4G30270 (xyloglucan endotransferase, GH16, AT1G68560 (bifunctional α-l-arabinofuranosidase/XYL, GH31, AT1G12240 (invertase, GH32 and AT2G28470 (β-galactosidase 8, GH35, were identified by the in-gel solution method only. Notably, more than half of above identified GHs are xylan- or hemicellulose-modifying enzymes, and will likely have an impact on cellulose accessibility, which is a critical factor for downstream enzymatic hydrolysis of plant tissues for biofuels production. The implications of these cell wall proteins identified at the late growth stage for the genetic engineering of bioenergy crops are discussed.

  6. Identifying new lignin bioengineering targets: impact of epicatechin, quercetin glycoside, and gallate derivatives on the lignification and fermentation of maize cell walls

    Science.gov (United States)

    Apoplastic targeting of secondary metabolites compatible with monolignol polymerization may provide new avenues for designing lignins that are less inhibitory toward fiber fermentation. To identify suitable monolignol substitutes, we artificially lignified maize cell walls with normal monolignols pl...

  7. The Lamportian cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Keiliszewski, M.; Lamport, D. (Michigan State Univ. Plant Research Lab., East Lansing (United States))

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  8. Recent advances in plant cell wall proteomics.

    Science.gov (United States)

    Jamet, Elisabeth; Albenne, Cécile; Boudart, Georges; Irshad, Muhammad; Canut, Hervé; Pont-Lezica, Rafael

    2008-02-01

    The plant extracellular matrix contains typical polysaccharides such as cellulose, hemicelluloses, and pectins that interact to form dense interwoven networks. Plant cell walls play crucial roles during development and constitute the first barrier of defense against invading pathogens. Cell wall proteomics has greatly contributed to the description of the protein content of a compartment specific to plants. Around 400 cell wall proteins (CWPs) of Arabidopsis, representing about one fourth of its estimated cell wall proteome, have been described. The main points to note are that: (i) the diversity of enzymes acting on polysaccharides suggests a great plasticity of cell walls; (ii) CWPs such as proteases, polysaccharide hydrolytic enzymes, and lipases may contribute to the generation of signals; (iii) proteins of unknown functions were identified, suggesting new roles for cell walls. Recently, the characterization of PTMs such as N- and O-glycosylations improved our knowledge of CWP structure. The presence of many glycoside hydrolases and proteases suggests a complex regulation of CWPs involving various types of post-translational events. The first 3-D structures to be resolved gave clues about the interactions between CWPs, or between CWPs and polysaccharides. Future work should include: extracting and identifying CWPs still recalcitrant to proteomics, describing the cell wall interactome, improving quantification, and unraveling the roles of each of the CWPs.

  9. Steviol Glycosides Modulate Glucose Transport in Different Cell Types

    Science.gov (United States)

    Rizzo, Benedetta; Zambonin, Laura; Leoncini, Emanuela; Vieceli Dalla Sega, Francesco; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway. PMID:24327825

  10. Steviol Glycosides Modulate Glucose Transport in Different Cell Types

    Directory of Open Access Journals (Sweden)

    Benedetta Rizzo

    2013-01-01

    Full Text Available Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  11. Steviol glycosides modulate glucose transport in different cell types.

    Science.gov (United States)

    Rizzo, Benedetta; Zambonin, Laura; Angeloni, Cristina; Leoncini, Emanuela; Dalla Sega, Francesco Vieceli; Prata, Cecilia; Fiorentini, Diana; Hrelia, Silvana

    2013-01-01

    Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

  12. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox

    2011-01-01

    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  13. Cell wall degrading enzymes in Trichoderma asperellum grown on wheat bran

    DEFF Research Database (Denmark)

    Bech, Lasse; Busk, Peter Kamp; Lange, Lene

    2015-01-01

    Trichoderma asperellum is a filamentous fungus that is able to produce and secrete a wide range of extracellular hydrolytic enzymes used for plant cell wall degradation. The Trichoderma genus has attracted considerable attention from the biorefinery industry due to the production of cell wall...... degrading enzymes and strong secretion ability of this genus. Here we report extensive transcriptome analysis of plant cell wall degrading enzymes in T. asperellum. The production of cell wall degrading enzymes by T. asperellum was tested on a range of cellulosic materials under various conditions. When T...... the theory that the glycoside hydrolases have evolved from a common ancestor, followed by a specialization in which saprotrophic fungi such as T. reesei and T. longibrachiatum lost a significant number of genes including several glycoside hydrolases....

  14. Isolation of the Cell Wall.

    Science.gov (United States)

    Canut, Hervé; Albenne, Cécile; Jamet, Elisabeth

    2017-01-01

    This chapter describes a method allowing the purification of the cell wall for studying both polysaccharides and proteins. The plant primary cell wall is mainly composed of polysaccharides (90-95 % in mass) and of proteins (5-10 %). At the end of growth, specialized cells may synthesize a lignified secondary wall composed of polysaccharides (about 65 %) and lignin (about 35 %). Due to its composition, the cell wall is the cellular compartment having the highest density and this property is used for its purification. It plays critical roles during plant development and in response to environmental constraints. It is largely used in the food and textile industries as well as for the production of bioenergy. All these characteristics and uses explain why its study as a true cell compartment is of high interest. The proposed method of purification can be used for large amount of material but can also be downscaled to 500 mg of fresh material. Tools for checking the quality of the cell wall preparation, such as protein analysis and microscopy observation, are also provided.

  15. The Structure of Plant Cell Walls: II. The Hemicellulose of the Walls of Suspension-cultured Sycamore Cells.

    Science.gov (United States)

    Bauer, W D; Talmadge, K W; Keegstra, K; Albersheim, P

    1973-01-01

    The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus) cells are described. The sycamore wall xyloglucan is compared to the extracellular xyloglucan secreted by suspension-cultured sycamore cells into their culture medium and is also compared to the seed "amyloid" xyloglucans.Xyloglucan-or fragments of xyloglucan-and acidic fragments of the pectic polysaccharides are released from endopolygalacturonase-pretreated sycamore walls by treatment of these walls with 8 m urea, endoglucanase, or 0.5 n NaOH. Some of the xyloglucan thus released is found to cochromatograph with the acidic pectic fragments on diethylaminoethyl Sephadex. The chemical or enzymic treatments required for the release of xyloglucan from the walls and the cochromatography of xyloglucan with the acidic pectic fragments indicate that xyloglucan is covalently linked to the pectic polysaccharides and is noncovalently bound to the cellulose fibrils of the sycamore cell wall.The molecular structure of sycamore xyloglucan was characterized by methylation analysis of the oligosaccharides obtained by endoglucanase treatment of the polymer. The structure of the polymer is based on a repeating heptasaccharide unit which consists of 4 residues of beta-1-4-linked glucose and 3 residues of terminal xylose. A single xylose residue is glycosidically linked to carbon 6 of 3 of the glucosyl residues.

  16. Catalysts of plant cell wall loosening

    OpenAIRE

    Cosgrove, Daniel J.

    2016-01-01

    The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyl...

  17. New castanospermine glycoside analogues inhibit breast cancer cell proliferation and induce apoptosis without affecting normal cells.

    Directory of Open Access Journals (Sweden)

    Ghada Allan

    Full Text Available sp²-Iminosugar-type castanospermine analogues have been shown to exhibit anti-tumor activity. However, their effects on cell proliferation and apoptosis and the molecular mechanism at play are not fully understood. Here, we investigated the effect of two representatives, namely the pseudo-S- and C-octyl glycoside 2-oxa-3-oxocastanospermine derivatives SO-OCS and CO-OCS, on MCF-7 and MDA-MB-231 breast cancer and MCF-10A mammary normal cell lines. We found that SO-OCS and CO-OCS inhibited breast cancer cell viability in a concentration- and time-dependent manner. This effect is specific to breast cancer cells as both molecules had no impact on normal MCF-10A cell proliferation. Both drugs induced a cell cycle arrest. CO-OCS arrested cell cycle at G1 and G2/M in MCF-7 and MDA-MB-231 cells respectively. In MCF-7 cells, the G1 arrest is associated with a reduction of CDK4 (cyclin-dependent kinase 4, cyclin D1 and cyclin E expression, pRb phosphorylation, and an overexpression of p21(Waf1/Cip1. In MDA-MB-231 cells, CO-OCS reduced CDK1 but not cyclin B1 expression. SO-OCS accumulated cells in G2/M in both cell lines and this blockade was accompanied by a decrease of CDK1, but not cyclin B1 expression. Furthermore, both drugs induced apoptosis as demonstrated by the increased percentage of annexin V positive cells and Bax/Bcl-2 ratio. Interestingly, in normal MCF-10A cells the two drugs failed to modify cell proliferation, cell cycle progression, cyclins, or CDKs expression. These results demonstrate that the effect of CO-OCS and SO-OCS is triggered by both cell cycle arrest and apoptosis, suggesting that these castanospermine analogues may constitute potential anti-cancer agents against breast cancer.

  18. Induction of apoptosis in colon cancer cells treated with isorhamnetin glycosides from Opuntia ficus-indica pads.

    Science.gov (United States)

    Antunes-Ricardo, Marilena; Moreno-García, Beatriz E; Gutiérrez-Uribe, Janet A; Aráiz-Hernández, Diana; Alvarez, Mario M; Serna-Saldivar, Sergio O

    2014-12-01

    (OFI) contains health-promoting compounds like flavonoids, being the isorhamnetin glycosides the most abundant. We evaluated the effect of OFI extracts with different isorhamnetin glycosides against two different human colon cancer cells (HT-29 and Caco2). The extracts were obtained by alkaline hydrolysis with NaOH at 40 °C during 15, 30 or 60 min. Tri and diglycosides were the most abundant isorhamnetin glycosides, therefore these compounds were isolated to compare their cytotoxic effect with the obtained from the extracts. The OFI extracts and purified isorhamnetin glycosides were more cytotoxic against HT-29 cells than Caco2 cells. OFI-30 exhibited the lowest IC50 value against HT-29 (4.9 ± 0.5 μg/mL) and against Caco2 (8.2 ± 0.3 μg/mL). Isorhamnetin diglycosides IG5 and IG6 were more cytotoxic than pure isorhamnetin aglycone or triglycosides when they were tested in HT-29 cells. Bioluminescent analysis revealed increased activity of caspase 3/7 in OFI extracts-treated cells, particularly for the extract with the highest concentration of isorhamnetin triglycosides. Flow cytometry analysis confirmed that OFI extract and isorhamnetin glycosides induced a higher percentage of apoptosis in HT-29 than in Caco2, while isorhamnetin was more apoptotic in Caco2. This research demonstrated that glycosilation affected antiproliferative effect of pure isorhamnetin glycosides or when they are mixed with other phytochemicals in an extract obtained from OFI.

  19. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for

  20. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for 50

  1. Cardiac glycoside-induced cell death and Rho/Rho kinase pathway: Implication of different regulation in cancer cell lines.

    Science.gov (United States)

    Özdemir, Aysun; Şimay, Yaprak Dilber; İbişoğlu, Burçin; Yaren, Biljana; Bülbül, Döne; Ark, Mustafa

    2016-05-01

    Previously, we demonstrated that the Rho/ROCK pathway is involved in ouabain-induced apoptosis in HUVEC. In the current work, we investigated whether the Rho/ROCK pathway is functional during cardiac glycosides-induced cytotoxic effects in cancer cell lines, as well as in non-tumor cells. For that purpose, we evaluated the role of ROCK activation in bleb formation and cell migration over upstream and downstream effectors in addition to ROCK cleavage after cardiac glycosides treatment. All three cardiac glycosides (ouabain, digoxin and bufalin) induced cell death in HeLa and HepG2 cells and increased the formation of blebbing in HeLa cells. In contrast to our previous study, ROCK inhibitor Y27632 did not prevent bleb formation. Observation of ROCK II cleavage after ouabain, digoxin and oxaliplatin treatments in HeLa and/or HepG2 cells suggested that cleavage is independent of cell type and cell death induction. While inhibiting cleavage of ROCK II by the caspase inhibitors z-VAD-fmk, z-VDVAD-fmk and z-DEVD-fmk, evaluation of caspase 2 siRNA ineffectiveness on this truncation indicated that caspase-dependent ROCK II cleavage is differentially regulated in cancer cell lines. In HeLa cells, ouabain induced the activation of ROCK, although it did not induce phosphorylation of ERM, an upstream effector. While Y27632 inhibited the migration of HeLa cells, 10nM ouabain had no effect on cell migration. In conclusion, these findings indicate that the Rho/ROCK pathway is regulated differently in cancer cell lines compared to normal cells during cardiac glycosides-induced cell death.

  2. Cytotoxic activity of kaempferol glycosides against human leukaemic cell lines in vitro.

    Science.gov (United States)

    Dimas, K; Demetzos, C; Mitaku, S; Marselos, M; Tzavaras, T; Kokkinopoulos, D

    2000-01-01

    Two kaempferol coumaroyl glycosides (i.e. platanoside and tiliroside) isolated from the methanolic extract of Platanus orientalis L. buds, were examined for their in vitro cytotoxic activity against a panel of human leukaemic cell lines. Platanoside (1) exhibited cytotoxic activity against most of the cell lines tested, while tiliroside (2) was active against two of the nine tested cell lines. Compound 1, was examined for its effect on the uptake of [(3)H]thymidine as a marker of DNA synthesis. Kaempferol was used as a control.

  3. Shape dynamics of growing cell walls

    CERN Document Server

    Banerjee, Shiladitya; Dinner, Aaron R

    2015-01-01

    We introduce a general theoretical framework to study the shape dynamics of actively growing and remodeling surfaces. Using this framework we develop a physical model for growing bacterial cell walls and study the interplay of cell shape with the dynamics of growth and constriction. The model allows us to derive constraints on cell wall mechanical energy based on the observed dynamics of cell shape. We predict that exponential growth in cell size requires a constant amount of cell wall energy to be dissipated per unit volume. We use the model to understand and contrast growth in bacteria with different shapes such as spherical, ellipsoidal, cylindrical and toroidal morphologies. Coupling growth to cell wall constriction, we predict a discontinuous shape transformation, from partial constriction to cell division, as a function of the chemical potential driving cell-wall synthesis. Our model for cell wall energy and shape dynamics relates growth kinetics with cell geometry, and provides a unified framework to d...

  4. Microanalysis of Plant Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Nicolai Obel; Veronika Erben; Tatjana Schwarz; Stefan Kühne; Andrea Fodor; Markus Pauly

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first iso-lating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apo-plastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.

  5. [The cell wall of Coelastrum (Chlorophycees)].

    Science.gov (United States)

    Reymond, O

    1975-01-01

    The cell wall of Coelastrum is usually composed of three layers. The outermost layer was studied most extensively. It consists of erect tubules which often bear long bristles whose function may be to stabilize the algae in its enviroment. The cell wall can modify its morphology according to the enviroment.

  6. A Cell Wall-degrading Endopolygalacturonase Secreted by Colletotrichum lindemuthianum.

    Science.gov (United States)

    English, P D; Maglothin, A; Keegstra, K; Albersheim, P

    1972-03-01

    Cultures of Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner have been induced to secrete an endopolygalacturonase (polygalacturonide glycanohydrolase EC3.2. 1.15). This enzyme has been brought to a high state of purity by ion exchange, gel filtration, and agarose affinity chromatography. The enzyme has optimal activity at pH 5, has an apparent molecular weight as determined by gel filtration of about 70,000, and prefers polygalacturonic acid to pectin as its substrate. The enzyme, while hydrolyzing only 1% of the glycosidic bonds, reduces the viscosity of a polygalacturonic solution by 50%. Nevertheless, the initial as well as the final products of polygalacturonic acid hydrolysis are predominantly tri- and digalacturonic acid and, to a lesser extent, monogalacturonic acid. The purified enzyme catalyzes the removal of about 80% of the galacturonic acid residues of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus) as well as from the walls isolated from 8-day-old Red Kidney bean (Phaseolus vulgaris) hypocotyls.

  7. Isolation of plant cell wall proteins

    OpenAIRE

    Jamet, Elisabeth; Boudart, Georges; Borderies, Gisèle; Charmont, Stéphane; Lafitte, Claude; Rossignol, Michel; Canut, Hervé; Pont-Lezica, Rafael F

    2007-01-01

    The quality of a proteomic analysis of a cell compartment strongly depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific drawbacks: (i) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure; (ii) polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins; (iii) the presence of proteins ...

  8. Isolation of plant cell wall proteins.

    Science.gov (United States)

    Jamet, Elisabeth; Boudart, Georges; Borderies, Giséle; Charmont, Stephane; Lafitte, Claude; Rossignol, Michel; Canut, Herve; Pont-Lezica, Rafael

    2008-01-01

    The quality of a proteomic analysis of a cell compartment strongly depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific drawbacks: (1) the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP) during the isolation procedure; (2) polysaccharide networks of cellulose, hemicelluloses, and pectins form potential traps for contaminants such as intracellular proteins; (3) the presence of proteins interacting in many different ways with the polysaccharide matrix require different procedures to elute them from the cell wall. Three categories of CWP are distinguished: labile proteins that have little or no interactions with cell wall components, weakly bound proteins extractable with salts, and strongly bound proteins. Two alternative protocols are decribed for cell wall proteomics: (1) nondestructive techniques allowing the extraction of labile or weakly bound CWP without damaging the plasma membrane; (2) destructive techniques to isolate cell walls from which weakly or strongly bound CWP can be extracted. These protocols give very low levels of contamination by intracellular proteins. Their application should lead to a realistic view of the cell wall proteome at least for labile and weakly bound CWP extractable by salts.

  9. Cardiac glycosides stimulate Ca2+ increases and apoptosis in androgen-independent, metastatic human prostate adenocarcinoma cells.

    Science.gov (United States)

    McConkey, D J; Lin, Y; Nutt, L K; Ozel, H Z; Newman, R A

    2000-07-15

    Cardiac glycosides are used clinically to increase contractile force in patients with cardiac disorders. Their mechanism of action is well established and involves inhibition of the plasma membrane Na+/K+-ATPase, leading to alterations in intracellular K+ and Ca(2+) levels. Here, we report that the cardiac glycosides oleandrin, ouabain, and digoxin induce apoptosis in androgen-independent human prostate cancer cell lines in vitro. Cell death was associated with early release of cytochrome c from mitochondria, followed by proteolytic processing of caspases 8 and 3. Oleandrin also promoted caspase activation, detected by cleavage poly(ADP-ribose) polymerase and hydrolysis of a peptide substrate (DEVD-pNA). Comparison of the rates of apoptosis in poorly metastatic PC3 M-Pro4 and highly metastatic PC3 M-LN4 subclones demonstrated that cell death was delayed in the latter because of a delay in mitochondrial cytochrome c release. Single-cell imaging of intracellular Ca(2+) fluxes demonstrated that the proapoptotic effects of the cardiac glycosides were linked to their abilities to induce sustained Ca(2+) increases in the cells. Our results define a novel activity for cardiac glycosides that could prove relevant to the treatment of metastatic prostate cancer.

  10. Cell Wall Assembly in Fucus Zygotes

    Science.gov (United States)

    Quatrano, Ralph S.; Stevens, Patricia T.

    1976-01-01

    Fertilization triggers the assembly of a cell wall around the egg cell of three brown algae, Fucus vesiculosus, F. distichus, and F. inflatus. New polysaccharide polymers are continually being added to the cell wall during the first 24 hours of synchronous embryo development. This wall assembly involves the extracellular deposition of fibrillar material by cytoplasmic vesicles fusing with the plasma membrane. One hour after fertilization a fragmented wall can be isolated free of cytoplasm and contains equal amounts of cellulose and alginic acid with no fucose-containing polymers (fucans) present. Birefringence of the wall caused by oriented cellulose microfibrils is not detected in all zygotes until 4 hours, at which time intact cell walls can be isolated that retain the shape of the zygote. These walls have a relatively low ratio of fucose to xylose and little sulfate when compared to walls from older embryos. When extracts of walls from 4-hour zygotes are subjected to cellulose acetate electrophoresis at pH 7, a single fucan (F1) can be detected. By 12 hours, purified cell walls are composed of fucans containing a relatively high ratio of fucose to xylose and high levels of sulfate, and contain a second fucan (F2) which is electrophoretically distinct from F1. F2 appears to be deposited in only a localized region of the wall, that which elongates to form the rhizoid cell. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic (M) to guluronic (G) acid ratio (0.33-0.55) or its block distribution (MG, 54%; GG, 30%; MM, 16%). From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. Alginic acid is the major polymer and comprises about 60% of the total wall, while cellulose and the fucans each make-up about 20% of the remainder. During the extracellular assembly of this wall, the intracellular levels of the storage glucan laminaran

  11. Accelerating forward genetics for cell wall deconstruction

    Directory of Open Access Journals (Sweden)

    Danielle eVidaurre

    2012-06-01

    Full Text Available One of the biggest challenges of cell wall biology is the elucidation of the genes involved the cell wall and their function due to the recalcitrance of the cell wall. Through traditional genetic approaches, many simple yet elegant screens have been able to identify components of the cell wall and their networks. Despite progress in the identification of several genes of the cell wall, there remain many unknown players whose function has yet to be determined. Exhausting the genetic toolbox by performing secondary screens on a genetically mutated background, chemical genetics using small molecules and improved cell wall imaging hold promise for new gene discovery and function. With the recent introduction of next-generation sequencing technologies, it is now possible to quickly and efficiently map and clone genes of interest in Arabidopsis and any model organism with a completed genome sequence. The combination of a classical genetics approach and cutting edge technology will propel cell wall biology of Arabidopsis and other useful crops forward into the future.

  12. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  13. 2003 Plant Cell Walls Gordon Conference

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Cosgrove

    2004-09-21

    This conference will address recent progress in many aspects of cell wall biology. Molecular, genetic, and genomic approaches are yielding major advances in our understanding of the composition, synthesis, and architecture of plant cell walls and their dynamics during growth, and are identifying the genes that encode the machinery needed to make their biogenesis possible. This meeting will bring together international scientists from academia, industry and government labs to share the latest breakthroughs and perspectives on polysaccharide biosynthesis, wood formation, wall modification, expansion and interaction with other organisms, and genomic & evolutionary analyses of wall-related genes, as well as to discuss recent ''nanotechnological'' advances that take wall analysis to the level of a single cell.

  14. Isolation from Gluconacetobacter diazotrophicus cell walls of specific receptors for sugarcane glycoproteins, which act as recognition factors.

    Science.gov (United States)

    Blanco, Y; Arroyo, M; Legaz, M E; Vicente, C

    2005-11-04

    Glycoproteins from sugarcane stalks have been isolated from plants field-grown by size-exclusion chromatography. Some of these glycoproteins, previously labelled with fluorescein isothiocyanate, are able to bind to the cell wall of the sugarcane endophyte, N2-fixing Gluconacetobacter diazotrophicus, and largely removed after washing the bacterial cells with sucrose. This implies that sugarcane glycoproteins use beta-(1-->2)-fructofuranosyl fructose domains in their glycosidic moiety to bind to specific receptors in the bacterial cell walls. These receptors have been isolated by affinity chromatography on a sugarcane glycoprotein-agarose matrix, desorbed with sucrose and characterized by sodium dodecyl sulfate polyacrylamide gel electrophresisand capillary electrophoresis (CE).

  15. The cardiac glycoside oleandrin induces apoptosis in human colon cancer cells via the mitochondrial pathway.

    Science.gov (United States)

    Pan, Li; Zhang, Yuming; Zhao, Wanlu; Zhou, Xia; Wang, Chunxia; Deng, Fan

    2017-07-01

    Evidence indicates that the cardiac glycoside oleandrin exhibits cytotoxic activity against several different types of cancer. However, the specific mechanisms underlying oleandrin-induced anti-tumor effects remain largely unknown. The present study examined the anti-cancer effect and underlying mechanism of oleandrin on human colon cancer cells. The cytotoxicity and IC50 of five small molecule compounds (oleandrin, neriifolin, strophanthidin, gitoxigenin, and convallatoxin) in human colon cancer cell line SW480 cells and normal human colon cell line NCM460 cells were determined by cell counting and MTT assays, respectively. Apoptosis was determined by staining cells with annexin V-FITC and propidium iodide, followed by flow cytometry. Intracellular Ca(2+) was determined using Fluo-3 AM,glutathione (GSH) levels were measured using a GSH detection kit,and the activity of caspase-3, -9 was measured using a peptide substrate. BAX, pro-caspase-3, -9, cytochrome C and BCL-2 expression were determined by Western blotting. Oleandrin significantly decreased cell viabilities in SW480, HCT116 and RKO cells. The IC50 for SW480 cells was 0.02 µM, whereas for NCM460 cells 0.56 µM. More interestingly, the results of flow cytometry showed that oleandrin potently induced apoptosis in SW480 and RKO cells. Oleandrin downregulated protein expression of pro-caspase-3, -9, but enhanced caspase-3, -9 activities. These effects were accompanied by upregulation of protein expression of cytochrome C and BAX, and downregulation of BCL-2 protein expression in a concentration-dependent manner. Furthermore, oleandrin increased intracellular Ca(2+) concentration, but decreased GSH concentration in the cells. The present results suggest that oleandrin induces apoptosis in human colorectal cancer cells via the mitochondrial pathway. Our findings provide new insight into the mechanism of anti-cancer property of oleandrin.

  16. Immersion Refractometry of Isolated Bacterial Cell Walls

    Science.gov (United States)

    Marquis, Robert E.

    1973-01-01

    Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

  17. Function of laccases in cell wall biosynthesis

    DEFF Research Database (Denmark)

    Larsen, Anders; Holm, Preben Bach; Andersen, Jeppe Reitan

    2011-01-01

    substrate specificities and expression patterns. As part of the strategic research centre Bio4Bio, the present project deals with laccase functions in relation to cell wall formation in grasses based on a study of the model species Brachypodium distachyon. Thirty-one isozymes have been retrieved from......Laccases are multicopper oxidases capable of polymerizing monolignols. Histochemical assays have shown temporal and spatial correlation with secondary cell wall formation in both herbs and woody perennials. However, in plants laccases constitutes a relatively large group of isoenzymes with unique...... hybridization. Specific isozymes that show high correlation with the process of secondary cell wall formation will be further studied in a reverse genetic study in which candidates will be knocked out using RNA interference. Phenotypes of knock-out mutants are to be described in relation to cell wall...

  18. Annotation and comparative analysis of the glycoside hydrolase genes in Brachypodium distachyon

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Ludmila [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Bragg, Jennifer [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Wu, Jiajie [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany; Yang, Xiaohan [ORNL; Tuskan, Gerald A [ORNL; Vogel, John [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Albany

    2010-01-01

    Background Glycoside hydrolases cleave the bond between a carbohydrate and another carbohydrate, a protein, lipid or other moiety. Genes encoding glycoside hydrolases are found in a wide range of organisms, from archea to animals, and are relatively abundant in plant genomes. In plants, these enzymes are involved in diverse processes, including starch metabolism, defense, and cell-wall remodeling. Glycoside hydrolase genes have been previously cataloged for Oryza sativa (rice), the model dicotyledonous plant Arabidopsis thaliana, and the fast-growing tree Populus trichocarpa (poplar). To improve our understanding of glycoside hydrolases in plants generally and in grasses specifically, we annotated the glycoside hydrolase genes in the grasses Brachypodium distachyon (an emerging monocotyledonous model) and Sorghum bicolor (sorghum). We then compared the glycoside hydrolases across species, both at the whole-genome level and at the level of individual glycoside hydrolase families. Results We identified 356 glycoside hydrolase genes in Brachypodium and 404 in sorghum. The corresponding proteins fell into the same 34 families that are represented in rice, Arabidopsis, and poplar, helping to define a glycoside hydrolase family profile which may be common to flowering plants. Examination of individual glycoside hydrolase familes (GH5, GH13, GH18, GH19, GH28, and GH51) revealed both similarities and distinctions between monocots and dicots, as well as between species. Shared evolutionary histories appear to be modified by lineage-specific expansions or deletions. Within families, the Brachypodium and sorghum proteins generally cluster with those from other monocots. Conclusions This work provides the foundation for further comparative and functional analyses of plant glycoside hydrolases. Defining the Brachypodium glycoside hydrolases sets the stage for Brachypodium to be a monocot model for investigations of these enzymes and their diverse roles in planta. Insights

  19. Cell wall proteins: a new insight through proteomics.

    Science.gov (United States)

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Pont-Lezica, Rafael F

    2006-01-01

    Cell wall proteins are essential constituents of plant cell walls; they are involved in modifications of cell wall components, wall structure, signaling and interactions with plasma membrane proteins at the cell surface. The application of proteomic approaches to the cell wall compartment raises important questions: are there technical problems specific to cell wall proteomics? What kinds of proteins can be found in Arabidopsis walls? Are some of them unexpected? What sort of post-translational modifications have been characterized in cell wall proteins to date? The purpose of this review is to discuss the experimental results obtained to date using proteomics, as well as some of the new questions challenging future research.

  20. Dissecting the functional significance of non-catalytic carbohydrate binding modules in the deconstruction of plant cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center

    2017-03-16

    The project seeks to investigate the mechanism by which CBMs potentiate the activity of glycoside hydrolases against complete plant cell walls. The project is based on the hypothesis that the wide range of CBMs present in bacterial enzymes maximize the potential target substrates by directing the cognate enzymes not only to different regions of a specific plant cell wall, but also increases the range of plant cell walls that can be degraded. In addition to maximizing substrate access, it was also proposed that CBMs can target specific subsets of hydrolases with complementary activities to the same region of the plant cell wall, thereby maximizing the synergistic interactions between these enzymes. This synergy is based on the premise that the hydrolysis of a specific polysaccharide will increase the access of closely associated polymers to enzyme attack. In addition, it is unclear whether the catalytic module and appended CBM of modular enzymes have evolved unique complementary activities.

  1. Modes of deformation of walled cells.

    Science.gov (United States)

    Dumais, Jacques

    2013-11-01

    The bewildering morphological diversity found in cells is one of the starkest illustrations of life's ability to self-organize. Yet the morphogenetic mechanisms that produce the multifarious shapes of cells are still poorly understood. The shared similarities between the walled cells of prokaryotes, many protists, fungi, and plants make these groups particularly appealing to begin investigating how morphological diversity is generated at the cell level. In this review, I attempt a first classification of the different modes of surface deformation used by walled cells. Five modes of deformation were identified: inextensional bending, equi-area shear, elastic stretching, processive intussusception, and chemorheological growth. The two most restrictive modes-inextensional and equi-area deformations-are embodied in the exine of pollen grains and the wall-like pellicle of euglenoids, respectively. For these modes, it is possible to express the deformed geometry of the cell explicitly in terms of the undeformed geometry and other easily observable geometrical parameters. The greatest morphogenetic power is reached with the processive intussusception and chemorheological growth mechanisms that underlie the expansive growth of walled cells. A comparison of these two growth mechanisms suggests a possible way to tackle the complexity behind wall growth.

  2. Identification of Novel Cell Wall Components

    Energy Technology Data Exchange (ETDEWEB)

    Michelle Momany

    2009-10-26

    Our DOE Biosciences-funded work focused on the fungal cell wall and morphogenesis. We are especially interested in how new cell wall material is targeted to appropriate areas for polar (asymmetric) growth. Polar growth is the only way that filamentous fungi explore the environment to find suitable substrates to degrade. Work funded by this grant has resulted in a total of twenty peer-reviewed publications. In work funded by this grant, we identified nine Aspergillus nidulans temperature-sensitive (ts) mutants that fail to send out a germ tube and show a swollen cell phenotype at restrictive temperature, the swo mutants. In other organisms, a swollen cell phenotype is often associated with misdirected growth or weakened cell walls. Our work shows that several of the A. nidulans swo mutants have defects in the establishment and maintenance of polarity. Cloning of several swo genes by complementation also showed that secondary modification of proteins seems is important in polarity. We also investigated cell wall biosynthesis and branching based on leads in literature from other organisms and found that branching and nuclear division are tied and that the cell wall reorganizes during development. In our most recent work we have focused on gene expression during the shift from isotropic to polar growth. Surprisingly we found that genes previously thought to be involved only in spore formation are important in early vegetative growth as well.

  3. Stevia rebaudiana ethanolic extract exerts better antioxidant properties and antiproliferative effects in tumour cells than its diterpene glycoside stevioside.

    Science.gov (United States)

    López, Víctor; Pérez, Sergio; Vinuesa, Arturo; Zorzetto, Christian; Abian, Olga

    2016-04-01

    Steviol glycosides are currently being used as natural sweeteners by the food industry and Stevia rebaudiana has long been used as a sweet plant in South America for patients suffering from diabetes. In this study, a Stevia rebaudiana ethanolic extract (SREE) was prepared, analysed and tested for antioxidant activity in terms of free radical scavenging properties and antiproliferative effects in cervix (HeLa), pancreatic (MiaPaCa-2) and colonic (HCT116) cancer cells. The antiproliferative mechanism was confirmed by testing the effects on cyclin D1-CDK4. Bioassays were also performed for the diterpene glycoside stevioside. Our results demonstrate that the extract acts as an antioxidant being able to scavenge free radicals, but this activity was not due to stevioside. The extract also induced cell death in the three cell lines, being more active against cervix cancer cells (HeLa); however, the concentration of stevioside needed to produce antiproliferative effects was higher than the amount of steviol glycosides found in a lower dose of extract inducing cell death. In addition, the extract clearly inhibited CDK4 whereas stevioside did not, concluding that the antiproliferative activity of stevia may be due to inhibition of cyclin-dependent kinases performed by other compounds of the extract.

  4. "Steiner trees" between cell walls of sisal

    Institute of Scientific and Technical Information of China (English)

    LI GuanShi; YIN YaJun; LI Yan; ZHONG Zheng

    2009-01-01

    Through careful analysis on the cross-section of sisal fibers,it is found that the middle lamellae between the cell walls have clear geometric characteristics:between the cell walls of three neighboring cells,the middle lamellae form a three-way junction with 120°symmetry. If the neighboring three-way junctions are connected,a network of Steiner tree with angular symmetry and topological invariability is formed. If more and more Steiner trees are connected,a network of Steiner rings is generated. In another word,idealized cell walls and the middle lamellae are dominated by the Steiner geometry. This geometry not only depicts the geometric symmetry,the topological invariability and minimal property of the middle lamellae,but also controls the mechanics of sisal fibers.

  5. Eruberin A, a Natural Flavanol Glycoside, Exerts Anti-Fibrotic Action on Pancreatic Stellate Cells

    Directory of Open Access Journals (Sweden)

    Siu Wai Tsang

    2015-07-01

    Full Text Available Background: Eruberin A (2, 3-dehydroflavonoid, a flavanol glycoside isolated from Pronephrium penangianum, has been used as a blood-nourishing folk medicine for centuries; however, it indeed possesses a variety of other health-promoting benefits including anti-fibrotic bioactivity. Activation of pancreatic stellate cells (PSCs is the key initiating step in pancreatic fibrosis, which is a characteristic feature associated with chronic pancreatitis and pancreatic adenocarcinoma. Methods: The anti-fibrotic effect of eruberin A and the underlying mechanisms of its anti-fibrotic action in LTC-14 cells, which retained essential characteristics and morphological features of primary PSCs, were examined by means of real-time polymerase chain reactions, Western blotting and immunostaining. Results: The application of eruberin A (20 µg/ml effectively inhibited the expression levels of fibrotic mediators namely alpha-smooth muscle actin, fibronectin and type I-collagen, so as the sonic hedgehog signaling pathway components post transforming growth factor-beta (5 ng/ml stimulation. Eruberin A treatment also led to a notable decrease in the activation of nuclear factor-kappaB (NF-κB and the phosphorylation of phosphoinositide 3-kinase (PI3K/serine-threonine kinase (AKT. Conclusion: Our results demonstrated that eruberin A significantly suppressed the expression levels of fibrotic mediators in PSCs, and we suggest that its anti-fibrotic mechanism was associated with an attenuation of the PI3K/AKT/NF-κB signaling pathway.

  6. Effects of quercetin and quercetin-3-O-glycosides on oxidative damage in rat C6 glioma cells.

    Science.gov (United States)

    Zielińska, Małgorzata; Gülden, Michael; Seibert, Hasso

    2003-01-01

    Flavonoids are reported to be powerful antioxidants in cell free systems. They naturally occur as glycosides rather than as aglycon. In this study the ability of the flavonoid quercetin and its glycosides, quercetin-3-O-rutinoside (rutin), quercetin-3-O-glucoside and quercetin-3-O-(6″-O-acetyl)-glucoside, to protect in vitro rat C6 glioma cells from oxidative damage induced by cumene hydroperoxide was investigated. Cumene hydroperoxide induced cell death and lipid peroxidation. The cytotoxicity of cumene hydroperoxide could be prevented by the radical scavenger dimethyl thiourea and the ferric iron chelator deferoxamine, indicating that its cytotoxic activity is related to the generation of reactive oxygen radicals in the ferrous iron dependent Fenton reaction. Quercetin, in a concentration range of 10-100 μM, but neither rutin nor the other two glycosides, were able to protect C6 cells from cytotoxicity and lipid peroxidation. Furthermore, cytoprotective concentrations of quercetin proved to be cytotoxic itself. These results call in question potential beneficial effects of dietary intake or therapeutic use of naturally occurring flavonoids.

  7. Cell wall oxalate oxidase modifies the ferulate metabolism in cell walls of wheat shoots.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki

    2011-11-01

    Oxalate oxidase (OXO) utilizes oxalate to generate hydrogen peroxide, and thereby acts as a source of hydrogen peroxide. The present study was carried out to investigate whether apoplastic OXO modifies the metabolism of cell wall-bound ferulates in wheat seedlings. Histochemical staining of OXO showed that cell walls were strongly stained, indicating the presence of OXO activity in shoot walls. When native cell walls prepared from shoots were incubated with oxalate or hydrogen peroxide, the levels of ester-linked diferulic acid (DFA) isomers were significantly increased. On the other hand, the level of ester-linked ferulic acid (FA) was substantially decreased. The decrease in FA level was accounted neither by the increases in DFA levels nor by the release of FA from cell walls during the incubation. After the extraction of ester-linked ferulates, considerable ultraviolet absorption remained in the hemicellulosic and cellulose fractions, which was increased by the treatment with oxalate or hydrogen peroxide. Therefore, a part of FA esters may form tight linkages within cell wall architecture. These results suggest that cell wall OXO is capable of modifying the metabolism of ester-linked ferulates in cell walls of wheat shoots by promoting the peroxidase action via supply of hydrogen peroxide.

  8. Enzymatic Modification of Plant Cell Wall Polysaccharides

    DEFF Research Database (Denmark)

    Øbro, Jens; Hayashi, Takahisa; Mikkelsen, Jørn Dalgaard

    2011-01-01

    for sustainable processes that replace chemical treatments with white biotechnology. Plants can contribute significantly to this sustainable process by producing plant or microbialenzymes in planta that are necessary for plant cell wall modification or total degradation. This will give rise to superior food......Plant cell walls are intricate structures with remarkable properties, widely used in almost every aspect of our life. Cell walls consist largely of complex polysaccharides and there is often a need for chemical and biochemical processing before industrial use. There is an increasing demand...... fibres, hydrocolloids, paper,textile, animal feeds or biofuels. Classical microbial-based fermentation systems could in the future face serious competition from plant-based expression systems for enzyme production. Plant expressed enzymes can either be targeted to specific cellular compartments...

  9. Enzymatic Modification of Plant Cell Wall Polysaccharides

    DEFF Research Database (Denmark)

    Øbro, Jens; Hayashi, Takahisa; Mikkelsen, Jørn Dalgaard

    2011-01-01

    fibres, hydrocolloids, paper,textile, animal feeds or biofuels. Classical microbial-based fermentation systems could in the future face serious competition from plant-based expression systems for enzyme production. Plant expressed enzymes can either be targeted to specific cellular compartments......Plant cell walls are intricate structures with remarkable properties, widely used in almost every aspect of our life. Cell walls consist largely of complex polysaccharides and there is often a need for chemical and biochemical processing before industrial use. There is an increasing demand...... for sustainable processes that replace chemical treatments with white biotechnology. Plants can contribute significantly to this sustainable process by producing plant or microbialenzymes in planta that are necessary for plant cell wall modification or total degradation. This will give rise to superior food...

  10. Xyloglucan endotransglucosylase and cell wall extensibility.

    Science.gov (United States)

    Miedes, E; Zarra, I; Hoson, T; Herbers, K; Sonnewald, U; Lorences, E P

    2011-02-15

    Transgenic tomato hypocotyls with altered levels of an XTH gene were used to study how XET activity could affect the hypocotyl growth and cell wall extensibility. Transgenic hypocotyls showed significant over-expression (line 13) or co-suppression (line 33) of the SlXTH1 in comparison with the wild type, with these results being correlated with the results on specific soluble XET activity, suggesting that SlXTH1 translates mainly for a soluble XET isoenzyme. A relationship between XET activity and cell wall extensibility was found, and the highest total extensibility was located in the apical hypocotyl segment of the over-expressing SlXTH1 line, where the XET-specific activity and hypocotyl growth were also highest compared with the wild line. Also, in the co-suppression SlXTH1 line, total extensibility values were lower than in the wild type line. The study of linkages between cell wall polysaccharides by FTIR showed that hypocotyls over-expressing SlXTH1 and having a higher XET-specific activity, were grouped away from the wild line, indicating that the linkages between pectins and between cellulose and xyloglucans might differ. These results suggested that the action of the increased XET activity in the transgenic line could be responsible for the cell wall structural changes, and therefore, alter the cell wall extensibility. On the other hand, results on xyloglucan oligosaccharides composition of the xyloglucan by MALDI TOF-MS showed no differences between lines, indicating that the xyloglucan structure was not affected by the XET action. These results provide evidences that XTHs from group I are involved mainly in the restructuring of the cell wall during growth and development, but they are not the limiting factor for plant growth.

  11. Changes of CD4+ CD25+ Regulatory T Cells, FoxP3 in Adjuvant Arthritis Rats with Damage of Pulmonary Function and Effects of Tripterygium Glycosides Tablet

    OpenAIRE

    Wan Lei; Liu Jian

    2012-01-01

    Objective. To observe the effects of tripterygium glycosides tablet (TPT) on swelling degree, arthritis index (AI), pulmonary function, cytokines, the expression of regulatory T cells (Treg), and Foxp3 in rats of adjuvant arthritis. Methods. Rats were averagely divided into normal control (NC) group, model control (MC) group, methotrexate (MTX) group, and tripterygium glycosides tablet (TPT) group. Except for the rats of normal group, the others were intracutaneously injected with 0.1 mL of F...

  12. Microanalysis of Plant Cell Wall Polysaccharides

    NARCIS (Netherlands)

    Obel, N.; Erben, V.; Schwarz, T.; Kühnel, S.; Fodor, A.; Pauly, M.

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the s

  13. Cell Wall Diversity in Forage Maize

    NARCIS (Netherlands)

    Torres, A.F.; Noordam-Boot, C.M.M.; Dolstra, Oene; Weijde, van der Tim; Combes, Eliette; Dufour, Philippe; Vlaswinkel, Louis; Visser, R.G.F.; Trindade, L.M.

    2015-01-01

    Genetic studies are ideal platforms for assessing the extent of genetic diversity, inferring the genetic architecture, and evaluating complex trait interrelations for cell wall compositional and bioconversion traits relevant to bioenergy applications. Through the characterization of a forage maiz

  14. Cell wall integrity signaling and innate immunity in plants.

    Science.gov (United States)

    Nühse, Thomas S

    2012-01-01

    All plant pathogens and parasites have had to develop strategies to overcome cell walls in order to access the host's cytoplasm. As a mechanically strong, multi-layered composite exoskeleton, the cell wall not only enables plants to grow tall but also protects them from such attacks. Many plant pathogens employ an arsenal of cell wall degrading enzymes, and it has long been thought that the detection of breaches in wall integrity contributes to the induction of defense. Cell wall fragments are danger-associated molecular patterns or DAMPs that can trigger defense signaling pathways comparable to microbial signals, but the picture is likely to be more complicated. A wide range of defects in cell wall biosynthesis leads to enhanced pathogen resistance. We are beginning to understand the essential role of cell wall integrity surveillance for plant growth, and the connection of processes like cell expansion, plasma membrane-cell wall contact and secondary wall biosynthesis with plant immunity is emerging.

  15. Cell Wall Heterogeneity in Root Development of Arabidopsis

    Science.gov (United States)

    Somssich, Marc; Khan, Ghazanfar Abbas; Persson, Staffan

    2016-01-01

    Plant cell walls provide stability and protection to plant cells. During growth and development the composition of cell walls changes, but provides enough strength to withstand the turgor of the cells. Hence, cell walls are highly flexible and diverse in nature. These characteristics are important during root growth, as plant roots consist of radial patterns of cells that have diverse functions and that are at different developmental stages along the growth axis. Young stem cell daughters undergo a series of rapid cell divisions, during which new cell walls are formed that are highly dynamic, and that support rapid anisotropic cell expansion. Once the cells have differentiated, the walls of specific cell types need to comply with and support different cell functions. For example, a newly formed root hair needs to be able to break through the surrounding soil, while endodermal cells modify their walls at distinct positions to form Casparian strips between them. Hence, the cell walls are modified and rebuilt while cells transit through different developmental stages. In addition, the cell walls of roots readjust to their environment to support growth and to maximize nutrient uptake. Many of these modifications are likely driven by different developmental and stress signaling pathways. However, our understanding of how such pathways affect cell wall modifications and what enzymes are involved remain largely unknown. In this review we aim to compile data linking cell wall content and re-modeling to developmental stages of root cells, and dissect how root cell walls respond to certain environmental changes. PMID:27582757

  16. Arrangement of peptidoglycan in the cell wall of Staphylococcus spp.

    OpenAIRE

    Amako, K.; Umeda, A; Murata, K

    1982-01-01

    The arrangement of peptidoglycan in the cell wall of Staphylococcus was observed with the newly developed freeze-fracture technique, using n-octanol instead of water as the freezing medium. The replica of the trichloroacetic acid-extracted cell wall (TCA-wall) showed two areas. One of them has a concentric circular structure, a characteristic surface structure of the staphylococcal cell wall, and the other showed an irregular and rough surface. The chemical analysis of the wall revealed that ...

  17. Interconnections between cell wall polymers, wall mechanics, and cortical microtubules: Teasing out causes and consequences.

    Science.gov (United States)

    Xiao, Chaowen; Anderson, Charles T

    2016-09-01

    In plants, cell wall components including cellulose, hemicelluloses, and pectins interact with each other to form complex extracellular network structures that control cell growth and maintain cell shape. However, it is still not clear exactly how different wall polymers interact, how the conformations and interactions of cell wall polymers relate to wall mechanics, and how these factors impinge on intracellular structures such as the cortical microtubule cytoskeleton. Here, based on studies of Arabidopsis thaliana xxt1 xxt2 mutants, which lack detectable xyloglucan in their walls and display aberrant wall mechanics, altered cellulose patterning and biosynthesis, and reduced cortical microtubule stability, we discuss the potential relationships between cell wall biosynthesis, wall mechanics, and cytoskeletal dynamics in an effort to better understand their roles in controlling plant growth and morphogenesis.

  18. Plant Cell Wall Matrix Polysaccharide Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Ajay Pal S. Sandhu; Gursharn S. Randhawa; Kanwarpal S. Dhugga

    2009-01-01

    The wall of an expanding plant cell consists primarily of cellulose microfibrils embedded in a matrix of hemi-cellulosic and pectic polysaccharides along with small amounts of structural and enzymatic proteins. Matrix polysacchar-ides are synthesized in the Golgi and exported to the cell wall by exocytosis, where they intercalate among cellulose microfibrUs, which are made at the plasma membrane and directly deposited into the cell wall. Involvement of Golgi glucan synthesis in auxin-induced cell expansion has long been recognized; however, only recently have the genes corresponding to glucan synthases been identified. Biochemical purification was unsuccessful because of the labile nature and very low abundance of these enzymes. Mutational genetics also proved fruitless. Expression of candidate genes identified through gene expression profiling or comparative genomics in heterologous systems followed by functional characterization has been relatively successful. Several genes from the cellulose synthase-like (Cs/) family have been found to be involved in the synthesis of various hemicellulosic glycans. The usefulness of this approach, however, is limited to those enzymes that probably do not form complexes consisting of unrelated proteins. Nonconventional approaches will continue to incre-mentally unravel the mechanisms of Golgi polysaccharide biosynthesis.

  19. Alfalfa stem tissues: Cell wall deposition, composition, and degradability

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.

    2002-01-01

    Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue proliferatio

  20. Alfalfa stem tissues: Cell wall deposition, composition, and degradability

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.

    2002-01-01

    Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue

  1. Alfalfa stem tissues: Cell wall deposition, composition, and degradability

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.

    2002-01-01

    Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue proliferatio

  2. [Structure and function of fungal cell wall].

    Science.gov (United States)

    Ohno, Naohito

    2008-12-01

    Cell wall glycans of fungi/yeasts are reviewed. Fungi/yeasts produce various kinds of polysaccharides. As part of the cell wall they are interlinked with other components forming a huge network. The insolubility and complex with multiple components makes the research very tough. Studies on beta-glucan have been performed from various views, such as chemistry, conformation, solubility, tissue distribution and metabolism, biological activity, clinical application, receptor, biosynthesis, and antibody. Studies on mannan focus on immunotoxicity, such as anaphylactoid reaction and coronary arteritis induction. alpha-glucan, chitin, and capsular polysaccharide were also mentioned in relation to structure and genes. Compared with human and animal polysaccharides, fungi/yeasts polysaccharides have very characteristic properties.

  3. Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

    2016-05-31

    Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

  4. Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

    2016-05-31

    Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

  5. Beyond growth: novel functions for bacterial cell wall hydrolases.

    Science.gov (United States)

    Wyckoff, Timna J; Taylor, Jennifer A; Salama, Nina R

    2012-11-01

    The peptidoglycan cell wall maintains turgor pressure and cell shape of most bacteria. Cell wall hydrolases are essential, together with synthases, for growth and daughter cell separation. Recent work in diverse organisms has uncovered new cell wall hydrolases that act autonomously or on neighboring cells to modulate invasion of prey cells, cell shape, innate immune detection, intercellular communication, and competitor lysis. The hydrolases involved in these processes catalyze the cleavage of bonds throughout the sugar and peptide moities of peptidoglycan. Phenotypes associated with these diverse hydrolases reveal new functions of the bacterial cell wall beyond growth and division.

  6. Plant cell wall proteomics: the leadership of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Cécile eALBENNE

    2013-05-01

    Full Text Available Plant cell wall proteins (CWPs progressively emerged as crucial components of cell walls although present in minor amounts. Cell wall polysaccharides such as pectins, hemicelluloses and cellulose represent more than 90% of primary cell wall mass, whereas hemicelluloses, cellulose and lignins are the main components of lignified secondary walls. All these polymers provide mechanical properties to cell walls, participate in cell shape and prevent water loss in aerial organs. However, cells walls need to be modified and customized during plant development and in response to environmental cues, thus contributing to plant adaptation. CWPs play essential roles in all these physiological processes and particularly in the dynamics of cell walls, which requires organization and rearrangements of polysaccharides as well as cell-to-cell communication. In the last ten years, plant cell wall proteomics has greatly contributed to a wider knowledge of CWPs. This update will deal with (i a survey of plant cell wall proteomics studies with a focus on Arabidopsis thaliana; (ii the main protein families identified and the still missing peptides; (iii the persistent issue of the non-canonical CWPs; (iv the present challenges to overcome technological bottlenecks; and (v the perspectives beyond cell wall proteomics to understand CWP functions.

  7. Plant cell wall proteomics: the leadership of Arabidopsis thaliana.

    Science.gov (United States)

    Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth

    2013-01-01

    Plant cell wall proteins (CWPs) progressively emerged as crucial components of cell walls although present in minor amounts. Cell wall polysaccharides such as pectins, hemicelluloses, and cellulose represent more than 90% of primary cell wall mass, whereas hemicelluloses, cellulose, and lignins are the main components of lignified secondary walls. All these polymers provide mechanical properties to cell walls, participate in cell shape and prevent water loss in aerial organs. However, cell walls need to be modified and customized during plant development and in response to environmental cues, thus contributing to plant adaptation. CWPs play essential roles in all these physiological processes and particularly in the dynamics of cell walls, which requires organization and rearrangements of polysaccharides as well as cell-to-cell communication. In the last 10 years, plant cell wall proteomics has greatly contributed to a wider knowledge of CWPs. This update will deal with (i) a survey of plant cell wall proteomics studies with a focus on Arabidopsis thaliana; (ii) the main protein families identified and the still missing peptides; (iii) the persistent issue of the non-canonical CWPs; (iv) the present challenges to overcome technological bottlenecks; and (v) the perspectives beyond cell wall proteomics to understand CWP functions.

  8. Fermentation of the endosperm cell walls of monocotyledon and dicotyledon plant species: The relationship between cell wall characteristics and fermentability

    NARCIS (Netherlands)

    Laar, van H.; Tamminga, S.; Williams, B.A.; Verstegen, M.W.A.

    2000-01-01

    Cell walls from the endosperm of four monocotyledons (maize, wheat, rye, and rice) and four dicotyledons (soya bean, lupin, faba bean, and pea) seeds were studied to relate cell wall composition and structure with fermentation characteristics. Cell wall material was isolated from the endosperm of

  9. Fermentation of the endosperm cell walls of monocotyledon and dicotyledon plant species: The relationship between cell wall characteristics and fermentability

    NARCIS (Netherlands)

    Laar, van H.; Tamminga, S.; Williams, B.A.; Verstegen, M.W.A.

    2000-01-01

    Cell walls from the endosperm of four monocotyledons (maize, wheat, rye, and rice) and four dicotyledons (soya bean, lupin, faba bean, and pea) seeds were studied to relate cell wall composition and structure with fermentation characteristics. Cell wall material was isolated from the endosperm of th

  10. Grass Cell Walls: A Story of Cross-Linking

    Science.gov (United States)

    Hatfield, Ronald D.; Rancour, David M.; Marita, Jane M.

    2017-01-01

    Cell wall matrices are complex composites mainly of polysaccharides, phenolics (monomers and polymers), and protein. We are beginning to understand the synthesis of these major wall components individually, but still have a poor understanding of how cell walls are assembled into complex matrices. Valuable insight has been gained by examining intact components to understand the individual elements that make up plant cell walls. Grasses are a prominent group within the plant kingdom, not only for their important roles in global agriculture, but also for the complexity of their cell walls. Ferulate incorporation into grass cell wall matrices (C3 and C4 types) leads to a cross-linked matrix that plays a prominent role in the structure and utilization of grass biomass compared to dicot species. Incorporation of p-coumarates as part of the lignin structure also adds to the complexity of grass cell walls. Feruoylation results in a wall with individual hemicellulosic polysaccharides (arabinoxylans) covalently linked to each other and to lignin. Evidence strongly suggests that ferulates not only cross-link arabinoxylans, but may be important factors in lignification of the cell wall. Therefore, the distribution of ferulates on arabinoxylans could provide a means of structuring regions of the matrix with the incorporation of lignin and have a significant impact upon localized cell wall organization. The role of other phenolics in cell wall formation such as p-coumarates (which can have concentrations higher than ferulates) remains unknown. It is possible that p-coumarates assist in the formation of lignin, especially syringyl rich lignin. The uniqueness of the grass cell wall compared to dicot sepcies may not be so much in the gross composition of the wall, but how the distinctive individual components are organized into a functional wall matrix. These features are discussed and working models are provided to illustrate how changing the organization of feruoylation and p

  11. Plant and algal cell walls: diversity and functionality.

    Science.gov (United States)

    Popper, Zoë A; Ralet, Marie-Christine; Domozych, David S

    2014-10-01

    Although plants and many algae (e.g. the Phaeophyceae, brown, and Rhodophyceae, red) are only very distantly related they are united in their possession of carbohydrate-rich cell walls, which are of integral importance being involved in many physiological processes. Furthermore,wall components have applications within food, fuel, pharmaceuticals, fibres (e.g. for textiles and paper) and building materials and have long been an active topic of research. As shown in the 27 papers in this Special Issue, as the major deposit of photosynthetically fixed carbon, and therefore energy investment, cell walls are of undisputed importance to the organisms that possess them, the photosynthetic eukaryotes ( plants and algae). The complexities of cell wall components along with their interactions with the biotic and abiotic environment are becoming increasingly revealed. The importance of plant and algal cell walls and their individual components to the function and survival of the organism, and for a number of industrial applications, are illustrated by the breadth of topics covered in this issue, which includes papers concentrating on various plants and algae, developmental stages, organs, cell wall components, and techniques. Although we acknowledge that there are many alternative ways in which the papers could be categorized (and many would fit within several topics), we have organized them as follows: (1) cell wall biosynthesis and remodelling, (2) cell wall diversity, and (3) application of new technologies to cell walls. Finally, we will consider future directions within plant cell wall research. Expansion of the industrial uses of cell walls and potentially novel uses of cell wall components are both avenues likely to direct future research activities. Fundamentally, it is the continued progression from characterization (structure, metabolism, properties and localization) of individual cell wall components through to defining their roles in almost every aspect of plant

  12. Enzymes and other agents that enhance cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1999-01-01

    Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

  13. Neuroprotective effects of triterpene glycosides from glycine max against glutamate induced toxicity in primary cultured rat cortical cells.

    Science.gov (United States)

    Moon, Hyung-In; Lee, Jai-Heon

    2012-01-01

    To examine the neuroprotective effects of Glycine max, we tested its protection against the glutamate-induced toxicity in primary cortical cultured neurons. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. From such fractionation, two triterpene glycosides, 3-O-[α-l-rhamnopyranosyl(1-2)-β-d-glucopyranosyl(1-2)-β-d-glucuronopyranosyl]olean-12-en-3β,22β,24-triol (1) and 3-O-[β-d-glucopyranosyl(1-2)-β-d-galactopyranosyl(1-2)-β-d-glucuronopyranosyl]olean-12-en-3β,22β,24-triol (2) were isolated with the methanol extracts with of air-dried Glycine max. Among these compounds, compound 2 exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 50% at concentrations ranging from 0.1 μM to 10 μM. Therefore, the neuroprotective effect of Glycine max might be due to the inhibition of glutamate-induced toxicity by triterpene glycosides.

  14. Neuroprotective iridoid glycosides from Cornus officinalis fruits against glutamate-induced toxicity in HT22 hippocampal cells.

    Science.gov (United States)

    Jeong, Eun Ju; Kim, Tae Bum; Yang, Heejung; Kang, So Young; Kim, Sun Yeou; Sung, Sang Hyun; Kim, Young Choong

    2012-02-15

    The methanolic extract of the fruits of Cornus officinalis S et Z. (Cornaceae) showed the significant neuroprotective activity against glutamate-induced toxicity in HT22 hippocampal cells. Chemical profile of n-BuOH fraction of the methanolic extract of C. officinalis fruits, which showed the most potent activity, was established using HPLC-diode array detector-electrospray-MS (HPLC-DAD-ESI-MS). Through bioactivity-guided isolation, five iridoid glycosides including one new compound, 7-O-butylmorroniside (1), loganin (2), morroniside (3), 7R-O-methylmorroniside (4), 7S-O-methylmorroniside (5) were isolated from the n-BuOH fraction. The protective activities of the isolated compounds, themselves, were not statistically significant. However, the hydrolyzed products of compounds 1, 4 and 5 significantly protected glutamate-injured HT22 cells up to 78±2.2%, 60±3.2% and 59±2.5% of non-treated control, respectively.

  15. Steviol glycosides enhance pancreatic beta-cell function and taste sensation by potentiation of TRPM5 channel activity

    Science.gov (United States)

    Philippaert, Koenraad; Pironet, Andy; Mesuere, Margot; Sones, William; Vermeiren, Laura; Kerselaers, Sara; Pinto, Sílvia; Segal, Andrei; Antoine, Nancy; Gysemans, Conny; Laureys, Jos; Lemaire, Katleen; Gilon, Patrick; Cuypers, Eva; Tytgat, Jan; Mathieu, Chantal; Schuit, Frans; Rorsman, Patrik; Talavera, Karel; Voets, Thomas; Vennekens, Rudi

    2017-01-01

    Steviol glycosides (SGs), such as stevioside and rebaudioside A, are natural, non-caloric sweet-tasting organic molecules, present in extracts of the scrub plant Stevia rebaudiana, which are widely used as sweeteners in consumer foods and beverages. TRPM5 is a Ca2+-activated cation channel expressed in type II taste receptor cells and pancreatic β-cells. Here we show that stevioside, rebaudioside A and their aglycon steviol potentiate the activity of TRPM5. We find that SGs potentiate perception of bitter, sweet and umami taste, and enhance glucose-induced insulin secretion in a Trpm5-dependent manner. Daily consumption of stevioside prevents development of high-fat-diet-induced diabetic hyperglycaemia in wild-type mice, but not in Trpm5−/− mice. These results elucidate a molecular mechanism of action of SGs and identify TRPM5 as a potential target to prevent and treat type 2 diabetes. PMID:28361903

  16. Disruption of cell walls for enhanced lipid recovery

    Science.gov (United States)

    Knoshaug, Eric P; Donohoe, Bryon S; Gerken, Henri; Laurens, Lieve; Van Wychen, Stefanie Rose

    2015-03-24

    Presented herein are methods of using cell wall degrading enzymes for recovery of internal lipid bodies from biomass sources such as algae. Also provided are algal cells that express at least one exogenous gene encoding a cell wall degrading enzyme and methods for recovering lipids from the cells.

  17. Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, Daniel J.

    2015-11-25

    The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the ‘Young's modulus’ of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

  18. Two endogenous proteins that induce cell wall extension in plants

    Science.gov (United States)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  19. Evolution and diversity of green plant cell walls.

    Science.gov (United States)

    Popper, Zoë A

    2008-06-01

    Plant cells are surrounded by a dynamic cell wall that performs many essential biological roles, including regulation of cell expansion, the control of tissue cohesion, ion-exchange and defence against microbes. Recent evidence shows that the suite of polysaccharides and wall proteins from which the plant cell wall is composed shows variation between monophyletic plant taxa. This is likely to have been generated during the evolution of plant groups in response to environmental stress. Understanding the natural variation and diversity that exists between cell walls from different taxa is key to facilitating their future exploitation and manipulation, for example by increasing lignocellulosic content or reducing its recalcitrance for use in biofuel generation.

  20. Multidimensional solid-state NMR spectroscopy of plant cell walls.

    Science.gov (United States)

    Wang, Tuo; Phyo, Pyae; Hong, Mei

    2016-09-01

    Plant biomass has become an important source of bio-renewable energy in modern society. The molecular structure of plant cell walls is difficult to characterize by most atomic-resolution techniques due to the insoluble and disordered nature of the cell wall. Solid-state NMR (SSNMR) spectroscopy is uniquely suited for studying native hydrated plant cell walls at the molecular level with chemical resolution. Significant progress has been made in the last five years to elucidate the molecular structures and interactions of cellulose and matrix polysaccharides in plant cell walls. These studies have focused on primary cell walls of growing plants in both the dicotyledonous and grass families, as represented by the model plants Arabidopsis thaliana, Brachypodium distachyon, and Zea mays. To date, these SSNMR results have shown that 1) cellulose, hemicellulose, and pectins form a single network in the primary cell wall; 2) in dicot cell walls, the protein expansin targets the hemicellulose-enriched region of the cellulose microfibril for its wall-loosening function; and 3) primary wall cellulose has polymorphic structures that are distinct from the microbial cellulose structures. This article summarizes these key findings, and points out future directions of investigation to advance our fundamental understanding of plant cell wall structure and function.

  1. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

    Plant cell walls consist of polysaccharides, glycoproteins and phenolic polymers interlinked together in a highly complex network. The detailed analysis of cell walls is challenging because of their inherent complexity and heterogeneity. Also, complex carbohydrates, unlike proteins and nucleotides...... probes (monoclonal antibodies mAbs and carbohydrate binding modules, CBMs) to rapidly profile polysaccharides across a sample set. During my PhD I have further developed the CoMPP technique and used it for cell wall analysis within the context of a variety of applied and fundamental projects. The data...... produced has provided new insight into cell wall evolution and biosynthesis and has contributed to the commercial development of cell wall materials. A major focus of the work has been the wide scale sampling of cell wall diversity across the plant kingdom, from unicellular algae to highly evolved...

  2. Variants of glycoside hydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Teter, Sarah; Ward, Connie; Cherry, Joel; Jones, Aubrey; Harris, Paul; Yi, Jung

    2017-07-11

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  3. Variants of glycoside hydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Teter, Sarah (Davis, CA); Ward, Connie (Hamilton, MT); Cherry, Joel (Davis, CA); Jones, Aubrey (Davis, CA); Harris, Paul (Carnation, WA); Yi, Jung (Sacramento, CA)

    2011-04-26

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  4. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

    Plant cell walls consist of polysaccharides, glycoproteins and phenolic polymers interlinked together in a highly complex network. The detailed analysis of cell walls is challenging because of their inherent complexity and heterogeneity. Also, complex carbohydrates, unlike proteins and nucleotide...... angiosperms. This analysis has enabled cell wall diversity to be placed in a phylogenetic context, and, when integrated with transcriptomic and genomic analysis has contributed to our understanding of important aspects of plant evolution....

  5. Analysis of Papaya Cell Wall-Related Genes during Fruit Ripening Indicates a Central Role of Polygalacturonases during Pulp Softening

    Science.gov (United States)

    Fabi, João Paulo; Broetto, Sabrina Garcia; da Silva, Sarah Lígia Garcia Leme; Zhong, Silin; Lajolo, Franco Maria; do Nascimento, João Roberto Oliveira

    2014-01-01

    Papaya (Carica papaya L.) is a climacteric fleshy fruit that undergoes dramatic changes during ripening, most noticeably a severe pulp softening. However, little is known regarding the genetics of the cell wall metabolism in papayas. The present work describes the identification and characterization of genes related to pulp softening. We used gene expression profiling to analyze the correlations and co-expression networks of cell wall-related genes, and the results suggest that papaya pulp softening is accomplished by the interactions of multiple glycoside hydrolases. The polygalacturonase cpPG1 appeared to play a central role in the network and was further studied. The transient expression of cpPG1 in papaya results in pulp softening and leaf necrosis in the absence of ethylene action and confirms its role in papaya fruit ripening. PMID:25162506

  6. Molecular pharmacology of cell receptors for cardiac glycosides, opiates, ACTH and ion channel modulators

    Energy Technology Data Exchange (ETDEWEB)

    Hnatowich, M.R.

    1986-01-01

    The influence of light and oxygen on molecular interactions between the artificial food dye, erythrosine (ERY), and (/sup 3/H)ouabain ((/sup 3/H)OUA) binding sites on (Na/sup +/ + K/sup +/)-ATPase in rat brain and guinea pig heart was investigated. Putative endogenous digitalis-like factors (DLF's) were studied in four in vitro assays for cardiac glycosides. (/sup 3/H)Etorphine binding was characterized in rat brain homogenates, depleted of opioids, from animals acutely and chronically treated with morphine and naloxone, and either unstressed or cold-restraint-stressed. Binding sites for the ion channel modulators (/sup 3/H)verapamil ((/sup 3/H)VER) and (/sup 3/H) phencyclidine ((/sup 3/H)PCP) were characterized in rat brain.

  7. Cell wall degradation in the autolysis of filamentous fungi.

    Science.gov (United States)

    Perez-Leblic, M I; Reyes, F; Martinez, M J; Lahoz, R

    1982-12-27

    A systematic study on autolysis of the cell walls of fungi has been made on Neurospora crassa, Botrytis cinerea, Polystictus versicolor, Aspergillus nidulans, Schizophyllum commune, Aspergillus niger, and Mucor mucedo. During autolysis each fungus produces the necessary lytic enzymes for its autodegradation. From autolyzed cultures of each fungus enzymatic precipitates were obtained. The degree of lysis of the cell walls, obtained from non-autolyzed mycelia, was studied by incubating these cell walls with and without a supply of their own lytic enzymes. The degree of lysis increased with the incubation time and generally was higher with a supply of lytic enzymes. Cell walls from mycelia of different ages were obtained. A higher degree of lysis was always found, in young cell walls than in older cell walls, when exogenous lytic enzymes were present. In all the fungi studied, there is lysis of the cell walls during autolysis. This is confirmed by the change of the cell wall structure as well as by the degree of lysis reached by the cell wall and the release of substances, principally glucose and N-acetylglucosamine in the medium.

  8. Small molecule probes for plant cell wall polysaccharide imaging

    Directory of Open Access Journals (Sweden)

    Ian eWallace

    2012-05-01

    Full Text Available Plant cell walls are composed of interlinked polymer networks consisting of cellulose, hemicelluloses, pectins, proteins, and lignin. The ordered deposition of these components is a dynamic process that critically affects the development and differentiation of plant cells. However, our understanding of cell wall synthesis and remodeling, as well as the diverse cell wall architectures that result from these processes, has been limited by a lack of suitable chemical probes that are compatible with live-cell imaging. In this review, we summarize the currently available molecular toolbox of probes for cell wall polysaccharide imaging in plants, with particular emphasis on recent advances in small molecule-based fluorescent probes. We also discuss the potential for further development of small molecule probes for the analysis of cell wall architecture and dynamics.

  9. Cell wall ultrastructure of flocculent and non-flocculent Schizosaccharomyces pombe strains. Effect of cell wall hydrolysing enzymes on flocculation and cell wall ultastructure.

    Science.gov (United States)

    Geleta, Anna; Kristóf, Z; Maráz, Anna

    2007-03-01

    Scanning and transmission electron microscopic studies revealed the presence of slime-like, amorphous material on the surface of Schizosaccahromyces pombe RIVE 4-2-1 cells, independently, whether they were in flocculated or in non-flocculated state. Close contact of the adjacent cells via the merging outermost cell wall layers was found, however, only in the case of floc formation, which was induced by cultivating the cells in the presence of 6% (v/v) ethanol. Irreversible loss of the flocculation ability of the cells by treatment with proteinases suggests that proteinaceous cell surface molecules as lectins contribute to the cell-to-cell interaction during flocculation. Both proteinase K and pronase treatments removed a distinct outer layer of the cell wall, which indicated that the protein moieties of the phosphogalactomannan outer surface layer has a crucial role in the maintenance of cell wall integrity. In the case of lysing enzyme treatment the removal of the outermost layer was also observed as the first step of the cell wall digestion, while driselase treatment resulted in almost complete digestion of the cell wall.

  10. Mechanical Properties of Plant Cell Walls Probed by Relaxation Spectra

    DEFF Research Database (Denmark)

    Hansen, Steen Laugesen; Ray, Peter Martin; Karlsson, Anders Ola

    2011-01-01

    Transformants and mutants with altered cell wall composition are expected to display a biomechanical phenotype due to the structural role of the cell wall. It is often quite difficult, however, to distinguish the mechanical behavior of a mutant's or transformant's cell walls from that of the wild...... type. This may be due to the plant’s ability to compensate for the wall modification or because the biophysical method that is often employed, determination of simple elastic modulus and breakstrength, lacks the resolving power necessary for detecting subtle mechanical phenotypes. Here, we apply...... a method, determination of relaxation spectra, which probes, and can separate, the viscoelastic properties of different cell wall components (i.e. those properties that depend on the elastic behavior of load-bearing wall polymers combined with viscous interactions between them). A computer program, Bayes...

  11. Mechanical Properties of Plant Cell Walls Probed by Relaxation Spectra

    DEFF Research Database (Denmark)

    Hansen, Steen Laugesen; Ray, Peter Martin; Karlsson, Anders Ola

    2011-01-01

    Transformants and mutants with altered cell wall composition are expected to display a biomechanical phenotype due to the structural role of the cell wall. It is often quite difficult, however, to distinguish the mechanical behavior of a mutant's or transformant's cell walls from that of the wild...... type. This may be due to the plant’s ability to compensate for the wall modification or because the biophysical method that is often employed, determination of simple elastic modulus and breakstrength, lacks the resolving power necessary for detecting subtle mechanical phenotypes. Here, we apply...... a method, determination of relaxation spectra, which probes, and can separate, the viscoelastic properties of different cell wall components (i.e. those properties that depend on the elastic behavior of load-bearing wall polymers combined with viscous interactions between them). A computer program, Bayes...

  12. Investigations in vitro on the behaviour of chromosomes and the mitotic apparatus in endosperm cells of Haemanthus katherinae Baker treated with oleander glycosides

    Directory of Open Access Journals (Sweden)

    J. A. Tarkowska

    2015-01-01

    Full Text Available The effect of oleander glycosides on dividing endosperm cells of Haemanthus katherine was investigated in vitro. The disturbances in the successive cell division phases were analysed in reference to cytokinesis. A strong tendency was noted to restitution nuclei formation in all phases of mitosis, and particularly in prophase. The observed chromosome pattern is the result of disturbances in prometaphase and anaphase chromosome movements owing to disturbances in the function of 'the 'mitotic spindle. It is probable that oleander glycosides inhibit formatiom of 'the microtubules of the mitotic spindle and disorganize the already formed spindle. They cause minor disturbances in cytokinesis, although frequently cell plates arise in quite unexpected places. The results of the present study are compared with those obtained in the case of root meristematic cells (Tarkowska, 1971a, b.

  13. Structural Studies of Complex Carbohydrates of Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

    2015-02-17

    Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

  14. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

    Directory of Open Access Journals (Sweden)

    Kouki eYoshida

    2013-10-01

    Full Text Available Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs can regulate secondary wall formation in rice (Oryza sativa and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S has very low transcriptional activation ability, but the longer protein (OsSWN2L and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications.

  15. Characterising the cellulose synthase complexes of cell walls

    NARCIS (Netherlands)

    Mansoori Zangir, N.

    2012-01-01

    One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as the c

  16. Hemicellulose biosynthesis and degradation in tobacco cell walls

    NARCIS (Netherlands)

    Compier, M.G.M.

    2005-01-01

    Natural fibres have a wide range of technological applications, such as in paper and textile industries. The basic properties and the quality of plant fibres are determined by the composition of the plant cell wall. Characteristic for fibres are thick secondary cell walls, which consist of cellulose

  17. Hemicellulose biosynthesis and degradation in tobacco cell walls

    NARCIS (Netherlands)

    Compier, M.G.M.

    2005-01-01

    Natural fibres have a wide range of technological applications, such as in paper and textile industries. The basic properties and the quality of plant fibres are determined by the composition of the plant cell wall. Characteristic for fibres are thick secondary cell walls, which consist of cellulose

  18. On-Off Switches for Secondary Cell Wall Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Huan-Zhong Wang; Richard A.Dixon

    2012-01-01

    Secondary cell walls provide plants with rigidity and strength to support their body weight and ensure water and nutrient transport.They also provide textiles,timber,and potentially second-generation biofuels for human use.Genes responsible for synthesis of the different cell wall components,namely cellulose,hemicelluloses,and lignin,are coordinately expressed and under transcriptional regulation.In the past several years,cell wall-related NAC and MYB transcription factors have been intensively investigated in different species and shown to be master switches of secondary cell wall biosynthesis.Positive and negative regulators,which function upstream of NAC master switches,have also been identified in different plant tissues.Further elucidation of the regulatory mechanisms of cell wall synthesis will facilitate the engineering of plant feedstocks suitable for biofuel production.

  19. Brassinosteroid Mediated Cell Wall Remodeling in Grasses under Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Xiaolan Rao

    2017-05-01

    Full Text Available Unlike animals, plants, being sessile, cannot escape from exposure to severe abiotic stresses such as extreme temperature and water deficit. The dynamic structure of plant cell wall enables them to undergo compensatory changes, as well as maintain physical strength, with changing environments. Plant hormones known as brassinosteroids (BRs play a key role in determining cell wall expansion during stress responses. Cell wall deposition differs between grasses (Poaceae and dicots. Grass species include many important food, fiber, and biofuel crops. In this article, we focus on recent advances in BR-regulated cell wall biosynthesis and remodeling in response to stresses, comparing our understanding of the mechanisms in grass species with those in the more studied dicots. A more comprehensive understanding of BR-mediated changes in cell wall integrity in grass species will benefit the development of genetic tools to improve crop productivity, fiber quality and plant biomass recalcitrance.

  20. A Cell Wall-degrading Endopolygalacturonase Secreted by Colletotrichum lindemuthianum1

    Science.gov (United States)

    English, Patricia D.; Maglothin, Austin; Keegstra, Kenneth; Albersheim, Peter

    1972-01-01

    Cultures of Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner have been induced to secrete an endopolygalacturonase (polygalacturonide glycanohydrolase EC3.2. 1.15). This enzyme has been brought to a high state of purity by ion exchange, gel filtration, and agarose affinity chromatography. The enzyme has optimal activity at pH 5, has an apparent molecular weight as determined by gel filtration of about 70,000, and prefers polygalacturonic acid to pectin as its substrate. The enzyme, while hydrolyzing only 1% of the glycosidic bonds, reduces the viscosity of a polygalacturonic solution by 50%. Nevertheless, the initial as well as the final products of polygalacturonic acid hydrolysis are predominantly tri- and digalacturonic acid and, to a lesser extent, monogalacturonic acid. The purified enzyme catalyzes the removal of about 80% of the galacturonic acid residues of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus) as well as from the walls isolated from 8-day-old Red Kidney bean (Phaseolus vulgaris) hypocotyls. PMID:16657947

  1. Identification of Quantitative Trait Loci Affecting Hemicellulose Characteristics Based on Cell Wall Composition in a Wild and Cultivated Rice Species

    Institute of Scientific and Technical Information of China (English)

    Si-Ju Zhang; Xue-Qin Song; Bai-Sheng Yu; Bao-Cai Zhang; Chuan-Qing Sun; J. Paul Knox; Yi-Hua Zhou

    2012-01-01

    Cell wall hemicellulosic polysaccharides are structurally complex and diverse.Knowledge about the synthesisof cell wall hemicelluloses and their biological roles is limited.Quantitative trait loci (QTL) mapping is a helpful tool for the dissection of complex phenotypes for gene identification.In this study,we exploited the natural variation in cell wall monosaccharide levels between a common wild rice,Yuanj,and an elite indica cultivar,Teqing,and performed QTL mapping with their introgression lines (ILs).Chemical analyses conducted on the culms of Yuanj and Teqing showed that the major alterations are found in glucose and xylose levels,which are correlated with specific hemicellulosic polymers.Glycosidic linkage examination revealed that,in Yuanj,an increase in glucose content results from a higher level of mixed linkage β-glucan (MLG),whereas a reduction in xylose content reflects a low level of xylan backbone and a varied arabinoxylan (AX) structure.Seventeen QTLs for monosaccharides have been identified through composition analysis of the culm residues of 95 core ILs.Four major QTLs affecting xylose and glucose levels are responsible for 19 and 21% of the phenotypic variance,respectively.This study provides a unique resource for the genetic dissection of rice cell wall formation and remodeling in the vegetative organs.

  2. Cell surfaces in plant-microorganism interactions. I. A structural investigation of cell wall hydroxyproline-rich glycoproteins which accumulate in fungus-infected plants

    Energy Technology Data Exchange (ETDEWEB)

    Esquerre-Tugaye, M.T. (Universite Paul Sabatier, Toulouse, France); Lamport, D.T.A.

    1979-08-01

    Infection of muskmelon Cucumis melo seedlings by the fungus Colletotrichum lagenarium causes a 10-fold increase in the amount of cell wall hydroxyproline-rich glycoprotein. Evidence for this increase was provided by studying two specific markers of this glycoprotein, namely hydroxyproline and glycosylated serine. The lability of the O-glycosidic linkage of wall-bound glycosylated serine in the presence of hydrazine was used to determine the amount of serine which is glycosylated. A large increase in the hydroxyproline content of infected plants is shown, but the ratios of glycosylated serine to hydroxyproline are similar in healthy and infected plants. As far as these markers are concerned, the hydroxyproline-rich glycoproteins secreted into the wall as a result of the disease are similar to those of healthy plants. In addition, the extent of glycosylation of the wall serine, in both healthy and infected plants, decreases as the plant ages. Serine- and hydroxyproline-rich (glyco)peptides were also isolated after trypsinolysis of the wall. These (glyco)peptides include the galactosyl-containing pentapeptide, serine-hydroxyproline. This pentapeptide is characteristic of cell wall protein.

  3. Dynamic metabolic flux analysis of plant cell wall synthesis.

    Science.gov (United States)

    Chen, Xuewen; Alonso, Ana P; Shachar-Hill, Yair

    2013-07-01

    The regulation of plant cell wall synthesis pathways remains poorly understood. This has become a bottleneck in designing bioenergy crops. The goal of this study was to analyze the regulation of plant cell wall precursor metabolism using metabolic flux analysis based on dynamic labeling experiments. Arabidopsis T87 cells were cultured heterotrophically with (13)C labeled sucrose. The time course of ¹³C labeling patterns in cell wall precursors and related sugar phosphates was monitored using liquid chromatography tandem mass spectrometry until steady state labeling was reached. A kinetic model based on mass action reaction mechanisms was developed to simulate the carbon flow in the cell wall synthesis network. The kinetic parameters of the model were determined by fitting the model to the labeling time course data, cell wall composition, and synthesis rates. A metabolic control analysis was performed to predict metabolic regulations that may improve plant biomass composition for biofuel production. Our results describe the routes and rates of carbon flow from sucrose to cell wall precursors. We found that sucrose invertase is responsible for the entry of sucrose into metabolism and UDP-glucose-4-epimerase plays a dominant role in UDP-Gal synthesis in heterotrophic Aradidopsis cells under aerobic conditions. We also predicted reactions that exert strong regulatory influence over carbon flow to cell wall synthesis and its composition.

  4. Maize development: Cell wall changes in leaves and sheaths

    Science.gov (United States)

    Developmental changes occur in maize (Zea mays L.) as it transitions from juvenile stages to the mature plant. Changes also occur as newly formed cells mature into adult cells. Maize leaf blades, including the midribs and sheaths, undergo cell wall changes as cells transition to fully mature cell ty...

  5. Nitrate Uptake Affects Cell Wall Synthesis and Modeling

    Directory of Open Access Journals (Sweden)

    Simone Landi

    2017-08-01

    Full Text Available Nowadays, the relationship(s about N assimilation and cell wall remodeling in plants remains generally unclear. Enzymes involved in cell wall synthesis/modification, and nitrogen transporters play a critical role in plant growth, differentiation, and response to external stimuli. In this review, a co-expression analysis of nitrate and ammonium transporters of Arabidopsis thaliana was performed in order to explore the functional connection of these proteins with cell-wall related enzymes. This approach highlighted a strict relationship between inorganic nitrogen transporters and cell wall formation, identifying a number of co-expressed remodeling enzymes. The enzymes involved in pectin and xyloglucan synthesis resulted particularly co-regulated together with nitrate carriers, suggesting a connection between nitrate assimilation and cell wall growth regulation. Major Facilitator Carriers, and one chloride channel, are similarly co-expressed with pectin lyase, pectinacetylesterase, and cellulose synthase. Contrarily, ammonium transporters show little or no connection with those genes involved in cell wall synthesis. Different aspects related to plant development, embryogenesis, and abiotic stress response will be discussed, given the importance in plant growth of cell wall synthesis and nitrate uptake. Intriguingly, the improvement of abiotic stress tolerance in crops concerns both these processes indicating the importance in sensing the environmental constraints and mediating a response. These evaluations could help to identify candidate genes for breeding purposes.

  6. Verticillium longisporum Infection Affects the Leaf Apoplastic Proteome, Metabolome, and Cell Wall Properties in Arabidopsis thaliana

    Science.gov (United States)

    Floerl, Saskia; Majcherczyk, Andrzej; Possienke, Mareike; Feussner, Kirstin; Tappe, Hella; Gatz, Christiane; Feussner, Ivo; Kües, Ursula; Polle, Andrea

    2012-01-01

    Verticillium longisporum (VL) is one of the most devastating diseases in important oil crops from the family of Brassicaceae. The fungus resides for much time of its life cycle in the extracellular fluid of the vascular system, where it cannot be controlled by conventional fungicides. To obtain insights into the biology of VL-plant interaction in the apoplast, the secretome consisting of the extracellular proteome and metabolome as well as cell wall properties were studied in the model Brassicaceae, Arabidopsis thaliana. VL infection resulted in increased production of cell wall material with an altered composition of carbohydrate polymers and increased lignification. The abundance of several hundred soluble metabolites changed in the apoplast of VL-infected plants including signalling and defence compounds such as glycosides of salicylic acid, lignans and dihydroxybenzoic acid as well as oxylipins. The extracellular proteome of healthy leaves was enriched in antifungal proteins. VL caused specific increases in six apoplast proteins (three peroxidases PRX52, PRX34, P37, serine carboxypeptidase SCPL20, α-galactosidase AGAL2 and a germin-like protein GLP3), which have functions in defence and cell wall modification. The abundance of a lectin-like, chitin-inducible protein (CILLP) was reduced. Since the transcript levels of most of the induced proteins were not elevated until late infection time points (>20 dpi), whereas those of CILLP and GLP3 were reduced at earlier time points, our results may suggest that VL enhances its virulence by rapid down-regulation and delay of induction of plant defence genes. PMID:22363647

  7. Novel Enzymes for Targeted Hydrolysis of Algal Cell Walls

    DEFF Research Database (Denmark)

    Schultz-Johansen, Mikkel

    are incapable of breaking the complex polysaccharides found in seaweed cell walls. Therefore, new enzymes are needed for degradation of seaweed biomass. Bacteria that colonize the surfaces of seaweed secrete enzymes that allow them to degrade and utilize seaweed polysaccharides as energy. In addition, sea...... urchins are known algae-eaters and may therefore be inhabited by endosymbiotic bacteria that help in degradation of algal cell wall constituents. This thesis work investigated bacteria associated with seaweed, seagrass and sea urchins for their enzymatic activities against algal cell wall polysaccharides...

  8. Regulation of Meristem Morphogenesis by Cell Wall Synthases in Arabidopsis.

    Science.gov (United States)

    Yang, Weibing; Schuster, Christoph; Beahan, Cherie T; Charoensawan, Varodom; Peaucelle, Alexis; Bacic, Antony; Doblin, Monika S; Wightman, Raymond; Meyerowitz, Elliot M

    2016-06-06

    The cell walls of the shoot apical meristem (SAM), containing the stem cell niche that gives rise to the above-ground tissues, are crucially involved in regulating differentiation. It is currently unknown how these walls are built and refined or their role, if any, in influencing meristem developmental dynamics. We have combined polysaccharide linkage analysis, immuno-labeling, and transcriptome profiling of the SAM to provide a spatiotemporal plan of the walls of this dynamic structure. We find that meristematic cells express only a core subset of 152 genes encoding cell wall glycosyltransferases (GTs). Systemic localization of all these GT mRNAs by in situ hybridization reveals members with either enrichment in or specificity to apical subdomains such as emerging flower primordia, and a large class with high expression in dividing cells. The highly localized and coordinated expression of GTs in the SAM suggests distinct wall properties of meristematic cells and specific differences between newly forming walls and their mature descendants. Functional analysis demonstrates that a subset of CSLD genes is essential for proper meristem maintenance, confirming the key role of walls in developmental pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Cell Wall Metabolism in Response to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Hyacinthe Le Gall

    2015-02-01

    Full Text Available This review focuses on the responses of the plant cell wall to several abiotic stresses including drought, flooding, heat, cold, salt, heavy metals, light, and air pollutants. The effects of stress on cell wall metabolism are discussed at the physiological (morphogenic, transcriptomic, proteomic and biochemical levels. The analysis of a large set of data shows that the plant response is highly complex. The overall effects of most abiotic stress are often dependent on the plant species, the genotype, the age of the plant, the timing of the stress application, and the intensity of this stress. This shows the difficulty of identifying a common pattern of stress response in cell wall architecture that could enable adaptation and/or resistance to abiotic stress. However, in most cases, two main mechanisms can be highlighted: (i an increased level in xyloglucan endotransglucosylase/hydrolase (XTH and expansin proteins, associated with an increase in the degree of rhamnogalacturonan I branching that maintains cell wall plasticity and (ii an increased cell wall thickening by reinforcement of the secondary wall with hemicellulose and lignin deposition. Taken together, these results show the need to undertake large-scale analyses, using multidisciplinary approaches, to unravel the consequences of stress on the cell wall. This will help identify the key components that could be targeted to improve biomass production under stress conditions.

  10. 2D-immunoblotting analysis of Sporothrix schenckii cell wall

    Directory of Open Access Journals (Sweden)

    Estela Ruiz-Baca

    2011-03-01

    Full Text Available We utilized two-dimensional gel electrophoresis and immunoblotting (2D-immunoblotting with anti-Sporothrix schenckii antibodies to identify antigenic proteins in cell wall preparations obtained from the mycelial and yeast-like morphologies of the fungus. Results showed that a 70-kDa glycoprotein (Gp70 was the major antigen detected in the cell wall of both morphologies and that a 60-kDa glycoprotein was present only in yeast-like cells. In addition to the Gp70, the wall from filament cells showed four proteins with molecular weights of 48, 55, 66 and 67 kDa, some of which exhibited several isoforms. To our knowledge, this is the first 2D-immunoblotting analysis of the S. schenckii cell wall.

  11. Up against the wall: is yeast cell wall integrity ensured by mechanosensing in plasma membrane microdomains?

    Science.gov (United States)

    Kock, Christian; Dufrêne, Yves F; Heinisch, Jürgen J

    2015-02-01

    Yeast cell wall integrity (CWI) signaling serves as a model of the regulation of fungal cell wall synthesis and provides the basis for the development of antifungal drugs. A set of five membrane-spanning sensors (Wsc1 to Wsc3, Mid2, and Mtl1) detect cell surface stress and commence the signaling pathway upon perturbations of either the cell wall structure or the plasma membrane. We here summarize the latest advances in the structure/function relationship primarily of the Wsc1 sensor and critically review the evidence that it acts as a mechanosensor. The relevance and physiological significance of the information obtained for the function of the other CWI sensors, as well as expected future developments, are discussed.

  12. Structural analysis of cell wall polysaccharides using PACE

    Energy Technology Data Exchange (ETDEWEB)

    Mortimer, Jennifer C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Institute

    2017-01-01

    The plant cell wall is composed of many complex polysaccharides. The composition and structure of the polysaccharides affect various cell properties including cell shape, cell function and cell adhesion. Many techniques to characterize polysaccharide structure are complicated, requiring expensive equipment and specialized operators e.g. NMR, MALDI-MS. PACE (Polysaccharide Analysis using Carbohydrate gel Electrophoresis) uses a simple, rapid technique to analyze polysaccharide quantity and structure (Goubet et al. 2002). Whilst the method here describes xylan analysis, it can be applied (by use of the appropriate glycosyl hydrolase) to any cell wall polysaccharide.

  13. Cimicifoetisides A and B, two cytotoxic cycloartane triterpenoid glycosides from the rhizomes of Cimicifuga foetida, inhibit proliferation of cancer cells

    Directory of Open Access Journals (Sweden)

    Qiu Ming-Hua

    2007-01-01

    Full Text Available Abstract Two new cycloartane-type triterpene glycosides, namely cimicifoetisides A (1 and B (2, along with seven known compounds cimigenol, 25-O-acetylcimigenol, cimigenol 3-O-β-D-xylopyranoside, 12β-hydroxycimigenol 3-O-β-D-xylopyranoside, cimigenol 3-O-α-L-arabinopyranoside, 25-deoxyshengmanol 3-O-β-D-xylopyranoside and cimilactone A, were isolated from the rhizomes of Cimicifuga foetida. Their structures were elucidated as cimigenol 3-O-(2'-O-acetyl-α-L-arabinopyranoside (1 and 25-O-acetylcimigenol 3-O-(2'-O-acetyl-α-L-arabinopyranoside (2. Both compounds 1 and 2 exhibited potent cytotoxicity against rat EAC (Ehrlich ascites carcinoma and MDA-MB-A231 (human breast cancer cells with IC50 values of 0.52 and 6.74 μM for 1, and 0.19 and 10.21 μM for 2, suggesting their potential for further investigation as anti-cancer agents.

  14. Cell wall-associated malate dehydrogenase activity from maize roots.

    Science.gov (United States)

    Hadži-Tašković Šukalović, Vesna; Vuletić, Mirjana; Marković, Ksenija; Vučinić, Zeljko

    2011-10-01

    Isolated cell walls from maize (Zea mays L.) roots exhibited ionically and covalently bound NAD-specific malate dehydrogenase activity. The enzyme catalyses a rapid reduction of oxaloacetate and much slower oxidation of malate. The kinetic and regulatory properties of the cell wall enzyme solubilized with 1M NaCl were different from those published for soluble, mitochondrial or plasma membrane malate dehydrogenase with respect to their ATP, Pi, and pH dependence. Isoelectric focusing of ionically-bound proteins and specific staining for malate dehydrogenase revealed characteristic isoforms present in cell wall isolate, different from those present in plasma membranes and crude homogenate. Much greater activity of cell wall-associated malate dehydrogenase was detected in the intensively growing lateral roots compared to primary root with decreased growth rates. Presence of Zn(2+) and Cu(2+) in the assay medium inhibited the activity of the wall-associated malate dehydrogenase. Exposure of maize plants to excess concentrations of Zn(2+) and Cu(2+) in the hydroponic solution inhibited lateral root growth, decreased malate dehydrogenase activity and changed isoform profiles. The results presented show that cell wall malate dehydrogenase is truly a wall-bound enzyme, and not an artefact of cytoplasmic contamination, involved in the developmental processes, and detoxification of heavy metals.

  15. original article the use of morphological and cell wall chemical ...

    African Journals Online (AJOL)

    boaz

    and plant debris to skin. Actinomycetoma is ... species) and plants (Streptomyces scabies) (6, 12,. 13). The cultural ... Cell wall components of Actinomycetes enable rapid qualitative identification of certain ..... morphological differentiation of an.

  16. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

    Cell walls are a defining feature of plants and have numerous crucial roles in growth and development. They are also the largest source of terrestrial biomass and have many important industrial applications - ranging from bulk products to functional food ingredients. There is considerable interest......-D-glucan is not unique to the Poales and is an abundant component of Equisetum arvense cell walls. Plant J 2008; 54:510-21....... in the structure and functions of cell walls, and in the evolution of their remarkably complex polysaccharide structures. The grasses and cereals (order Poales), have long been regarded as being unique in that their cell walls contain an unbranched homopolymer, (1¿3)(1¿4)-ß-D-glucan, in which short blocks of (1...

  17. Boric Acid Disturbs Cell Wall Synthesis in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Martin Schmidt

    2010-01-01

    Full Text Available Boric acid (BA has broad antimicrobial activity that makes it a popular treatment for yeast vaginitis in complementary and alternative medicine. In the model yeast S. cerevisiae, BA disturbs the cytoskeleton at the bud neck and impairs the assembly of the septation apparatus. BA treatment causes cells to form irregular septa and leads to the synthesis of irregular cell wall protuberances that extend far into the cytoplasm. The thick, chitin-rich septa that are formed during BA exposure prevent separation of cells after abscission and cause the formation of cell chains and clumps. As a response to the BA insult, cells signal cell wall stress through the Slt2p pathway and increase chitin synthesis, presumably to repair cell wall damage.

  18. Patterns of expression of cell wall related genes in sugarcane

    Directory of Open Access Journals (Sweden)

    Lima D.U.

    2001-01-01

    Full Text Available Our search for genes related to cell wall metabolism in the sugarcane expressed sequence tag (SUCEST database (http://sucest.lbi.dcc.unicamp.br resulted in 3,283 reads (1% of the total reads which were grouped into 459 clusters (potential genes with an average of 7.1 reads per cluster. To more clearly display our correlation coefficients, we constructed surface maps which we used to investigate the relationship between cell wall genes and the sugarcane tissues libraries from which they came. The only significant correlations that we found between cell wall genes and/or their expression within particular libraries were neutral or synergetic. Genes related to cellulose biosynthesis were from the CesA family, and were found to be the most abundant cell wall related genes in the SUCEST database. We found that the highest number of CesA reads came from the root and stem libraries. The genes with the greatest number of reads were those involved in cell wall hydrolases (e.g. beta-1,3-glucanases, xyloglucan endo-beta-transglycosylase, beta-glucosidase and endo-beta-mannanase. Correlation analyses by surface mapping revealed that the expression of genes related to biosynthesis seems to be associated with the hydrolysis of hemicelluloses, pectin hydrolases being mainly associated with xyloglucan hydrolases. The patterns of cell wall related gene expression in sugarcane based on the number of reads per cluster reflected quite well the expected physiological characteristics of the tissues. This is the first work to provide a general view on plant cell wall metabolism through the expression of related genes in almost all the tissues of a plant at the same time. For example, developing flowers behaved similarly to both meristematic tissues and leaf-root transition zone tissues. Besides providing a basis for future research on the mechanisms of plant development which involve the cell wall, our findings will provide valuable tools for plant engineering in the

  19. Cell wall deposition during morphogenesis in fucoid algae.

    Science.gov (United States)

    Bisgrove, S R; Kropf, D L

    2001-04-01

    Cell was deposition was investigated during morphogenesis in zygotes of Pelvetia compressa (J. Agardh) De Toni. Young zygotes are spherical and wall is deposited uniformly, but at germination (about 10 h after fertilization) wall deposition becomes localized to the apex of the tip-growing rhizoid. Wall deposition was investigated before and after the initiation of tip growth by disrupting cytoskeleton, secretion or cellulose deposition; effects on wall strength and structure were examined. All three were involved in generating wall strength in both spherical and tip-growing zygotes, but their relative importance were different at the two developmental stages. Much of the wall strength in young zygotes was dependent on F-actin, whereas cellulose and a sulfated component, probably a fucan (F2), were most important in tip growing zygotes. Some treatments had contrasting effects at the two developmental stages; for example, disruption of F-actin or inhibition of secretion weakened walls in spherical zygotes but strengthened those in tip-growing zygotes. Transmission electron microscopic analysis showed that most treatments that altered wall strength induced modifications of internal wall structure.

  20. Reduced Wall Acetylation Proteins Play Vital and Distinct Roles in Cell Wall O-Acetylation in Arabidopsis

    DEFF Research Database (Denmark)

    Manabe, Yuzuki; Verhertbruggen, Yves; Gille, Sascha

    2013-01-01

    The Reduced Wall Acetylation (RWA) proteins are involved in cell wall acetylation in plants. Previously, we described a single mutant, rwa2, which has about 20% lower level of O-acetylation in leaf cell walls and no obvious growth or developmental phenotype. In this study, we generated double...... differentiation of cell types with secondary cell walls......., triple, and quadruple loss-of-function mutants of all four members of the RWA family in Arabidopsis (Arabidopsis thaliana). In contrast to rwa2, the triple and quadruple rwa mutants display severe growth phenotypes revealing the importance of wall acetylation for plant growth and development...

  1. Pectin, a versatile polysaccharide present in plant cell walls

    NARCIS (Netherlands)

    Voragen, A.G.J.; Coenen, G.J.; Verhoef, R.P.; Schols, H.A.

    2009-01-01

    Pectin or pectic substances are collective names for a group of closely associated polysaccharides present in plant cell walls where they contribute to complex physiological processes like cell growth and cell differentiation and so determine the integrity and rigidity of plant tissue. They also pla

  2. How the deposition of cellulose microfibrils builds cell wall architecture

    NARCIS (Netherlands)

    Emons, A.M.C.; Mulder, B.M.

    2000-01-01

    Cell walls, the extracytoplasmic matrices of plant cells, consist of an ordered array of cellulose microfibrils embedded in a matrix of polysaccharides and glycoproteins. This construction is reminiscent of steel rods in reinforced concrete. How a cell organizes these ordered textures around itself,

  3. Characterization and localization of insoluble organic matrices associated with diatom cell walls: insight into their roles during cell wall formation.

    Directory of Open Access Journals (Sweden)

    Benoit Tesson

    Full Text Available Organic components associated with diatom cell wall silica are important for the formation, integrity, and function of the cell wall. Polysaccharides are associated with the silica, however their localization, structure, and function remain poorly understood. We used imaging and biochemical approaches to describe in detail characteristics of insoluble organic components associated with the cell wall in 5 different diatom species. Results show that an insoluble organic matrix enriched in mannose, likely the diatotepum, is localized on the proximal surface of the silica cell wall. We did not identify any organic matrix embedded within the silica. We also identified a distinct material consisting of glucose polymer with variable localization depending on the species. In some species this component was directly involved in the morphogenesis of silica structure while in others it appeared to be only a structural component of the cell wall. A novel glucose-rich structure located between daughter cells during division was also identified. This work for the first time correlates the structure, composition, and localization of insoluble organic matrices associated with diatom cell walls. Additionally we identified a novel glucose polymer and characterized its role during silica structure formation.

  4. Cardiac glycosides suppress the maintenance of stemness and malignancy via inhibiting HIF-1α in human glioma stem cells

    Science.gov (United States)

    Lee, Dae-Hee; Oh, Sang Cheul; Giles, Amber J.; Jung, Jinkyu; Gilbert, Mark R.; Park, Deric M.

    2017-01-01

    Tissue hypoxia contributes to solid tumor pathogenesis by activating a series of adaptive programs. We previously showed that hypoxia promotes the preferential expansion and maintenance of CD133 positive human glioma stem cells (GSC) in a hypoxia inducible factor 1 alpha (HIF-1α)-dependent mechanism. Here, we examined the activity of digitoxin (DT), a cardiac glycoside and a putative inhibitor of HIF-1α, on human GSC in vitro and in vivo. During hypoxic conditions (1% O2), we observed the effect of DT on the intracellular level of HIF-1α and the extracellular level of vascular endothelial growth factor (VEGF) in human GSC. We found that DT at clinically achievable concentrations, suppressed HIF-1α accumulation during hypoxic conditions in human GSC and established glioma cell lines. DT treatment also significantly attenuated hypoxia-induced expression of VEGF, a downstream target of HIF-1α. Exposure to DT also reduced hypoxia-induced activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Furthermore, DT potently inhibited neurosphere formation, and decreased CD133 expression even at concentrations that were not overtly cytotoxic. Lastly, treatment with DT reduced GSC engraftment in an in vivo xenograft model of glioblastoma. Intraperitoneal injections of DT significantly inhibited the growth of established glioblastoma xenografts, and suppressed expression of HIF-1α and carbonic anhydrase (CA9), a surrogate marker of hypoxia. Taken together, these results suggest that DT at clinically achievable concentration functions as an inhibitor of HIF-1α, worthy of further investigations in the therapy of glioblastoma. PMID:28410215

  5. Role of the plant cell wall in gravity resistance.

    Science.gov (United States)

    Hoson, Takayuki; Wakabayashi, Kazuyuki

    2015-04-01

    Gravity resistance, mechanical resistance to the gravitational force, is a principal graviresponse in plants, comparable to gravitropism. The cell wall is responsible for the final step of gravity resistance. The gravity signal increases the rigidity of the cell wall via the accumulation of its constituents, polymerization of certain matrix polysaccharides due to the suppression of breakdown, stimulation of cross-link formation, and modifications to the wall environment, in a wide range of situations from microgravity in space to hypergravity. Plants thus develop a tough body to resist the gravitational force via an increase in cell wall rigidity and the modification of growth anisotropy. The development of gravity resistance mechanisms has played an important role in the acquisition of responses to various mechanical stresses and the evolution of land plants.

  6. Ferulic acid is esterified to glucuronoarabinoxylans in pineapple cell walls.

    Science.gov (United States)

    Smith, B G; Harris, P J

    2001-03-01

    The ester-linkage of ferulic acid (mainly E) to polysaccharides in primary cell walls of pineapple fruit (Ananas comosus) (Bromeliaceae) was investigated by treating a cell-wall preparation with 'Driselase' which contains a mixture of endo- and exo-glycanases, but no hydroxycinnamoyl esterase activity. The most abundant feruloyl oligosaccharide released was O-[5-O-(E-feruloyl)-alpha-L-arabinofuranosyl](1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (FAXX). This indicated that the ferulic acid is ester-linked to glucuronoarabinoxylans in the same way as in the primary walls of grasses and cereals (Poaceae). Glucuronoarabinoxylans are the major non-cellulosic polysaccharides in the pineapple cell walls.

  7. Sorption of volatile phenols by yeast cell walls

    Directory of Open Access Journals (Sweden)

    Nerea Jiménez-Moreno

    2009-01-01

    Full Text Available Nerea Jiménez-Moreno, Carmen Ancín-AzpilicuetaDepartment of Applied Chemistry, Universidad Pública de Navarra, Pamplona, SpainAbstract: Yeast walls can retain different wine compounds and so its use is interesting in order to eliminate harmful substances from the must which affect alcoholic fermentation (medium chain fatty acids or which affect wine quality in a negative way (ethyl phenols, ochratoxin A. The aim of this study was to examine the capacity of commercial yeast cell walls in eliminating volatile phenols (4-ethylphenol and 4-ethylguaiacol from a synthetic wine that contained 1 mg/L of each one of these compounds. The binding of these compounds to the wall was quite fast which would seem to indicate that the yeast wall-volatile compound union is produced in the outer surface layers of this enological additive. The cell walls used reduced the concentration of 4-ethylphenol and 4-ethylguaiacol, although it would seem that on modifying the matrix of the wine the number of free binding sites on the walls is also modified.Keywords: volatile phenols, yeast cell walls, wine, sorption

  8. Glycosides from the root of Iodes cirrhosa.

    Science.gov (United States)

    Gan, Maoluo; Zhang, Yanling; Lin, Sheng; Liu, Mingtao; Song, Weixia; Zi, Jiachen; Yang, Yongchun; Fan, Xiaona; Shi, Jiangong; Hu, Jinfeng; Sun, Jiandong; Chen, Naihong

    2008-04-01

    Seven new neolignan glycosides ( 1- 7), two arylglycerol glycosides ( 8, 9), and 18 known glycosides have been isolated from an ethanolic extract of the root of Iodes cirrhosa. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Based on analysis of the NMR data of threo and erythro 8-4'-oxyneolignans and arylglycerols in different solvents, the validity of J 7,8 and Deltadelta C8-C7 values to distinguish threo and erythro derivatives was discussed. In the in vitro assays, compound 4 and liriodendrin ( 17) both showed activity against glutamate-induced PC12 cell damage at 10 (-5) M.

  9. Electron Microscopy of Staphylococcus aureus Cell Wall Lysis

    Science.gov (United States)

    Virgilio, R.; González, C.; Muñoz, Nubia; Mendoza, Silvia

    1966-01-01

    Virgilio, Rafael (Escuela de Química y Farmacia, Universidad de Chile, Santiago, Chile), C. González, Nubia Muñoz, and Silvia Mendoza. Electron microscopy of Staphylococcus aureus cell wall lysis. J. Bacteriol. 91:2018–2024. 1966.—A crude suspension of Staphylococcus aureus cell walls (strain Cowan III) in buffer solution was shown by electron microscopy to lyse slightly after 16 hr, probably owing to the action of autolysin. The lysis was considerably faster and more intense after the addition of lysozyme. A remarkable reduction in thickness and rigidity of the cell walls, together with the appearance of many irregular protrusions in their outlines, was observed after 2 hr; after 16 hr, there remained only a few recognizable cell wall fragments but many residual particulate remnants. When autolysin was previously inactivated by trypsin, there was a complete inhibition of the lytic action of lysozyme; on the other hand, when autolysin was inactivated by heat and lysozyme was added, a distinct decrease in the thickness of the cell walls was observed, but there was no destruction of the walls. The lytic action of lysozyme, after treatment with hot 5% trichloroacetic acid, gave rise to a marked dissolution of the structure of the cell walls, which became lost against the background, without, however, showing ostensible alteration of wall outlines. From a morphological point of view, the lytic action of autolysin plus lysozyme was quite different from that of trichloroacetic acid plus lysozyme, as shown by electron micrographs, but in both cases it was very intense. This would suggest different mechanisms of action for these agents. Images PMID:5939482

  10. Evaluation of cell wall preparations for proteomics: a new procedure for purifying cell walls from Arabidopsis hypocotyls

    Directory of Open Access Journals (Sweden)

    Canut Hervé

    2006-05-01

    Full Text Available Abstract Background The ultimate goal of proteomic analysis of a cell compartment should be the exhaustive identification of resident proteins; excluding proteins from other cell compartments. Reaching such a goal closely depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific difficulties: (i the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP during the isolation procedure, (ii polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins. Several reported procedures to isolate cell walls for proteomic analyses led to the isolation of a high proportion (more than 50% of predicted intracellular proteins. Since isolated cell walls should hold secreted proteins, one can imagine alternative procedures to prepare cell walls containing a lower proportion of contaminant proteins. Results The rationales of several published procedures to isolate cell walls for proteomics were analyzed, with regard to the bioinformatic-predicted subcellular localization of the identified proteins. Critical steps were revealed: (i homogenization in low ionic strength acid buffer to retain CWP, (ii purification through increasing density cushions, (iii extensive washes with a low ionic strength acid buffer to retain CWP while removing as many cytosolic proteins as possible, and (iv absence of detergents. A new procedure was developed to prepare cell walls from etiolated hypocotyls of Arabidopsis thaliana. After salt extraction, a high proportion of proteins predicted to be secreted was released (73%, belonging to the same functional classes as proteins identified using previously described protocols. Finally, removal of intracellular proteins was obtained using detergents, but their amount represented less than 3% in mass of the total protein extract, based on protein quantification. Conclusion The

  11. A model for cell wall dissolution in mating yeast cells: polarized secretion and restricted diffusion of cell wall remodeling enzymes induces local dissolution.

    Directory of Open Access Journals (Sweden)

    Lori B Huberman

    Full Text Available Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells.

  12. A model for cell wall dissolution in mating yeast cells: polarized secretion and restricted diffusion of cell wall remodeling enzymes induces local dissolution.

    Science.gov (United States)

    Huberman, Lori B; Murray, Andrew W

    2014-01-01

    Mating of the budding yeast, Saccharomyces cerevisiae, occurs when two haploid cells of opposite mating types signal using reciprocal pheromones and receptors, grow towards each other, and fuse to form a single diploid cell. To fuse, both cells dissolve their cell walls at the point of contact. This event must be carefully controlled because the osmotic pressure differential between the cytoplasm and extracellular environment causes cells with unprotected plasma membranes to lyse. If the cell wall-degrading enzymes diffuse through the cell wall, their concentration would rise when two cells touched each other, such as when two pheromone-stimulated cells adhere to each other via mating agglutinins. At the surfaces that touch, the enzymes must diffuse laterally through the wall before they can escape into the medium, increasing the time the enzymes spend in the cell wall, and thus raising their concentration at the point of attachment and restricting cell wall dissolution to points where cells touch each other. We tested this hypothesis by studying pheromone treated cells confined between two solid, impermeable surfaces. This confinement increases the frequency of pheromone-induced cell death, and this effect is diminished by reducing the osmotic pressure difference across the cell wall or by deleting putative cell wall glucanases and other genes necessary for efficient cell wall fusion. Our results support the model that pheromone-induced cell death is the result of a contact-driven increase in the local concentration of cell wall remodeling enzymes and suggest that this process plays an important role in regulating cell wall dissolution and fusion in mating cells.

  13. Another brick in the cell wall: biosynthesis dependent growth model.

    Science.gov (United States)

    Barbacci, Adelin; Lahaye, Marc; Magnenet, Vincent

    2013-01-01

    Expansive growth of plant cell is conditioned by the cell wall ability to extend irreversibly. This process is possible if (i) a tensile stress is developed in the cell wall due to the coupling effect between turgor pressure and the modulation of its mechanical properties through enzymatic and physicochemical reactions and if (ii) new cell wall elements can be synthesized and assembled to the existing wall. In other words, expansive growth is the result of coupling effects between mechanical, thermal and chemical energy. To have a better understanding of this process, models must describe the interplay between physical or mechanical variable with biological events. In this paper we propose a general unified and theoretical framework to model growth in function of energy forms and their coupling. This framework is based on irreversible thermodynamics. It is then applied to model growth of the internodal cell of Chara corallina modulated by changes in pressure and temperature. The results describe accurately cell growth in term of length increment but also in term of cell pectate biosynthesis and incorporation to the expanding wall. Moreover, the classical growth model based on Lockhart's equation such as the one proposed by Ortega, appears as a particular and restrictive case of the more general growth equation developed in this paper.

  14. Another brick in the cell wall: biosynthesis dependent growth model.

    Directory of Open Access Journals (Sweden)

    Adelin Barbacci

    Full Text Available Expansive growth of plant cell is conditioned by the cell wall ability to extend irreversibly. This process is possible if (i a tensile stress is developed in the cell wall due to the coupling effect between turgor pressure and the modulation of its mechanical properties through enzymatic and physicochemical reactions and if (ii new cell wall elements can be synthesized and assembled to the existing wall. In other words, expansive growth is the result of coupling effects between mechanical, thermal and chemical energy. To have a better understanding of this process, models must describe the interplay between physical or mechanical variable with biological events. In this paper we propose a general unified and theoretical framework to model growth in function of energy forms and their coupling. This framework is based on irreversible thermodynamics. It is then applied to model growth of the internodal cell of Chara corallina modulated by changes in pressure and temperature. The results describe accurately cell growth in term of length increment but also in term of cell pectate biosynthesis and incorporation to the expanding wall. Moreover, the classical growth model based on Lockhart's equation such as the one proposed by Ortega, appears as a particular and restrictive case of the more general growth equation developed in this paper.

  15. Altered cell wall disassembly during ripening of Cnr tomato fruit : implications for cell wall adhesion and fruit softening

    NARCIS (Netherlands)

    Orfila, C.; Huisman, M.M.H.; Willats, W.G.T.; Alebeek, van G.J.W.M.; Schols, H.A.; Seymour, G.B.; Knox, J.P.

    2002-01-01

    The Cnr (Colourless non-ripening) tomato (Lycopersicon esculentum Mill.) mutant has an aberrant fruit-ripening phenotype in which fruit do not soften and have reduced cell adhesion between pericarp cells. Cell walls from Cnr fruit were analysed in order to assess the possible contribution of pectic

  16. Spectroscopic characterization and antiproliferative activity on HepG2 human hepatoblastoma cells of flavonoid C-glycosides from Petrorhagia velutina.

    Science.gov (United States)

    Pacifico, Severina; Scognamiglio, Monica; D'Abrosca, Brigida; Piccolella, Simona; Tsafantakis, Nikolaos; Gallicchio, Marialuisa; Ricci, Andreina; Fiorentino, Antonio

    2010-12-27

    Eight flavonoid C-glycosides, including three new analogues, have been isolated from leaf and root methanolic extracts of Petrorhagia velutina, a Mediterranean herbaceous plant. The antiproliferative activity against human hepatoblastoma cancer cell line HepG2 has been analyzed by the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) test. Isoorientin (4) significantly reduces the proliferation of HepG2 cells as determined by the complete conversion of the tetrazolium probe into formazan after 48 h of exposure.

  17. Delivery of acetylthevetin B, an antitumor cardiac glycoside, using polymeric micelles for enhanced therapeutic efficacy against lung cancer cells

    Science.gov (United States)

    Zhu, Jing-jing; Zhang, Xin-xin; Miao, Yun-qiu; He, Shu-fang; Tian, Dan-mei; Yao, Xin-sheng; Tang, Jin-shan; Gan, Yong

    2017-01-01

    Acetylthevetin B (ATB), a cardiac glycoside from the seed of Thevetia peruviana (Pers) K Schum (yellow oleander), exhibits not only antitumor activity but also potential cardiac toxicity. In the present study, we attempted to enhance its antitumor action and decrease its adverse effects via chitosan-Pluronic P123 (CP) micelle encapsulation. Two ATB-loaded CP micelles (ATB-CP1, ATB-CP2) were prepared using an emulsion/solvent evaporation technique. They were spherical in shape with a particle size of 40–50 nm, showed a neutral zeta potential, and had acceptable encapsulation efficiency (>90%). Compared to the free ATB (IC50=2.94 μmol/L), ATB-loaded CP micelles exerted much stronger cytotoxicity against human lung cancer A549 cells with lower IC50 values (0.76 and 1.44 μmol/L for ATB-CP1 and ATB-CP2, respectively). After administration of a single dose in mice, the accumulation of ATB-loaded CP1 micelles in the tumor and lungs, respectively, was 15.31-fold and 9.49-fold as high as that of free ATB. A549 xenograft tumor mice treated with ATB-loaded CP1 micelles for 21 d showed the smallest tumor volume (one-fourth of that in the control group) and the highest inhibition rate (85.6%) among all the treatment groups. After 21-d treatment, no significant pathological changes were observed in hearts and other main tissues. In summary, ATB may serve as a promising antitumor chemotherapeutic agent for lung cancer, and its antitumor efficacy was significantly improved by CP micelles, with lower adverse effects. PMID:27917871

  18. Simulated microgravity inhibits cell wall regeneration of Penicillium decumbens protoplasts

    Science.gov (United States)

    Zhao, C.; Sun, Y.; Yi, Z. C.; Rong, L.; Zhuang, F. Y.; Fan, Y. B.

    2010-09-01

    This work compares cell wall regeneration from protoplasts of the fungus Penicillium decumbens under rotary culture (simulated microgravity) and stationary cultures. Using an optimized lytic enzyme mixture, protoplasts were successfully released with a yield of 5.3 × 10 5 cells/mL. Under simulated microgravity conditions, the protoplast regeneration efficiency was 33.8%, lower than 44.9% under stationary conditions. Laser scanning confocal microscopy gave direct evidence for reduced formation of polysaccharides under simulated conditions. Scanning electron microscopy showed the delayed process of cell wall regeneration by simulated microgravity. The delayed regeneration of P. decumbens cell wall under simulated microgravity was likely caused by the inhibition of polysaccharide synthesis. This research contributes to the understanding of how gravitational loads affect morphological and physiological processes of fungi.

  19. Magnetic domain wall conduits for single cell applications

    DEFF Research Database (Denmark)

    Donolato, Marco; Torti, A.; Kostesha, Natalie;

    2011-01-01

    The ability to trap, manipulate and release single cells on a surface is important both for fundamental studies of cellular processes and for the development of novel lab-on-chip miniaturized tools for biological and medical applications. In this paper we demonstrate how magnetic domain walls...... generated in micro- and nano-structures fabricated on a chip surface can be used to handle single yeast cells labeled with magnetic beads. In detail, first we show that the proposed approach maintains the microorganism viable, as proven by monitoring the division of labeled yeast cells trapped by domain...... walls over 16 hours. Moreover, we demonstrate the controlled transport and release of individual yeast cells via displacement and annihilation of individual domain walls in micro- and nano-sized magnetic structures. These results pave the way to the implementation of magnetic devices based on domain...

  20. Primary Cell Wall Structure in the Evolution of Land Plants

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Investigation of the primary cell walls of lower plants improves our understanding of the cell biology of these organisms but also has the potential to improve our understanding of cell wall structure and function in angiosperms that evolved from lower plants. Cell walls were prepared from eight species, ranging from a moss to advanced gymnosperms, and subjected to sequential chemical extraction to separate the main polysaccharide fractions. The glycosyl compositions of these fractions were then determined by gas chromatography. The results were compared among the eight plants and among data from related studies reported in the existing published reports to identify structural features that have been either highly conserved or clearly modified during evolution. Among the highly conserved features are the presence of a cellulose framework, the presence of certain hemicelluloses such as xyloglucan, and the presence of rhamnogalacturonan Ⅱ, a domain in pectic polysaccharides. Among the modified features are the abundance of mannosyl-containing hemicelluloses and the presence of methylated sugars.

  1. Diffusion of an organic cation into root cell walls.

    Science.gov (United States)

    Meychik, N R; Yermakov, I P; Prokoptseva, O S

    2003-07-01

    Uptake of a cationic dye (methylene blue) by isolated root cell walls, roots of whole transpiring seedlings, and excised roots was investigated using 7-day-old seedlings of cucumber, maize, and wheat. The number of ionogenic groups per 1 g dry and wet weight of the root cell walls, their swelling capacity (K(cw)), time-dependence of methylene blue (M(cw)) ion exchange capacity, and diffusion coefficients of the cation diffusion in the polymer matrix of the cell walls (D(cw)) were determined. The M(cw) value depended on pH (or carboxyl group dissociation); it changed in accordance with the number of carboxyl groups per 1 g cell wall dry weight. This parameter decreased in the order: cucumber > wheat > maize. For description of experimental kinetic curves and calculation of cation diffusion coefficients, the equation for ion diffusion into a cylinder of infinite length was used. The chosen model adequately described cation diffusion in cell walls and roots. Diffusion coefficient values for cucumber, wheat, and maize were 3.1*10(-8), 1.3*10(-8), and 8.4*10(-8) cm(2)/sec, respectively. There was a statistically significant linear dependence between K(cw) and D(cw) values, which characterize the same property of the polymer matrix, rigidity of its polymer structure or the degree of cross-linkage or permeability. This also confirms the right choice of the model selected for calculation of methylene blue diffusion coefficients, because K(cw) and D(cw) values were obtained in independent experiments. The coefficients determined for methylene blue diffusion in transpiring seedling roots (D(ts)) and excised roots (D(er)) depended on the plant species. The rate of methylene blue diffusion into the excised roots was either 1.5-fold lower (cucumber) or 3-4-times lower (maize, wheat) than in cell walls. The values of diffusion coefficients in roots of whole seedlings were comparable which those for the cell walls. On the basis of the experimental data and results of calculations

  2. Analyzing Cell Wall Elasticity After Hormone Treatment: An Example Using Tobacco BY-2 Cells and Auxin.

    Science.gov (United States)

    Braybrook, Siobhan A

    2017-01-01

    Atomic force microscopy, and related nano-indentation techniques, is a valuable tool for analyzing the elastic properties of plant cell walls as they relate to changes in cell wall chemistry, changes in development, and response to hormones. Within this chapter I will describe a method for analyzing the effect of the phytohormone auxin on the cell wall elasticity of tobacco BY-2 cells. This general method may be easily altered for different experimental systems and hormones of interest.

  3. How cell wall complexity influences saccharification efficiency in Miscanthus sinensis

    NARCIS (Netherlands)

    Souza, De Amanda P.; Lessa Alvim Kamei, Claire; Torres Salvador, Andres Francisco; Pattathil, Sivakumar; Hahn, Michael G.; Trindade, Luisa M.; Buckeridge, Marcos S.

    2015-01-01

    The production of bioenergy from grasses has been developing quickly during the last decade, with Miscanthus being among the most important choices for production of bioethanol. However, one of the key barriers to producing bioethanol is the lack of information about cell wall structure. Cell wal

  4. Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line.

    Science.gov (United States)

    Dietrich, Fabrícia; Kaiser, Samuel; Rockenbach, Liliana; Figueiró, Fabrício; Bergamin, Letícia Scussel; da Cunha, Fernanda Monte; Morrone, Fernanda Bueno; Ortega, George González; Battastini, Ana Maria Oliveira

    2014-05-01

    Bladder cancer is the second most prevalent malignancy in the genitourinary tract and remains a therapeutic challenge. In the search for new treatments, researchers have attempted to find compounds with low toxicity. With this goal in mind, Uncaria tomentosa is noteworthy because the bark and root of this species are widely used in traditional medicine and in adjuvant therapy for the treatment of numerous diseases. The objective of this study was to investigate the antitumor effect of one purified bioactive fraction of U.tomentosa bark on cell proliferation in two human bladder cancer cell lines, T24 and RT4. Quinovic acid glycosides purified fraction (QAPF) of U.tomentosa decreased the growth and viability of both T24 and RT4 cell lines. In T24 cells, QAPF induced apoptosis by activating caspase-3 and NF-κB. Further study showed that this fraction does not induce cell cycle arrest and does not alter PTEN and ERK levels. In conclusion, we demonstrated that QAPF of U.tomentosa has a potent inhibitory effect on the growth of human bladder cancer cell lines by inducing apoptosis through modulation of NF-κB, and we suggest that QAPF may become a potential therapeutic agent for the prevention and/or treatment of this cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Cell wall proteome analysis of Arabidopsis thaliana mature stems.

    Science.gov (United States)

    Duruflé, Harold; Clemente, Hélène San; Balliau, Thierry; Zivy, Michel; Dunand, Christophe; Jamet, Elisabeth

    2017-04-01

    Plant stems carry flowers necessary for species propagation and need to be adapted to mechanical disturbance and environmental factors. The stem cell walls are different from other organs and can modify their rigidity or viscoelastic properties for the integrity and the robustness required to withstand mechanical impacts and environmental stresses. Plant cell wall is composed of complex polysaccharide networks also containing cell wall proteins (CWPs) crucial to perceive and limit the environmental effects. The CWPs are fundamental players in cell wall remodeling processes, and today, only 86 have been identified from the mature stems of the model plant Arabidopsis thaliana. With a destructive method, this study has enlarged its coverage to 302 CWPs. This new proteome is mainly composed of 27.5% proteins acting on polysaccharides, 16% proteases, 11.6% oxido-reductases, 11% possibly related to lipid metabolism and 11% of proteins with interacting domains with proteins or polysaccharides. Compared to stem cell wall proteomes already available (Brachypodium distachyon, Sacharum officinarum, Linum usitatissimum, Medicago sativa), that of A. thaliana stems has a higher proportion of proteins acting on polysaccharides and of proteases, but a lower proportion of oxido-reductases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Growth and cell wall changes in rice roots during spaceflight.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Tanimoto, Eiichi

    2003-08-01

    We analyzed the changes in growth and cell wall properties of roots of rice (Oryza sativa L. cv. Koshihikari) grown for 68.5, 91.5, and 136 h during the Space Shuttle STS-95 mission. In space, most of rice roots elongated in a direction forming a constant mean angle of about 55 degrees with the perpendicular base line away from the caryopsis in the early phase of growth, but later the roots grew in various directions, including away from the agar medium. In space, elongation growth of roots was stimulated. On the other hand, some of elasticity moduli and viscosity coefficients were higher in roots grown in space than on the ground, suggesting that the cell wall of space-grown roots has a lower capacity to expand than the controls. The levels of both cellulose and the matrix polysaccharides per unit length of roots decreased greatly, whereas the ratio of the high molecular mass polysaccharides in the hemicellulose fraction increased in space-grown roots. The prominent thinning of the cell wall could overwhelm the disadvantageous changes in the cell wall mechanical properties, leading to the stimulation of elongation growth in rice roots in space. Thus, growth and the cell wall properties of rice roots were strongly modified under microgravity conditions during spaceflight.

  7. Pectic homogalacturonan masks abundant sets of xyloglucan epitopes in plant cell walls

    DEFF Research Database (Denmark)

    Marcus, Susan E; Verhertbruggen, Yves; Hervé, Cécile

    2008-01-01

    is associated with pectin in plant cell walls. They also indicate that documented patterns of cell wall epitopes in relation to cell development and cell differentiation may need to be re-considered in relation to the potential masking of cell wall epitopes by other cell wall components.......BACKGROUND: Molecular probes are required to detect cell wall polymers in-situ to aid understanding of their cell biology and several studies have shown that cell wall epitopes have restricted occurrences across sections of plant organs indicating that cell wall structure is highly developmentally...... regulated. Xyloglucan is the major hemicellulose or cross-linking glycan of the primary cell walls of dicotyledons although little is known of its occurrence or functions in relation to cell development and cell wall microstructure. RESULTS: Using a neoglycoprotein approach, in which a XXXG heptasaccharide...

  8. Fluorescent Probes for Exploring Plant Cell Wall Deconstruction: A Review

    Directory of Open Access Journals (Sweden)

    Gabriel Paës

    2014-07-01

    Full Text Available Plant biomass is a potential resource of chemicals, new materials and biofuels that could reduce our dependency on fossil carbon, thus decreasing the greenhouse effect. However, due to its chemical and structural complexity, plant biomass is recalcitrant to green biological transformation by enzymes, preventing the establishment of integrated bio-refineries. In order to gain more knowledge in the architecture of plant cell wall to facilitate their deconstruction, many fluorescent probes bearing various fluorophores have been devised and used successfully to reveal the changes in structural motifs during plant biomass deconstruction, and the molecular interactions between enzymes and plant cell wall polymers. Fluorescent probes are thus relevant tools to explore plant cell wall deconstruction.

  9. The role of the cell wall in fungal pathogenesis.

    Science.gov (United States)

    Arana, David M; Prieto, Daniel; Román, Elvira; Nombela, César; Alonso-Monge, Rebeca; Pla, Jesús

    2009-05-01

    Fungal infections are a serious health problem. In recent years, basic research is focusing on the identification of fungal virulence factors as promising targets for the development of novel antifungals. The wall, as the most external cellular component, plays a crucial role in the interaction with host cells mediating processes such as adhesion or phagocytosis that are essential during infection. Specific components of the cell wall (called PAMPs) interact with specific receptors in the immune cell (called PRRs), triggering responses whose molecular mechanisms are being elucidated. We review here the main structural carbohydrate components of the fungal wall (glucan, mannan and chitin), how their biogenesis takes place in fungi and the specific receptors that they interact with. Different model fungal pathogens are chosen to illustrate the functional consequences of this interaction. Finally, the identification of the key components will have important consequences in the future and will allow better approaches to treat fungal infections.

  10. Transcriptional Wiring of Cell Wall-Related Genes in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Marek Mutwil; Colin Ruprecht; Federico M. Giorgi; Martin Bringmann; Bj(o)rn Usadel; Staffan Persson

    2009-01-01

    Transcriptional coordination, or co-expression, of genes may signify functional relatedness of the correspond-ing proteins. For example, several genes involved in secondary cell wall cellulose biosynthesis are co-expressed with genes engaged in the synthesis of xylan, which is a major component of the secondary cell wall. To extend these types of anal-yses, we investigated the co-expression relationships of all Carbohydrate-Active enZYmes (CAZy)-related genes for Arabidopsis thaliana. Thus, the intention was to transcriptionally link different cell wall-related processes to each other, and also to other biological functions. To facilitate easy manual inspection, we have displayed these interactions as networks and matrices, and created a web-based interface (http://aranet.mpimp-golm.mpg.de/corecarb) containing downloadable files for all the transcriptional associations.

  11. Structural basis for selective recognition of pneumococcal cell wall by modular endolysin from phage Cp-1.

    Science.gov (United States)

    Hermoso, Juan A; Monterroso, Begoña; Albert, Armando; Galán, Beatriz; Ahrazem, Oussama; García, Pedro; Martínez-Ripoll, Martín; García, José Luis; Menéndez, Margarita

    2003-10-01

    Pneumococcal bacteriophage-encoded lysins are modular choline binding proteins that have been shown to act as enzymatic antimicrobial agents (enzybiotics) against streptococcal infections. Here we present the crystal structures of the free and choline bound states of the Cpl-1 lysin, encoded by the pneumococcal phage Cp-1. While the catalytic module displays an irregular (beta/alpha)(5)beta(3) barrel, the cell wall-anchoring module is formed by six similar choline binding repeats (ChBrs), arranged into two different structural regions: a left-handed superhelical domain configuring two choline binding sites, and a beta sheet domain that contributes in bringing together the whole structure. Crystallographic and site-directed mutagenesis studies allow us to propose a general catalytic mechanism for the whole glycoside hydrolase family 25. Our work provides the first complete structure of a member of the large family of choline binding proteins and reveals that ChBrs are versatile elements able to tune the evolution and specificity of the pneumococcal surface proteins.

  12. Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice.

    Science.gov (United States)

    Li, Hua; Ji, Hyeon-Seon; Kang, Ji-Hyun; Shin, Dong-Ha; Park, Ho-Yong; Choi, Myung-Sook; Lee, Chul-Ho; Lee, In-Kyung; Yun, Bong-Sik; Jeong, Tae-Sook

    2015-08-19

    This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved β-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and β-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated β-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice.

  13. Particle Trajectories in Rotating Wall Cell Culture Devices

    Science.gov (United States)

    Ramachandran N.; Downey, J. P.

    1999-01-01

    Cell cultures are extremely important to the medical community since such cultures provide an opportunity to perform research on human tissue without the concerns inherent in experiments on individual humans. Development of cells in cultures has been found to be greatly influenced by the conditions of the culture. Much work has focused on the effect of the motions of cells in the culture relative to the solution. Recently rotating wall vessels have been used with success in achieving improved cellular cultures. Speculation and limited research have focused on the low shear environment and the ability of rotating vessels to keep cells suspended in solution rather than floating or sedimenting as the primary reasons for the improved cellular cultures using these devices. It is widely believed that the cultures obtained using a rotating wall vessel simulates to some degree the effect of microgravity on cultures. It has also been speculated that the microgravity environment may provide the ideal acceleration environment for culturing of cellular tissues due to the nearly negligible levels of sedimentation and shear possible. This work predicts particle trajectories of cells in rotating wall vessels of cylindrical and annular design consistent with the estimated properties of typical cellular cultures. Estimates of the shear encountered by cells in solution and the interactions with walls are studied. Comparisons of potential experiments in ground and microgravity environments are performed.

  14. Characters of Fractal Ultrastructure in Wood Cell Wall

    Institute of Scientific and Technical Information of China (English)

    LI Beimei; ZHAO Guangjie

    2006-01-01

    Fractal theory was introduced in order to describe the ultrastructure of wood cell wall in this paper.The cellulose chain clusters around nano-scale were viewed as a fractal object that consists of many fibrillar structural units with different scales including microfibrils.On the basis of the morphological data of wood cell wall.fractal dimensions of multi-level fibrillar structural units were calculated by fractal-geometry approach,and then the morphological and structural characteristics of fibers as well as the influences on wood properties were investigated according to the dimensions.Besides,the fractal self-nesting character of the ultrastruture was also analyzed.

  15. Hematopoietic Stem Cells Expansionin Rotating Wall Vessel

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionClinical trials have demonstrated that ex vivo expanded hematopoietic stem cells (HSCs) and progenitors offer great promise in reconstituting in vivo hematopoiesis in patients who have undergone intensive chemotherapy. It is therefore necessary to develop a clinical-scale culture system to provide the expanded HSCs and progenitors. Static culture systems such as T-flasks and gas-permeable blood bags are the most widely used culture devices for expanding hematopoietic cells. But they reveal sev...

  16. Phagocytic properties of lung alveolar wall cells

    Directory of Open Access Journals (Sweden)

    Tanaka,Akisuke

    1974-04-01

    Full Text Available For the purpose to define the mechanism of heavy metal intoxication by inhalation, morphologic observations were made on rat lungs after nasal instillation of iron colloid particles of positive and negative electric charges. Histochemical observation was also made on the liver and spleen of these animals. The instilled iron colloid particles reach the alveolar cavity easily, as can be seen in the tissue sections stained by Prussian blue reaction. Alveolar macrophages do take up them avidly both of positive and negative charges, though much less the positive particles than negative ones. In contrast, the alveolar epithelial cells take up solely positive particles by phagocytosis but not negative ones. Electron microscope observation revealed that the positive particles are ingested by Type I epithelial cells by pinocytosis and by Type II cells by phagocytosis as well. Then the iron colloid particles are transferred into the basement membrane by exocytosis. Travelling through the basement membrane they are again taken up by capillary endothelial cells by phagocytosis. Some particles were found in the intercellular clefts of capillary endothelial cells but not any iron colloid particles in the intercellular spaces of epithelial cells and in the capillary lumen. However, the liver and spleen tissues of the animals given iron colloid showed a strong positive iron reaction. On the basis of these observations, the mechanism of acute intoxication by inhaling heavy metal dusts like lead fume is discussed from the view point of selective uptake of alveolar epithelial and capillary endothelial cells for the particles of the positive electric cha'rge.

  17. Molecular mechanisms for vascular development and secondary cell wall formation

    Directory of Open Access Journals (Sweden)

    Jung Hyun eYang

    2016-03-01

    Full Text Available Vascular tissues are important for transporting water and nutrients throughout the plant and as physical support of upright growth. The primary constituents of vascular tissues, xylem and phloem, are derived from the meristematic vascular procambium and cambium. Xylem cells develop secondary cell walls that form the largest part of plant lignocellulosic biomass that serve as a renewable feedstock for biofuel production. For the last decade, research on vascular development and secondary cell wall biosynthesis has seen rapid progress due to the importance of these processes to plant biology and to the biofuel industry. Plant hormones, transcriptional regulators and peptide signaling regulate procambium/cambium proliferation, vascular patterning, and xylem differentiation. Transcriptional regulatory pathways play a pivot role in secondary cell wall biosynthesis. Although most of these discoveries are derived from research in Arabidopsis, many genes have shown conserved functions in biofuel feedstock species. Here, we review the recent advances in our understanding of vascular development and secondary cell wall formation and discuss potential biotechnological uses.

  18. Bacterial Cell Wall Growth, Shape and Division

    NARCIS (Netherlands)

    Derouaux, A.; Terrak, M.; den Blaauwen, T.; Vollmer, W.; Remaut, H.; Fronzes, R.

    2014-01-01

    The shape of a bacterial cell is maintained by its peptidoglycan sacculus that completely surrounds the cytoplasmic membrane. During growth the sacculus is enlarged by peptidoglycan synthesis complexes that are controlled by components linked to the cytoskeleton and, in Gram-negative bacteria, by ou

  19. Cell wall modification in grapevine cells in response to UV stress investigated by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lesniewska, E.; Adrian, M.; Klinguer, A.; Pugin, A

    2004-08-15

    Despite cell wall reinforcement being a well-known defence mechanism of plants, it remains poorly characterized from a physical point of view. The objective of this work was to further describe this mechanism. Vitis vinifera cv Gamay cells were treated with UV-light (254 nm), a well-known elicitor of defence mechanisms in grapevines, and physical cell wall modifications were observed using the atomic force microscopy (AFM) under native conditions. The grapevine cell suspensions were continuously observed in their culture medium from 30 min to 24 h after elicitation. In the beginning, cellulose fibrils covered by a matrix surrounded the control and treated cells. After 3 h, the elicited cells displayed sprouted expansions around the cell wall that correspond to pectin chains. These expansions were not observed on untreated grapevine cells. The AFM tip was used to determine the average surface elastic modulus of cell wall that account for cell wall mechanical properties. The elasticity is diminished in UV-treated cells. In a comparative study, grapevine cells showed the same decrease in cell wall elasticity when treated with a fungal biotic elicitor of defence response. These results demonstrate cell wall strengthening by UV stress.

  20. O-acetylation of Plant Cell Wall Polysaccharides

    Directory of Open Access Journals (Sweden)

    Sascha eGille

    2012-01-01

    Full Text Available Plant cell walls are composed of structurally diverse polymers, many of which are O-acetylated. How plants O-acetylate wall polymers and what its function is remained elusive until recently, when two protein families were identified in the model plant Arabidopsis that are involved in the O-acetylation of wall polysaccharides – the reduced wall acetylation (RWA and the trichome birefringence-like (TBL proteins. This review discusses the role of these two protein families in polysaccharide O-acetylation and outlines the differences and similarities of polymer acetylation mechanisms in plants, fungi, bacteria and mammals. Members of the TBL protein family had been shown to impact pathogen resistance, freezing tolerance, and cellulose biosynthesis. The connection of TBLs to polysaccharide O-acetylation thus gives crucial leads into the biological function of wall polymer O-acetylation.From a biotechnological point understanding the O-acetylation mechanism is important as acetyl-substituents inhibit the enzymatic degradation of wall polymers and released acetate can be a potent inhibitor in microbial fermentations, thus impacting the economic viability of e.g. lignocellulosic based biofuel production.

  1. An emerging role of pectic rhamnogalacturonanII for cell wall integrity.

    Science.gov (United States)

    Reboul, Rebecca; Tenhaken, Raimund

    2012-02-01

    The plant cell wall is a complex network of different polysaccharides and glycoproteins, showing high diversity in nature. The essential components, tethering cell wall are under debate, as novel mutants challenge established models. The mutant ugd2,3 with a reduced supply of the important wall precursor UDP-glucuronic acid reveals the critical role of the pectic compound rhamnogalacturonanII for cell wall stability. This polymer seems to be more important for cell wall integrity than the previously favored xyloglucan.

  2. Cell wall structure and function in lactic acid bacteria.

    Science.gov (United States)

    Chapot-Chartier, Marie-Pierre; Kulakauskas, Saulius

    2014-08-29

    The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts.

  3. New Model of Wood Cell Wall Microfibril and Its Implications

    Science.gov (United States)

    Umesh P. Agarwal; Sally A. Ralph; Rick S. Reiner; Carlos Baez

    2015-01-01

    Traditionally it has been accepted that the cell walls are made up of microfibrils which are partly crystalline. However, based on the recently obtained Raman evidence that showed that the interior of the microfibril was significantly disordered and water accessible, a new model is proposed. In this model, the molecular chains of cellulose are still organized along the...

  4. Polymer mobility in cell walls of cucumber hypocotyls

    Science.gov (United States)

    Fenwick, K. M.; Apperley, D. C.; Cosgrove, D. J.; Jarvis, M. C.

    1999-01-01

    Cell walls were prepared from the growing region of cucumber (Cucumis sativus) hypocotyls and examined by solid-state 13C NMR spectroscopy, in both enzymically active and inactivated states. The rigidity of individual polymer segments within the hydrated cell walls was assessed from the proton magnetic relaxation parameter, T2, and from the kinetics of cross-polarisation from 1H to 13C. The microfibrils, including most of the xyloglucan in the cell wall, as well as cellulose, behaved as very rigid solids. A minor xyloglucan fraction, which may correspond to cross-links between microfibrils, shared a lower level of rigidity with some of the pectic galacturonan. Other pectins, including most of the galactan side-chain residues of rhamnogalacturonan I, were much more mobile and behaved in a manner intermediate between the solid and liquid states. The only difference observed between the enzymically active and inactive cell walls, was the loss of a highly mobile, methyl-esterified galacturonan fraction, as the result of pectinesterase activity.

  5. The Mechanisms of Plant Cell Wall Deconstruction during Enzymatic Hydrolysis

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; E. Thybring, Emil; Johansen, Katja Salomon;

    2014-01-01

    . Here we put forward a simple model based on mechanical principles capable of capturing the result of the interaction between mechanical forces and cell wall weakening via hydrolysis of glucosidic bonds. This study illustrates that basic material science insights are relevant also within biochemistry......, particularly when it comes to up-scaling of processes based on insoluble feed stocks....

  6. The role of the cell wall in plant immunity

    DEFF Research Database (Denmark)

    Malinovsky, Frederikke Gro; Fangel, Jonatan Ulrik; Willats, William George Tycho

    2014-01-01

    The battle between plants and microbes is evolutionarily ancient, highly complex, and often co-dependent. A primary challenge for microbes is to breach the physical barrier of host cell walls whilst avoiding detection by the plant's immune receptors. While some receptors sense conserved microbial...

  7. Analyzing the complex machinery of cell wall biosynthesis

    NARCIS (Netherlands)

    Timmers, J.F.P.

    2009-01-01

    The plant cell wall polymers make up most of the plant biomass and provide the raw material for many economically important products including food, feed, bio-materials, chemicals, textiles, and biofuel. This broad range of functions and applications make the biosynthesis of these polysaccharides a

  8. In planta modification of the potato tuber cell wall

    NARCIS (Netherlands)

    Oomen, R.J.F.J.

    2003-01-01

    Apart from its well known uses in the human diet a large amount of the grown potatoes (about one third in the Netherlands) is used for the isolation of starch which is used in several food and non-food applications. The cell wall fibres comprise a large portion of the waste material remaining after

  9. Titration of Isolated Cell Walls of Lemna minor L 1

    Science.gov (United States)

    Morvan, Claudine; Demarty, Maurice; Thellier, Michel

    1979-01-01

    A theoretical model has been built to bypass the equation of titration of the cell wall. This equation, which is an extension of the Henderson-Hasselbach equation, underlines the importance of the exchange constant, the ionic strength as well as the rate of neutralization. The model is restricted to the case when the ionization degree is equal to the neutralization degree. The shape of the titration curve is shown to be strongly dependent on the valency of the base used. Experimental results have shown that isolated cell walls bear at least two kinds of sites. The first sites which are titrated after a short time of equilibration are attributed to polyuronic acids (capacity: 0.3 milliequivalents per gram fresh cell walls). The second sites, are obtained after a long time of equilibration (capacity: 1.2 to 1.3 milliequivalents per gram, fresh cell walls). Titrations have been performed with different bases [KOH, NaOH, and Ca(OH)2] and under different ionic strengths. The results obtained with NaOH and KOH do not exhibit any difference of selectivity. Conversely, the sites have a much bigger affinity for the Ca2+ ions than for the monovalent ones. The apparent pKa of the uronic acids was estimated to lie between 3.0 and 3.4; this is consistent with the values obtained with polyuronic acid solutions. PMID:16660868

  10. Evidence for a Melanin Cell Wall Component in Pneumocystis carinii

    OpenAIRE

    Icenhour, Crystal R.; Kottom, Theodore J.; Limper, Andrew H

    2003-01-01

    Fluorescein isothiocyanate-labeled monoclonal antibodies specific for fungal melanin were used in this study to visualize melanin-like components of the Pneumocystis carinii cell wall. A colorimetric enzyme assay confirmed these findings. This is the first report of melanin-like pigments in Pneumocystis.

  11. Characterisation of cell wall polysaccharides in bilberries and black currants

    NARCIS (Netherlands)

    Hilz, H.

    2007-01-01

    During berry juice production, polysaccharides are released from the cell walls and cause thickening and high viscosity when the berries are mashed. Consequences are a low juice yield and a poor colour. This can be prevented by the use of enzymes that degrade these polysaccharides. To use these enzy

  12. Analyzing the complex machinery of cell wall biosynthesis

    NARCIS (Netherlands)

    Timmers, J.F.P.

    2009-01-01

    The plant cell wall polymers make up most of the plant biomass and provide the raw material for many economically important products including food, feed, bio-materials, chemicals, textiles, and biofuel. This broad range of functions and applications make the biosynthesis of these polysaccharides a

  13. Characterisation of cell-wall polysaccharides from mandarin segment membranes

    NARCIS (Netherlands)

    Coll-Almela, L.; Saura-Lopez, D.; Laencina-Sanchez, J.; Schols, H.A.; Voragen, A.G.J.; Ros-García, J.M.

    2015-01-01

    In an attempt to develop a process of enzymatic peeling of mandarin segments suitable for use on an industrial scale, the cell wall fraction of the segment membrane of Satsuma mandarin fruits was extracted to obtain a chelating agent-soluble pectin fraction (ChSS), a dilute sodium hydroxide-soluble

  14. Aspergillus enzymes involved in degradation of plant cell wall polysaccharides

    NARCIS (Netherlands)

    Vries, de R.P.; Visser, J.

    2001-01-01

    Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a m

  15. Roles of tRNA in cell wall biosynthesis

    DEFF Research Database (Denmark)

    Dare, Kiley; Ibba, Michael

    2012-01-01

    Recent research into various aspects of bacterial metabolism such as cell wall and antibiotic synthesis, degradation pathways, cellular stress, and amino acid biosynthesis has elucidated roles of aminoacyl-transfer ribonucleic acid (aa-tRNA) outside of translation. Although the two enzyme families...

  16. The digestion of yeast cell wall polysaccharides in veal calves

    NARCIS (Netherlands)

    Gaillard, B.D.E.; Weerden, van E.J.

    1976-01-01

    1. The digestibility of the cell wall polysaccharides of an alkane-grown yeast in different parts of the digestive tract of two veal calves fitted with re-entrant cannulas at the end of the ileum was studied by replacing part of the skim-milk powder of their ‘normal’, milk-substitute (all-milk-prote

  17. Action of xyloglucan hydrolase within the native cell wall architecture and its effect on cell wall extensibility in azuki bean epicotyls.

    Science.gov (United States)

    Kaku, Tomomi; Tabuchi, Akira; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

    2002-01-01

    Xyloglucan hydrolase (XGH) has recently been purified from the cell wall of azuki bean (Vigna angularis Ohwi et Ohashi) epicotyls as a new type of xyloglucan-degrading enzyme [Tabuchi et al. (2001) Plant Cell Physiol. 42: 154]. In the present study, the effects of XGH on the mechanical properties of the cell wall and on the level and the molecular size of xyloglucans within the native wall architecture were examined in azuki bean epicotyls. When the epidermal tissue strips from the growing regions of azuki bean epicotyls were incubated with XGH, the mechanical extensibility of the cell wall dramatically increased. XGH exogenously applied to cell wall materials (homogenates) or epidermal tissue strips decreased the amount of xyloglucans via the solubilization of the polysaccharides. Also, XGH substantially decreased the molecular mass of xyloglucans in both materials. These results indicate that XGH is capable of hydrolyzing xyloglucans within the native cell wall architecture and thereby increasing the cell wall extensibility in azuki bean epicotyls.

  18. Molecular deformation mechanisms of the wood cell wall material.

    Science.gov (United States)

    Jin, Kai; Qin, Zhao; Buehler, Markus J

    2015-02-01

    Wood is a biological material with outstanding mechanical properties resulting from its hierarchical structure across different scales. Although earlier work has shown that the cellular structure of wood is a key factor that renders it excellent mechanical properties at light weight, the mechanical properties of the wood cell wall material itself still needs to be understood comprehensively. The wood cell wall material features a fiber reinforced composite structure, where cellulose fibrils act as stiff fibers, and hemicellulose and lignin molecules act as soft matrix. The angle between the fiber direction and the loading direction has been found to be the key factor controlling the mechanical properties. However, how the interactions between theses constitutive molecules contribute to the overall properties is still unclear, although the shearing between fibers has been proposed as a primary deformation mechanism. Here we report a molecular model of the wood cell wall material with atomistic resolution, used to assess the mechanical behavior under shear loading in order to understand the deformation mechanisms at the molecular level. The model includes an explicit description of cellulose crystals, hemicellulose, as well as lignin molecules arranged in a layered nanocomposite. The results obtained using this model show that the wood cell wall material under shear loading deforms in an elastic and then plastic manner. The plastic regime can be divided into two parts according to the different deformation mechanisms: yielding of the matrix and sliding of matrix along the cellulose surface. Our molecular dynamics study provides insights of the mechanical behavior of wood cell wall material at the molecular level, and paves a way for the multi-scale understanding of the mechanical properties of wood.

  19. Structure of Plant Cell Walls: XI. GLUCURONOARABINOXYLAN, A SECOND HEMICELLULOSE IN THE PRIMARY CELL WALLS OF SUSPENSION-CULTURED SYCAMORE CELLS.

    Science.gov (United States)

    Darvill, J E; McNeil, M; Darvill, A G; Albersheim, P

    1980-12-01

    The isolation, purification, and partial characterization of a glucuronoarabinoxylan, a previously unobserved component of the primary cell walls of dicotyledonous plants, are described. The glucuronoarabinoxylan constitutes approximately 5% of the primary walls of suspension-cultured sycamore cells. This glucuronoarabinoxylan possesses many of the structural characteristics of analogous polysaccharides that have been isolated from the primary and secondary cell walls of monocots as well as from the secondary cell walls of dicots. The glucuronoarabinoxylan of primary dicot cell walls has a linear beta-1,4-linked d-xylopyranosyl backbone with both neutral and acidic sidechains attached at intervals along its length. The acidic sidechains are terminated with glucuronosyl or 4-O-methyl glucuronosyl residues, whereas the neutral sidechains are composed of arabinosyl and/or xylosyl residues.

  20. Phenotypic screening of Arabidopsis T-DNA insertion lines for cell wall mechanical properties revealed ANTHOCYANINLESS2, a cell wall-related gene.

    Science.gov (United States)

    Mabuchi, Atsushi; Soga, Kouichi; Wakabayashi, Kazuyuki; Hoson, Takayuki

    2016-02-01

    We performed a phenotypic screening of confirmed homozygous T-DNA insertion lines in Arabidopsis for cell wall extensibility, in an attempt to identify genes involved in the regulation of cell wall mechanical properties. Seedlings of each line were cultivated and the cell wall extensibility of their hypocotyls was measured with a tensile tester. Hypocotyls of lines with known cell wall-related genes showed higher or lower extensibility than those of the wild-type at high frequency, indicating that the protocol used was effective. In the first round of screening of randomly selected T-DNA insertion lines, we identified ANTHOCYANINLESS2 (ANL2), a gene involved in the regulation of cell wall mechanical properties. In the anl2 mutant, the cell wall extensibility of hypocotyls was significantly lower than that of the wild-type. Levels of cell wall polysaccharides per hypocotyl, particularly cellulose, increased in anl2. Microarray analysis showed that in anl2, expression levels of the major peroxidase genes also increased. Moreover, the activity of ionically wall-bound peroxidases clearly increased in anl2. The activation of peroxidases as well as the accumulation of cell wall polysaccharides may be involved in decreased cell wall extensibility. The approach employed in the present study could contribute to our understanding of the mechanisms underlying the regulation of cell wall mechanical properties.

  1. Evaluating the Cancer Therapeutic Potential of Cardiac Glycosides

    Directory of Open Access Journals (Sweden)

    José Manuel Calderón-Montaño

    2014-01-01

    Full Text Available Cardiac glycosides, also known as cardiotonic steroids, are a group of natural products that share a steroid-like structure with an unsaturated lactone ring and the ability to induce cardiotonic effects mediated by a selective inhibition of the Na+/K+-ATPase. Cardiac glycosides have been used for many years in the treatment of cardiac congestion and some types of cardiac arrhythmias. Recent data suggest that cardiac glycosides may also be useful in the treatment of cancer. These compounds typically inhibit cancer cell proliferation at nanomolar concentrations, and recent high-throughput screenings of drug libraries have therefore identified cardiac glycosides as potent inhibitors of cancer cell growth. Cardiac glycosides can also block tumor growth in rodent models, which further supports the idea that they have potential for cancer therapy. Evidence also suggests, however, that cardiac glycosides may not inhibit cancer cell proliferation selectively and the potent inhibition of tumor growth induced by cardiac glycosides in mice xenografted with human cancer cells is probably an experimental artifact caused by their ability to selectively kill human cells versus rodent cells. This paper reviews such evidence and discusses experimental approaches that could be used to reveal the cancer therapeutic potential of cardiac glycosides in preclinical studies.

  2. Studying biomolecule localization by engineering bacterial cell wall curvature.

    Directory of Open Access Journals (Sweden)

    Lars D Renner

    Full Text Available In this article we describe two techniques for exploring the relationship between bacterial cell shape and the intracellular organization of proteins. First, we created microchannels in a layer of agarose to reshape live bacterial cells and predictably control their mean cell wall curvature, and quantified the influence of curvature on the localization and distribution of proteins in vivo. Second, we used agarose microchambers to reshape bacteria whose cell wall had been chemically and enzymatically removed. By combining microstructures with different geometries and fluorescence microscopy, we determined the relationship between bacterial shape and the localization for two different membrane-associated proteins: i the cell-shape related protein MreB of Escherichia coli, which is positioned along the long axis of the rod-shaped cell; and ii the negative curvature-sensing cell division protein DivIVA of Bacillus subtilis, which is positioned primarily at cell division sites. Our studies of intracellular organization in live cells of E. coli and B. subtilis demonstrate that MreB is largely excluded from areas of high negative curvature, whereas DivIVA localizes preferentially to regions of high negative curvature. These studies highlight a unique approach for studying the relationship between cell shape and intracellular organization in intact, live bacteria.

  3. The cell wall compound of Saccharomyces cerevisiae as a novel wall material for encapsulation of probiotics.

    Science.gov (United States)

    Mokhtari, Samira; Jafari, Seid Mahdi; Khomeiri, Morteza; Maghsoudlou, Yahya; Ghorbani, Mohammad

    2017-06-01

    Yeast cell wall is known as a food grade ingredient which is recently being used increasingly as a novel coating for encapsulation of different materials in the food industry. This application is limited to core materials smaller than yeast in size. In this study, we have tried to encapsulate larger particles by crushing yeast cells. Hence, probiotic bacteria of Lactobacillus acidophilus and Bifidobacterium bifidum were encapsulated firstly by calcium alginate using the emulsion method and these microbeads were coated again by Saccharomyces cerevisiae cell wall compound and another layer of calcium alginate. The average diameter of microcapsules for single layer microbeads (M), microbeads coated by two layers of alginate (MCA), and microbeads coated by a layer of yeast cell and two layers of alginate (MCYA) were 54.25±0.18, 77.43±8.24 and 103.66±13.33μm, respectively. In simulated gastrointestinal conditions, there was a significant (Pprobiotics and it can improve the survival of probiotics within food products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Resistance to antibiotics targeted to the bacterial cell wall.

    Science.gov (United States)

    Nikolaidis, I; Favini-Stabile, S; Dessen, A

    2014-03-01

    Peptidoglycan is the main component of the bacterial cell wall. It is a complex, three-dimensional mesh that surrounds the entire cell and is composed of strands of alternating glycan units crosslinked by short peptides. Its biosynthetic machinery has been, for the past five decades, a preferred target for the discovery of antibacterials. Synthesis of the peptidoglycan occurs sequentially within three cellular compartments (cytoplasm, membrane, and periplasm), and inhibitors of proteins that catalyze each stage have been identified, although not all are applicable for clinical use. A number of these antimicrobials, however, have been rendered inactive by resistance mechanisms. The employment of structural biology techniques has been instrumental in the understanding of such processes, as well as the development of strategies to overcome them. This review provides an overview of resistance mechanisms developed toward antibiotics that target bacterial cell wall precursors and its biosynthetic machinery. Strategies toward the development of novel inhibitors that could overcome resistance are also discussed.

  5. Dislocation-mediated growth of bacterial cell walls

    CERN Document Server

    Amir, Ariel

    2012-01-01

    Recent experiments have illuminated a remarkable growth mechanism of rod-shaped bacteria: proteins associated with cell wall extension move at constant velocity in circles oriented approximately along the cell circumference (Garner et al., Science (2011), Dominguez-Escobar et al. Science (2011), van Teeffelen et al. PNAS (2011). We view these as dislocations in the partially ordered peptidoglycan structure, activated by glycan strand extension machinery, and study theoretically the dynamics of these interacting defects on the surface of a cylinder. Generation and motion of these interacting defects lead to surprising effects arising from the cylindrical geometry, with important implications for growth. We also discuss how long range elastic interactions and turgor pressure affect the dynamics of the fraction of actively moving dislocations in the bacterial cell wall.

  6. Cell wall staining with Trypan Blue enables quantitative analysis of morphological changes in yeast cells

    Directory of Open Access Journals (Sweden)

    Johannes eLiesche

    2015-02-01

    Full Text Available Yeast cells are protected by a cell wall that plays an important role in the exchange of substances with the environment. The cell wall structure is dynamic and can adapt to different physiological states or environmental conditions. For the investigation of morphological changes, selective staining with fluorescent dyes is a valuable tool. Furthermore, cell wall staining is used to facilitate sub-cellular localization experiments with fluorescently-labeled proteins and the detection of yeast cells in non-fungal host tissues. Here, we report staining of Saccharomyces cerevisiae cell wall with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals, demonstrating the potential of this approach for morphological investigations or screening assays.

  7. Identification of Cell Wall Synthesis Regulatory Genes Controlling Biomass Characteristics and Yield in Rice (Oryza Sativa)

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Zhaohua PEng [Mississippi State University; Ronald, Palmela [UC-Davis; Wang, Guo-Liang [The Ohio State University

    2013-04-26

    This project aims to identify the regulatory genes of rice cell wall synthesis pathways using a cell wall removal and regeneration system. We completed the gene expression profiling studies following the time course from cell wall removal to cell wall regeneration in rice suspension cells. We also completed, total proteome, nuclear subproteome and histone modification studies following the course from cell wall removal and cell wall regeneration process. A large number of differentially expressed regulatory genes and proteins were identified. Meanwhile, we generated RNAi and over-expression transgenic rice for 45 genes with at least 10 independent transgenic lines for each gene. In addition, we ordered T-DNA and transposon insertion mutants for 60 genes from Korea, Japan, and France and characterized the mutants. Overall, we have mutants and transgenic lines for over 90 genes, exceeded our proposed goal of generating mutants for 50 genes. Interesting Discoveries a) Cell wall re-synthesis in protoplasts may involve a novel cell wall synthesis mechanism. The synthesis of the primary cell wall is initiated in late cytokinesis with further modification during cell expansion. Phragmoplast plays an essential role in cell wall synthesis. It services as a scaffold for building the cell plate and formation of a new cell wall. Only one phragmoplast and one new cell wall is produced for each dividing cell. When the cell wall was removed enzymatically, we found that cell wall re-synthesis started from multiple locations simultaneously, suggesting that a novel mechanism is involved in cell wall re-synthesis. This observation raised many interesting questions, such as how the starting sites of cell wall synthesis are determined, whether phragmoplast and cell plate like structures are involved in cell wall re-synthesis, and more importantly whether the same set of enzymes and apparatus are used in cell wall re-synthesis as during cytokinesis. Given that many known cell wall

  8. Pectic arabinan side chains are essential for pollen cell wall integrity during pollen development

    NARCIS (Netherlands)

    Cankar, K.; Kortstee, A.J.; Toonen, M.A.J.; Wolters-Arts, M.; Houbein, R.; Mariani, C.; Ulvskov, P.; Jorgensen, B.; Schols, H.A.; Visser, R.G.F.; Trindade, L.M.

    2014-01-01

    Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure–function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pec

  9. Targeted and non-targeted effects in cell wall polysaccharides from transgenetically modified potato tubers

    NARCIS (Netherlands)

    Huang, J.H.

    2016-01-01

    The plant cell wall is a chemically complex network composed mainly of polysaccharides. Cell wall polysaccharides surround and protect plant cells and are responsible for the stability and rigidity of plant tissue. Pectin is a major component of primary cell wall and the middle lamella of plants. Ho

  10. Enzymatic synthesis of beta-glucosylglycerol using a continuous-flow microreactor containing thermostable beta-glycoside hydrolase CelB immobilized on coated microchannel walls.

    Science.gov (United States)

    Schwarz, Alexandra; Thomsen, Malene S; Nidetzky, Bernd

    2009-08-01

    beta-Glucosylglycerol (betaGG) has potential applications as a moisturizing agent in cosmetic products. A stereochemically selective method of its synthesis is kinetically controlled enzymatic transglucosylation from a suitable donor substrate to glycerol as acceptor. Here, the thermostable beta-glycosidase CelB from Pyrococcus furiosus was used to develop a microstructured immobilized enzyme reactor for production of betaGG under conditions of continuous flow at 70 degrees C. Using CelB covalently attached onto coated microchannel walls to give an effective enzyme activity of 30 U per total reactor working volume of 25 microL, substrate conversion and formation of transglucosylation product was monitored in dependence of glucosyl donor (2-nitrophenyl-beta-D-glucoside (oNPGlc), 3.0 or 15 mM; cellobiose, 250 mM), the concentration of glycerol (0.25-1.0 M), and the average residence time (0.2-90 s). Glycerol caused a concentration-dependent decrease in the conversion of the glucosyl donor via hydrolysis and strongly suppressed participation of the substrate in the reaction as glucosyl acceptor. The yields of betaGG were > or =80% and approximately 60% based on oNPGlc and cellobiose converted, respectively, and maintained up to near exhaustion of substrate (> or =80%), giving about 120 mM (30 g/L) of betaGG from the reaction of cellobiose and 1 M glycerol. The structure of the transglucosylation products, 1-O-beta-D-glucopyranosyl-rac-glycerol (79%) and 2-O-beta-D-glucopyranosyl-sn-glycerol (21%), was derived from NMR analysis of the product mixture of cellobiose conversion. The microstructured reactor showed conversion characteristics similar to those for a batchwise operated stirred reactor employing soluble CelB. The advantage of miniaturization to the microfluidic format lies in the fast characterization of full reaction time courses for a range of process conditions using only a minimum amount of enzyme.

  11. Ectopic lignification in primary cellulose-deficient cell walls of maize cell suspension cultures

    Institute of Scientific and Technical Information of China (English)

    Hugo Melida; Antonio Encina; Asier Largo-Gosens; Esther Novo-Uzal; Rogelio Santiago; Federico Pomar; Pedro Garca; Penelope Garca-Angulo; Jose Luis Acebes; Jesus Alvarez

    2015-01-01

    Maize (Zea mays L.) suspension-cultured cells with up to 70% less cellulose were obtained by stepwise habituation to dichlobenil (DCB), a cellulose biosynthesis inhibitor. Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by Fourier transform infrared (FTIR) spectroscopy. Cell wall compositional analysis indicated that the cellulose-deficient cell walls showed an enhancement of highly branched and cross-linked arabinoxylans, as well as an increased content in ferulic acid, diferulates and p-coumaric acid, and the presence of a polymer that stained positive for phloroglucinol. In accordance with this, cellulose-deficient cell walls showed a fivefold increase in Klason-type lignin. Thioacidolysis/GC-MS analysis of cellulose-deficient cell walls indicated the presence of a lignin-like polymer with a Syringyl/Guaiacyl ratio of 1.45, which differed from the sensu stricto stress-related lignin that arose in response to short-term DCB-treatments. Gene expression analysis of these cells indicated an overexpression of genes specific for the biosynthesis of monolignol units of lignin. A study of stress signaling pathways revealed an overexpression of some of the jasmonate signaling pathway genes, which might trigger ectopic lignification in response to cell wall integrity disruptions. In summary, the structural plasticity of primary cell walls is proven, since a lignification process is possible in response to cellulose impoverishment.

  12. Iridoid glycosides from Globularia trichosantha.

    Science.gov (United States)

    Caliş, I; Kirmizibekmez, H; Sticher, O

    2001-01-01

    A new iridoid glycoside, deacetylalpinoside (2), was isolated from the aerial parts of Globularia trichosantha together with nine known iridoid glycosides: catalpol, 10-O-benzoyl-catalpol, aucubin, asperuloside, deacetylasperuloside, asperulosidic acid, scandoside, geniposidic acid, and alpinoside (1). From the underground parts of the same plant, two new bisiridoid glycosides, globulosides A (3) and B (4); a known iridoid glycoside, globularidin; a lignan glycoside, liriodendrin; and seven phenylethanoid glycosides, arenarioside, verbascoside (= acteoside), isoacteoside, crenatoside, isocrenatoside, and trichosanthosides A and B, were isolated. Compounds 2-4 are new iridoids containing an 8,9 double bond representing a rare carbon skeleton. Their structures were established by spectroscopic methods.

  13. New flav-3-en-3-ol glycosides, kaempferiaosides C and D, and acetophenone glycosides, kaempferiaosides E and F, from the rhizomes of Kaempferia parviflora.

    Science.gov (United States)

    Chaipech, Saowanee; Morikawa, Toshio; Ninomiya, Kiyofumi; Yoshikawa, Masayuki; Pongpiriyadacha, Yutana; Hayakawa, Takao; Muraoka, Osamu

    2012-07-01

    Two new flav-3-en-3-ol glycosides, kaempferiaosides C (3) and D(4), and two new acetophenone glycosides, kaempferiaosides E (5) and F (6), were isolated from the Thai natural medicine Krachai Dum, the rhizomes of Kaempferia parviflora Wall. ex Baker. Their structures were established mainly on the basis of 1D and 2D NMR spectral data.

  14. Tomato Fruit Cell Wall Synthesis during Development and Senescence : In Vivo Radiolabeling of Wall Fractions Using [C]Sucrose.

    Science.gov (United States)

    Mitcham, E J; Gross, K C; Ng, T J

    1989-02-01

    The pedicel of tomato fruit (Lycopersicon esculentum Mill., cv ;Rutgers') of different developmental stages from immature-green (IG) to red was injected on the vine with 7 microcuries [(14)C(U)]sucrose and harvested after 18 hours. Cell walls were isolated from outer pericarp and further fractionated yielding ionically associated pectin, covalently bound pectin, hemicellulosic fraction I, hemicellulosic fraction II, and cellulosic fraction II. The dry weight of the total cell wall and of each cell wall fraction per gram fresh weight of pericarp tissue decreased after the mature-green (MG) stage of development. Incorporation of radiolabeled sugars into each fraction decreased from the IG to MG3 (locules jellied but still green) stage. Incorporation in all fractions increased from MG3 to breaker and turning (T) and then decreased from T to red. Data indicate that cell wall synthesis continues throughout ripening and increases transiently from MG4 (locules jellied and yellow to pink in color) to T, corresponding to the peak in respiration and ethylene synthesis during the climacteric. Synthesis continued at a time when total cell wall fraction dry weight decreased indicating the occurrence of cell wall turnover. Synthesis and insertion of a modified polymer with removal of other polymers may produce a less rigid cell wall and allow softening of the tissue integrity during ripening.

  15. Analysis of the soluble cell wall proteome of gymnosperms.

    Science.gov (United States)

    Uzal, Esther Novo; Gómez-Ros, Laura V; Hernández, Jose A; Pedreño, María A; Cuello, Juan; Ros Barceló, Alfonso

    2009-05-15

    We analyzed the cell wall proteome of lignifying suspension cell cultures (SCCs) from four gymnosperms that differ in evolution degree. This analysis showed the presence of "peptide sequence tags" (PSTs) corresponding to glucan endo-1,3-beta-D-glucosidase, xyloglucan-endotrans-glucosylase/hydrolase, chitinases, thaumatin-like proteins and proteins involved in lignin/lignan biosynthesis, such as dirigent-like proteins and peroxidases. Surprisingly, and given the abundance of peroxidases in the cell wall proteome of these gymnosperms, PSTs corresponding to peroxidases were only detected in tryptic fragments of the cell wall proteome of Cycas revoluta. The current lack of knowledge regarding C. revoluta peroxidases led us to purify, characterize and partially sequence the peroxidases responsible for lignin biosynthesis in this species. This yielded three peroxidase-enriched fractions: CrPrx 1, CrPrx 2 and CrPrx 3. Analyses of tryptic peptides of CrPrx 2 (32kDa) and CrPrx 3 (26kDa) suggest that CrPrx 3 arises from CrPrx 2 by protein truncation, and that CrPrx 3 apparently constitutes a post-translational modification of CrPrx 2. That CrPrx 2 and CrPrx 3 are apparently the same enzyme was also deduced from the similarity between the k(cat) shown by both peroxidases for the three monolignols. These results emphasize the analogies between the cell wall proteome of gymnosperms and angiosperms, the complexity of the peroxidase proteome, and the difficulties involved in establishing fine structure-function relationships.

  16. Orbital wall infarction in child with sickle cell disease.

    Science.gov (United States)

    Janssens, C; Claeys, L; Maes, P; Boiy, T; Wojciechowski, M

    2015-12-01

    We present the case of a 17-year-old boy, known with homozygous sickle cell disease, who was admitted because of generalised pain. He developed bilateral periorbital oedema and proptosis, without pain or visual disturbances. In addition to hyperhydration, oxygen and analgesia IV antibiotics were started, to cover a possible osteomyelitis. Patients with sickle cell disease are at risk for vaso-occlusive crises, when the abnormally shaped red blood cells aggregate and block the capillaries. Such a crisis typically presents at a location with high bone marrow activity, as the vertebrae and long bones. At an early age, the bone marrow is still active at other sites, for example the orbital wall, and thus infarction can also occur there. Thus, in young persons with sickle cell disease, it is important to consider orbital wall infarction in the differential diagnosis, since the approach is different from osteomyelitis. If the disease is complicated by an orbital compression syndrome, corticosteroids or surgical intervention may be necessary to preserve the vision. In our patient, an MRI of the orbitae demonstrated periorbital oedema with bone anomalies in the orbital and frontal bones, confirming orbital wall infarction. Ophthalmological examination revealed no signs of pressure on the nervus opticus. The patient recovered gradually with conservative treatment.

  17. Anticancer Activity of Sea Cucumber Triterpene Glycosides

    Directory of Open Access Journals (Sweden)

    Dmitry L. Aminin

    2015-03-01

    Full Text Available Triterpene glycosides are characteristic secondary metabolites of sea cucumbers (Holothurioidea, Echinodermata. They have hemolytic, cytotoxic, antifungal, and other biological activities caused by membranotropic action. These natural products suppress the proliferation of various human tumor cell lines in vitro and, more importantly, intraperitoneal administration in rodents of solutions of some sea cucumber triterpene glycosides significantly reduces both tumor burden and metastasis. The anticancer molecular mechanisms include the induction of tumor cell apoptosis through the activation of intracellular caspase cell death pathways, arrest of the cell cycle at S or G2/M phases, influence on nuclear factors, NF-κB, and up-down regulation of certain cellular receptors and enzymes participating in cancerogenesis, such as EGFR (epidermal growth factor receptor, Akt (protein kinase B, ERK (extracellular signal-regulated kinases, FAK (focal adhesion kinase, MMP-9 (matrix metalloproteinase-9 and others. Administration of some glycosides leads to a reduction of cancer cell adhesion, suppression of cell migration and tube formation in those cells, suppression of angiogenesis, inhibition of cell proliferation, colony formation and tumor invasion. As a result, marked growth inhibition of tumors occurs in vitro and in vivo. Some holothurian triterpene glycosides have the potential to be used as P-gp mediated MDR reversal agents in combined therapy with standard cytostatics.

  18. Cell wall staining with Trypan blue enables quantitative analysis of morphological changes in yeast cells

    DEFF Research Database (Denmark)

    Liesche, Johannes; Marek, Magdalena; Günther-Pomorski, Thomas

    2015-01-01

    with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain...... Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals...

  19. Cell wall polysaccharides in black currants and bilberries-characterisation in berries, juice, and press cake

    NARCIS (Netherlands)

    Hilz, H.; Bakx, E.J.; Schols, H.A.; Voragen, A.G.J.

    2005-01-01

    Cell wall polysaccharides from black currants and bilberries were characterised in three approaches. First, compositions of skin, pulp, and seeds show the distribution of polysaccharides over these tissues. A sequential extraction of cell wall material with different aqueous extractants informs

  20. The Cell Walls of Green Algae: A Journey through Evolution and Diversity

    National Research Council Canada - National Science Library

    Domozych, David S; Ciancia, Marina; Fangel, Jonatan U; Mikkelsen, Maria Dalgaard; Ulvskov, Peter; Willats, William G T

    2012-01-01

    .... The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings...

  1. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

    Cell walls are a defining feature of plants and have numerous crucial roles in growth and development. They are also the largest source of terrestrial biomass and have many important industrial applications - ranging from bulk products to functional food ingredients. There is considerable interest......¿4)-linked ß-D-Glcp are joined by occasional (1¿3)-linkages. This mixed linkage glucan (MLG) has been the subject of extensive research because of the economic importance of several Poales species including rice, barley and wheat and because MLG has proven health benefits. The recent discovery of MLG......-D-glucan is not unique to the Poales and is an abundant component of Equisetum arvense cell walls. Plant J 2008; 54:510-21....

  2. Cell wall bound anionic peroxidases from asparagus byproducts.

    Science.gov (United States)

    Jaramillo-Carmona, Sara; López, Sergio; Vazquez-Castilla, Sara; Jimenez-Araujo, Ana; Rodriguez-Arcos, Rocio; Guillen-Bejarano, Rafael

    2014-10-08

    Asparagus byproducts are a good source of cationic soluble peroxidases (CAP) useful for the bioremediation of phenol-contaminated wastewaters. In this study, cell wall bound peroxidases (POD) from the same byproducts have been purified and characterized. The covalent forms of POD represent >90% of the total cell wall bound POD. Isoelectric focusing showed that whereas the covalent fraction is constituted primarily by anionic isoenzymes, the ionic fraction is a mixture of anionic, neutral, and cationic isoenzymes. Covalently bound peroxidases were purified by means of ion exchange chromatography and affinity chromatography. In vitro detoxification studies showed that although CAP are more effective for the removal of 4-CP and 2,4-DCP, anionic asparagus peroxidase (AAP) is a better option for the removal of hydroxytyrosol (HT), the main phenol present in olive mill wastewaters.

  3. Pulsed electric field reduces the permeability of potato cell wall.

    Science.gov (United States)

    Galindo, Federico Gómez; Vernier, P Thomas; Dejmek, Petr; Vicente, António; Gundersen, Martin A

    2008-05-01

    The effect of the application of pulsed electric fields to potato tissue on the diffusion of the fluorescent dye FM1-43 through the cell wall was studied. Potato tissue was subjected to field strengths ranging from 30 to 500 V/cm, with one 1 ms rectangular pulse, before application of FM1-43 and microscopic examination. Our results show a slower diffusion of FM1-43 in the electropulsed tissue when compared with that in the non-pulsed tissue, suggesting that the electric field decreased the cell wall permeability. This is a fast response that is already detected within 30 s after the delivery of the electric field. This response was mimicked by exogenous H2O2 and blocked by sodium azide, an inhibitor of the production of H2O2 by peroxidases. (c) 2007 Wiley-Liss, Inc.

  4. Cytoplasmic streaming in plant cells: the role of wall slip.

    Science.gov (United States)

    Wolff, K; Marenduzzo, D; Cates, M E

    2012-06-01

    We present a computer simulation study, via lattice Boltzmann simulations, of a microscopic model for cytoplasmic streaming in algal cells such as those of Chara corallina. We modelled myosin motors tracking along actin lanes as spheres undergoing directed motion along fixed lines. The sphere dimension takes into account the fact that motors drag vesicles or other organelles, and, unlike previous work, we model the boundary close to which the motors move as walls with a finite slip layer. By using realistic parameter values for actin lane and myosin density, as well as for endoplasmic and vacuole viscosity and the slip layer close to the wall, we find that this simplified view, which does not rely on any coupling between motors, cytoplasm and vacuole other than that provided by viscous Stokes flow, is enough to account for the observed magnitude of streaming velocities in intracellular fluid in living plant cells.

  5. Life behind cell walls: paradigm lost, paradigm regained.

    Science.gov (United States)

    Lamport, D T

    2001-09-01

    This review of the living cell wall and its protein components is in two parts. The first is anecdotal. A personal account spanning over 40 years research may perhaps be an antidote to one stereotypical view of scientists as detached and humorless. The second part deals with the meaning of function, particularly as it applies to hydroxyproline-rich glycoproteins. Function is a difficult word to define objectively. However, with help from such luminaries as Humpty Dumpty: "A word means what I want it to mean, neither more nor less," and Wittgenstein: "Giving examples of usage ... is the only way to talk about meaning," it is possible to construct a ziggurat representing increasingly complex levels of organization from molecular structure to ecology. Forty years ago I suggested that hydroxyproline-rich structural proteins played a key role in cell wall functioning. But because the bulk of the wall is carbohydrate, there has been an understandable resistance to paradigm change. Expansins, paradoxically, contribute greatly to this resistance because their modus operandi as cell-wall-loosening proteins is based on the idea that they break hydrogen bonds between polysaccharide chains allowing slippage. However, this view is not consistent with the recent discovery [Grobe et al. (1999) Eur. J. Biochem 263: 33-40] that beta-expansins may be proteases, as it implies that the extensin network is not a straightjacket but a substrate for expansin in muro. Such a direct role for extensins in both negative and positive regulation of cell expansion and elongation may constitute a major morphogenetic mechanism operating at all levels of plant growth and development.

  6. Progress Towards the Tomato Fruit Cell Wall Proteome

    Directory of Open Access Journals (Sweden)

    Eliel eRuiz May

    2013-05-01

    Full Text Available The plant cell wall (CW compartment, or apoplast, is host to a highly dynamic proteome, comprising large numbers of both enzymatic and structural proteins. This reflects its importance as the interface between adjacent cells and the external environment, the presence of numerous extracellular metabolic and signaling pathways, and the complex nature of wall structural assembly and remodeling during cell growth and differentiation. Tomato fruit ontogeny, with its distinct phases of rapid growth and ripening, provides a valuable experimental model system for CW proteomic studies, in that it involves substantial wall assembly, remodeling and coordinated disassembly. Moreover, diverse populations of secreted proteins must be deployed to resist microbial infection and protect against abiotic stresses. Tomato fruits also provide substantial amounts of biological material, which is a significant advantage for many types of biochemical analyses, and facilitates the detection of lower abundance proteins. In this review we describe a variety of orthogonal techniques that have been applied to identify CW localized proteins from tomato fruit, including approaches that: target the proteome of the CW and the overlying cuticle; functional ‘secretome’ screens; lectin affinity chromatography; and computational analyses to predict proteins that enter the secretory pathway. Each has its merits and limitations, but collectively they are providing important insights into CW proteome composition and dynamics, as well as some potentially controversial issues, such as the prevalence of non-canonical protein secretion.

  7. Cell wall proteins in seedling cotyledons of Prosopis chilensis.

    Science.gov (United States)

    Rodríguez, J G; Cardemil, L

    1994-01-01

    Four cell wall proteins of cotyledons of Prosopis chilensis seedlings were characterized by PAGE and Western analyses using a polyclonal antibody, generated against soybean seed coat extensin. These proteins had M(r)s of 180,000, 126,000, 107,000 and 63,000, as determined by SDS-PAGE. The proteins exhibited a fluorescent positive reaction with dansylhydrazine suggesting that they are glycoproteins; they did not show peroxidase activity. The cell wall proteins were also characterized by their amino acid composition and by their amino-terminal sequence. These analyses revealed that there are two groups of related cell wall proteins in the cotyledons. The first group comprises the proteins of M(r)s 180,000, 126,000, 107,000 which are rich in glutamic acid/glutamine and aspartic acid/asparagine and they have almost identical NH2-terminal sequences. The second group comprises the M(r) 63,000 protein which is rich in proline, glycine, valine and tyrosine, with an NH2-terminal sequence which was very similar to that of soybean proline-rich proteins.

  8. Regulation of plant cells, cell walls and development by mechanical signals

    Energy Technology Data Exchange (ETDEWEB)

    Meyerowitz, Elliot M. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-06-14

    The overall goal of the revised scope of work for the final year of funding was to characterize cell wall biosynthesis in developing cotyledons and in the shoot apical meristem of Arabidopsis thaliana, as a way of learning about developmental control of cell wall biosynthesis in plants, and interactions between cell wall biosynthesis and the microtubule cytoskeleton. The proposed work had two parts – to look at the effect of mutation in the SPIRAL2 gene on microtubule organization and reorganization, and to thoroughly characterize the glycosyltransferase genes expressed in shoot apical meristems by RNA-seq experiments, by in situ hybridization of the RNAs expressed in the meristem, and by antibody staining of the products of the glycosyltransferases in meristems. Both parts were completed; the spiral2 mutant was found to speed microtubule reorientation after ablation of adjacent cells, supporting our hypothesis that reorganization correlates with microtubule severing, the rate of which is increased by the mutation. The glycosyltransferase characterization was completed and published as Yang et al. (2016). Among the new things learned was that primary cell wall biosynthesis is strongly controlled both by cell type, and by stage of cell cycle, implying not only that different, even adjacent, cells can have different sugar linkages in their (nonshared) walls, but also that a surprisingly large proportion of glycosyltransferases is regulated in the cell cycle, and therefore that the cell cycle regulates wall maturation to a degree previously unrecognized.

  9. Adsorption of polycyclic aromatic hydrocarbons (PAHs) on Rhizopus oryzae cell walls: application of cosolvent models for validating the cell wall-water partition coefficient.

    Science.gov (United States)

    Ma, Bin; Xu, Minmin; Wang, Jiaojiao; Chen, Huaihai; He, Yan; Wu, Laosheng; Wang, Haizhen; Xu, Jianming

    2011-11-01

    The cell wall-cosolvent partition coefficients (Km) of polycyclic aromatic hydrocarbons (PAHs) were determined for Rhizopus oryzae cell walls by controlling the volume fraction of methanol (f) ranging from 0.1 to 0.5. Five cosolvent models were employed for extrapolating the cell wall-water partition coefficients (Kw) in pure water. The extrapolated Kw values of four PAHs on R. oryzae cell walls were ranged from 2.9 to 5.1. Comparison of various Kw values of pyrene generated from extrapolation and the QSPR model, together with predicted different (PD), mean percentage deviations (MPD), and root mean square errors (RSE), revealed that the performance of the LL and Bayesian models were the best among all five tested cosolvent models. This study suggests that R. oryzae cell walls play an important role in the partitioning of PAHs during bioremediation because of the high Kw of fungal cell walls.

  10. Steviol glycoside biosynthesis.

    Science.gov (United States)

    Brandle, J E; Telmer, P G

    2007-07-01

    Steviol glycosides are found in high concentrations in the leaves of the Paraguayan perennial herb Stevia rebaudiana and their intense sweetness, as well as high concentration in Stevia leaf tissue, has made them the subject of research interest for over 100 years. Steviol glycosides are diterpenoids whose biosynthetic pathways share four steps in common with gibberellic acid formation. The convergence of genomics and plant biochemistry has led to the rapid elucidation of the genes coding for the various enzymes in the biosynthetic pathway. Functional characterization of the enzymes coded for by those genes is on-going. The first committed step in the pathway is the synthesis of the aglycone steviol and the various glycosides found in the leaf tissue result from the elaboration of steviol by a number of glucosyltransferases.

  11. Cell Wall Composition and Candidate Biosynthesis Gene Expression During Rice Development

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fan; Manisseri, Chithra; Fagerström, Alexandra; Peck, Matthew L.; Vega-Sánchez, Miguel E.; Williams, Brian; Chiniquy, Dawn M.; Saha, Prasenjit; Pattathil, Sivakumar; Conlin, Brian; Zhu, Lan; Hahn, Michael G.; Willats, William G. T.; Scheller, Henrik V.; Ronald, Pamela C.; Bartley, Laura E.

    2016-08-01

    Cell walls of grasses, including cereal crops and biofuel grasses, comprise the majority of plant biomass and intimately influence plant growth, development and physiology. However, the functions of many cell wall synthesis genes, and the relationships among and the functions of cell wall components remain obscure. To better understand the patterns of cell wall accumulation and identify genes that act in grass cell wall biosynthesis, we characterized 30 samples from aerial organs of rice (Oryza sativa cv. Kitaake) at 10 developmental time points, 3-100 d post-germination. Within these samples, we measured 15 cell wall chemical components, enzymatic digestibility and 18 cell wall polysaccharide epitopes/ligands. We also used quantitative reverse transcription-PCR to measure expression of 50 glycosyltransferases, 15 acyltransferases and eight phenylpropanoid genes, many of which had previously been identified as being highly expressed in rice. Most cell wall components vary significantly during development, and correlations among them support current understanding of cell walls. We identified 92 significant correlations between cell wall components and gene expression and establish nine strong hypotheses for genes that synthesize xylans, mixed linkage glucan and pectin components. This work provides an extensive analysis of cell wall composition throughout rice development, identifies genes likely to synthesize grass cell walls, and provides a framework for development of genetically improved grasses for use in lignocellulosic biofuel production and agriculture.

  12. Cell wall composition and candidate biosynthesis gene expression during rice development

    DEFF Research Database (Denmark)

    Lin, Fan; Manisseri, Chithra; Fagerström, Alexandra

    2016-01-01

    Cell walls of grasses, including cereal crops and biofuel grasses, comprise the majority of plant biomass and intimately influence plant growth, development and physiology. However, the functions of many cell wall synthesis genes, and the relationships among and the functions of cell wall...

  13. Plectasin, a Fungal Defensin, Targets the Bacterial Cell Wall Precursor Lipid II

    DEFF Research Database (Denmark)

    Schneider, Tanja; Kruse, Thomas; Wimmer, Reinhard

    2010-01-01

    that plectasin, a fungal defensin, acts by directly binding the bacterial cell-wall precursor Lipid II. A wide range of genetic and biochemical approaches identify cell-wall biosynthesis as the pathway targeted by plectasin. In vitro assays for cell-wall synthesis identified Lipid II as the specific cellular...

  14. Pea border cell maturation and release involve complex cell wall structural dynamics

    DEFF Research Database (Denmark)

    Mravec, Jozef; Guo, Xiaoyuan; Hansen, Aleksander Riise

    2017-01-01

    The adhesion of plant cells is vital for support and protection of the plant body and is maintained by a variety of molecular associations between cell wall components. In some specialized cases though, plant cells are programmed to detach and root cap-derived border cells are examples of this....... Border cells (in some species known as border-like cells) provide an expendable barrier between roots and the environment. Their maturation and release is an important but poorly characterized cell separation event. To gain a deeper insight into the complex cellular dynamics underlying this process, we...... undertook a systematic, detailed analysis of pea (Pisum sativum) root tip cell walls. Our study included immuno-carbohydrate microarray profiling, monosaccharide composition determination, Fourier-transformed infrared microspectroscopy (FT-IR), quantitative RT-PCR of cell wall biosynthetic genes, analysis...

  15. Triterpene Glycosides from Sea Cucumber Holothuria scabra with Cytotoxic Activity

    Institute of Scientific and Technical Information of China (English)

    HAN Hua; LI Ling; YI Yang-hua; WANG Xiao-hua; PAN Min-xiang

    2012-01-01

    Objective To study the new triterpene glycosides from sea cucumber Holothuria scabra with cytotoxic activity.Methods Triterpene glycosides from H.scabra were separated and purified by chromatography on DA-101,silica gel,and reversed-phase silica gel column,as well as RP-HPLC.Their structures were elucidated on the basis of spectral data and chemical evidence.Results Three triterpene glycosides were identified as scabraside D (1),fuscocineroside C (2),and 24-dehydroechinoside A (3).Their inhibition on P-388,A549,MKN-28,HCT116,and MCF-7 cells were significant.Conclusion Scabraside D (1) is a new triterpene glycoside,and compounds 2 and 3 are isolated from H.scabra for the first time.The glycosides 1-3 show the in vitro cytotoxicity against five human tumor cell lines in comparison to 10-hydroxycamptothecin.

  16. Effect of Wall Charge on Striation in Plasma Display Cells

    Institute of Scientific and Technical Information of China (English)

    HE Feng; OUYANG Jiting; CAO Jing; FENG Shuo; MIAO Jinsong; WANG Jianqi

    2007-01-01

    Different configurations and driving voltages have been employed to investigate the effect of the wall charge on the striations in macroscopic plasma display panel (PDP) cells.The experimental results show that a discharge channel near the dielectric layer is indispensable to striation occurring in the anode area during a discharge,while the pre-accumulated charge on the dielectric layer and the surface state are not important.The origin of the striation is related only to the physical process in the cell.The dielectric layer acts as a charge collector during a PDP discharge.

  17. Stress analysis for wall structure in mobile hot cell design

    Energy Technology Data Exchange (ETDEWEB)

    Bahrin, Muhammad Hannan, E-mail: hannan@nuclearmalaysia.gov.my; Rahman, Anwar Abdul, E-mail: anwar@nuclearmalaysia.gov.my; Hamzah, Mohd Arif, E-mail: arif@nuclearmalaysia.gov.my; Mamat, Mohd Rizal; Azman, Azraf; Hasan, Hasni [Prototype and Plant Development Centre, Technical Services Division, Malaysian Nuclear Agency (Malaysia)

    2016-01-22

    Malaysian Nuclear Agency is developing a Mobile Hot Cell (MHC) in order to handle and manage Spent High Activity Radioactive Sources (SHARS) such as teletherapy heads and irradiators. At present, there are only two units of MHC in the world, in South Africa and China. Malaysian Mobile Hot cell is developed by Malaysian Nuclear Agency with the assistance of IAEA expert, based on the design of South Africa and China, but with improved features. Stress analysis has been performed on the design in order to fulfil the safety requirement in operation of MHC. This paper discusses the loading analysis effect from the sand to the MHC wall structure.

  18. Evidence for 'silicon' within the cell walls of suspension-cultured rice cells.

    Science.gov (United States)

    He, Congwu; Wang, Lijun; Liu, Jian; Liu, Xin; Li, Xiuli; Ma, Jie; Lin, Yongjun; Xu, Fangsen

    2013-11-01

    Despite the ubiquity and beneficial role of silicon (Si) in plant biology, structural and chemical mechanisms operating at the single-cell level have not been extensively studied. To obtain insights regarding the effect of Si on individual cells, we cultivated suspended rice (Oryza sativa) cells in the absence and presence of Si and analyzed single cells using a combination of physical techniques including atomic force microscopy (AFM). Si is naturally present as a constituent of the cell walls, where it is firmly bound to the cell wall matrix rather than occurring within intra- or extracellular silica deposition, as determined by using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray photoelectron spectroscopy (XPS). This species of Si, linked with the cell wall matrix, improves the structural stability of cell walls during their expansion and subsequent cell division. Maintaining cell shape is thereby enhanced, which may be crucial for the function and survival of cells. This study provides further evidence that organosilicon is present in plant cell walls, which broadens our understanding of the chemical nature of 'anomalous Si' in plant biology.

  19. Comparative analysis of fungal genomes reveals different plant cell wall degrading capacity in fungi

    Science.gov (United States)

    2013-01-01

    Background Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported. Results In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 103 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed. Importantly, cellulases of some GH families are present in fungi that are not known to have cellulose-degrading ability. In addition, our results also showed that in general, plant pathogenic fungi have the highest number of CAZymes. Biotrophic fungi tend to have fewer CAZymes than necrotrophic and hemibiotrophic fungi. Pathogens of dicots often contain more pectinases than fungi infecting monocots. Interestingly, besides yeasts, many saprophytic fungi that are highly active in degrading plant biomass contain fewer CAZymes than plant pathogenic fungi. Furthermore, analysis of the gene expression profile of the wheat scab fungus Fusarium graminearum revealed that most of the CAZyme genes related to cell wall degradation were up-regulated during plant infection. Phylogenetic analysis also

  20. Dammarane-type glycosides from Gynostemma pentaphyllum and their effects on IL-4-induced eotaxin expression in human bronchial epithelial cells.

    Science.gov (United States)

    Hung, Tran Manh; Thu, Cao Van; Cuong, To Dao; Hung, Nguyen Phi; Kwack, Seung Jun; Huh, Jung-Im; Min, Byung Sun; Choi, Jae Sue; Lee, Hyeong Kyu; Bae, KiHwan

    2010-02-26

    Two new dammarane-type glycosides, 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-[beta-d-glucopyranosyl(1-->4)-beta-d-glucopyranosyl]-20-O-[beta-d-xylopyranosyl-(1-->6)-beta-d-glucopyranoside] (1) and 2alpha,3beta,12beta,20S-tetrahydroxydammar-24-ene-3-O-beta-d-glucopyranosyl-20-O-[beta-d-6-O-acetylglucopyranosyl-(1-->2)-beta-d-glucopyranoside] (2), were isolated from a MeOH extract of the leaves of Gynostemma pentaphyllum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The isolated compounds showed potential inhibitory effects on eotaxin expression in BEAS-2B bronchial epithelial cells.

  1. In situ analysis of cell wall polymers associated with phloem fibre cells in stems of hemp, Cannabis sativa L.

    Science.gov (United States)

    Blake, Anthony W; Marcus, Susan E; Copeland, James E; Blackburn, Richard S; Knox, J Paul

    2008-06-01

    A study of stem anatomy and the sclerenchyma fibre cells associated with the phloem tissues of hemp (Cannabis sativa L.) plants is of interest for both understanding the formation of secondary cell walls and for the enhancement of fibre utility as industrial fibres and textiles. Using a range of molecular probes for cell wall polysaccharides we have surveyed the presence of cell wall components in stems of hemp in conjunction with an anatomical survey of stem and phloem fibre development. The only polysaccharide detected to occur abundantly throughout the secondary cell walls of phloem fibres was cellulose. Pectic homogalacturonan epitopes were detected in the primary cell walls/intercellular matrices between the phloem fibres although these epitopes were present at a lower level than in the surrounding parenchyma cell walls. Arabinogalactan-protein glycan epitopes displayed a diversity of occurrence in relation to fibre development and the JIM14 epitope was specific to fibre cells, binding to the inner surface of secondary cell walls, throughout development. Xylan epitopes were found to be present in the fibre cells (and xylem secondary cell walls) and absent from adjacent parenchyma cell walls. Analysis of xylan occurrence in the phloem fibre cells of hemp and flax indicated that xylan epitopes were restricted to the primary cell walls of fibre cells and were not present in the secondary cell walls of these cells.

  2. A novel beta-glucosidase from the cell wall of maize (Zea mays L.): rapid purification and partial characterization

    Science.gov (United States)

    Nematollahi, W. P.; Roux, S. J.

    1999-01-01

    Plants have a variety of glycosidic conjugates of hormones, defense compounds, and other molecules that are hydrolyzed by beta-glucosidases (beta-D-glucoside glucohydrolases, E.C. 3.2.1.21). Workers have reported several beta-glucosidases from maize (Zea mays L.; Poaceae), but have localized them mostly by indirect means. We have purified and partly characterized a 58-Ku beta-glucosidase from maize, which we conclude from a partial sequence analysis, from kinetic data, and from its localization is not identical to any of those already reported. A monoclonal antibody, mWP 19, binds this enzyme, and localizes it in the cell walls of maize coleoptiles. An earlier report showed that mWP19 inhibits peroxidase activity in crude cell wall extracts and can immunoprecipitate peroxidase activity from these extracts, yet purified preparations of the 58 Ku protein had little or no peroxidase activity. The level of sequence similarity between beta-glucosidases and peroxidases makes it unlikely that these enzymes share epitopes in common. Contrary to a previous conclusion, these results suggest that the enzyme recognized by mWP19 is not a peroxidase, but there is a wall peroxidase closely associated with the 58 Ku beta-glucosidase in crude preparations. Other workers also have co-purified distinct proteins with beta-glucosidases. We found no significant charge in the level of immunodetectable beta-glucosidase in mesocotyls or coleoptiles that precedes the red light-induced changes in the growth rate of these tissues.

  3. Clear Cell Adenocarcinoma Arising from Abdominal Wall Endometriosis

    Directory of Open Access Journals (Sweden)

    Thouraya Achach

    2008-01-01

    Full Text Available Endometriosis is a frequent benign disorder. Malignancy arising in extraovarian endometriosis is a rare event. A 49-year-old woman is presented with a large painful abdominal wall mass. She underwent a myomectomy, 20 years before, for uterus leiomyoma. Computed tomography suggested that this was a desmoid tumor and she underwent surgery. Histological examination showed a clear cell adenocarcinoma associated with endometriosis foci. Pelvic ultrasound, computed tomography, and endometrial curettage did not show any malignancy or endometriosis in the uterus and ovaries. Adjuvant chemotherapy was recommended, but the patient was lost to follow up. Six months later, she returned with a recurrence of the abdominal wall mass. She was given chemotherapy and then she was reoperated.

  4. Pressure Dependent Wall Relaxation in Polarized $^3$He Gaseous Cells

    CERN Document Server

    Peng, C; Chu, P -H; Gao, H; Zhang, Y

    2013-01-01

    Pressure dependence of longitudinal relaxation time (T$_1$) due to the cell wall was observed previously at both room temperature and low temperature in valved Rb-coated refillable $^3$He gaseous cells in \\cite{Zheng2}. The diffusion of $^3$He from measurement cell through a capillary tube to the valve and the subsequent depolarization on the surface of the valve was proposed to possibly explain such a pressure dependence at room temperature \\cite{Saam}. In this paper, we investigate this diffusion effect through measurements of T$_1$ with newly designed Rb-coated Pyrex glass cells at 295 K as well as finite element analysis (FEA) studies. Both the experimental results and FEA studies show that the diffusion effect is insufficient to explain the observed linear pressure-dependent behavior of T$_1$.

  5. Change in wall composition of transfer and aleurone cells during wheat grain development.

    Science.gov (United States)

    Robert, P; Jamme, F; Barron, C; Bouchet, B; Saulnier, L; Dumas, P; Guillon, F

    2011-02-01

    In addition to the starchy endosperm, a specialized tissue accumulating storage material, the endosperm of wheat grain, comprises the aleurone layer and the transfer cells next to the crease. The transfer cells, located at the ventral region of the grain, are involved in nutrient transfer from the maternal tissues to the developing endosperm. Immunolabeling techniques, Raman spectroscopy, and synchrotron infrared micro-spectroscopy were used to study the chemistry of the transfer cell walls during wheat grain development. The kinetic depositions of the main cell wall polysaccharides of wheat grain endosperm, arabinoxylan, and (1-3)(1-4)-β-glucan in transfer cell walls were different from kinetics previously observed in the aleurone cell walls. While (1-3)(1-4)-β-glucan appeared first in the aleurone cell walls at 90°D, arabinoxylan predominated in the transfer cell walls from 90 to 445°D. Both aleurone and transfer cell walls were enriched in (1-3)(1-4)-β-glucan at the mature stage of wheat grain development. Arabinoxylan was more substituted in the transfer cell walls than in the aleurone walls. However, arabinoxylan was more feruloylated in the aleurone than in the transfer cell walls, whatever the stage of grain development. In the transfer cells, the ferulic acid was less abundant in the outer periclinal walls while para-coumarate was absent. Possible implications of such differences are discussed.

  6. Stimulation of elongation growth and cell wall loosening in rice coleoptiles under microgravity conditions in space.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Mori, Ryuji; Saiki, Mizue; Nakamura, Yukiko; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro

    2002-09-01

    We analyzed the growth rate and the cell wall properties of coleoptiles of rice seedlings grown at 23.6 degrees C for 68.5, 91.5 and 136 h during the Space Shuttle STS-95 mission. In space, elongation growth of coleoptiles was stimulated and the cell wall extensibility increased. Also, the levels of the cell wall polysaccharides per unit length of coleoptiles and the relative content of the high molecular mass matrix polysaccharides decreased in space. These differences in the cell wall polysaccharides could be involved in increasing the cell wall extensibility, leading to growth stimulation of rice coleoptiles in space.

  7. [Hydroxyproline: Rich glycoproteins of the plant and cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Varner, J.E.

    1993-01-01

    Since xylem tissue includes the main cell types which are lignified, we are interested in gene expression of glycine-rich proteins and proline-rich proteins, and other proteins which are involved in secondary cell wall thickening during xylogenesis. Since the main feature of xylogenesis is the deposition of additional wall components, study of the mechanism of xylogenesis will greatly advance our knowledge of the synthesis and assembly of wall macromolecules. We are using the in vitro xylogenesis system from isolated Zinnia mesophyll cells to isolate genes which are specifically expressed during xylogenesis. We have used subtractive hybridization methods to isolate a number of cDNA clones for differentially regulated genes from the cells after hormonal induction. So far, we have partially characterized 18 different cDNA clones from 239 positive clones. These differentially regulated genes can be divided into three sets according to the characteristics of gene expression in the induction medium and the control medium. The first set is induced in both the induction medium and the control medium without hormones. The second set is induced mainly in the induction medium and in the control medium with the addition of NAA alone. Two of thesegenes are exclusively induced by auxin. The third set of genes is induced mainly in the induction medium. Since these genes are not induced by either auxin or cytokinin alone, they may be directly involved in the process of xylogenesis. Our experiments on the localization of H[sub 2]O[sub 2] production reinforce the earlier ideas of others that H[sub 2]O[sub 2] is involved in normal lignification.

  8. Measuring the Mechanical Properties of Plant Cell Walls

    Directory of Open Access Journals (Sweden)

    Hannes Vogler

    2015-03-01

    Full Text Available The size, shape and stability of a plant depend on the flexibility and integrity of its cell walls, which, at the same time, need to allow cell expansion for growth, while maintaining mechanical stability. Biomechanical studies largely vanished from the focus of plant science with the rapid progress of genetics and molecular biology since the mid-twentieth century. However, the development of more sensitive measurement tools renewed the interest in plant biomechanics in recent years, not only to understand the fundamental concepts of growth and morphogenesis, but also with regard to economically important areas in agriculture, forestry and the paper industry. Recent advances have clearly demonstrated that mechanical forces play a crucial role in cell and organ morphogenesis, which ultimately define plant morphology. In this article, we will briefly review the available methods to determine the mechanical properties of cell walls, such as atomic force microscopy (AFM and microindentation assays, and discuss their advantages and disadvantages. But we will focus on a novel methodological approach, called cellular force microscopy (CFM, and its automated successor, real-time CFM (RT-CFM.

  9. Principles of Bacterial Cell-Size Determination Revealed by Cell-Wall Synthesis Perturbations

    Directory of Open Access Journals (Sweden)

    Carolina Tropini

    2014-11-01

    Full Text Available Although bacterial cell morphology is tightly controlled, the principles of size regulation remain elusive. In Escherichia coli, perturbation of cell-wall synthesis often results in similar morphologies, making it difficult to deconvolve the complex genotype-phenotype relationships underlying morphogenesis. Here we modulated cell width through heterologous expression of sequences encoding the essential enzyme PBP2 and through sublethal treatments with drugs that inhibit PBP2 and the MreB cytoskeleton. We quantified the biochemical and biophysical properties of the cell wall across a wide range of cell sizes. We find that, although cell-wall chemical composition is unaltered, MreB dynamics, cell twisting, and cellular mechanics exhibit systematic large-scale changes consistent with altered chirality and a more isotropic cell wall. This multiscale analysis enabled identification of distinct roles for MreB and PBP2, despite having similar morphological effects when depleted. Altogether, our results highlight the robustness of cell-wall synthesis and physical principles dictating cell-size control.

  10. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  11. Solid-state NMR Reveals the Carbon-based Molecular Architecture of Cryptococcus neoformans Fungal Eumelanins in the Cell Wall.

    Science.gov (United States)

    Chatterjee, Subhasish; Prados-Rosales, Rafael; Itin, Boris; Casadevall, Arturo; Stark, Ruth E

    2015-05-29

    Melanin pigments protect against both ionizing radiation and free radicals and have potential soil remediation capabilities. Eumelanins produced by pathogenic Cryptococcus neoformans fungi are virulence factors that render the fungal cells resistant to host defenses and certain antifungal drugs. Because of their insoluble and amorphous characteristics, neither the pigment bonding framework nor the cellular interactions underlying melanization of C. neoformans have yielded to comprehensive molecular-scale investigation. This study used the C. neoformans requirement of exogenous obligatory catecholamine precursors for melanization to produce isotopically enriched pigment "ghosts" and applied 2D (13)C-(13)C correlation solid-state NMR to reveal the carbon-based architecture of intact natural eumelanin assemblies in fungal cells. We demonstrated that the aliphatic moieties of solid C. neoformans melanin ghosts include cell-wall components derived from polysaccharides and/or chitin that are associated proximally with lipid membrane constituents. Prior to development of the mature aromatic fungal pigment, these aliphatic moieties form a chemically resistant framework that could serve as the scaffold for melanin synthesis. The indole-based core aromatic moieties show interconnections that are consistent with proposed melanin structures consisting of stacked planar assemblies, which are associated spatially with the aliphatic scaffold. The pyrrole aromatic carbons of the pigments bind covalently to the aliphatic framework via glycoside or glyceride functional groups. These findings establish that the structure of the pigment assembly changes with time and provide the first biophysical information on the mechanism by which melanin is assembled in the fungal cell wall, offering vital insights that can advance the design of bioinspired conductive nanomaterials and novel therapeutics.

  12. Profiling the Hydrolysis of Isolated Grape Berry Skin Cell Walls by Purified Enzymes.

    Science.gov (United States)

    Zietsman, Anscha J J; Moore, John P; Fangel, Jonatan U; Willats, William G T; Vivier, Melané A

    2015-09-23

    The unraveling of crushed grapes by maceration enzymes during winemaking is difficult to study because of the complex and rather undefined nature of both the substrate and the enzyme preparations. In this study we simplified both the substrate, by using isolated grape skin cell walls, and the enzyme preparations, by using purified enzymes in buffered conditions, to carefully follow the impact of the individual and combined enzymes on the grape skin cell walls. By using cell wall profiling techniques we could monitor the compositional changes in the grape cell wall polymers due to enzyme activity. Extensive enzymatic hydrolysis, achieved with a preparation of pectinases or pectinases combined with cellulase or hemicellulase enzymes, completely removed or drastically reduced levels of pectin polymers, whereas less extensive hydrolysis only opened up the cell wall structure and allowed extraction of polymers from within the cell wall layers. Synergistic enzyme activity was detectable as well as indications of specific cell wall polymer associations.

  13. Cell wall swelling, fracture mode, and the mechanical properties of cherry fruit skins are closely related.

    Science.gov (United States)

    Brüggenwirth, Martin; Knoche, Moritz

    2017-04-01

    Cell wall swelling, fracture mode (along the middle lamellae vs. across cell walls), stiffness, and pressure at fracture of the sweet cherry fruit skin are closely related. Skin cracking is a common phenomenon in many crops bearing fleshy fruit. The objectives were to investigate relationships between the mode of fracture, the extent of cell wall swelling, and the mechanical properties of the fruit skin using sweet cherry (Prunus avium) as a model. Cracking was induced by incubating whole fruit in deionised water or by fracturing exocarp segments (ESs) in biaxial tensile tests. The fracture mode of epidermal cells was investigated by light microscopy. In biaxial tensile tests, the anticlinal cell walls of the ES fractured predominantly across the cell walls (rather than along) and showed no cell wall swelling. In contrast, fruit incubated in water fractured predominantly along the anticlinal epidermal cell walls and the cell walls were swollen. Swelling of cell walls also occurred when ESs were incubated in malic acid, in hypertonic solutions of sucrose, or in water. Compared to the untreated controls, these treatments resulted in more frequent fractures along the cell walls, lower pressures at fracture (p fracture), and lower moduli of elasticity (E, i.e., less stiff). Conversely, compared to the untreated controls, incubating the ES in CaCl2 and in high concentrations of ethanol resulted in thinner cell walls, in less frequent fractures along the cell walls, higher E and p fracture. Our study demonstrates that fracture mode, stiffness, and pressure at fracture are closely related to cell wall swelling. A number of other factors, including cultivar, ripening stage, turgor, CaCl2, and malic acid, exert their effects only indirectly, i.e., by affecting cell wall swelling.

  14. Changes of CD4+ CD25+ Regulatory T Cells, FoxP3 in Adjuvant Arthritis Rats with Damage of Pulmonary Function and Effects of Tripterygium Glycosides Tablet

    Directory of Open Access Journals (Sweden)

    Wan Lei

    2012-01-01

    Full Text Available Objective. To observe the effects of tripterygium glycosides tablet (TPT on swelling degree, arthritis index (AI, pulmonary function, cytokines, the expression of regulatory T cells (Treg, and Foxp3 in rats of adjuvant arthritis. Methods. Rats were averagely divided into normal control (NC group, model control (MC group, methotrexate (MTX group, and tripterygium glycosides tablet (TPT group. Except for the rats of normal group, the others were intracutaneously injected with 0.1 mL of Freund’s complete adjuvant in the right hindlimb. NC group and MC group were treated with physiological saline. MTX group and TPT group were treated with MTX, TPT, respectively. Results. The levels of swelling degree, AI, the alveolar inflammation integral, TNF alpha (TNF-, and endothelium-1 (ET-1 in MC group were significantly increased (, and the levels of forced vital capacity (FVC, 25% vital capacity of the peak expiratory flow (FEF25, 50% vital capacity of the peak expiratory flow (FEF50, 75% vital capacity of the peak expiratory flow (FEF75, maximum midexpiratory flow (MMF, peak expiratory flow (PEF, interleukin-10 (IL-10, CD4+ CD25+ Treg, and Foxp3 were decreased (. The scores of alveolitis and ET-1 were decreased with treatment of TPT. The levels of FVC, FEF25, FEF50, FEF75, MMF, PEF, IL-10, and CD4+ CD25+ Treg in peripheral blood were increased. The expressions of Foxp3 protein and mRNA in lung tissue were also increased in TPT group. Conclusions. The paw swelling can be inhibited by TPT, and the inflammatory response in lung tissue was also decreased, which is a significant improvement in pulmonary function. The mechanism is probably associated with upregulating the expression of IL-10, Foxp3, and downregulating the level of TNF-.

  15. Direct measurement of cell wall stress-stiffening and turgor pressure in live bacterial cells

    CERN Document Server

    Deng, Yi; Shaevitz, Joshua W

    2011-01-01

    The mechanical properties of gram-negative bacteria are governed by a rigid peptidoglycan (PG) cell wall and the turgor pressure generated by the large concentration of solutes in the cytoplasm. The elasticity of the PG has been measured in bulk and in isolated sacculi and shown to be compliant compared to the overall stiffness of the cell itself. However, the stiffness of the cell wall in live cells has not been measured. In particular, the effects that pressure-induced stress might have on the stiffness of the mesh-like PG network have not been addressed even though polymeric materials often exhibit large amounts of stress-stiffening. We study bulging Escherichia coli cells using atomic force microscopy to separate the contributions of the cell wall and turgor pressure to the overall cell stiffness. We find strong evidence of power-law stress-stiffening in the E. coli cell wall, with an exponent of $1.07 \\pm 0.25$, such that the wall is significantly stiffer in live cells ($E\\sim32\\pm10$ MPa) than in unpres...

  16. Multi-Walled Carbon Nanotubes Inhibit Breast Cancer Cell Migration.

    Science.gov (United States)

    Graham, Elizabeth G; Wailes, Elizabeth M; Levi-Polyachenko, Nicole H

    2016-02-01

    According to the American Cancer Society, breast cancer is the second leading cause of cancer death in the US. Cancerous cells may have inadequate adhesions to the extracellular matrix and adjacent cells. Previous work has suggested that restoring these contacts may negate the cancer phenotype. This work aims to restore those contacts using multi-walled carbon nanotubes (MWNTs). Varying concentrations of carboxylated MWNTs in water, with or without type I collagen, were dried to create a thin film upon which one of three breast cell lines were seeded: cancerous and metastatic MDA- MB-231 cells, cancerous but non-metastatic MCF7 cells, or non-cancerous MCF10A cells. Proliferation, adhesion, scratch and autophagy assays, western blots, and immunochemical staining were used to assess adhesion and E-cadherin expression. Breast cancer cells grown on a MWNT-collagen coated surface displayed increased adhesion and decreased migration which correlated with an increase in E-cadherin. This work suggests an alternative approach to cancer treatment by physically mediating the cells' microenvironment.

  17. Transient sedimentation in a cell with top and bottom walls

    Science.gov (United States)

    Dance, Sarah; Maxey, Martin

    2002-11-01

    Wall boundary conditions may play a role in the screening of particle velocity fluctuations in Stokes suspensions. Using a Force-Coupling Method (Maxey and Patel, Int. J. Multiphase Flow 27 (2001)) we simulate transient sedimentation. The numerical scheme is a mixed Fourier-spectral element method, based on the Uzawa algorithm for Stokes flows. The sedimentation cell has top and bottom wall boundaries and periodic boundaries in the horizontal. These boundaries are chosen both for computational convenience, and to determine the relative importance of bottom and side walls in screening the velocity fluctuations. We consider several different box sizes, in an attempt to elucidate the connection between particle velocity fluctuation levels and box width. We quantify the evolution of particle mean velocities and fluctuations as well as the particle microstructure. In each case we observe an initial growth, followed by a decay in both the mean particle velocity and fluctuations. We also observe that a stable stratification develops. We suggest that the stratification is important in the evolution of the bulk mean velocity. We propose a mechanism involving particle cluster dynamics to explain the behaviour of the velocity fluctuations.

  18. High-resolution solution-state NMR of unfractionated plant cell walls

    Science.gov (United States)

    John Ralph; Fachuang Lu; Hoon Kim; Dino Ress; Daniel J. Yelle; Kenneth E. Hammel; Sally A. Ralph; Bernadette Nanayakkara; Armin Wagner; Takuya Akiyama; Paul F. Schatz; Shawn D. Mansfield; Noritsugu Terashima; Wout Boerjan; Bjorn Sundberg; Mattias Hedenstrom

    2009-01-01

    Detailed structural studies on the plant cell wall have traditionally been difficult. NMR is one of the preeminent structural tools, but obtaining high-resolution solution-state spectra has typically required fractionation and isolation of components of interest. With recent methods for dissolution of, admittedly, finely divided plant cell wall material, the wall can...

  19. Cellulose-hemicellulose interaction in wood secondary cell-wall

    Science.gov (United States)

    Zhang, Ning; Li, Shi; Xiong, Liming; Hong, Yu; Chen, Youping

    2015-12-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose.

  20. A radioimmunoassay for lignin in plant cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Dawley, R.M.

    1989-01-01

    Lignin detection and determination in herbaceous tissue requires selective, specific assays which are not currently available. A radioimmunoassay (RIA) was developed to study lignin metabolism in these tissues. A {beta}-aryl ether lignin model compound was synthesized, linked to keyhole limpet hemocyanin using a water-soluble carbodiimide, and injected into rabbits. The highest titer of the antiserum obtained was 34 {eta}g/mL of model derivatized BSA. An in vitro system was developed to characterize the RIA. The model compound was linked to amino activated polyacrylamide beads to mimic lignin in the cell walls. {sup 125}I Radiolabelled protein A was used to detect IgG antibody binding. The RIA was shown in the in vitro system to exhibit saturable binding. The amount of antibody bound decreased when the serum was diluted. Immunoelectrophoresis and competitive binding experiments confirmed that both aromatic rings of the lignin model compound had been antigenic. Chlorogenic acid, a phenolic known to be present in plant cells, did not compete for antibody binding. The RIA was used to measure lignin in milled plant samples and barley seedlings. Antiserum binding to wheat cell walls and stressed barley segments was higher than preimmune serum binding. Antibody binding to stressed barley tissue decreased following NaClO{sub 2} delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed.

  1. Modification of chemical properties of cell walls by silicon and its role in regulation of the cell wall extensibility in oat leaves.

    Science.gov (United States)

    Hossain, Mohammad Talim; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Fujii, Shuhei; Yamamoto, Ryoichi; Hoson, Takayuki

    2007-04-01

    Effects of silicon on the mechanical and chemical properties of cell walls in the second leaf of oat (Avena sativa L.) seedlings were investigated. The cell wall extensibility in the basal region of the second leaf was considerably higher than that in the middle and subapical regions. Externally applied silicon increased the cell wall extensibility in the basal region, but it did not affect the extensibility in the middle and subapical regions. The amounts of cell wall polysaccharides and phenolic compounds, such as diferulic acid (DFA) and ferulic acid (FA), per unit length were lower in the basal region than in the middle and subapical regions of the leaf, and silicon altered these amounts in the basal region. In this region, silicon decreased the amounts of matrix polymers and cellulose per unit length and of DFA and FA, both per unit length and unit matrix polymer content. Silicon treatment also lowered the activity of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) in the basal region. In contrast, the amount of silicon in cell walls increased in response to silicon treatment in three regions. These results suggest that in the basal region, silicon reduces the net wall mass and the formation of phenolic acid-mediated cross-linkages between wall polysaccharides. Such modifications of wall architecture may be responsible for the silicon-induced increase in the cell wall extensibility in oat leaves.

  2. Mass spectrometry for characterizing plant cell wall polysaccharides

    Directory of Open Access Journals (Sweden)

    Stefan eBauer

    2012-03-01

    Full Text Available Mass spectrometry is a selective and powerful technique to obtain identification and structural information on compounds present in complex mixtures. Since it requires only small sample amount it is an excellent tool for researchers interested in detecting changes in composition of complex carbohydrates of plants. This mini-review gives an overview of common mass spectrometry techniques applied to the analysis of plant cell wall carbohydrates. It presents examples in which mass spectrometry has been used to elucidate the structure of oligosaccharides derived from hemicelluloses and pectins and illustrates how information on sequence, linkages, branching and modifications are obtained from characteristic fragmentation patterns.

  3. Chitosan Obtained from Cell Wall of Aspergillus Niger Mycelium

    Institute of Scientific and Technical Information of China (English)

    HUANG Hui-li; LIN Wen-luan; LIN Jian-ming

    2004-01-01

    Chitin from cell walls of Aspergillus Niger mycelium was prepared. A new method for the preparation of high deacetylation degree chitosan was studied in a dilute sodium hydroxide solution at a high pressure. The experimental results indicate that the deacetylation degree of the chitosan can reach 80% under the condition of a 5.00 mol/L sodium hydroxide solution at 0.1 MPa of pressure for 1 h. This method shows the advantages of the applications in the industry production and environment protection.

  4. Feruloyl oligosaccharides from cell walls of suspension-cultured spinach cells and sugar beet pulp.

    Science.gov (United States)

    Ishii, T

    1994-06-01

    Cell walls of suspension-cultured spinach cells and sugar beet pulp were separately hydrolyzed with Driselase. A feruloyl arabinobiose was isolated from both spinach cells and sugar beet. Four feruloyl oligosaccharides were obtained from sugar beet. The four oligosaccharides were characterized by NMR spectroscopy, methylation analysis and FAB-MS.

  5. Employing proteomic analysis to compare Paracoccidioides lutzii yeast and mycelium cell wall proteins.

    Science.gov (United States)

    Araújo, Danielle Silva; de Sousa Lima, Patrícia; Baeza, Lilian Cristiane; Parente, Ana Flávia Alves; de Melo Bailão, Alexandre; Borges, Clayton Luiz; de Almeida Soares, Célia Maria

    2017-08-24

    Paracoccidioidomycosis is an important systemic mycosis caused by thermodimorphic fungi of the Paracoccidioides genus. During the infective process, the cell wall acts at the interface between the fungus and the host. In this way, the cell wall has a key role in growth, environment sensing and interaction, as well as morphogenesis of the fungus. Since the cell wall is absent in mammals, it may present molecules that are described as target sites for new antifungal drugs. Despite its importance, up to now few studies have been conducted employing proteomics in for the identification of cell wall proteins in Paracoccidioides spp. Here, a detailed proteomic approach, including cell wall-fractionation coupled to NanoUPLC-MS(E), was used to study and compare the cell wall fractions from Paracoccidioides lutzii mycelia and yeast cells. The analyzed samples consisted of cell wall proteins extracted by hot SDS followed by extraction by mild alkali. In summary, 512 proteins constituting different cell wall fractions were identified, including 7 predicted GPI-dependent cell wall proteins that are potentially involved in cell wall metabolism. Adhesins previously described in Paracoccidioides spp. such as enolase, glyceraldehyde-3-phosphate dehydrogenase were identified. Comparing the proteins in mycelium and yeast cells, we detected some that are common to both fungal phases, such as Ecm33, and some specific proteins, as glucanase Crf1. All of those proteins were described in the metabolism of cell wall. Our study provides an important elucidation of cell wall composition of fractions in Paracoccidioides, opening a way to understand the fungus cell wall architecture. Copyright © 2017. Published by Elsevier B.V.

  6. Binding of /sup 18/F by cell membranes and cell walls of Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Yotis, W.W.; Zeb, M.; McNulty, J.; Kirchner, F.; Reilly, C.; Glendenin, L.

    1983-07-01

    The binding of /sup 18/F to isolated cell membranes and cell walls of Streptococcus mutans GS-5 or other bacteria was assayed. The attachment of /sup 18/F to these cell envelopes proceeded slowly and reached equilibrium within 60 min. /sup 18/F binding was stimulated by Ca/sup 2 +/ (1 mM). The binding of /sup 18/F to cellular components was dependent upon the pH, as well as the amount of /sup 18/F and dose of the binder employed. The binding of /sup 18/F by cell walls prepared from fluoride-sensitive and fluoride-resistant cells of S. salivarius and S. mutans did not differ significantly. The pretreatment of cell walls or cell membranes for 60 min at 30 degrees C with 1 mg of RNase, DNase, or trypsin per ml did not influence the binding of /sup 18/F by the walls and membranes of S. mutans GS-5. However, prior exposure of cell membranes to sodium dodecyl sulfate caused a significant reduction in the number of /sup 18/F atoms bound by the membranes. In saturated assay systems, cell membranes of S. mutans GS-5 bound 10(15) to 10(16) atoms of /sup 18/F per mg (dry weight), whereas cell walls from S. mutans GS-5, FA-1, and HS-6 or Actinomyces viscosus T14V and T14AV bound 10(12) to 10(13) atoms of /sup 18/F per mg (dry weight). /sup 18/F in this quantity (10(12) to 10(13) atoms) cannot be detected with the fluoride electrode. The data provide, for the first time, a demonstration of /sup 18/F binding by cell membranes and walls of oral flora.

  7. The Role of Pectin Acetylation in the Organization of Plant Cell Walls

    DEFF Research Database (Denmark)

    Fimognari, Lorenzo

    All plant cells are surrounded by one or more cell wall layers. The cell wall serves as a stiff mechanical support while it allows cells to expand and provide a protective barrier to invading pathogens. Cell walls are dynamic structures composed of entangled cell wall polysaccharides that must...... adopt defined 3D organization to allow their composition/interactions to be tweaked upon developmental need. Failure to build functional cell wall architecture will affect plant growth and resistance to stresses. In this PhD dissertation I explored the role of pectin acetylation in controlling...... that the loss of structural integrity in the cell wall was the underlying cause for triggering defenses response. This hypothesis was tested in Manuscript II. Through a suppressor screen of 30.000 Arabidopsis rwa2 plants and mapping of mutations by next generation sequencing, we pinpointed pectin deacetylation...

  8. Properties of lead deposits in cell walls of radish (Raphanus sativus) roots.

    Science.gov (United States)

    Inoue, Hiroshi; Fukuoka, Daisuke; Tatai, Yuri; Kamachi, Hiroyuki; Hayatsu, Manabu; Ono, Manami; Suzuki, Suechika

    2013-01-01

    Various mechanisms are involved in detoxification of heavy metals such as lead (Pb) in plant cells. Most of the Pb taken up by plants accumulates in their roots. However, the detailed properties of Pb complexes in roots remain unclear. We have investigated the properties of Pb deposits in root cell walls of radish (Raphanus sativus L.) seedlings grown on glass beads bed containing Pb pellets, which are the source of Pb-contamination in shooting range soils. Pb deposits were tightly bound to cell walls. Cell wall fragments containing about 50,000 ppm Pb were prepared from the roots. After extracting Pb from the cell wall fragments using HCl, Pb ions were recombined with the Pb-extracted cell wall fragments in a solution containing Pb acetate. When the cell wall fragments were treated with pectinase (E.C. 3.2.1.15) and were chemically modified with 1-ethyl-3-dimethylamino-propylcarboimide, the Pb-rebinding ability of the treated cell wall fragments decreased. When acid-treated cell wall fragments were incubated in a solution containing Pb(2+) and excess amounts of a chelating agent, Pb recombined with the cell wall fragments were measured to estimate the affinity between Pb(2+) and the cell wall fragments. Our data show that Pb(2+) binds to carboxyl groups of cell walls. The source of the carboxyl groups is suggested to be pectic compounds. A stability constant of the Pb-cell wall complex was estimated to be about 10(8). The role of root cell walls in the mechanism underlying heavy metal tolerance was discussed.

  9. Dental pulp response to bacterial cell wall material.

    Science.gov (United States)

    Warfvinge, J; Dahlén, G; Bergenholtz, G

    1985-08-01

    Lipopolysaccharides (LPS) from Bacteroides oralis and Veillonella parvula and cell wall material from Lactobacillus casei were studied for their capacity to induce leukocyte migration in the dental pulp and in an implanted wound chamber. Three adult monkeys were challenged using lyophilized material sealed into buccal Class V cavities prepared in dentin. Pulp tissue responses were observed histologically eight and 72 hours after initiation of the experiment. Subjacent to cut dentinal tubules, bacterial materials induced polymorphonuclear leukocyte (PMN's) infiltration in the pulp tissue of the majority of test teeth examined. Responses were similar for the three bacterial test materials at both time periods. Topical applications of bovine serum albumin (BSA), used as a control, induced significantly less accumulation of PMN's. Assessments of induced exudate volumes and leukocyte densities in chambers implanted in rats showed comparable rankings with pulpal experiment between test (i.e., bacterial) and control (BSA) materials. Analysis of the data indicates that high-molecular-weight complexes of bacterial cell walls may adversely affect pulpal tissue across freshly exposed dentin.

  10. Chemical Profiling of the Plant Cell Wall through Raman Microspectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Han, Ju; Singh, Seema; Sun, Lan; Simmons, Blake; Auer, Manfred; Parvin, Bahram

    2010-03-02

    This paper presents a computational framework for chemical pro.ling of the plant cell wall through the Raman spectroscopy. The system enables query of known spectral signatures and clustering of spectral data based on intrinsic properties. As a result, presence and relative concentration of speci.c chemical bonds can be quanti.ed. The primary contribution of this paper is in representation of raman pro.le in terms of .uorescence background and multiscale peak detection at each grid point (voxel). Such a representation allows ef.cient spatial segmentation based on the coupling between high-level salient properties and low-level symbolic representation at each voxel. The high-level salient properties refer to preferred peaks and their attributes for the entire image. The low-level symbolic representations are based on .uorescence background, spectral peak locations, and their attributes. We present results on a corn stover tissue section that is imaged through Raman microscopy, and the results are consistent with the literature. In addition, automatic clustering indicates several distinct layers of the cell walls with different spectral signatures.

  11. Ultrastructure of the Epidermal Cell Wall and Cuticle of Tomato Fruit (Solanum lycopersicum L.) during Development.

    Science.gov (United States)

    Segado, Patricia; Domínguez, Eva; Heredia, Antonio

    2016-02-01

    The epidermis plays a pivotal role in plant development and interaction with the environment. However, it is still poorly understood, especially its outer epidermal wall: a singular wall covered by a cuticle. Changes in the cuticle and cell wall structures are important to fully understand their functions. In this work, an ultrastructure and immunocytochemical approach was taken to identify changes in the cuticle and the main components of the epidermal cell wall during tomato fruit development. A thin and uniform procuticle was already present before fruit set. During cell division, the inner side of the procuticle showed a globular structure with vesicle-like particles in the cell wall close to the cuticle. Transition between cell division and elongation was accompanied by a dramatic increase in cuticle thickness, which represented more than half of the outer epidermal wall, and the lamellate arrangement of the non-cutinized cell wall. Changes in this non-cutinized outer wall during development showed specific features not shared with other cell walls. The coordinated nature of the changes observed in the cuticle and the epidermal cell wall indicate a deep interaction between these two supramolecular structures. Hence, the cuticle should be interpreted within the context of the outer epidermal wall. © 2016 American Society of Plant Biologists. All Rights Reserved.

  12. Cell wall proteins of Sporothrix schenckii as immunoprotective agents.

    Science.gov (United States)

    Alba-Fierro, Carlos A; Pérez-Torres, Armando; López-Romero, Everardo; Cuéllar-Cruz, Mayra; Ruiz-Baca, Estela

    2014-01-01

    Sporothrix schenckii is the etiological agent of sporotrichosis, an endemic subcutaneous mycosis in Latin America. Cell wall (CW) proteins located on the cell surface are inducers of cellular and humoral immune responses, potential candidates for diagnosis purposes and to generate vaccines to prevent fungal infections. This mini-review emphasizes the potential use of S. schenckii CW proteins as protective and therapeutic immune response inducers against sporotrichosis. A number of pathogenic fungi display CW components that have been characterized as inducers of protective cellular and humoral immune responses against the whole pathogen from which they were originally purified. The isolation and characterization of immunodominant protein components of the CW of S. schenckii have become relevant because of their potential in the development of protective and therapeutic immune responses against sporotrichosis. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

  13. MreB: pilot or passenger of cell wall synthesis?

    Science.gov (United States)

    White, Courtney L; Gober, James W

    2012-02-01

    The discovery that the bacterial cell shape determinant MreB is related to actin spurred new insights into bacterial morphogenesis and development. The trafficking and mechanical roles of the eukaryotic cytoskeleton were hypothesized to have a functional ancestor in MreB based on evidence implicating MreB as an organizer of cell wall synthesis. Genetic, biochemical and cytological studies implicate MreB as a coordinator of a large multi-protein peptidoglycan (PG) synthesizing holoenzyme. Recent advances in microscopy and new biochemical evidence, however, suggest that MreB may function differently than previously envisioned. This review summarizes our evolving knowledge of MreB and attempts to refine the generalized model of the proteins organizing PG synthesis in bacteria. This is generally thought to be conserved among eubacteria and the majority of the discussion will focus on studies from a few well-studied model organisms.

  14. Murein and pseudomurein cell wall binding domains of bacteria and archaea-a comparative view

    NARCIS (Netherlands)

    Visweswaran, Ganesh Ram R.; Dijkstra, Bauke W.; Kok, Jan

    2011-01-01

    The cell wall, a major barrier protecting cells from their environment, is an essential compartment of both bacteria and archaea. It protects the organism from internal turgor pressure and gives a defined shape to the cell. The cell wall serves also as an anchoring surface for various proteins and a

  15. Plant Cell Wall Proteins: A Large Body of Data, but What about Runaways?

    Science.gov (United States)

    Albenne, Cécile; Canut, Hervé; Hoffmann, Laurent; Jamet, Elisabeth

    2014-04-17

    Plant cell wall proteomics has been a very dynamic field of research for about fifteen years. A full range of strategies has been proposed to increase the number of identified proteins and to characterize their post-translational modifications. The protocols are still improving to enlarge the coverage of cell wall proteomes. Comparisons between these proteomes have been done based on various working strategies or different physiological stages. In this review, two points are highlighted. The first point is related to data analysis with an overview of the cell wall proteomes already described. A large body of data is now available with the description of cell wall proteomes of seventeen plant species. CWP contents exhibit particularities in relation to the major differences in cell wall composition and structure between these plants and between plant organs. The second point is related to methodology and concerns the present limitations of the coverage of cell wall proteomes. Because of the variety of cell wall structures and of the diversity of protein/polysaccharide and protein/protein interactions in cell walls, some CWPs can be missing either because they are washed out during the purification of cell walls or because they are covalently linked to cell wall components.

  16. Plant Cell Wall Proteins: A Large Body of Data, but What about Runaways?

    Directory of Open Access Journals (Sweden)

    Cécile Albenne

    2014-04-01

    Full Text Available Plant cell wall proteomics has been a very dynamic field of research for about fifteen years. A full range of strategies has been proposed to increase the number of identified proteins and to characterize their post-translational modifications. The protocols are still improving to enlarge the coverage of cell wall proteomes. Comparisons between these proteomes have been done based on various working strategies or different physiological stages. In this review, two points are highlighted. The first point is related to data analysis with an overview of the cell wall proteomes already described. A large body of data is now available with the description of cell wall proteomes of seventeen plant species. CWP contents exhibit particularities in relation to the major differences in cell wall composition and structure between these plants and between plant organs. The second point is related to methodology and concerns the present limitations of the coverage of cell wall proteomes. Because of the variety of cell wall structures and of the diversity of protein/polysaccharide and protein/protein interactions in cell walls, some CWPs can be missing either because they are washed out during the purification of cell walls or because they are covalently linked to cell wall components.

  17. Soya beans and Maize : The effect of chemical and physical structure of cell wall polysaccharides on fermentation kinetics

    OpenAIRE

    Laar, van de, P.

    2000-01-01

    The analysis of the relationship between cell wall composition and fermentation of endosperm cell walls of soya beans and maize was approached from three different angles. Firstly, the fermentation (rate and extent of fermentation, the sugar degradation pattern, and volatile fatty acid production) of soya bean and maize cell walls was analysed, both in situ and in vitro. This analysis revealed that the physical structure of the cell wall (particle size and cell wall thickness) influences cell...

  18. The connection of cytoskeletal network with plasma membrane and the cell wall

    Institute of Scientific and Technical Information of China (English)

    Zengyu Liu; Staffan Persson; Yi Zhang

    2015-01-01

    The cell wall provides external support of the plant cells, while the cytoskeletons including the microtubules and the actin filaments constitute an internal framework. The cytoskeletons contribute to the cell wall biosynthesis by spatially and temporarily regulating the transportation and deposition of cell wall components. This tight control is achieved by the dynamic behavior of the cytoskeletons, but also through the tethering of these structures to the plasma membrane. This tethering may also extend beyond the plasma membrane and impact on the cell wall, possibly in the form of a feedback loop. In this review, we discuss the linking components between the cytoskeletons and the plasma membrane, and/or the cell wall. We also discuss the prospective roles of these components in cell wall biosyn-thesis and modifications, and aim to provide a platform for further studies in this field.

  19. Regeneration and maturation of daughter cell walls in the autospore-forming green alga Chlorella vulgaris (Chlorophyta, Trebouxiophyceae).

    Science.gov (United States)

    Yamamoto, Maki; Fujishita, Mariko; Hirata, Aiko; Kawano, Shigeyuki

    2004-08-01

    Cell-wall synthesis in Chlorella vulgaris, an autospore-forming alga, was observed using the cell wall-specific fluorescent dye Fluostain I. The observation suggested two clearly distinguishable stages in cell-wall synthesis: moderate synthesis during the cell-growth process and rapid synthesis at the cell-division stage. We used electron microscopy to examine the structural changes that occurred with growth in the premature daughter cell wall during the cell-growth and cell-division phases. The cell began to synthesize a new daughter cell wall shortly after its release from the autosporangium. A very thin daughter cell wall, with a thickness of about 2 nm, was formed inside the mother cell wall and completely enveloped the outer surface of the plasma membrane of the cell. The daughter cell wall gradually increased in thickness from 2 to 3.8 nm. During the protoplast-division phase in the cell-division stage, the daughter cell wall expanded on the surface of the invaginating plasma membrane of the cleavage furrow, accompanied by active synthesis of the cell wall, which increased in thickness from 3.8 to 6.1 nm. The daughter cell matured into an autospore while completely enclosed by its own thickening (from 6.1 to 17 nm) wall. Finally, the released daughter cell was enclosed by its own cell wall after the mother cell wall burst. The daughter cell with mature wall thickness (17-21 nm) emerged as a small, but complete, autospore.

  20. Hematopoietic Stem Cells Expansion in Rotating Wall Vessel

    Institute of Scientific and Technical Information of China (English)

    Yang LIU; Tian-Qing LIU; Xiu-Bo FAN; Dan GE; Zhan-Feng CUI; Xue-Hu MA

    2005-01-01

    @@ 1 Introduction Clinical trials have demonstrated that ex vivo expanded hematopoietic stem cells (HSCs) and progenitors offer great promise in reconstituting in vivo hematopoiesis in patients who have undergone intensive chemotherapy.It is therefore necessary to develop a clinical-scale culture system to provide the expanded HSCs and progenitors.Static culture systems such as T-flasks and gas-permeable blood bags are the most widely used culture devices for expanding hematopoietic cells. But they reveal several inherent limitations: ineffective mixing, lack of control options for dissolved oxygen and pH and difficulty in continuous feeding, which restricts the usefulness of static systems. Several advanced bioreactors have been used in the field of HSCs expansion. But hematopoietic cells are extremely sensitive to shear, so cells in bioreactors such as stirred and perfusion culture systems may suffer physical damage. This problem will be improved by applying the rotating wall vessel (RWV) bioreactor in clinic because of its low shear and unique structure. In this research, cord blood (CB) HSCs were expanded by means of a cell-dilution feeding protocol in RWV.

  1. Genes Required for Bacillus anthracis Secondary Cell Wall Polysaccharide Synthesis

    Science.gov (United States)

    Oh, So-Young; Lunderberg, J. Mark; Chateau, Alice; Schneewind, Olaf

    2016-01-01

    ABSTRACT The secondary cell wall polysaccharide (SCWP) is thought to be essential for vegetative growth and surface (S)-layer assembly in Bacillus anthracis; however, the genetic determinants for the assembly of its trisaccharide repeat structure are not known. Here, we report that WpaA (BAS0847) and WpaB (BAS5274) share features with membrane proteins involved in the assembly of O-antigen lipopolysaccharide in Gram-negative bacteria and propose that WpaA and WpaB contribute to the assembly of the SCWP in B. anthracis. Vegetative forms of the B. anthracis wpaA mutant displayed increased lengths of cell chains, a cell separation defect that was attributed to mislocalization of the S-layer-associated murein hydrolases BslO, BslS, and BslT. The wpaB mutant was defective in vegetative replication during early logarithmic growth and formed smaller colonies. Deletion of both genes, wpaA and wpaB, did not yield viable bacilli, and when depleted of both wpaA and wpaB, B. anthracis could not maintain cell shape, support vegetative growth, or assemble SCWP. We propose that WpaA and WpaB fulfill overlapping glycosyltransferase functions of either polymerizing repeat units or transferring SCWP polymers to linkage units prior to LCP-mediated anchoring of the polysaccharide to peptidoglycan. IMPORTANCE The secondary cell wall polysaccharide (SCWP) is essential for Bacillus anthracis growth, cell shape, and division. SCWP is comprised of trisaccharide repeats (→4)-β-ManNAc-(1→4)-β-GlcNAc-(1→6)-α-GlcNAc-(1→) with α-Gal and β-Gal substitutions; however, the genetic determinants and enzymes for SCWP synthesis are not known. Here, we identify WpaA and WpaB and report that depletion of these factors affects vegetative growth, cell shape, and S-layer assembly. We hypothesize that WpaA and WpaB are involved in the assembly of SCWP prior to transfer of this polymer onto peptidoglycan. PMID:27795328

  2. The plant cell wall in the feeding sites of cyst nematodes.

    Science.gov (United States)

    Bohlmann, Holger; Sobczak, Miroslaw

    2014-01-01

    Plant parasitic cyst nematodes (genera Heterodera and Globodera) are serious pests for many crops. They enter the host roots as migratory second stage juveniles (J2) and migrate intracellularly toward the vascular cylinder using their stylet and a set of cell wall degrading enzymes produced in the pharyngeal glands. They select an initial syncytial cell (ISC) within the vascular cylinder or inner cortex layers to induce the formation of a multicellular feeding site called a syncytium, which is the only source of nutrients for the parasite during its entire life. A syncytium can consist of more than hundred cells whose protoplasts are fused together through local cell wall dissolutions. While the nematode produces a cocktail of cell wall degrading and modifying enzymes during migration through the root, the cell wall degradations occurring during syncytium development are due to the plants own cell wall modifying and degrading proteins. The outer syncytial cell wall thickens to withstand the increasing osmotic pressure inside the syncytium. Furthermore, pronounced cell wall ingrowths can be formed on the outer syncytial wall at the interface with xylem vessels. They increase the surface of the symplast-apoplast interface, thus enhancing nutrient uptake into the syncytium. Processes of cell wall degradation, synthesis and modification in the syncytium are facilitated by a variety of plant proteins and enzymes including expansins, glucanases, pectate lyases and cellulose synthases, which are produced inside the syncytium or in cells surrounding the syncytium.

  3. The plant cell wall in the feeding sites of cyst nematodes

    Directory of Open Access Journals (Sweden)

    Holger eBohlmann

    2014-03-01

    Full Text Available Plant parasitic cyst nematodes (genera Heterodera and Globodera are serious pests for many crops. They enter the host roots as migratory second stage juveniles (J2 and migrate intracellularly towards the vascular cylinder using their stylet and a set of cell wall degrading enzymes produced in the pharyngeal glands. They select an initial syncytial cell (ISC within the vascular cylinder or inner cortex layers to induce the formation of a multicellular feeding site called a syncytium, which is the only source of nutrients for the parasite during its entire life. A syncytium can consist of more than hundred cells whose protoplasts are fused together through local cell wall dissolutions. While the nematode produces a cocktail of cell wall degrading and modifying enzymes during migration through the root, the cell wall degradations occurring during syncytium development are due to the plants own cell wall modifying and degrading proteins. The outer syncytial cell wall thickens to withstand the increasing osmotic pressure inside the syncytium. Furthermore, pronounced cell wall ingrowths can be formed on the outer syncytial wall at the interface with xylem vessels. They increase the surface of the symplast-apoplast interface, thus enhancing nutrient uptake into the syncytium. Processes of cell wall degradation, synthesis and modification in the syncytium are facilitated by a variety of plant proteins and enzymes including expansins, glucanases, pectate lyases and cellulose synthases, which are produced inside the syncytium or in cells surrounding the syncytium.

  4. Nine New Triterpene Glycosides, Magnumosides A₁-A₄, B₁, B₂, C₁, C₂ and C₄, from the Vietnamese Sea Cucumber Neothyonidium (=Massinium) magnum: Structures and Activities against Tumor Cells Independently and in Synergy with Radioactive Irradiation.

    Science.gov (United States)

    Silchenko, Alexandra S; Kalinovsky, Anatoly I; Avilov, Sergey A; Kalinin, Vladimir I; Andrijaschenko, Pelageya V; Dmitrenok, Pavel S; Chingizova, Ekaterina A; Ermakova, Svetlana P; Malyarenko, Olesya S; Dautova, Tatyana N

    2017-08-16

    Nine new sulfated triterpene glycosides, magnumosides A₁ (1), A₂ (2), A₃ (3), A₄ (4), B₁ (5), B₂ (6), C₁ (7), C₂ (8) and C₄ (9) as well as a known colochiroside B₂ (10) have been isolated from the tropical Indo-West Pacific sea cucumber Neothynidium (=Massinium) magnum (Phyllophoridae, Dendrochirotida) collected in the Vietnamese shallow waters. The structures of new glycosides were elucidated by 2D NMR spectroscopy and mass-spectrometry. All the isolated new glycosides were characterized by the non-holostane type lanostane aglycones having 18(16)-lactone and 7(8)-double bond and differed from each other by the side chains and carbohydrate moieties structures. Magnumoside A₁ (1) has unprecedented 20(24)-epoxy-group in the aglycone side chain. Magnumosides of the group A (1-4) contained disaccharide monosulfated carbohydrate moieties, of the group B (5, 6)-tetrasaccharide monosulfated carbohydrate moieties and, finally, of the group C (7-9)-tetrasaccharide disulfated carbohydrate moieties. The cytotoxic activities of the compounds 1-9 against mouse spleen lymphocytes, the ascites form of mouse Ehrlich carcinoma cells, human colorectal carcinoma DLD-1 cells as well as their hemolytic effects have been studied. Interestingly, the erythrocytes were more sensitive to the glycosides action than spleenocytes and cancer cells tested. The compounds 3 and 7 significantly inhibited the colony formation and decreased the size of colonies of DLD-1 cancer cells at non-cytotoxic concentrations. Moreover, the synergism of effects of radioactive irradiation and compounds 3 and 7-9 at subtoxic doses on proliferation of DLD-1 cells was demonstrated.

  5. Role of the cell wall integrity and filamentous growth mitogen-activated protein kinase pathways in cell wall remodeling during filamentous growth.

    Science.gov (United States)

    Birkaya, Barbara; Maddi, Abhiram; Joshi, Jyoti; Free, Stephen J; Cullen, Paul J

    2009-08-01

    Many fungal species including pathogens exhibit filamentous growth (FG) as a means of foraging for nutrients. Genetic screens were performed to identify genes required for FG in the budding yeast Saccharomyces cerevisiae. Genes encoding proteins with established functions in transcriptional activation (MCM1, MATalpha2, PHD1, MSN2, SIR4, and HMS2), cell wall integrity (MPT5, WSC2, and MID2), and cell polarity (BUD5) were identified as potential regulators of FG. The transcription factors MCM1 and MATalpha2 induced invasive growth by promoting diploid-specific bipolar budding in haploid cells. Components of the cell wall integrity pathway including the cell surface proteins Slg1p/Wsc1p, Wsc2p, Mid2p, and the mitogen-activated protein kinase (MAPK) Slt2p/Mpk1p contributed to multiple aspects of the FG response including cell elongation, cell-cell adherence, and agar invasion. Mid2p and Wsc2p stimulated the FG MAPK pathway through the signaling mucin Msb2p and components of the MAPK cascade. The FG pathway contributed to cell wall integrity in parallel with the cell wall integrity pathway and in opposition with the high osmolarity glycerol response pathway. Mass spectrometry approaches identified components of the filamentous cell wall including the mucin-like proteins Msb2p, Flo11p, and subtelomeric (silenced) mucin Flo10p. Secretion of Msb2p, which occurs as part of the maturation of the protein, was inhibited by the ss-1,3-glucan layer of the cell wall, which highlights a new regulatory aspect to cell wall remodeling in this organism. Disruption of ss-1,3-glucan linkages induced mucin shedding and resulted in defects in cell-cell adhesion and invasion of cells into the agar matrix.

  6. Structural constraints and dynamics of bacterial cell wall architecture

    Directory of Open Access Journals (Sweden)

    Miguel Angel De Pedro

    2015-05-01

    Full Text Available The peptidoglycan wall (PG is a unique structure which confers physical strength and defined shape to bacteria. It consists of a net-like macromolecule of peptide interlinked glycan chains overlying the cell membrane. The structure and layout of the PG dictates that the wall has to be continuously modified as bacteria go through division, morphological differentiation and adaptive responses. The PG is poorly known in structural terms. However, to understand morphogenesis a precise knowledge of glycan strand arrangement and of local effects of the different kinds of subunits is essential. The scarcity of data led to a conception of the PG as a regular, highly ordered structure which strongly influenced growth models. Here, we review the structure of the PG to define a more realistic conceptual framework. We discuss the consequences of the plasticity of murein architecture in morphogenesis and try to define a set of minimal structural constraints that must be fulfilled by any model to be compatible with present day information.

  7. Electrostatic effects and the dynamics of enzyme reactions at the surface of plant cells. 3. Interplay between limited cell-wall autolysis, pectin methyl esterase activity and electrostatic effects in soybean cell walls.

    Science.gov (United States)

    Nari, J; Noat, G; Diamantidis, G; Woudstra, M; Ricard, J

    1986-02-17

    Soybean cell walls display a process of autolysis which results in the release of reducing sugars from the walls. Loosening and autolysis of cell wall are involved in the cell-wall growth process, for autolysis is maximum during both cell extension and cell-wall synthesis. Autolysis goes to completion within about 50 h and is an enzymatic process that results from the activity of cell wall exo- and endo-glycosyltransferases. The optimum pH of autolysis is about 5. Increasing the ionic strength of the bulk phase where cell-wall fragments are suspended, results in a shift of the pH profile towards low pH. This is consistent with the view that at 'low' ionic strength, the local pH in the cell wall is lower than in the bulk phase. One of the main ideas of the model proposed in a preceding paper, is that pectin methyl esterase reaction, by building up a high fixed charge density, results in proton attraction in the wall. Low pH must then activate the wall loosening enzymes involved in autolysis and cell growth. This view may be directly confirmed experimentally. The pH of a cell-wall suspension, initially equal to 5, was brought to 8 for 20 min, then back to 5. Under these conditions, the rate of cell-wall autolysis was enhanced with respect to the rate of autolysis obtained with cell-wall fragments kept at pH 5. The pH response of the multienzyme plant cell-wall system basically relies on opposite pH sensitivities of the two types of enzymes involved in the growth process. Pectin methyl esterase, which generates the cell-wall Donnan potential, is inhibited by protons, whereas the wall-loosening enzymes involved in cell growth are activated by protons.

  8. Area Expansivity Moduli of Regenerating Plant Protoplast Cell Walls Exposed to Shear Flows

    Science.gov (United States)

    Fujimura, Yuu; Iino, Masaaki; Watanabe, Ugai

    2005-05-01

    To control the elasticity of the plant cell wall, protoplasts isolated from cultured Catharanthus roseus cells were regenerated in shear flows of 115 s-1 (high shear) and 19.2 s-1 (low shear, as a control). The surface area expansivity modulus and the surface breaking strength of these regenerating protoplasts were measured by a micropipette aspiration technique. Cell wall synthesis was also measured using a cell wall-specific fluorescent dye. High shear exposure for 3 h doubled both the surface area modulus and breaking strength observed under low shear, significantly decreased cell wall synthesis, and roughly quadrupled the moduli of the cell wall. Based on the cell wall synthesis data, we estimated the three-dimensional modulus of the cell wall to be 4.1± 1.2 GPa for the high shear, and 0.35± 0.2 GPa for the low shear condition, using the surface area expansivity modulus divided by the cell wall thickness, which is identical with the Young’s modulus divided by 2(1-σ), where σ is Poisson's ratio. We concluded that high shear exposure considerably strengthens the newly synthesized cell wall.

  9. Characterization of nonderivatized plant cell walls using high-resolution solution-state NMR spectroscopy

    Science.gov (United States)

    Daniel J. Yelle; John Ralph; Charles R. Frihart

    2008-01-01

    A recently described plant cell wall dissolution system has been modified to use perdeuterated solvents to allow direct in-NMR-tube dissolution and high-resolution solution-state NMR of the whole cell wall without derivatization. Finely ground cell wall material dissolves in a solvent system containing dimethylsulfoxide-d6 and 1-methylimidazole-d6 in a ratio of 4:1 (v/...

  10. Composition and architecture of the cell walls of grasses and the mechanisms of synthesis of cell wall polysaccharides. Final report for period September 1, 1988 - April 30, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas C.

    2001-10-18

    This program was devoted toward complete understanding of the polysaccharide structure and architecture of the primary cell walls grasses and cereals, and the biosynthesis of the mixed-linkage beta-glucane, a cellulose interacting polymer that is synthesized uniquely by grass species and close relatives. With these studies as focal point, the support from DOE was instrumental in the development of new analytical means that enabled us to characterize carbohydrate structure, to reveal new features of cell wall dynamics during cell growth, and to apply these techniques in other model organisms. The support by DOE in these basic studies was acknowledged on numerous occasions in review articles covering current knowledge of cell wall structure, architecture, dynamics, biosynthesis, and in all genes related to cell wall biogenesis.

  11. Pectinous cell wall thickenings formation - A common defense strategy of plants to cope with Pb.

    Science.gov (United States)

    Krzesłowska, Magdalena; Rabęda, Irena; Basińska, Aneta; Lewandowski, Michał; Mellerowicz, Ewa J; Napieralska, Anna; Samardakiewicz, Sławomir; Woźny, Adam

    2016-07-01

    Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization. Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity. As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation.

  12. Antioxidant properties of cell wall polysaccharides of Stevia rebaudiana leaves

    Directory of Open Access Journals (Sweden)

    Mediesse Kengne Francine

    2014-12-01

    Full Text Available Objective: To examine the total phenolic and protein contents, and the antioxidant activities of cell wall polysaccharide fractions of Stevia rebaudiana leaves. Methods: Three different polysaccharide-enriched fractions, namely FPE (extract with 50 mmol/ L ethylene diamine tetra acetic acid, FPK (extract with 0.05 mol/L KOH and FH (extract with 4 mol/L KOH were extracted from Stevia rebaudiana leaves. The antioxidant activity of these fractions was evaluated based on their ability to scavenge DPPH (1, 1-diphenyl-2-picryl hydrazyl free radical, to reduce ferric power, to chelate ferrous ion and to protect human DNA. Results: The results indicated that protein content was found to be higher in FPK polysaccharide enriched fraction (47.48 µg per mg of FPK. Furthermore, the phenolic compound analysis according to the Folin-Ciocalteu method was higher in FPK (17.71 µg ferulic acid. The DPPH maximal inhibition percentage of the three polysaccharide-enriched fractions at 400 µg/mL was 27.66%, 59.90% and 23.21% respectively for FPE, FPK and FH. All the polysaccharide fractions exhibited a ferric reducing power except the FH one. The three fractions also exhibited lipid peroxidation inhibition, and they completely reverted the DNA damage induced by H2O2/FeCl2. FPK showed the strongest scavenging activity against the DPPH radical, the best chelating ability and lipid peroxidation inhibition. Conclusions: Stevia cell wall polysaccharide fractions are potent protective agents against oxidative stress. The analysis revealed major differences in the antioxidant activity in the three polysaccharides fractions. However, the 0.05 mol/L KOH pectin fraction (FPK showed better antioxidant activity.

  13. Antioxidant properties of cell wall polysaccharides of Stevia rebaudiana leaves

    Institute of Scientific and Technical Information of China (English)

    Mediesse Kengne Francine; Woguia Alice Louise; Fogue Souopgui Pythagore; Atogho-Tiedeu Barbara; Simo Gustave; Thadde Boudjeko

    2014-01-01

    Objective: To examine the total phenolic and protein contents, and the antioxidant activities of cell wall polysaccharide fractions of Stevia rebaudiana leaves.Methods:L ethylene diamine tetra acetic acid), FPK (extract with 0.05 mol/L KOH) and FH (extract with 4 mol/L KOH) were extracted from Stevia rebaudiana leaves. The antioxidant activity of these fractions was evaluated based on their ability to scavenge DPPH (1, 1-diphenyl-2-picryl hydrazyl) free radical, to reduce ferric power, to chelate ferrous ion and to protect human DNA. Three different polysaccharide-enriched fractions, namely FPE (extract with 50 mmol/Results: The results indicated that protein content was found to be higher in FPK polysaccharide enriched fraction (47.48 µg per mg of FPK). Furthermore, the phenolic compound analysis according to the Folin-Ciocalteu method was higher in FPK (17.71 µg ferulic acid). The DPPH maximal inhibition percentage of the three polysaccharide-enriched fractions at 400 µg/mL was 27.66%, 59.90% and 23.21% respectively for FPE, FPK and FH. All the polysaccharide fractions exhibited a ferric reducing power except the FH one. The three fractions also exhibited lipid peroxidation inhibition, and they completely reverted the DNA damage induced by H2O2/FeCl2. FPK showed the strongest scavenging activity against the DPPH radical, the best chelating ability and lipid peroxidation inhibition.Conclusions: Stevia cell wall polysaccharide fractions are potent protective agents against oxidative stress. The analysis revealed major differences in the antioxidant activity in the three polysaccharides fractions. However, the 0.05 mol/L KOH pectin fraction (FPK) showed better antioxidant activity.

  14. CELL-WALL GROWTH AND PROTEIN SECRETION IN FUNGI

    NARCIS (Netherlands)

    SIETSMA, JH; WOSTEN, HAB; WESSELS, JGH

    1995-01-01

    Secretion of proteins is a vital process in fungi. Because hyphal walls form a diffusion barrier for proteins, a mechanism different from diffusion probably exist to transport proteins across the wall. In Schizophyllum commune, evidence has been obtained for synthesis at the hyphal apex of wall comp

  15. Plant cell walls throughout evolution: towards a molecular understanding of their design principles

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

    2009-02-16

    Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

  16. Structural changes in cell wall pectins during strawberry fruit development.

    Science.gov (United States)

    Paniagua, Candelas; Santiago-Doménech, Nieves; Kirby, Andrew R; Gunning, A Patrick; Morris, Victor J; Quesada, Miguel A; Matas, Antonio J; Mercado, José A

    2017-09-01

    Strawberry (Fragaria × anannasa Duch.) is one of the most important soft fruit. Rapid loss of firmness occurs during the ripening process, resulting in a short shelf life and high economic losses. To get insight into the role of pectin matrix in the softening process, cell walls from strawberry fruit at two developmental stages, unripe-green and ripe-red, were extracted and sequentially fractionated with different solvents to obtain fractions enriched in a specific component. The yield of cell wall material as well as the per fresh weight contents of the different fractions decreased in ripe fruit. The largest reduction was observed in the pectic fractions extracted with a chelating agent (trans-1,2- diaminocyclohexane-N,N,N'N'-tetraacetic acid, CDTA fraction) and those covalently bound to the wall (extracted with Na2CO3). Uronic acid content of these two fractions also decreased significantly during ripening, but the amount of soluble pectins extracted with phenol:acetic acid:water (PAW) and water increased in ripe fruit. Fourier transform infrared spectroscopy of the different fractions showed that the degree of esterification decreased in CDTA pectins but increased in soluble fractions at ripen stage. The chromatographic analysis of pectin fractions by gel filtration revealed that CDTA, water and, mainly PAW polyuronides were depolymerised in ripe fruit. By contrast, the size of Na2CO3 pectins was not modified. The nanostructural characteristics of CDTA and Na2CO3 pectins were analysed by atomic force microscopy (AFM). Isolated pectic chains present in the CDTA fractions were significantly longer and more branched in samples from green fruit than those from red fruit. No differences in contour length were observed in Na2CO3 strands between samples of both stages. However, the percentage of branched chains decreased from 19.7% in unripe samples to 3.4% in ripe fruit. The number of pectin aggregates was higher in green fruit samples of both fractions. These

  17. Cell Wall Microstructure Analysis Implicates Hemicellulose Polysaccharides in Cell Adhesion in Tomato Fruit Pericarp Parenchyma

    Institute of Scientific and Technical Information of China (English)

    Jose J. Ordaz-Ortiz; Susan E. Marcus; J. Paul Knox

    2009-01-01

    Methods developed to isolate intact cells from both unripe and ripe tomato fruit pericarp parenchyma have allowed the cell biological analysis of polysaccharide epitopes at the surface of separated cells. The LM7 pectic homoga-lacturonan epitope is a marker of the junctions of adhesion planes and intercellular spaces in parenchyma systems. The LM7 epitope persistently marked the former edge of adhesion planes at the surface of cells separated from unripe and ripened tomato fruit and also from fruits with the Cnr mutation. The LM 11 xylan epitope was associated, in sections, with cell walls lining intercellular space but the epitope was not detected at the surface of isolated cells, being lost during cell isolation. The LM15 xyloglucan epitope was present at the surface of cells isolated from unripe fruit in a pattern reflecting the former edge of cell adhesion planes/intercellular space but with gaps and apparent breaks, An equivalent pattern ofLM15 epitope occurrence was revealed at the surface of cells isolated by pectate lyase action but was not present in cells isolated from ripe fruit or from Cnr fruit. In contrast to wild-type cells, the LM5 galactan and LM21 mannan epitopes oc-curred predominantly in positions reflecting intercellular space in Cnr, suggesting a concerted alteration in cell wall mi-crostructure in response to this mutation. Galactanase and mannanase, along with pectic homogalacturonan-degrading enzymes, were capable of releasing cells from unripe fruit parenchyma. These observations indicate that hemicellulose polymers are present in architectural contexts reflecting cell adhesion and that several cell wall polysaccharide classes are likely to contribute to cell adhesion/cell separation in tomato fruit pericarp parenchyma.

  18. Evidence that pulsed electric field treatment enhances the cell wall porosity of yeast cells.

    Science.gov (United States)

    Ganeva, Valentina; Galutzov, Bojidar; Teissie, Justin

    2014-02-01

    The application of rectangular electric pulses, with 0.1-2 ms duration and field intensity of 2.5-4.5 kV/cm, to yeast suspension mediates liberation of cytoplasmic proteins without cell lysis. The aim of this study was to evaluate the effect of pulsed electric field with similar parameters on cell wall porosity of different yeast species. We found that electrically treated cells become more susceptible to lyticase digestion. In dependence on the strain and the electrical conditions, cell lysis was obtained at 2-8 times lower enzyme concentration in comparison with control untreated cells. The increase of the maximal lysis rate was between two and nine times. Furthermore, when applied at low concentration (1 U/ml), the lyticase enhanced the rate of protein liberation from electropermeabilized cells without provoking cell lysis. Significant differences in the cell surface of control and electrically treated cells were revealed by scanning electron microscopy. Data presented in this study allow us to conclude that electric field pulses provoke not only plasma membrane permeabilization, but also changes in the cell wall structure, leading to increased wall porosity.

  19. Wall extensibility: its nature, measurement and relationship to plant cell growth

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    Expansive growth of plant cells is controlled principally by processes that loosen the wall and enable it to expand irreversibly. The central role of wall relaxation for cell expansion is reviewed. The most common methods for assessing the extension properties of plant cell walls ( wall extensibility') are described, categorized and assessed critically. What emerges are three fundamentally different approaches which test growing cells for their ability (a) to enlarge at different values of turgor, (b) to induce wall relaxation, and (c) to deform elastically or plastically in response to an applied tensile force. Analogous methods with isolated walls are similarly reviewed. The results of these different assays are related to the nature of plant cell growth and pertinent biophysical theory. I argue that the extensibilities' measured by these assays are fundamentally different from one another and that some are more pertinent to growth than others.

  20. Structural basis of cell wall cleavage by a staphylococcal autolysin.

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    Sebastian Zoll

    2010-03-01

    Full Text Available The major autolysins (Atl of Staphylococcus epidermidis and S. aureus play an important role in cell separation, and their mutants are also attenuated in virulence. Therefore, autolysins represent a promising target for the development of new types of antibiotics. Here, we report the high-resolution structure of the catalytically active amidase domain AmiE (amidase S. epidermidis from the major autolysin of S. epidermidis. This is the first protein structure with an amidase-like fold from a bacterium with a gram-positive cell wall architecture. AmiE adopts a globular fold, with several alpha-helices surrounding a central beta-sheet. Sequence comparison reveals a cluster of conserved amino acids that define a putative binding site with a buried zinc ion. Mutations of key residues in the putative active site result in loss of activity, enabling us to propose a catalytic mechanism. We also identified and synthesized muramyltripeptide, the minimal peptidoglycan fragment that can be used as a substrate by the enzyme. Molecular docking and digestion assays with muramyltripeptide derivatives allow us to identify key determinants of ligand binding. This results in a plausible model of interaction of this ligand not only for AmiE, but also for other PGN-hydrolases that share the same fold. As AmiE active-site mutations also show a severe growth defect, our findings provide an excellent platform for the design of specific inhibitors that target staphylococcal cell separation and can thereby prevent growth of this pathogen.

  1. DBIO Best Thesis Award: Mechanics, Dynamics, and Organization of the Bacterial Cytoskeleton and Cell Wall

    Science.gov (United States)

    Wang, Siyuan

    2012-02-01

    Bacteria come in a variety of shapes. While the peptidoglycan (PG) cell wall serves as an exoskeleton that defines the static cell shape, the internal bacterial cytoskeleton mediates cell shape by recruiting PG synthesis machinery and thus defining the pattern of cell-wall synthesis. While much is known about the chemistry and biology of the cytoskeleton and cell wall, much of their biophysics, including essential aspects of the functionality, dynamics, and organization, remain unknown. This dissertation aims to elucidate the detailed biophysical mechanisms of cytoskeleton guided wall synthesis. First, I find that the bacterial cytoskeleton MreB contributes nearly as much to the rigidity of an Escherichia coli cell as the cell wall. This conclusion implies that the cytoskeletal polymer MreB applies meaningful force to the cell wall, an idea favored by theoretical modeling of wall growth, and suggests an evolutionary origin of cytoskeleton-governed cell rigidity. Second, I observe that MreB rotates around the long axis of E. coli, and the motion depends on wall synthesis. This is the first discovery of a cell-wall assembly driven molecular motor in bacteria. Third, I prove that both cell-wall synthesis and the PG network have chiral ordering, which is established by the spatial pattern of MreB. This work links the molecular structure of the cytoskeleton and of the cell wall with organismal-scale behavior. Finally, I develop a mathematical model of cytoskeleton-cell membrane interactions, which explains the preferential orientation of different cytoskeleton components in bacteria.

  2. Combining proteomics and transcriptome sequencing to identify active plant-cell-wall-degrading enzymes in a leaf beetle

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    Kirsch Roy

    2012-11-01

    Full Text Available Abstract Background The primary plant cell wall is a complex mixture of polysaccharides and proteins encasing living plant cells. Among these polysaccharides, cellulose is the most abundant and useful biopolymer present on earth. These polysaccharides also represent a rich source of energy for organisms which have evolved the ability to degrade them. A growing body of evidence suggests that phytophagous beetles, mainly species from the superfamilies Chrysomeloidea and Curculionoidea, possess endogenous genes encoding complex and diverse families of so-called plant cell wall degrading enzymes (PCWDEs. The presence of these genes in phytophagous beetles may have been a key element in their success as herbivores. Here, we combined a proteomics approach and transcriptome sequencing to identify PCWDEs present in larval gut contents of the mustard leaf beetle, Phaedon cochleariae. Results Using a two-dimensional proteomics approach, we recovered 11 protein bands, isolated using activity assays targeting cellulose-, pectin- and xylan-degrading enzymes. After mass spectrometry analyses, a total of 13 proteins putatively responsible for degrading plant cell wall polysaccharides were identified; these proteins belong to three glycoside hydrolase (GH families: GH11 (xylanases, GH28 (polygalacturonases or pectinases, and GH45 (β-1,4-glucanases or cellulases. Additionally, highly stable and proteolysis-resistant host plant-derived proteins from various pathogenesis-related protein (PRs families as well as polygalacturonase-inhibiting proteins (PGIPs were also identified from the gut contents proteome. In parallel, transcriptome sequencing revealed the presence of at least 19 putative PCWDE transcripts encoded by the P. cochleariae genome. All of these were specifically expressed in the insect gut rather than the rest of the body, and in adults as well as larvae. The discrepancy observed in the number of putative PCWDEs between transcriptome and proteome

  3. Neural network analyses of infrared spectra for classifying cell wall architectures.

    Science.gov (United States)

    McCann, Maureen C; Defernez, Marianne; Urbanowicz, Breeanna R; Tewari, Jagdish C; Langewisch, Tiffany; Olek, Anna; Wells, Brian; Wilson, Reginald H; Carpita, Nicholas C

    2007-03-01

    About 10% of plant genomes are devoted to cell wall biogenesis. Our goal is to establish methodologies that identify and classify cell wall phenotypes of mutants on a genome-wide scale. Toward this goal, we have used a model system, the elongating maize (Zea mays) coleoptile system, in which cell wall changes are well characterized, to develop a paradigm for classification of a comprehensive range of cell wall architectures altered during development, by environmental perturbation, or by mutation. Dynamic changes in cell walls of etiolated maize coleoptiles, sampled at one-half-d intervals of growth, were analyzed by chemical and enzymatic assays and Fourier transform infrared spectroscopy. The primary walls of grasses are composed of cellulose microfibrils, glucuronoarabinoxylans, and mixed-linkage (1 --> 3),(1 --> 4)-beta-D-glucans, together with smaller amounts of glucomannans, xyloglucans, pectins, and a network of polyphenolic substances. During coleoptile development, changes in cell wall composition included a transient appearance of the (1 --> 3),(1 --> 4)-beta-D-glucans, a gradual loss of arabinose from glucuronoarabinoxylans, and an increase in the relative proportion of cellulose. Infrared spectra reflected these dynamic changes in composition. Although infrared spectra of walls from embryonic, elongating, and senescent coleoptiles were broadly discriminated from each other by exploratory principal components analysis, neural network algorithms (both genetic and Kohonen) could correctly classify infrared spectra from cell walls harvested from individuals differing at one-half-d interval of growth. We tested the predictive capabilities of the model with a maize inbred line, Wisconsin 22, and found it to be accurate in classifying cell walls representing developmental stage. The ability of artificial neural networks to classify infrared spectra from cell walls provides a means to identify many possible classes of cell wall phenotypes. This classification

  4. Evaluation of the intestinal transport of a phenylethanoid glycoside-rich extract from Cistanche deserticola across the Caco-2 cell monolayer model.

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    Yuan Gao

    Full Text Available Phenylethanoid glycosides (PhGs, a class of polyphenolic compounds, are considered one of major bioactive constituents of Cistanche deserticola Y.C. Ma (CD, whose extract is orally used in traditional Chinese medicine. Although previous pharmacological studies have reported that PhGs exert many activities, their intestinal transport profiles have not been clarified. In this study, we investigated the intestinal permeability of a PhG-rich extract (PRE from CD as an integrated system in the Caco-2 cell monolayer model using a bioassay system. The results showed that PRE is primarily transported via poorly absorbed passive diffusion down a concentration gradient without efflux, which provides the pharmacokinetic basis for the clinical application of PhGs in CD. We also determined the intestinal permeability of three major PhGs [acteoside (AC, isoacteoside (IS and echinacoside (EC] by HLPC. Furthermore, we developed a novel HPLC-fluorescence detection method to accurately determine the flux amount of AC and IS. As expected, the transport characteristics of the three PhGs are consistent with those of PRE, indicating that the present bioassay system is appropriate and reliable for the evaluation of the transport characteristics of active ingredient groups (AIG in PRE. Moreover, this system may also be suitable for other plant extracts given appropriate bioactivity.

  5. Antioxidant activity and protective effects against oxidative damage of human cells induced by X-radiation of phenolic glycosides isolated from pepper fruits Capsicum annuum L.

    Science.gov (United States)

    Materska, Małgorzata; Konopacka, Maria; Rogoliński, Jacek; Ślosarek, Krzysztof

    2015-02-01

    The antioxidant and radioprotective effects of the phenolic glycosides from Capsicum annuum L. were examined. There were: sinapoyl-E-glucoside, quercetin-3-O-rhamnoside-7-O-glucoside, quercetin-3-O-rhamnoside and luteolin-7-O-(2-apiosyl)-glucoside. To the best of our knowledge, this is the first study to assay these compounds for their radioprotective effect on human cell lymphocytes in response to oxidative damage induced by X radiation and their antioxidant abilities. Investigated compounds showed weaker antiradical activities, but their radioprotective potentials were higher than those of their aglycones. Quercetin-3-O-rhamnoside showed the highest radioprotective activity (50% according to control). Furthermore, quercetin and luteolin derivatives, in contrast to free aglycones, were not cytotoxic against human lymphocytes for all concentrations tested. The best correlation between radioprotective and antiradical activities of the investigated compounds was observed in the relationship to O2(-) generated using the NADH/PMS method (R(2)=0.859). Thus, we propose that superoxide radical scavenging activity is a useful method for screening for compounds with promising radioprotective potential.

  6. Three new labdane-type diterpene glycosides from fruits of Rubus chingii and their cytotoxic activities against five humor cell lines.

    Science.gov (United States)

    Zhong, Ruijian; Guo, Qing; Zhou, Guoping; Fu, Huizheng; Wan, Kaihua

    2015-04-01

    Three new labdane-type diterpene glycosides, 15,18-di-O-β-d-glucopyranosyl-13(E)-ent-labda-7(8),13(14)-diene-3β,15,18-triol (1), 15,18-di-O-β-d-glucopyranosyl-13(E)-ent-labda-8(9),13(14)-diene-3β,15,18-triol (2), and 15-O-β-d-apiofuranosyl-(1→2)-β-d-glucopyranosyl-18-O-β-d-glucopyranosyl-13(E)-ent-labda-8(9),13(14)-diene-3β,15,18-triol (3), were isolated from the fruits of Rubus chingii. Their structures were elucidated on the basis of spectroscopic data and chemical methods. The cytotoxic activities of compounds 1-3 were evaluated against five human tumor cell lines (HCT-8, BGC-823, A549, and A2780). Compounds 3 showed cytotoxic activity against A549 with an IC50 value of 2.32μM.

  7. Construction of a rice glycoside hydrolase phylogenomic database and identification of targets for biofuel research

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    Rita eSharma

    2013-08-01

    Full Text Available Glycoside hydrolases (GH catalyze the hydrolysis of glycosidic bonds in cell wall polymers and can have major effects on cell wall architecture. Taking advantage of the massive datasets available in public databases, we have constructed a rice phylogenomic database of GHs (http://ricephylogenomics.ucdavis.edu/cellwalls/gh/. This database integrates multiple data types including the structural features, orthologous relationships, mutant availability and gene expression patterns for each GH family in a phylogenomic context. The rice genome encodes 437 GH genes classified into 34 families. Based on pairwise comparison with eight dicot and four monocot genomes, we identified 138 GH genes that are highly diverged between monocots and dicots, 57 of which have diverged further in rice as compared with four monocot genomes scanned in this study. Chromosomal localization and expression analysis suggest a role for both whole-genome and localized gene duplications in expansion and diversification of GH families in rice. We examined the meta-profiles of expression patterns of GH genes in twenty different anatomical tissues of rice. Transcripts of 51 genes exhibit tissue or developmental stage-preferential expression, whereas, seventeen other genes preferentially accumulate in actively growing tissues. When queried in RiceNet, a probabilistic functional gene network that facilitates functional gene predictions, nine out of seventeen genes form a regulatory network with the well-characterized genes involved in biosynthesis of cell wall polymers including cellulose synthase and cellulose synthase-like genes of rice. Two-thirds of the GH genes in rice are up regulated in response to biotic and abiotic stress treatments indicating a role in stress adaptation. Our analyses identify potential GH targets for cell wall modification.

  8. Mycobacterium tuberculosis CwsA overproduction modulates cell division and cell wall synthesis.

    Science.gov (United States)

    Plocinski, P; Martinez, L; Sarva, K; Plocinska, R; Madiraju, M; Rajagopalan, M

    2013-12-01

    We recently showed that two small membrane proteins of Mycobacterium tuberculosis, CwsA and CrgA, interact with each other, and that loss of CwsA in M. smegmatis is associated with defects in the cell division and cell wall synthesis processes. Here we show that CwsA overproduction also affected growth, cell division and cell shape of M. smegmatis and M. tuberculosis. CwsA overproduction in M. tuberculosis led to increased sensitivity to cefsulodin, a penicillin-binding protein (PBP) 1A/1B targeting beta (β) -lactam, but was unaffected by other β-lactams and vancomycin. A M. smegmatis cwsA overexpressing strain showed bulgy cells, increased fluorescent vancomycin staining and altered localization of Wag31-mCherry fusion protein. However, the levels of phosphorylated Wag31, important for optimal peptidoglycan synthesis and growth in mycobacteria, were not affected. Interestingly, CwsA overproduction in E. coli led to the formation of large rounded cells that eventually lysed whereas the overproduction of FtsZ along with CwsA reversed this phenotype. Together, our results emphasize that optimal levels of CwsA are required for regulated cell wall synthesis, hence maintenance of cell shape, and that CwsA likely interacts with and modulates the activities of other cell wall synthetic components including PBPs.

  9. Glycosides from Bougainvillea glabra.

    Science.gov (United States)

    Simon, András; Tóth, Gábor; Duddeck, Helmut; Soliman, Hesham S M; Mahmoud, Ibrahim I; Samir, Hanan

    2006-01-01

    Three glycosides were isolated from Bougainvillea glabra and their structures were determined by extensive use of 1D and 2D NMR spectroscopy ((1)H and (13)C). First compound was identical to momordin IIc (quinoside D) [beta-D-glucopyranosyl 3-O-[beta-D-xylopyranosyl-(1 --> 3)-O-(beta-D-glucopyranosyluronic acid)] oleanolate], second compound was quercetin 3-O-alpha-L-(rhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopy-ranosyl(1 --> 2)]-beta-D-galactopyranoside and third compound was its derivative quercetin 3-O-alpha-L-(4-caffeoylrhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopyranosyl (1 --> 2)]-beta-D-galactopyranoside, a new natural product.

  10. Furostanol glycosides from the rhizomes of Helleborus orientalis.

    Science.gov (United States)

    Mimaki, Yoshihiro; Matsuo, Yukiko; Watanabe, Kazuki; Sakagami, Hiroshi

    2010-10-01

    Eight new furostanol glycosides (1-8), together with two known ones (9 and 10), have been isolated from a glycoside-enriched fraction prepared from the rhizomes of Helleborus orientalis (Ranunculaceae). The structures of 1-8 were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 cells.

  11. Bufadienolide and spirostanol glycosides from the rhizomes of helleborusorientalis.

    Science.gov (United States)

    Watanabe, Kazuki; Mimaki, Yoshihiro; Sakagami, Hiroshi; Sashida, Yutaka

    2003-02-01

    The rhizomes of Helleborus orientalis have been analyzed for the bufadienolide glycoside and spirostanol saponin constituents, resulting in the isolation of a new bufadienolide rhamnoside (1), along with two known bufadienolide glycosides (2 and 3) and five new spirostanol saponins (4-8). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activities against cultured tumor and normal cells.

  12. Triterpene glycosides from the aerial parts of Larrea tridentata.

    Science.gov (United States)

    Jitsuno, Maki; Mimaki, Yoshihiro

    2010-12-01

    Chemical study of the aerial parts of Larrea tridentata (Zygophyllaceae) resulted in the isolation of 25 triterpene glycosides, 13 of which were previously unknown. Their structures were determined on the basis of comprehensive spectroscopic analyses, including 2D NMR spectroscopy, and hydrolytic cleavage followed by chromatographic and spectroscopic analyses. This is the first systematic phytochemical study of L. tridentata with attention paid to its triterpene glycoside constituents. The isolated compounds were evaluated for their cytotoxic activity against HL-60 human promyelocytic leukemia cells.

  13. Traffic monitors at the cell periphery: the role of cell walls during early female reproductive cell differentiation in plants.

    Science.gov (United States)

    Tucker, Matthew R; Koltunow, Anna M G

    2014-02-01

    The formation of female gametes in plants occurs within the ovule, a floral organ that is also the precursor of the seed. Unlike animals, plants lack a typical germline separated from the soma early in development and rely on positional signals, including phytohormones, mobile mRNAs and sRNAs, to direct diploid somatic precursor cells onto a reproductive program. In addition, signals moving between plant cells must overcome the architectural limitations of a cell wall which surrounds the plasma membrane. Recent studies have addressed the molecular and histological signatures of young ovule cells and indicate that dynamic cell wall changes occur over a short developmental window. These changes in cell wall properties impact signal flow and ovule cell identity, thereby aiding the establishment of boundaries between reproductive and somatic ovule domains. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

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    António Rego

    2014-08-01

    Full Text Available Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria.

  15. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    Science.gov (United States)

    Rego, António; Duarte, Ana M.; Azevedo, Flávio; Sousa, Maria J.; Côrte-Real, Manuela; Chaves, Susana R.

    2014-01-01

    Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria. PMID:28357256

  16. Osmotic Stress Suppresses Cell Wall Stiffening and the Increase in Cell Wall-Bound Ferulic and Diferulic Acids in Wheat Coleoptiles.

    Science.gov (United States)

    Wakabayashi, K.; Hoson, T.; Kamisaka, S.

    1997-01-01

    The relationship between the mechanical properties of cell walls and the levels of wall-bound ferulic (FA) and diferulic (DFA) acids was investigated in wheat (Triticum aestivum L.) coleoptiles grown under osmotic stress (60 mM polyethylene glycol [PEG] 4000) conditions. The cell walls of stressed coleoptiles remained extensible compared with those of the unstressed ones. The contents of wall-bound FA and DFA increased under unstressed conditions, but the increase was substantially reduced by osmotic stress. In response to PEG removal, these contents increased and reached almost the same levels as those of the unstressed coleoptiles. A close correlation was observed between the contents of FA and DFA and the mechanical properties of cell walls. The activities of phenylalanine ammonia-lyase and tyrosine ammonia-lyase increased rapidly under unstressed conditions. Osmotic stress substantially reduced the increases in enzyme activities. When PEG was removed, however, the enzyme activities increased rapidly. There was a close correlation between the FA levels and enzyme activities. These results suggest that in osmotically stressed wheat coleoptiles, reduced rates of increase in phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities suppress phenylpropanoid biosynthesis, resulting in the reduced level of wall-bound FA that, in turn, probably causes the reduced level of DFA and thereby maintains cell wall extensibility. PMID:12223657

  17. Primary abdominal wall clear cell carcinoma arising from incisional endometriosis

    Institute of Scientific and Technical Information of China (English)

    Burcu Gundogdu; Isin Ureyen; Gunsu Kimyon; Hakan Turan; Nurettin Boran; Gokhan Tulunay; Dilek Bulbul; Taner Turan; M Faruk Kose

    2013-01-01

    A 49 year-old patient with the complaint of a mass located in the caesarean scar was admitted. There was a fixed mass 30í30 mm in diameter with regular contour located at the right corner of the pfannenstiel incision. Computed tomography revealed a (40í50í50) mm solid mass lesion with margins that cannot be distinguished from the uterus, bladder and small intestines and a heterogeneous mass lesion (50í45í55) mm in diameter, located in the right side of the anterior abdominal wall. Cytoreductive surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Final pathology was clear cell carcinoma. Clear cell carcinoma arising from an extraovarian endometriotic focus was diagnosed and the patient received 6 cycles paclitaxel-carboplatin chemotherapy as adjuvant treatment. The patient who was lost to follow-up applied to our clinic 2 years after surgery with a recurrent mass in the left inguinal region. After 3 cycles of chemotherapy, the patient's tumoral mass in the left inguinal region was excised. The result of the pathology was carcinoma metastasis. It is decided that the following treatment of the patient should be palliative radiation therapy. The patient who underwent palliative radiation therapy died of disease after 4 months of the second operation.

  18. Cell-free layer and wall shear stress variation in microvessels.

    Science.gov (United States)

    Yin, Xuewen; Zhang, Junfeng

    2012-01-01

    In this study, we simulated multiple red blood cells flowing through straight microvessels with the immersed-boundary lattice-Boltzmann model to examine the shear stress variation on the microvessel surface and its relation to the properties of cell-free layer. Significant variation in shear stress has been observed due to the irregular configuration of blood cells flowing near the microvessel wall. A low shear stress is typically found at locations where there is a cell flowing close to the wall, and a large shear stress at locations with a relatively wide gap between cell and wall. This relationship between the shear stress magnitude and the distance between cell and wall has been attributed to the reverse pressure difference developed between the front and rear sides of a cell flowing near the vessel wall. We further studied the effects of several hemodynamic factors on the variation of shear stress, including the cell deformability, the flow rate, and the aggregation among red blood cells. These simulations show that the shear stress variation is less profound in situations with wider cell-free layers, since the reverse pressure difference around the edge cells is less evident, and the influence of this pressure difference on wall shear stress becomes weaker. This study also demonstrates the complexity of the flow field in the gap between cell and wall. More precise experimental techniques are required accurately measure such shear stress variation in microcirculation.

  19. Relating Nanoscale Accessibility within Plant Cell Walls to Improved Enzyme Hydrolysis Yields in Corn Stover Subjected to Diverse Pretreatments.

    Science.gov (United States)

    Crowe, Jacob D; Zarger, Rachael A; Hodge, David B

    2017-10-04

    Simultaneous chemical modification and physical reorganization of plant cell walls via alkaline hydrogen peroxide or liquid hot water pretreatment can alter cell wall structural properties impacting nanoscale porosity. Nanoscale porosity was characterized using solute exclusion to assess accessible pore volumes, water retention value as a proxy for accessible water-cell walls surface area, and solute-induced cell wall swelling to measure cell wall rigidity. Key findings concluded that delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity and that the subsequent cell wall swelling resulted increased nanoscale porosity and improved enzyme binding and hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 Å dextran probe within the cell wall was found to be correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields.

  20. Pectic homogalacturonan masks abundant sets of xyloglucan epitopes in plant cell walls

    Directory of Open Access Journals (Sweden)

    Pedersen Henriette L

    2008-05-01

    Full Text Available Abstract Background Molecular probes are required to detect cell wall polymers in-situ to aid understanding of their cell biology and several studies have shown that cell wall epitopes have restricted occurrences across sections of plant organs indicating that cell wall structure is highly developmentally regulated. Xyloglucan is the major hemicellulose or cross-linking glycan of the primary cell walls of dicotyledons although little is known of its occurrence or functions in relation to cell development and cell wall microstructure. Results Using a neoglycoprotein approach, in which a XXXG heptasaccharide of tamarind seed xyloglucan was coupled to BSA to produce an immunogen, we have generated a rat monoclonal antibody (designated LM15 to the XXXG structural motif of xyloglucans. The specificity of LM15 has been confirmed by the analysis of LM15 binding using glycan microarrays and oligosaccharide hapten inhibition of binding studies. The use of LM15 for the analysis of xyloglucan in the cell walls of tamarind and nasturtium seeds, in which xyloglucan occurs as a storage polysaccharide, indicated that the LM15 xyloglucan epitope occurs throughout the thickened cell walls of the tamarind seed and in the outer regions, adjacent to middle lamellae, of the thickened cell walls of the nasturtium seed. Immunofluorescence analysis of LM15 binding to sections of tobacco and pea stem internodes indicated that the xyloglucan epitope was restricted to a few cell types in these organs. Enzymatic removal of pectic homogalacturonan from equivalent sections resulted in the abundant detection of distinct patterns of the LM15 xyloglucan epitope across these organs and a diversity of occurrences in relation to the cell wall microstructure of a range of cell types. Conclusion These observations support ideas that xyloglucan is associated with pectin in plant cell walls. They also indicate that documented patterns of cell wall epitopes in relation to cell

  1. Modification of antioxidant systems in cell walls of maize roots by different nitrogen sources

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    Vesna Hadži-Tašković Šukalović

    2016-12-01

    Full Text Available Antioxidant systems of maize root cell walls grown on different nitrogen sources were evaluated. Plants were grown on a medium containing only NO3- or the mixture of NO3-+NH4+, in a 2:1 ratio. Eleven-day old plants, two days after the initiation of lateral roots, were used for the experiments. Cell walls were isolated from lateral roots and primary root segments, 2-7 cm from tip to base, representing zones of intense or decreased growth rates, respectively. Protein content and the activity of enzymes peroxidase, malate dehydrogenase and ascorbate oxidase ionically or covalently bound to the walls, as well as cell wall phenolic content and antioxidant capacity, were determined. Cell walls of plants grown on mixed N possess more developed enzymatic antioxidant systems and lower non-enzymatic antioxidant defenses than cell walls grown on NO3-. Irrespective of N treatment, the activities of all studied enzymes and protein content were higher in cell walls of lateral compared to primary roots. Phenolic content of cell walls isolated from lateral roots was higher in NO3--grown than in mixed N grown plants. No significant differences could be observed in the isozyme patterns of cell wall peroxidases isolated from plants grown on different nutrient solution. Our results indicate that different N treatments modify the antioxidant systems of root cell walls. Treatment with NO3- resulted in an increase of constitutive phenolic content, while the combination of NO3-+NH4+ elevated the redox enzyme activities in root cell walls.

  2. Feruloyl Oligosaccharides from Cell Walls of Suspension-Cultured Spinach Cells and Sugar Beet Pulp : STRUCTURE AND FUNCTION OF CELLS

    OpenAIRE

    Tadashi, Ishii; Forestry and Forest Products Research Institute

    1994-01-01

    Cell walls of suspension-cultured spinach cells and sugar beet pulp were separately hydrolyzed with Driselase. A feruloyl arabinobiose was isolated from both spinach cells and sugar beet. Four feruloyl oligosaccharides were obtained from sugar beet. The four oligosaccharides were characterized by NMR spectroscopy, methylation analysis and FAB-MS.

  3. Immuno and Affinity Cytochemical Analysis of Cell Wall Composition in the Moss Physcomitrella patens.

    Science.gov (United States)

    Berry, Elizabeth A; Tran, Mai L; Dimos, Christos S; Budziszek, Michael J; Scavuzzo-Duggan, Tess R; Roberts, Alison W

    2016-01-01

    In contrast to homeohydric vascular plants, mosses employ a poikilohydric strategy for surviving in the dry aerial environment. A detailed understanding of the structure, composition, and development of moss cell walls can contribute to our understanding of not only the evolution of overall cell wall complexity, but also the differences that have evolved in response to selection for different survival strategies. The model moss species Physcomitrella patens has a predominantly haploid lifecycle consisting of protonemal filaments that regenerate from protoplasts and enlarge by tip growth, and leafy gametophores composed of cells that enlarge by diffuse growth and differentiate into several different types. Advantages for genetic studies include methods for efficient targeted gene modification and extensive genomic resources. Immuno and affinity cytochemical labeling were used to examine the distribution of polysaccharides and proteins in regenerated protoplasts, protonemal filaments, rhizoids, and sectioned gametophores of P. patens. The cell wall composition of regenerated protoplasts was also characterized by flow cytometry. Crystalline cellulose was abundant in the cell walls of regenerating protoplasts and protonemal cells that developed on media of high osmolarity, whereas homogalactuonan was detected in the walls of protonemal cells that developed on low osmolarity media and not in regenerating protoplasts. Mannan was the major hemicellulose detected in all tissues tested. Arabinogalactan proteins were detected in different cell types by different probes, consistent with structural heterogneity. The results reveal developmental and cell type specific differences in cell wall composition and provide a basis for analyzing cell wall phenotypes in knockout mutants.

  4. Immuno and affinity cytochemical analysis of cell wall composition in the moss Physcomitrella patens

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Berry

    2016-03-01

    Full Text Available In contrast to homeohydric vascular plants, mosses employ a poikilohydric strategy for surviving in the dry aerial environment. A detailed understanding of the structure, composition, and development of moss cell walls can contribute to our understanding of not only the evolution of overall cell wall complexity, but also the differences that have evolved in response to selection for different survival strategies. The model moss species Physcomitrella patens has a predominantly haploid lifecycle consisting of protonemal filaments that regenerate from protoplasts and enlarge by tip growth, and leafy gametophores composed of cells that enlarge by diffuse growth and differentiate into several different types. Advantages for genetic studies include methods for efficient targeted gene modification and extensive genomic resources. Immuno and affinity cytochemical labeling were used to examine the distribution of polysaccharides and proteins in regenerated protoplasts, protonemal filaments, rhizoids, and sectioned gametophores of P. patens. The cell wall composition of regenerated protoplasts was also characterized by flow cytometry. Crystalline cellulose was abundant in the cell walls of regenerating protoplasts and protonemal cells that developed on media of high osmolarity, whereas homogalacturonan was detected in the walls of protonemal cells that developed on low osmolarity media and not in regenerating protoplasts. Mannan was the major hemicellulose detected in all tissues tested. Arabinogalactan proteins were detected in different cell types by different probes, consistent with structural heterogeneity. The results reveal developmental and cell type specific differences in cell wall composition and provide a basis for analyzing cell wall phenotypes in knockout mutants.

  5. CELL WALL CARBOHYDRATE EPITOPES IN THE GREEN ALGA OEDOGONIUM BHARUCHAE F. MINOR (OEDOGONIALES, CHLOROPHYTA)(1).

    Science.gov (United States)

    Estevez, José M; Leonardi, Patricia I; Alberghina, Josefina S

    2008-10-01

    Cell wall changes in vegetative and suffultory cells (SCs) and in oogonial structures from Oedogonium bharuchae N. D. Kamat f. minor Vélez were characterized using monoclonal antibodies against several carbohydrate epitopes. Vegetative cells and SCs develop only a primary cell wall (PCW), whereas mature oogonial cells secrete a second wall, the oogonium cell wall (OCW). Based on histochemical and immunolabeling results, (1→4)-β-glucans in the form of crystalline cellulose together with a variable degree of Me-esterified homogalacturonans (HGs) and hydroxyproline-rich glycoprotein (HRGP) epitopes were detected in the PCW. The OCW showed arabinosides of the extensin type and low levels of arabinogalactan-protein (AGP) glycans but lacked cellulose, at least in its crystalline form. Surprisingly, strong colabeling in the cytoplasm of mature oogonia cells with three different antibodies (LM-5, LM-6, and CCRC-M2) was found, suggesting the presence of rhamnogalacturonan I (RG-I)-like structures. Our results are discussed relating the possible functions of these cell wall epitopes with polysaccharides and O-glycoproteins during oogonium differentiation. This study represents the first attempt to characterize these two types of cell walls in O. bharuchae, comparing their similarities and differences with those from other green algae and land plants. This work represents a contribution to the understanding of how cell walls have evolved from simple few-celled to complex multicelled organisms.

  6. Multi-scale visualization and characterization of lignocellulosic plant cell wall deconstruction during thermochemical pretreatment

    Science.gov (United States)

    Shishir P. S. Chundawat; Bryon S. Donohoe; Leonardo da Costa Sousa; Thomas Elder; Umesh P. Agarwal; Fachuang Lu; John Ralph; Michael E. Himmel; Venkatesh Balan; Bruce E. Dale

    2011-01-01

    Deconstruction of lignocellulosic plant cell walls to fermentable sugars by thermochemical and/or biological means is impeded by several poorly understood ultrastructural and chemical barriers. A promising thermochemical pretreatment called ammonia fiber expansion (AFEX) overcomes the native recalcitrance of cell walls through subtle morphological and physicochemical...

  7. CONSTITUTIVE MELANIN IN THE CELL WALL OF THE ETIOLOGIC AGENT OF LOBO'S DISEASE

    Directory of Open Access Journals (Sweden)

    TABORDA Valeria B.A.

    1999-01-01

    Full Text Available Lobo's disease is a chronic granulomatous disease caused by the obligate pathogenic fungus, whose cell walls contain constitutive melanin. In contrast, melanin does not occur in the cell walls of Paracoccidioides brasiliensis when stained by the Fontana-Masson stain.

  8. Cell wall composition as a maize defense mechanism against corn borers.

    Science.gov (United States)

    Barros-Rios, Jaime; Malvar, Rosa A; Jung, Hans-Joachim G; Santiago, Rogelio

    2011-04-01

    European and Mediterranean corn borers are two of the most economically important insect pests of maize (Zea mays L.) in North America and southern Europe, respectively. Cell wall structure and composition were evaluated in pith and rind tissues of resistant and susceptible inbred lines as possible corn borer resistance traits. Composition of cell wall polysaccharides, lignin concentration and composition, and cell wall bound forms of hydroxycinnamic acids were measured. As expected, most of the cell wall components were found at higher concentrations in the rind than in the pith tissues, with the exception of galactose and total diferulate esters. Pith of resistant inbred lines had significantly higher concentrations of total cell wall material than susceptible inbred lines, indicating that the thickness of cell walls could be the initial barrier against corn borer larvae attack. Higher concentrations of cell wall xylose and 8-O-4-coupled diferulate were found in resistant inbreds. Stem tunneling by corn borers was negatively correlated with concentrations of total diferulates, 8-5-diferulate and p-coumarate esters. Higher total cell wall, xylose, and 8-coupled diferulates concentrations appear to be possible mechanisms of corn borer resistance. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Detection of 2 immunoreactive antigens in the cell wall of Sporothrix brasiliensis and Sporothrix globosa.

    Science.gov (United States)

    Ruiz-Baca, Estela; Hernández-Mendoza, Gustavo; Cuéllar-Cruz, Mayra; Toriello, Conchita; López-Romero, Everardo; Gutiérrez-Sánchez, Gerardo

    2014-07-01

    The cell wall of members of the Sporothrix schenckii complex contains highly antigenic molecules which are potentially useful for the diagnosis and treatment of sporotrichosis. In this study, 2 immunoreactive antigens of 60 (Gp60) and 70 kDa (Gp70) were detected in the cell wall of the yeast morphotypes of Sporothrix brasiliensis and Sporothrix globosa.

  10. Features and functions of covalently linked proteins in fungal cell walls.

    NARCIS (Netherlands)

    de Groot, P.W.J.; Ram, A.F.; Klis, F.M.

    2005-01-01

    The cell walls of many ascomycetous yeasts consist of an internal network of stress-bearing polysaccharides, which serve as a scaffold for a dense external layer of glycoproteins. GPI-modified proteins are the most abundant cell wall proteins and often display a common organization. Their C-terminus

  11. Modification of cell wall architecture of wheat coleoptiles grown under hypergravity conditions.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Kamisaka, Seiichiro; Hoson, Takayuki

    2003-10-01

    Cell wall structure of wheat coleoptiles grown under continuous hypergravity (300 g) conditions was investigated. Length of coleoptiles exposed to hypergravity for 2-4 days from germination stage was 60-70% of that of 1 g control. The amounts of cell wall polysaccharides substantially increased during the incubation period both in 1 g control and hypergravity-treated coleoptiles. As a results, the levels of cell wall polysaccharides per unit length of coleoptile, which mean the thickness of cell walls, largely increased under hypergravity conditions. The major sugar components of the hemicellulose fraction, a polymer fraction extracted from cell walls with strong alkali, were arabinose (Ara), xylose (Xyl) and glucose (Glc). The molar ratios of Ara and Xyl to Glc in hypergravity-treated coleoptiles were higher than those in control coleoptiles. Furthermore, the fractionation of hemicellulosic polymers into the neutral and acidic polymers by the anion-exchange column showed that the levels of acidic polymers in cell walls of hypergravity-treated coleoptiles were higher than those of control coleoptiles. These results suggest that hypergravity stimuli bias the synthesis of hemicellulosic polysaccharides and increase the proportion of acidic polymers, such as arabinoxylans, in cell walls of wheat coleoptiles. These structural changes in cell walls may contribute to plant resistance to hypergravity stimuli.

  12. [Studies on active ingredients in Corydalis, broken cell wall corydalis and its processed products].

    Science.gov (United States)

    Cao, Liu; Diu, Zhi-Ying; Wang, Ping; Sun, Wei; Tian, Yong-Liang

    2008-06-01

    To compare the contents of tetrahydropalmatine and dehydrocorydaline in corydalis, broken cell wall corydalis and its different processed products. The broken cell wall technique was used to corydalis, and then both the corydalis and broken cell wall corydalis were processed. The method of chromatography which was used to determine the contents of tetrahydropalmatine and dehydrocorydaline in corydalis broken cell wall corydalis and its different processed products was performed by RP-HPLC with Kromasil ODS-C18 (4.6 mm x 250 mm, 5 microm) column was used at 35 degrees C, acetonitrile-acetate buffer solution (pH 6.0) (30:70) as mobile phase of 1 mL x min(-1) flow rate, detection wavelength was set at 280 nm. The contents of the two active components in broken cell wall corydalis were higher than that in corydalis, while that in broken cell wall and vinegar-fried corydalis was highest in the products of breaked cell wall corydalis. Breaking the cell wall of corydalis can help to dissolute alkaloids.

  13. In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation Growth

    NARCIS (Netherlands)

    Muller, K.; Linkies, A.; Vreeburg, R.A.M.; Fry, S.C.; Krieger-Liszkay, A.; Leubner-Metzger, G.

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (·OH)-mediated cell wall loosening during plant seed germination and se

  14. Cell wall growth during elongation and division : one ring to bind them?

    NARCIS (Netherlands)

    Scheffers, Dirk-Jan

    2007-01-01

    The role of the cell division protein FtsZ in bacterial cell wall (CW) synthesis is believed to be restricted to localizing proteins involved in the synthesis of the septal wall. Elsewhere, compelling evidence is provided that in Caulobacter crescentus, FtsZ plays an additional role in CW synthesis

  15. Structure of Plant Cell Walls : XXVI. The Walls of Suspension-Cultured Sycamore Cells Contain a Family of Rhamnogalacturonan-I-Like Pectic Polysaccharides.

    Science.gov (United States)

    Ishii, T; Thomas, J; Darvill, A; Albersheim, P

    1989-02-01

    Considerable information has been obtained about the primary structures of suspension-cultured sycamore (Acer pseudoplatanus) cell-wall pectic polysaccharides, i.e. rhamnogalacturonan I, rhamnogalacturonan II, and homogalacturonan. However, these polysaccharides, which are solubilized from the walls by endo-alpha-1,4-polygalacturonase, account for only about half of the pectic polysaccharides known to be present in sycamore cell walls. We now report that, after exhaustive treatment with endo-alpha-1,4-polygalacturonase, additional pectic polysaccharides were extracted from sycamore cell walls by treatment with Na(2)CO(3) at 1 and 22 degrees C. These previously uncharacterized polysaccharides accounted for approximately 4% of the cell wall. Based on the glycosyl and glycosyl-linkage compositions and the nature of the products obtained by treating the quantitatively predominant NaCO(3)-extracted polysaccharides with lithium metal dissolved in ethylenediamine, the polysaccharides were found to strongly resemble rhamnogalacturonan I. However, unlike rhamnogalacturonan I that characteristically had equal amounts of 2- and 2,4-linked rhamnosyl residues in its backbone, the polysaccharides extracted in Na(2)CO(3) at 1 degrees C had markedly disparate ratios of 2- to 2,4-linked rhamnosyl residues. We concluded that polysaccharides similar to rhamnogalacturonan I but with different degrees of branching are present in the walls of suspension-cultured sycamore cells.

  16. Experimental approaches to study plant cell walls during plant-microbe interactions.

    Science.gov (United States)

    Xia, Ye; Petti, Carloalberto; Williams, Mark A; DeBolt, Seth

    2014-01-01

    Plant cell walls provide physical strength, regulate the passage of bio-molecules, and act as the first barrier of defense against biotic and abiotic stress. In addition to providing structural integrity, plant cell walls serve an important function in connecting cells to their extracellular environment by sensing and transducing signals to activate cellular responses, such as those that occur during pathogen infection. This mini review will summarize current experimental approaches used to study cell wall functions during plant-pathogen interactions. Focus will be paid to cell imaging, spectroscopic analyses, and metabolic profiling techniques.

  17. Experimental approaches to study plant cell walls during plant-microbe interactions

    Directory of Open Access Journals (Sweden)

    Ye eXia

    2014-10-01

    Full Text Available Plant cell walls provide physical strength, regulate the passage of bio-molecules, and act as the first barrier of defense against biotic and abiotic stress. In addition to providing structural integrity, plant cell walls serve an important function in connecting cells to their extracellular environment by sensing and transducing signals to activate cellular responses, such as those that occur during pathogen infection. This mini review will summarize current experimental approaches used to study cell wall functions during plant-pathogen interactions. Focus will be paid to cell imaging, spectroscopic analyses, and metabolic profiling techniques

  18. Interactions between grape skin cell wall material and commercial enological tannins. Practical implications.

    Science.gov (United States)

    Bautista-Ortín, Ana Belén; Cano-Lechuga, Mario; Ruiz-García, Yolanda; Gómez-Plaza, Encarna

    2014-01-01

    Commercial enological tannins were used to investigate the role that cell wall material plays in proanthocyanidin adsorption. Insoluble cell wall material, prepared from the skin of Vitis vinifera L. cv. Monastrell berries, was combined with solutions containing six different commercial enological tannins (proanthocyanidin-type tannins). Analysis of the proanthocyanidins in the solution, after fining with cell wall material, using phloroglucinolysis and size exclusion chromatography, provided quantitative and qualitative information on the non-adsorbed compounds. Cell wall material showed strong affinity for the proanthocyanidins, one of the commercial tannins being bound up to 61% in the experiment. Comparison of the molecular mass distribution of the commercial enological tannins in solution, before and after fining, suggested that cell walls affinity for proanthocyanidins was more related with the proanthocyanidin molecular mass than with their percentage of galloylation. These interactions may have some enological implications, especially as regards the time of commercial tannins addition to the must/wine.

  19. Clinostation influence on regeneration of cell wall in Solanum Tuberosum L. protoplasts

    Science.gov (United States)

    Nedukha, Elena M.; Sidorov, V. A.; Samoylov, V. M.

    1994-08-01

    Regeneration of cell walls in protoplasts was investigated using light- and electronmicroscopic methods. The protoplasts were isolated from mesophyll of Solanum tuberosum leaves and were cultivated on the horizontal low rotating clinostat (2 rpm) and in control for 10 days. Using a fluorescent method (with Calcofluor white) it was demonstrated that changes in vector gravity results in an regeneration inhibition of cell wall. With electron-microscopical and electro-cytochemical methods (staining with alcianum blue) dynamics of the regeneration of cell walls in protoplasts was studied; carbohydrate matrix of cell walls is deposited at the earliest stages of this process. The influence of microgravity on the cell wall regeneration is discussed in higher plants.

  20. Trans-Golgi Network-An Intersection of Trafficking Cell Wall Components

    Institute of Scientific and Technical Information of China (English)

    Natasha Worden; Eunsook Park; Georgia Drakakaki

    2012-01-01

    The cell wall,a crucial cell compartment,is composed of a network of polysaccharides and proteins,providing structural support and protection from external stimuli.While the cell wall structure and biosynthesis have been extensively studied,very little is known about the transport of polysaccharides and other components into the developing cell wall.This review focuses on endomembrane trafficking pathways involved in cell wall deposition.Cellulose synthase complexes are assembled in the Golgi,and are transported in vesicles to the plasma membrane.Non-cellulosic polysaccharides are synthesized in the Golgi apparatus,whereas cellulose is produced by enzyme complexes at the plasma membrane.Polvsaccharides and enzymes that are involved in cell wall modification and assembly are transported by distinct vesicle types to their destinations; however,the precise mechanisms involved in selection,sorting and delivery remain to be identified.The endomembrane system orchestrates the delivery of Golgi-derived and possibly endocytic vesicles carrying cell wall and cell membrane components to the newly-formed cell plate.However,the nature of these vesicles,their membrane compositions,and the timing of their delivery are largely unknown.Emerging technologies such as chemical genomics and proteomics are promising avenues to gain insight into the trafficking of cell wall components.

  1. Generation of hydroxyl radical in isolated pea root cell wall, and the role of cell wall-bound peroxidase, Mn-SOD and phenolics in their production.

    Science.gov (United States)

    Kukavica, Biljana; Mojovic, Milos; Vuccinic, Zeljko; Maksimovic, Vuk; Takahama, Umeo; Jovanovic, Sonja Veljovic

    2009-02-01

    The hydroxyl radical produced in the apoplast has been demonstrated to facilitate cell wall loosening during cell elongation. Cell wall-bound peroxidases (PODs) have been implicated in hydroxyl radical formation. For this mechanism, the apoplast or cell walls should contain the electron donors for (i) H(2)O(2) formation from dioxygen; and (ii) the POD-catalyzed reduction of H(2)O(2) to the hydroxyl radical. The aim of the work was to identify the electron donors in these reactions. In this report, hydroxyl radical (.OH) generation in the cell wall isolated from pea roots was detected in the absence of any exogenous reductants, suggesting that the plant cell wall possesses the capacity to generate .OH in situ. Distinct POD and Mn-superoxide dismutase (Mn-SOD) isoforms different from other cellular isoforms were shown by native gel electropho-resis to be preferably bound to the cell walls. Electron paramagnetic resonance (EPR) spectroscopy of cell wall isolates containing the spin-trapping reagent, 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO), was used for detection of and differentiation between .OH and the superoxide radical (O(2)(-).). The data obtained using POD inhibitors confirmed that tightly bound cell wall PODs are involved in DEPMPO/OH adduct formation. A decrease in DEPMPO/OH adduct formation in the presence of H(2)O(2) scavengers demonstrated that this hydroxyl radical was derived from H(2)O(2). During the generation of .OH, the concentration of quinhydrone structures (as detected by EPR spectroscopy) increased, suggesting that the H(2)O(2) required for the formation of .OH in isolated cell walls is produced during the reduction of O(2) by hydroxycinnamic acids. Cell wall isolates in which the proteins have been denaturated (including the endogenous POD and SOD) did not produce .OH. Addition of exogenous H(2)O(2) again induced the production of .OH, and these were shown to originate from the Fenton reaction with tightly bound metal ions

  2. The Cell Wall Lipid PDIM Contributes to Phagosomal Escape and Host Cell Exit of Mycobacterium tuberculosis

    Science.gov (United States)

    Quigley, Jeff; Hughitt, V. Keith; Velikovsky, Carlos A.; Mariuzza, Roy A.

    2017-01-01

    ABSTRACT The cell wall of Mycobacterium tuberculosis is composed of unique lipids that are important for pathogenesis. Indeed, the first-ever genetic screen in M. tuberculosis identified genes involved in the biosynthesis and transport of the cell wall lipid PDIM (phthiocerol dimycocerosates) as crucial for the survival of M. tuberculosis in mice. Here we show evidence for a novel molecular mechanism of the PDIM-mediated virulence in M. tuberculosis. We characterized the DNA interaction and the regulon of Rv3167c, a transcriptional repressor that is involved in virulence regulation of M. tuberculosis, and discovered that it controls the PDIM operon. A loss-of-function genetic approach showed that PDIM levels directly correlate with the capacity of M. tuberculosis to escape the phagosome and induce host cell necrosis and macroautophagy. In conclusion, our study attributes a novel role of the cell wall lipid PDIM in intracellular host cell modulation, which is important for host cell exit and dissemination of M. tuberculosis. PMID:28270579

  3. Identification and characterization of Arabidopsis thaliana genes involved in xylem secondary cell walls.

    Science.gov (United States)

    Yokoyama, Ryusuke; Nishitani, Kazuhiko

    2006-05-01

    The xylem of higher plants offers support to aerial portions of the plant body and serves as conduit for the translocation of water and nutrients. Terminal differentiation of xylem cells typically involves deposition of thick secondary cell walls. This is a dynamic cellular process accompanied by enhanced rates of cellulose deposition and the induction of synthesis of specific secondary-wall matrix polysaccharides and lignin. The secondary cell wall is essential for the function of conductive and supportive xylem tissues. Recently, significant progress has been made in identifying the genes responsible for xylem secondary cell wall formation. However, our present knowledge is still insufficient to account for the molecular processes by which this complex system operates. To acquire further information about xylem secondary cell walls, we initially focused our research effort on a set of genes specifically implicated in secondary cell wall formation, as well as on loss-of-function mutants. Results from two microarray screens identified several key candidate genes responsible for secondary cell wall formation. Reverse genetic analyses led to the identification of a glycine-rich protein involved in maintaining the stable structure of protoxylem, which is essential for the transport of water and nutrients. A combination of expression analyses and reverse genetics allows us to systematically identify new genes required for the development of physical properties of the xylem secondary wall.

  4. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Nathan T Reem

    2016-05-01

    Full Text Available The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity and function remains unclear. Modifications of cell wall composition can induce plant responses known as Cell Wall Integrity control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, increased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant cell wall integrity, which contributes to plant resistance to necrotrophic pathogens.

  5. Immunoprofiling reveals unique cell-specific patterns of wall epitopes in the expanding Arabidopsis stem.

    Science.gov (United States)

    Hall, Hardy C; Cheung, Jingling; Ellis, Brian E

    2013-04-01

    The Arabidopsis inflorescence stem undergoes rapid directional growth, requiring massive axial cell-wall extension in all its tissues, but, at maturity, these tissues are composed of cell types that exhibit markedly different cell-wall structures. It is not clear whether the cell-wall compositions of these cell types diverge rapidly following axial growth cessation, or whether compositional divergence occurs at earlier stages in differentiation, despite the common requirement for cell-wall extensibility. To examine this question, seven cell types were assayed for the abundance and distribution of 18 major cell-wall glycan classes at three developmental stages along the developing inflorescence stem, using a high-throughput immunolabelling strategy. These stages represent a phase of juvenile growth, a phase displaying the maximum rate of stem extension, and a phase in which extension growth is ceasing. The immunolabelling patterns detected demonstrate that the cell-wall composition of most stem tissues undergoes pronounced changes both during and after rapid extension growth. Hierarchical clustering of the immunolabelling signals identified cell-specific binding patterns for some antibodies, including a sub-group of arabinogalactan side chain-directed antibodies whose epitope targets are specifically associated with the inter-fascicular fibre region during the rapid cell expansion phase. The data reveal dynamic, cell type-specific changes in cell-wall chemistry across diverse cell types during cell-wall expansion and maturation in the Arabidopsis inflorescence stem, and highlight the paradox between this structural diversity and the uniform anisotropic cell expansion taking place across all tissues during stem growth.

  6. Comparative in situ analyses of cell wall matrix polysaccharide dynamics in developing rice and wheat grain.

    Science.gov (United States)

    Palmer, Richard; Cornuault, Valérie; Marcus, Susan E; Knox, J Paul; Shewry, Peter R; Tosi, Paola

    2015-03-01

    Cell wall polysaccharides of wheat and rice endosperm are an important source of dietary fibre. Monoclonal antibodies specific to cell wall polysaccharides were used to determine polysaccharide dynamics during the development of both wheat and rice grain. Wheat and rice grain present near synchronous developmental processes and significantly different endosperm cell wall compositions, allowing the localisation of these polysaccharides to be related to developmental changes. Arabinoxylan (AX) and mixed-linkage glucan (MLG) have analogous cellular locations in both species, with deposition of AX and MLG coinciding with the start of grain filling. A glucuronoxylan (GUX) epitope was detected in rice, but not wheat endosperm cell walls. Callose has been reported to be associated with the formation of cell wall outgrowths during endosperm cellularisation and xyloglucan is here shown to be a component of these anticlinal extensions, occurring transiently in both species. Pectic homogalacturonan (HG) was abundant in cell walls of maternal tissues of wheat and rice grain, but only detected in endosperm cell walls of rice in an unesterified HG form. A rhamnogalacturonan-I (RG-I) backbone epitope was observed to be temporally regulated in both species, detected in endosperm cell walls from 12 DAA in rice and 20 DAA in wheat grain. Detection of the LM5 galactan epitope showed a clear distinction between wheat and rice, being detected at the earliest stages of development in rice endosperm cell walls, but not detected in wheat endosperm cell walls, only in maternal tissues. In contrast, the LM6 arabinan epitope was detected in both species around 8 DAA and was transient in wheat grain, but persisted in rice until maturity.

  7. [Heterocysts with reduced cell walls in populations of cycad cyanobionts].

    Science.gov (United States)

    Baulina, O I; Lobakova, E S

    2003-01-01

    The ultrastructure of the cyanobionts of the greenhouse-grown cycads Cycads circinalis, Ceratozamia mexicana, and Encephalartos villosus was studied. In addition to heterocysts with the typical ultrastructure, the cyanobiont microcolonies also contained altered heterocysts with reduced cell walls, which might dominate in all regions of the coralloid roots. The altered heterocysts represented a protoplast enclosed in a heterocyst-specific envelope with additional layers. Some heterocysts contained an additional reticular protoplast-enclosing sheath below the heterocyst-specific envelope, whereas the other heterocysts contained an additional electron-opaque outer layer. The substance of the inner sheath of the former heterocysts resembled the polysaccharides of mucilage, which fills the intercellular space of plant tissues, whereas the electron-opaque outer layer of the latter heterocysts probably had a protein nature. The substances that constitute the sheath and the outer layer are likely to be synthesized intracellularly and then released with the aid of membrane-bounded vesicles or by channels in the cytoplasmic membrane.

  8. Modifications of Saccharomyces pastorianus cell wall polysaccharides with brewing process.

    Science.gov (United States)

    Bastos, Rita; Coelho, Elisabete; Coimbra, Manuel A

    2015-06-25

    The cell wall polysaccharides of brewers spent yeast Saccharomyces pastorianus (BSY) and the inoculum yeast (IY) were studied in order to understand the changes induced by the brewing process. The hot water and alkali extractions performed solubilized mainly mannoproteins, more branched for BSY than those of IY. Also, (31)P solid state NMR showed that the BSY mannoproteins were 3 times more phosphorylated. By electron microscopy it was observed that the final residues of alkali sequential extraction until 4M KOH preserved the yeast three-dimensional structure. The final residues, composed mainly by glucans (92%), showed that the BSY, when compared with IY, contained higher amount of (1→4)-linked Glc (43% for BSY and 16% for IY) and lower (1→3)-linked Glc (17% for BSY and 42% for IY). The enzymatic treatment of final residue showed that both BSY and IY had (α1→4)-linked Glc and (β1→4)-linked Glc, in a 2:1 ratio, showing that S. pastorianus increases their cellulose-like linkages with the brewing process.

  9. Phosphatase activity on the cell wall of Fonsecaea pedrosoi.

    Science.gov (United States)

    Kneipp, L F; Palmeira, V F; Pinheiro, A A S; Alviano, C S; Rozental, S; Travassos, L R; Meyer-Fernandes, J R

    2003-12-01

    The activity of a phosphatase was characterized in intact mycelial forms of Fonsecaea pedrosoi, a pathogenic fungus that causes chromoblastomycosis. At pH 5.5, this fungus hydrolyzed p-nitrophenylphosphate (p-NPP) to p-nitrophenol (p-NP) at a rate of 12.78 +/- 0.53 nmol p-NP per h per mg hyphal dry weight. The values of Vmax and apparent Km for p-NPP hydrolyses were measured as 17.89 +/- 0.92 nmol p-NP per h per mg hyphal dry weight and 1.57 +/- 0.26 mmol/l, respectively. This activity was inhibited at increased pH, a finding compatible with an acid phosphatase. The enzymatic activity was strongly inhibited by classical inhibitors of acid phosphatases such as sodium orthovanadate (Ki = 4.23 micromol/l), sodium molybdate (Ki = 7.53 micromol/l) and sodium fluoride (Ki = 126.78 micromol/l) in a dose-dependent manner. Levamizole (1 mmol/l) and sodium tartrate (10 mmol/l), had no effect on the enzyme activity. Cytochemical localization of the acid phosphatase showed electrondense cerium phosphate deposits on the cell wall, as visualized by transmission electron microscopy. Phosphatase activity in F. pedrosoi seems to be associated with parasitism, as sclerotic cells, which are the fungal forms mainly detected in chromoblastomycosis lesions, showed much higher activities than conidia and mycelia did. A strain of F. pedrosoi recently isolated from a human case of chromoblastomycosis also showed increased enzyme activity, suggesting that the expression of surface phosphatases may be stimulated by interaction with the host.

  10. Serologic response to cell wall mannoproteins and proteins of Candida albicans.

    Science.gov (United States)

    Martínez, J P; Gil, M L; López-Ribot, J L; Chaffin, W L

    1998-01-01

    The cell wall of Candida albicans not only is the structure in which many biological functions essential for the fungal cells reside but also is a significant source of candidal antigens. The major cell wall components that elicit a response from the host immune system are proteins and glycoproteins, the latter being predominantly mannoproteins. Both the carbohydrate and protein moieties are able to trigger immune responses. Although cell-mediated immunity is often considered to be the most important line of defense against candidiasis, cell wall protein and glycoprotein components also elicit a potent humoral response from the host that may include some protective antibodies. Proteins and glycoproteins exposed at the most external layers of the wall structure are involved in several types of interactions of fungal cells with the exocellular environment. Thus, coating of fungal cells with host antibodies has the potential to influence profoundly the host-parasite interaction by affecting antibody-mediated functions such as opsonin-enhanced phagocytosis and blocking the binding activity of fungal adhesins for host ligands. In this review, the various members of the protein and glycoprotein fraction of the C. albicans cell wall that elicit an antibody response in vivo are examined. Although a number of proteins have been shown to stimulate an antibody response, for some of these species the response is not universal. On the other hand, some of the studies demonstrate that certain cell wall antigens and anti-cell wall antibodies may be the basis for developing specific and sensitive serologic tests for the diagnosis of candidasis, particularly the disseminated form. In addition, recent studies have focused on the potential for antibodies to cell wall protein determinants to protect the host against infection. Hence, a better understanding of the humoral response to cell wall antigens of C. albicans may provide the basis for the development of (i) effective procedures

  11. Stomatal cell wall composition: distinctive structural patterns associated with different phylogenetic groups.

    Science.gov (United States)

    Shtein, Ilana; Shelef, Yaniv; Marom, Ziv; Zelinger, Einat; Schwartz, Amnon; Popper, Zoë A; Bar-On, Benny; Harpaz-Saad, Smadar

    2017-04-01

    Stomatal morphology and function have remained largely conserved throughout ∼400 million years of plant evolution. However, plant cell wall composition has evolved and changed. Here stomatal cell wall composition was investigated in different vascular plant groups in attempt to understand their possible effect on stomatal function. A renewed look at stomatal cell walls was attempted utilizing digitalized polar microscopy, confocal microscopy, histology and a numerical finite-elements simulation. The six species of vascular plants chosen for this study cover a broad structural, ecophysiological and evolutionary spectrum: ferns ( Asplenium nidus and Platycerium bifurcatum ) and angiosperms ( Arabidopsis thaliana and Commelina erecta ) with kidney-shaped stomata, and grasses (angiosperms, family Poaceae) with dumbbell-shaped stomata ( Sorghum bicolor and Triticum aestivum ). Three distinct patterns of cellulose crystallinity in stomatal cell walls were observed: Type I (kidney-shaped stomata, ferns), Type II (kidney-shaped stomata, angiosperms) and Type III (dumbbell-shaped stomata, grasses). The different stomatal cell wall attributes investigated (cellulose crystallinity, pectins, lignin, phenolics) exhibited taxon-specific patterns, with reciprocal substitution of structural elements in the end-walls of kidney-shaped stomata. According to a numerical bio-mechanical model, the end walls of kidney-shaped stomata develop the highest stresses during opening. The data presented demonstrate for the first time the existence of distinct spatial patterns of varying cellulose crystallinity in guard cell walls. It is also highly intriguing that in angiosperms crystalline cellulose appears to have replaced lignin that occurs in the stomatal end-walls of ferns serving a similar wall strengthening function. Such taxon-specific spatial patterns of cell wall components could imply different biomechanical functions, which in turn could be a consequence of differences in

  12. Genetic modification of plant cell walls to enhance biomass yield and biofuel production in bioenergy crops.

    Science.gov (United States)

    Wang, Yanting; Fan, Chunfen; Hu, Huizhen; Li, Ying; Sun, Dan; Wang, Youmei; Peng, Liangcai

    2016-01-01

    Plant cell walls represent an enormous biomass resource for the generation of biofuels and chemicals. As lignocellulose property principally determines biomass recalcitrance, the genetic modification of plant cell walls has been posed as a powerful solution. Here, we review recent progress in understanding the effects of distinct cell wall polymers (cellulose, hemicelluloses, lignin, pectin, wall proteins) on the enzymatic digestibility of biomass under various physical and chemical pretreatments in herbaceous grasses, major agronomic crops and fast-growing trees. We also compare the main factors of wall polymer features, including cellulose crystallinity (CrI), hemicellulosic Xyl/Ara ratio, monolignol proportion and uronic acid level. Furthermore, the review presents the main gene candidates, such as CesA, GH9, GH10, GT61, GT43 etc., for potential genetic cell wall modification towards enhancing both biomass yield and enzymatic saccharification in genetic mutants and transgenic plants. Regarding cell wall modification, it proposes a novel groove-like cell wall model that highlights to increase amorphous regions (density and depth) of the native cellulose microfibrils, providing a general strategy for bioenergy crop breeding and biofuel processing technology.

  13. Synthetic Genistein Glycosides Inhibiting EGFR Phosphorylation Enhance the Effect of Radiation in HCT 116 Colon Cancer Cells

    Directory of Open Access Journals (Sweden)

    Aleksandra Gruca

    2014-11-01

    Full Text Available The need to find new EGFR inhibitors for use in combination with radiotherapy in the treatment of solid tumors has drawn our attention to compounds derived from genistein, a natural isoflavonoid. The antiproliferative potential of synthetic genistein derivatives used alone or in combination with ionizing radiation was evaluated in cancer cell lines using clonogenic assay. EGFR phosphorylation was assessed with western blotting. Genistein derivatives inhibited clonogenic growth of HCT 116 cancer cells additively or synergistically when used in combination with ionizing radiation, and decreased EGFR activation. Our preclinical evaluation of genistein-derived EGFR inhibitors suggests that these compounds are much more potent sensitizers of cells to radiation than the parent isoflavonoid, genistein and indicate that these compounds may be useful in the treatment of colon cancer with radiation therapy.

  14. Changes in Cell Wall Composition during Ripening of Grape Berries1

    Science.gov (United States)

    Nunan, Kylie J.; Sims, Ian M.; Bacic, Antony; Robinson, Simon P.; Fincher, Geoffrey B.

    1998-01-01

    Cell walls were isolated from the mesocarp of grape (Vitis vinifera L.) berries at developmental stages from before veraison through to the final ripe berry. Fluorescence and light microscopy of intact berries revealed no measurable change in cell wall thickness as the mesocarp cells expanded in the ripening fruit. Isolated walls were analyzed for their protein contents and amino acid compositions, and for changes in the composition and solubility of constituent polysaccharides during development. Increases in protein content after veraison were accompanied by an approximate 3-fold increase in hydroxyproline content. The type I arabinogalactan content of the pectic polysaccharides decreased from approximately 20 mol % of total wall polysaccharides to about 4 mol % of wall polysaccharides during berry development. Galacturonan content increased from 26 to 41 mol % of wall polysaccharides, and the galacturonan appeared to become more soluble as ripening progressed. After an initial decrease in the degree of esterification of pectic polysaccharides, no further changes were observed nor were there large variations in cellulose (30–35 mol % of wall polysaccharides) or xyloglucan (approximately 10 mol % of wall polysaccharides) contents. Overall, the results indicate that no major changes in cell wall polysaccharide composition occurred during softening of ripening grape berries, but that significant modification of specific polysaccharide components were observed, together with large changes in protein composition. PMID:9808722

  15. Lipid Transfer Proteins Enhance Cell Wall Extension in TobaccoW⃞

    Science.gov (United States)

    Nieuwland, Jeroen; Feron, Richard; Huisman, Bastiaan A.H.; Fasolino, Annalisa; Hilbers, Cornelis W.; Derksen, Jan; Mariani, Celestina

    2005-01-01

    Plant cells are enclosed by a rigid cell wall that counteracts the internal osmotic pressure of the vacuole and limits the rate and direction of cell enlargement. When developmental or physiological cues induce cell extension, plant cells increase wall plasticity by a process called loosening. It was demonstrated previously that a class of proteins known as expansins are mediators of wall loosening. Here, we report a type of cell wall–loosening protein that does not share any homology with expansins but is a member of the lipid transfer proteins (LTPs). LTPs are known to bind a large range of lipid molecules to their hydrophobic cavity, and we show here that this cavity is essential for the cell wall–loosening activity of LTP. Furthermore, we show that LTP-enhanced wall extension can be described by a logarithmic time function. We hypothesize that LTP associates with hydrophobic wall compounds, causing nonhydrolytic disruption of the cell wall and subsequently facilitating wall extension. PMID:15937228

  16. Immunomodulatory properties of cell wall extract from Enterococcus faecalis CECT7121

    Directory of Open Access Journals (Sweden)

    Mónica Sparo

    Full Text Available The aim of this study was to investigate the immunomodulatory properties of cell wall extract from Enterococcus faecalis CECT7121, measuring the induction of cytokines TNF-α, IL-6, IL-10 and IL-12 from human peripheral blood mononuclear cells (PBMCs. Cell wall extract was prepared from their growth in brain heart infusion broth (18 h, 35 °C. Subsequently, toxicity of the obtained cell wall extract was tested in Balb-C mice. PBMCs were isolated from buffy coats at the Blood Transfusion Service of Hospital Ramón Santamarina (Tandil, Argentina. PBMCs were purified using standard Ficoll-Paque gradient centrifugation. Aliquots of purified leukocytes were incubated at 37 °C for 24 h with heat-killed E. faecalis CECT7121 and cell wall extract. Concentrations of IL-6, TNF-α, IL-10 and IL-12 (p70 were measured by solid phase sandwich ELISA. Changes in appearance and behavior of mice were evidenced only in the group with the maximal concentration of wall cell extract used (10,000 μg. Cell wall extract and heat-killed E. faecalisCECT7121 induced the production of significantly higher amounts of Il-12, IL-6, TNF-α and IL-10 cytokines compared to the nonstimulated PBMCs. These findings provide helpful information on immunomodulation activity by cell wall extract in sight of the application of this compound in controlling certain infectious diseases.

  17. Immunogold localization of xyloglucan and rhamnogalacturonan I in the cell walls of suspension-cultured sycamore cells.

    Science.gov (United States)

    Moore, P J; Darvill, A G; Albersheim, P; Staehelin, L A

    1986-11-01

    PLANT CELL WALLS SERVE SEVERAL FUNCTIONS: they impart rigidity to the plant, provide a physical and chemical barrier between the cell and its environment, and regulate the size and shape of each cell. Chemical studies have provided information on the biochemical composition of the plant cell walls as well as detailed knowledge of individual cell wall molecules. In contrast, very little is known about the distribution of specific cell wall components around individual cells and throughout tissues. To address this problem, we have produced polyclonal antibodies against two cell wall matrix components; rhamnogalacturonan I (RG-I), a pectic polysaccharide, and xyloglucan (XG), a hemicellulose. By using the antibiodies as specific markers we have been able to localize these polymers on thin sections of suspension-cultured sycamore cells (Acer pseudoplatanus). Our results reveal that each molecule has a unique distribution. XG is localized throughout the entire wall and middle lamella. RG-I is restricted to the middle lamella and is especially evident in the junctions between cells. These observations indicate that plant cell walls may have more distinct chemical (and functional?) domains than previously envisaged.

  18. Phenylalanine ammonia-lyase and cell wall peroxidase are cooperatively involved in the extensive formation of ferulate network in cell walls of developing rice shoots.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki

    2012-02-15

    The relationship between the formation of cell wall-bound ferulic acid (FA) and diferulic acid (DFA) and the change in activities of phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) was studied in rice shoots. The length and the fresh mass of shoots increased during the growth period from day 4 to 6, while coleoptiles ceased elongation growth on day 5. The amounts of FA and DFA isomers as well as cell wall polysaccharides continued to increase during the whole period. The activities of PAL and CW-PRX greatly increased in the same manner during the period. There were close correlations between the PAL activity and ferulate content or between the CW-PRX activity and DFA content. The expression levels of investigated genes for PAL and putative CW-PRX showed good accordance with the activities of these enzymes. These results suggest that increases in PAL and CW-PRX activities are cooperatively involved in the formation of ferulate network in cell walls of rice shoots and that investigated genes may be, at least in part, associated with the enzyme activities. The substantial increase in such network probably causes the maturation of cell walls and thus the cessation of elongation growth of coleoptiles.

  19. Growth regulation mechanisms in higher plants under microgravity conditions - changes in cell wall metabolism.

    Science.gov (United States)

    Hoson, T; Kamisaka, S; Wakabayashi, K; Soga, K; Tabuchi, A; Tokumoto, H; Okamura, K; Nakamura, Y; Mori, R; Tanimoto, E; Takeba, G; Nishitani, K; Izumi, R; Ishioka, N; Kamigaichi, S; Aizawa, S; Yoshizaki, I; Shimazu, T; Fukui, K

    2000-06-01

    During Space Shuttle STS-95 mission, we cultivated seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) and Arabidopsis (Arabidopsis thaliana L. cv. Columbia and cv. etr1-1) for 68.5, 91.5, and 136 hr on board, and then analyzed changes in the nature of their cell walls, growth, and morphogenesis under microgravity conditions. In space, elongation growth of both rice coleoptiles and Arabidopsis hypocotyls was stimulated. Also, the increase in the cell wall extensibility, especially that in the irreversible extensibility, was observed for such materials. The analyses of the amounts, the structure, and the physicochemical properties of the cell wall constituents indicated that the decreases in levels and molecular masses of cell wall polysaccharides were induced under microgravity conditions, which appeared to contribute to the increase in the wall extensibility. The activity of certain wall enzymes responsible for the metabolic turnover of the wall polysaccharides was increased in space. By the space flight, we also confirmed the occurrence of automorphogenesis of both seedlings under microgravity conditions; rice coleoptiles showed an adaxial bending, whereas Arabidopsis hypocotyls elongated in random directions. Furthermore, it was shown that spontaneous curvatures of rice coleoptiles in space were brought about uneven modifications of cell wall properties between the convex and the concave sides.

  20. Critical cell wall hole size for lysis in Gram-positive bacteria

    Science.gov (United States)

    Mitchell, Gabriel; Wiesenfeld, Kurt; Nelson, Daniel; Weitz, Joshua

    2013-03-01

    Gram-positive bacteria transport molecules necessary for their survival through holes in their cell wall. The holes in cell walls need to be large enough to let critical nutrients pass through. However, the cell wall must also function to prevent the bacteria's membrane from protruding through a large hole into the environment and lysing the cell. As such, we hypothesize that there exists a range of cell wall hole sizes that allow for molecule transport but prevent membrane protrusion. Here we develop and analyze a biophysical theory of the response of a Gram-positive cell's membrane to the formation of a hole in the cell wall. We predict a critical hole size in the range 15-24nm beyond which lysis occurs. To test our theory, we measured hole sizes in Streptococcus pyogenes cells undergoing enzymatic lysis via transmission electron microscopy. The measured hole sizes are in strong agreement with our theoretical prediction. Together, the theory and experiments provide a means to quantify the mechanisms of death of Gram-positive cells via enzymatically mediated lysis and provides insight into the range of cell wall hole sizes compatible with bacterial homeostasis.

  1. A new picture of cell wall protein dynamics in elongating cells of Arabidopsis thaliana: Confirmed actors and newcomers

    Directory of Open Access Journals (Sweden)

    Jamet Elisabeth

    2008-09-01

    Full Text Available Abstract Background Cell elongation in plants requires addition and re-arrangements of cell wall components. Even if some protein families have been shown to play roles in these events, a global picture of proteins present in cell walls of elongating cells is still missing. A proteomic study was performed on etiolated hypocotyls of Arabidopsis used as model of cells undergoing elongation followed by growth arrest within a short time. Results Two developmental stages (active growth and after growth arrest were compared. A new strategy consisting of high performance cation exchange chromatography and mono-dimensional electrophoresis was established for separation of cell wall proteins. This work allowed identification of 137 predicted secreted proteins, among which 51 had not been identified previously. Apart from expected proteins known to be involved in cell wall extension such as xyloglucan endotransglucosylase-hydrolases, expansins, polygalacturonases, pectin methylesterases and peroxidases, new proteins were identified such as proteases, proteins related to lipid metabolism and proteins of unknown function. Conclusion This work highlights the CWP dynamics that takes place between the two developmental stages. The presence of proteins known to be related to cell wall extension after growth arrest showed that these proteins may play other roles in cell walls. Finally, putative regulatory mechanisms of protein biological activity are discussed from this global view of cell wall proteins.

  2. Malignant transformation of ectopic pancreatic cells in the duodenal wall

    Institute of Scientific and Technical Information of China (English)

    Roberto; Bini; Paolo; Voghera; Alberto; Tapparo; Raffaele; Nunziata; Andrea; Demarchi; Matteo; Capocefalo; Renzo; Leli

    2010-01-01

    Ectopic pancreas (EP) is the relatively uncommon presence of pancreatic tissue outside the normal location of the pancreas. This condition is usually asymptomatic and rarely complicated by pancreatitis and malignant transformation. A few cases of neoplastic phenomena that developed from EP into the duodenal wall are described in the literature. Herein we report a case of gastric outlet obstruction due to adenocarcinoma arising from EP of the duodenal wall. The patient underwent a Whipple's procedure and had...

  3. Altered cell wall properties are responsible for ammonium-reduced aluminium accumulation in rice roots.

    Science.gov (United States)

    Wang, Wei; Zhao, Xue Qiang; Chen, Rong Fu; Dong, Xiao Ying; Lan, Ping; Ma, Jian Feng; Shen, Ren Fang

    2015-07-01

    The phytotoxicity of aluminium (Al) ions can be alleviated by ammonium (NH4(+)) in rice and this effect has been attributed to the decreased Al accumulation in the roots. Here, the effects of different nitrogen forms on cell wall properties were compared in two rice cultivars differing in Al tolerance. An in vitro Al-binding assay revealed that neither NH4(+) nor NO3(-) altered the Al-binding capacity of cell walls, which were extracted from plants not previously exposed to N sources. However, cell walls extracted from NH4(+)-supplied roots displayed lower Al-binding capacity than those from NO3(-)-supplied roots when grown in non-buffered solutions. Fourier-transform infrared microspectroscopy analysis revealed that, compared with NO3(-)-supplied roots, NH4(+)-supplied roots possessed fewer Al-binding groups (-OH and COO-) and lower contents of pectin and hemicellulose. However, when grown in pH-buffered solutions, these differences in the cell wall properties were not observed. Further analysis showed that the Al-binding capacity and properties of cell walls were also altered by pHs alone. Taken together, our results indicate that the NH4(+)-reduced Al accumulation was attributed to the altered cell wall properties triggered by pH decrease due to NH4(+) uptake rather than direct competition for the cell wall binding sites between Al(3+) and NH4(+).

  4. Superoxide generation in extracts from isolated plant cell walls is regulated by fungal signal molecules.

    Science.gov (United States)

    Kiba, A; Miyake, C; Toyoda, K; Ichinose, Y; Yamada, T; Shiraishi, T

    1997-08-01

    ABSTRACT Fractions solubilized with NaCl from cell walls of pea and cowpea plants catalyzed the formation of blue formazan from nitroblue tetrazolium. Because superoxide dismutase decreased formazan production by over 90%, superoxide anion (O(2) ) may participate in the formation of formazan in the solubilized cell wall fractions. The formazan formation in the fractions solubilized from pea and cowpea cell walls was markedly reduced by exclusion of NAD(P)H, manganese ion, or p-coumaric acid from the reaction mixture. The formazan formation was severely inhibited by salicylhydroxamic acid and catalase, but not by imidazole, pyridine, quinacrine, and diphenyleneiodonium. An elicitor preparation from the pea pathogen Mycosphaerella pinodes enhanced the activities of formazan formation nonspecifically in both pea and cowpea fractions. The suppressor preparation from M. pinodes inhibited the activity in the pea fraction in the presence or absence of the elicitor. In the cowpea fraction, however, the suppressor did not inhibit the elicitor-enhanced activity, and the suppressor alone stimulated formazan formation. These results indicated that O(2) generation in the fractions solubilized from pea and cowpea cell walls seems to be catalyzed by cell wall-bound peroxidase(s) and that the plant cell walls alone are able to respond to the elicitor non-specifically and to the suppressor in a species-specific manner, suggesting the plant cell walls may play an important role in determination of plant-fungal pathogen specificity.

  5. Acylated flavone glycosides from Veronica.

    Science.gov (United States)

    Albach, Dirk C; Grayer, Renée J; Jensen, Søren Rosendal; Ozgökce, Fevzi; Veitch, Nigel C

    2003-12-01

    A survey of the flavonoid glycosides of selected taxa in the genus Veronica yielded two new acylated 5,6,7,3',4'-pentahydroxyflavone (6-hydroxyluteolin) glycosides and two unusual allose-containing acylated 5,7,8,4'-tetrahydroxyflavone (isoscutellarein) glycosides. The new compounds were isolated from V. liwanensis and V. longifolia and identified using NMR spectroscopy as 6-hydroxyluteolin 4'-methyl ether 7-O-alpha-rhamnopyranosyl(1"'-->2")[6"-O-acetyl-beta-glucopyranoside] and 6-hydroxyluteolin 7-O-(6"-O-(E)-caffeoyl)-beta-glucopyranoside, respectively. Isoscutellarein 7-O-(6"'-O-acetyl)-beta-allopyranosyl(1"'-->2")-beta-glucopyranoside was obtained from both V. intercedens and V. orientalis and its 4'-methyl ether from V. orientalis only. Complete 1H and 13C NMR spectral assignments are presented for both isoscutellarein glycosides. Two iridoid glucosides new to the genus Veronica (melittoside and globularifolin) were also isolated from V. intercedens.

  6. Navigating the transcriptional roadmap regulating plant secondary cell wall deposition

    Directory of Open Access Journals (Sweden)

    Steven Grant Hussey

    2013-08-01

    Full Text Available The current status of lignocellulosic biomass as an invaluable resource in industry, agriculture and health has spurred increased interest in understanding the transcriptional regulation of secondary cell wall (SCW biosynthesis. The last decade of research has revealed an extensive network of NAC, MYB and other families of transcription factors regulating Arabidopsis SCW biosynthesis, and numerous studies have explored SCW-related transcription factors in other dicots and monocots. Whilst the general structure of the Arabidopsis network has been a topic of several reviews, they have not comprehensively represented the detailed protein-DNA and protein-protein interactions described in the literature, and an understanding of network dynamics and functionality has not yet been achieved for SCW formation. Furthermore the methodologies employed in studies of SCW transcriptional regulation have not received much attention, especially in the case of non-model organisms. In this review, we have reconstructed the most exhaustive literature-based network representations to date of SCW transcriptional regulation in Arabidopsis. We include a manipulable Cytoscape representation of the Arabidopsis SCW transcriptional network to aid in future studies, along with a list of supporting literature for each documented interaction. Amongst other topics, we discuss the various components of the network, its evolutionary conservation in plants, putative modules and dynamic mechanisms that may influence network function, and the approaches that have been employed in network inference. Future research should aim to better understand network function and its response to dynamic perturbations, whilst the development and application of genome-wide approaches such as ChIP-seq and systems genetics are in progress for the study of SCW transcriptional regulation in non-model organisms.

  7. Xyloglucans from flaxseed kernel cell wall: Structural and conformational characterisation.

    Science.gov (United States)

    Ding, Huihuang H; Cui, Steve W; Goff, H Douglas; Chen, Jie; Guo, Qingbin; Wang, Qi

    2016-10-20

    The structure of ethanol precipitated fraction from 1M KOH extracted flaxseed kernel polysaccharides (KPI-EPF) was studied for better understanding the molecular structures of flaxseed kernel cell wall polysaccharides. Based on methylation/GC-MS, NMR spectroscopy, and MALDI-TOF-MS analysis, the dominate sugar residues of KPI-EPF fraction comprised of (1,4,6)-linked-β-d-glucopyranose (24.1mol%), terminal α-d-xylopyranose (16.2mol%), (1,2)-α-d-linked-xylopyranose (10.7mol%), (1,4)-β-d-linked-glucopyranose (10.7mol%), and terminal β-d-galactopyranose (8.5mol%). KPI-EPF was proposed as xyloglucans: The substitution rate of the backbone is 69.3%; R1 could be T-α-d-Xylp-(1→, or none; R2 could be T-α-d-Xylp-(1→, T-β-d-Galp-(1→2)-α-d-Xylp-(1→, or T-α-l-Araf-(1→2)-α-d-Xylp-(1→; R3 could be T-α-d-Xylp-(1→, T-β-d-Galp-(1→2)-α-d-Xylp-(1→, T-α-l-Fucp-(1→2)-β-d-Galp-(1→2)-α-d-Xylp-(1→, or none. The Mw of KPI-EPF was calculated to be 1506kDa by static light scattering (SLS). The structure-sensitive parameter (ρ) of KPI-EPF was calculated as 1.44, which confirmed the highly branched structure of extracted xyloglucans. This new findings on flaxseed kernel xyloglucans will be helpful for understanding its fermentation properties and potential applications. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  8. Chemical Synthesis of Oligosaccharides related to the Cell Walls of Plants and Algae

    DEFF Research Database (Denmark)

    Kinnaert, Christine; Daugaard, Mathilde; Nami, Faranak

    2017-01-01

    Plant cell walls are composed of an intricate network of polysaccharides and proteins that varies during the developmental stages of the cell. This makes it very challenging to address the functions of individual wall components in cells, especially for highly complex glycans. Fortunately, struct......, and arabinogalactans, as well as glycans unique to algae. Representative synthetic routes within each class are discussed in detail and the progress in carbohydrate chemistry over recent decades is highlighted....

  9. High-throughput mapping of cell-wall polymers within and between plants using novel microarrays

    DEFF Research Database (Denmark)

    Moller, Isabel Eva; Sørensen, Iben; Bernal Giraldo, Adriana Jimena

    2007-01-01

    multiple organs or tissues with the generation of microarrays, which are probed with monoclonal antibodies (mAbs) or carbohydrate-binding modules (CBMs) with specificities for cell-wall components. The profiles generated provide a global snapshot of cell-wall composition, and also allow comparative......We describe here a methodology that enables the occurrence of cell-wall glycans to be systematically mapped throughout plants in a semi-quantitative high-throughput fashion. The technique (comprehensive microarray polymer profiling, or CoMPP) integrates the sequential extraction of glycans from...

  10. Elevated CO2 concentration impacts cell wall polysaccharide composition of green microalgae of the genus Chlorella.

    Science.gov (United States)

    Cheng, Y-S; Labavitch, J M; VanderGheynst, J S

    2015-01-01

    The effect of CO2 concentration on the relative content of starch, lipid and cell wall carbohydrates in microalgal biomass was investigated for the four following Chlorella strains: C. vulgaris (UTEX 259), C. sorokiniana (UTEX 2805), C. minutissima (UTEX 2341) and C. variabilis (NC64A). Each strain had a different response to CO2 concentration. The starch content was higher in UTEX259 and NC64A cultured with 2% CO2 in the air supply than in cells cultured with ca. 0·04% CO2 (ambient air), while starch content was not affected for UTEX 2805 and UTEX 2341. The lipid content was higher in Chlorella minutissima UTEX 2341 cultured in 2% CO2 than in cells cultured in ambient air, but was unchanged for the other three strains. All four Chlorella strains tended to have a higher percentage of uronic acids and lower percentage of neutral sugars in their cell wall polysaccharide complement when grown with 2% CO2 supply. Although the percentage of neutral sugars in the cell walls varied with CO2 concentration, the relative proportions of different neutral sugar constituents remained constant for both CO2 conditions. The results demonstrate the importance of considering the effects of CO2 on the cell wall carbohydrate composition of microalgae. Microalgae have the potential to produce products that will reduce society's reliance on fossil fuels and address challenges related to food and feed production. An overlooked yet industrially relevant component of microalgae are their cell walls. Cell wall composition affects cell flocculation and the recovery of intracellular products. In this study, we show that increasing CO2 level results in greater cell wall polysaccharide and uronic acid content in the cell walls of three strains of microalgae. The results have implications on the management of systems for the capture of CO2 and production of fuels, chemicals and food from microalgae. © 2014 The Society for Applied Microbiology.

  11. Cytotoxic cardiac glycosides and other compounds from Asclepias syriaca.

    Science.gov (United States)

    Araya, Juan J; Kindscher, Kelly; Timmermann, Barbara N

    2012-03-23

    Phytochemical investigation of the dried biomass of Asclepias syriaca afforded five new compounds (1-5), along with 19 known structures. Overall, the secondary metabolites isolated and identified from this plant showed a wide structural diversity including pentacyclic triterpenes, cardiac glycosides, flavonoid glycosides, lignans, a phenylethanoid, and a glycosylated megastigmane. In addition, the isolates were tested against the cancer breast cell line Hs578T, and those showing IC(50) values lower than 50 μM (1 and 6-9) were further investigated in three additional breast cancer cell lines (MCF-7, T47D, and Sk-Br-3) and the normal breast cell line Hs578Bst.

  12. Metal octacarboxyphthalocyanine / multi-walled carbon nanotube hybrid for the development of dye solar cells

    CSIR Research Space (South Africa)

    Mphahlele, N

    2013-09-01

    Full Text Available octacarboxyphthalocyanines-multi-walled carbon nanotubes hybrid was prepared through non- covalent (Pi)p-(Pi)p stacking. The metallo-octacarboxyphthalocyanines-multi-walled carbon nanotubes hybrid was later employed in dye solar cells as a photosensitiser of choice...

  13. Specific labeling of peptidoglycan precursors as a tool for bacterial cell wall studies

    NARCIS (Netherlands)

    van Dam, V.|info:eu-repo/dai/nl/304833908; Olrichs, N.K.|info:eu-repo/dai/nl/304837571; Breukink, E.J.|info:eu-repo/dai/nl/120305100

    2009-01-01

    Wall chart: The predominant component of the bacterial cell wall, peptidoglycan, consists of long alternating stretches of aminosugar subunits interlinked in a large three-dimensional network and is formed from precursors through several cytosolic and membrane-bound steps. The high tolerance of the

  14. Comparative characterization of stromal vascular cells derived from three types of vascular wall and adipose tissue.

    Science.gov (United States)

    Yang, Santsun; Eto, Hitomi; Kato, Harunosuke; Doi, Kentaro; Kuno, Shinichiro; Kinoshita, Kahori; Ma, Hsu; Tsai, Chi-Han; Chou, Wan-Ting; Yoshimura, Kotaro

    2013-12-01

    Multipotent stem/progenitor cells localize perivascularly in many organs and vessel walls. These tissue-resident stem/progenitor cells differentiate into vascular endothelial cells, pericytes, and other mesenchymal lineages, and participate in physiological maintenance and repair of vasculatures. In this study, we characterized stromal vascular cells obtained through the explant culture method from three different vessel walls in humans: arterial wall (ART; >500 μm in diameter), venous wall (VN; >500 μm in diameter), and small vessels in adipose tissue (SV; arterioles and venules, adipose-derived stem/stromal cells (ASCs). All stromal vascular cells of different origins presented fibroblast-like morphology and we could not visually discriminate one population from another. Flow cytometry showed that the cultured population heterogeneously expressed a variety of surface antigens associated with stem/progenitor cells, but CD105 was expressed by most cells in all groups, suggesting that the cells generally shared the characteristics of mesenchymal stem cells. Our histological and flow cytometric data suggested that the main population of vessel wall-derived stromal vascular cells were CD34(+)/CD31(-) and came from the tunica adventitia and areola tissue surrounding the adventitia. CD271 (p75NTR) was expressed by the vasa vasorum in the VN adventitia and by a limited population in the adventitia of SV. All three populations differentiated into multiple lineages as did ASCs. ART cells induced the largest quantity of calcium formation in the osteogenic medium, whereas ASCs showed the greatest adipogenic differentiation. SV and VN stromal cells had greater potency for network formation than did ART stromal cells. In conclusion, the three stromal vascular populations exhibited differential functional properties. Our results have clinical implications for vascular diseases such as arterial wall calcification and possible applications to regenerative therapies

  15. The role of the secondary cell walls in plant resistance to pathogens

    Directory of Open Access Journals (Sweden)

    Eva eMiedes

    2014-08-01

    Full Text Available Plant resistance to pathogens relies on a complex network of constitutive and inducible defensive barriers. The plant cell wall is one of the barriers that pathogens need to overcome to successfully colonize plant tissues. The traditional view of the plant cell wall as a passive barrier has evolved to a concept that considers the wall as a dynamic structure that regulates both constitutive and inducible defence mechanisms, and as a source of signalling molecules that trigger immune responses. The secondary cell walls of plants also represent a carbon-neutral feedstock (lignocellulosic biomass for the production of biofuels and biomaterials. Therefore, engineering plants with improved secondary cell wall characteristics is an interesting strategy to ease the processing of lignocellulosic biomass in the biorefinery. However, modification of the integrity of the cell wall by impairment of proteins required for its biosynthesis or remodelling may impact the plants resistance to pathogens. This review summarizes our understanding of the role of the plant cell wall in pathogen resistance with a focus on the contribution of lignin to this biological process.

  16. Rice Brittleness Mutants: A Way to Open the 'Black Box' of Monocot Cell Wall Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Baocai Zhang; Yihua Zhou

    2011-01-01

    Rice is a model organism for studying the mechanism of cell wall biosynthesis and remolding in Gramineae.Mechanical strength is an important agronomy trait of rice(Oryza sativa L.)plants that affects crop lodging and grain yield.As a prominent physical property of cell walls,mechanical strength reflects upon the structure of different wall polymers and how they interact.Studies on the mechanisms that regulate the mechanical strength therefore consequently results in uncovering the genes functioning in cell wall biosynthesis and remodeling.Our group focuses on the study of isolation of brittle culm(bc)mutants and characterization of their corresponding genes.To date,several bc mutants have been reported.The identified genes have covered several pathways of cell wall biosynthesis,revealing many secrets of monocot cell wall biosynthesis.Here,we review the progress achieved in this research field and also highlight the perspectives in expectancy.All of those lend new insights into mechanisms of cell wall formation and are helpful for harnessing the waste rice straws for biofuel production.

  17. Altered cell wall disassembly during ripening of Cnr tomato fruit: implications for cell adhesion and fruit softening

    DEFF Research Database (Denmark)

    Orfila, C.; Huisman, M.M.H.; Willats, William George Tycho

    2002-01-01

    polysaccharides to the non-softening and altered cell adhesion phenotype. Cell wall material (CWM) and solubilised fractions of mature green and red ripe fruit were analysed by chemical, enzymatic and immunochemical techniques. No major differences in CWM sugar composition were detected although differences were...... that was chelator-soluble was 50% less in Cnr cell walls at both the mature green and red ripe stages. Chelator-soluble material from ripe-stage Cnr was more susceptible to endo-polygalacturonase degradation than the corresponding material from wild-type fruit. In addition, cell walls from Cnr fruit contained......The Cnr (Colourless non-ripening) tomato (Lycopersicon esculentum Mill.) mutant has an aberrant fruit-ripening phenotype in which fruit do not soften and have reduced cell adhesion between pericarp cells. Cell walls from Cnr fruit were analysed in order to assess the possible contribution of pectic...

  18. Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae

    DEFF Research Database (Denmark)

    Mikkelsen, Maria Dalgaard; Harholt, Jesper; Ulvskov, Peter

    2014-01-01

    to colonize land. These cell walls provide support and protection, are a source of signalling molecules, and provide developmental cues for cell differentiation and elongation. The cell wall of land plants is a highly complex fibre composite, characterized by cellulose cross-linked by non......BACKGROUND AND AIMS: The charophyte green algae (CGA) are thought to be the closest living relatives to the land plants, and ancestral CGA were unique in giving rise to the land plant lineage. The cell wall has been suggested to be a defining structure that enabled the green algal ancestor......-cellulosic polysaccharides, such as xyloglucan, embedded in a matrix of pectic polysaccharides. How the land plant cell wall evolved is currently unknown: early-divergent chlorophyte and prasinophyte algae genomes contain a low number of glycosyl transferases (GTs), while land plants contain hundreds. The number of GTs...

  19. Effect of commercial enzymes on berry cell wall deconstruction in the context of intravineyard ripeness variation under winemaking conditions

    DEFF Research Database (Denmark)

    Gao, Yu; Fangel, Jonatan Ulrik; Willats, William George Tycho;

    2016-01-01

    at the berry cell wall polymer level and occurred within the experimental vineyard block. Furthemore, all enzyme treatments reduced cell wall variation via depectination. Interestingly, cell wall esterification levels were unaffected by enzyme treatments. This study provides clear evidence that enzymes can...

  20. Improved methods for binding acma-type protein anchor fusions yo cell-wall material of micro-organisms

    NARCIS (Netherlands)

    Leenhouts, Cornelis; Ramasamy, R.; Steen, Anton; Kok, Jan; Buist, Girbe; Kuipers, Oscar

    2002-01-01

    The invention provides a method for improving binding of a proteinaceous substance to cell-wall material of a Gram-positive bacterium, said substance comprising an AcmA cell wall binding domain or homolog or functional derivative thereof, said method comprising treating said cell-wall material with

  1. Expression of S-adenosylmethionine Hydrolase in Tissues Synthesizing Secondary Cell Walls Alters Specific Methylated Cell Wall Fractions and Improves Biomass Digestibility

    Directory of Open Access Journals (Sweden)

    Aymerick Eudes

    2016-07-01

    Full Text Available Plant biomass is a large source of fermentable sugars for the synthesis of bioproducts using engineered microbes. These sugars are stored as cell wall polymers, mainly cellulose and hemicellulose, and are embedded with lignin, which makes their enzymatic hydrolysis challenging. One of the strategies to reduce cell wall recalcitrance is the modification of lignin content and composition. Lignin is a phenolic polymer of methylated aromatic alcohols and its synthesis in tissues developing secondary cell walls is a significant sink for the consumption of the methyl donor S-adenosylmethionine (AdoMet. In this study, we demonstrate in Arabidopsis stems that targeted expression of S-adenosylmethionine hydrolase (AdoMetase, E.C. 3.3.1.2 in secondary cell-wall synthesizing tissues reduces the AdoMet pool and impacts lignin content and composition. In particular, both NMR analysis and pyrolysis gas chromatography mass spectrometry of lignin in engineered biomass showed relative enrichment of non-methylated p-hydroxycinnamyl (H units and a reduction of dimethylated syringyl (S units. This indicates a lower degree of methylation compared to that in wild-type lignin. Quantification of cell wall-bound hydroxycinnamates revealed a reduction of ferulate in AdoMetase transgenic lines. Biomass from transgenic lines, in contrast to that in control plants, exhibits an enrichment of glucose content and a reduction in the degree of hemicellulose glucuronoxylan methylation. We also show that these modifications resulted in a reduction of cell wall recalcitrance, because sugar yield generated by enzymatic biomass saccharification was greater than that of wild type plants. Considering that transgenic plants show no important diminution of biomass yields, and that heterologous expression of AdoMetase protein can be spatiotemporally optimized, this novel approach provides a valuable option for the improvement of lignocellulosic biomass feedstock.

  2. Investigation on Adsorption of Lithospermum erythrorhizon onto Fungal Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    孟琴; 薛莲

    2003-01-01

    A culture of Lithosperrnum erythrorhizon adsorbed on fungal cell wall polysaccharides, a novel bioadsorbent made from fungal cell wall, has been established in this paper. Three steps were involved in this immobilization. The first step was preparation of suspended plant cells from tightly aggregated plant cell clumps. The disassembled ratio of 0.715g·g-1 (the disassembled cells over total cells) was obtained under optimum condition for the enzymatic reaction. Then, the adsorption of plant cells onto fungal cell wall polysaccharides was conducted and the saturated capacity of 12g cell per gram of carrier was obtained in adsorption immobilization. Finally, the culture of cells adsorbed on fungal cell wall polysaccharides was compared with that of cells entrapped in alginate or suspension cell culture. While exposed to in situ liquid paraffin extraction coupled with cell culture, the shikonin productivity of immobilized cells by adsorption was 10.67g·L-1, which was 1.8 times of that in suspension culture and 1.5 times of that entrapped in alginate.

  3. Diversity and strain specificity of plant cell wall degrading enzymes revealed by the draft genome of Ruminococcus flavefaciens FD-1.

    Directory of Open Access Journals (Sweden)

    Margret E Berg Miller

    Full Text Available BACKGROUND: Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels. METHODOLOGY/PRINCIPAL FINDINGS: The R. flavefaciens FD-1 genome was sequenced to 29x-coverage, based on pulsed-field gel electrophoresis estimates (4.4 Mb, and assembled into 119 contigs providing 4,576,399 bp of unique sequence. As much as 87.1% of the genome encodes ORFs, tRNA, rRNAs, or repeats. The GC content was calculated at 45%. A total of 4,339 ORFs was detected with an average gene length of 918 bp. The cellulosome model for R. flavefaciens was further refined by sequence analysis, with at least 225 dockerin-containing ORFs, including previously characterized cohesin-containing scaffoldin molecules. These dockerin-containing ORFs encode a variety of catalytic modules including glycoside hydrolases (GHs, polysaccharide lyases, and carbohydrate esterases. Additionally, 56 ORFs encode proteins that contain carbohydrate-binding modules (CBMs. Functional microarray analysis of the genome revealed that 56 of the cellulosome-associated ORFs were up-regulated, 14 were down-regulated, 135 were unaffected, when R. flavefaciens FD-1 was grown on cellulose versus cellobiose. Three multi-modular xylanases (ORF01222, ORF03896, and ORF01315 exhibited the highest levels of up-regulation. CONCLUSIONS/SIGNIFICANCE: The genomic evidence indicates that R. flavefaciens FD-1 has the largest known number of fiber-degrading enzymes likely to be arranged in a cellulosome architecture. Functional

  4. Nanostructured carbon electrocatalyst supports for intermediate-temperature fuel cells: Single-walled versus multi-walled structures

    Science.gov (United States)

    Papandrew, Alexander B.; Elgammal, Ramez A.; Tian, Mengkun; Tennyson, Wesley D.; Rouleau, Christopher M.; Puretzky, Alexander A.; Veith, Gabriel M.; Geohegan, David B.; Zawodzinski, Thomas A.

    2017-01-01

    It is unknown if nanostructured carbons possess the requisite electrochemical stability to be used as catalyst supports in the cathode of intermediate-temperature solid acid fuel cells (SAFCs) based on the CsH2PO4 electrolyte. To investigate this application, single-walled carbon nanohorns (SWNHs) and multi-walled carbon nanotubes (MWNTs) were used as supports for Pt catalysts in SAFCs operating at 250 °C. SWNH-based cathodes display greater maximum activity than their MWNT-based counterparts at a cell voltage of 0.8 V, but are unstable in the SAFC cathode as a consequence of electrochemical carbon corrosion. MWNT-based cells are resistant to this effect and capable of operation for at least 160 h at 0.6 V and 250 °C. Cells fabricated with nanostructured carbon supports are more active (52 mA cm-1vs. 28 mA cm-1 at 0.8 V) than state-of-the-art carbon-free formulations while simultaneously displaying enhanced Pt utilization (40 mA mgPt-1vs. 16 mA mgPt-1 at 0.8 V). These results suggest that MWNTs are a viable support material for developing stable, high-performance, low-cost air electrodes for solid-state electrochemical devices operating above 230 °C.

  5. Primary cell wall composition of bryophytes and charophytes.

    Science.gov (United States)

    Popper, Zoë A; Fry, Stephen C

    2003-01-01

    Major differences in primary cell wall (PCW) components between non-vascular plant taxa are reported. (1) Xyloglucan: driselase digestion yielded isoprimeverose (the diagnostic repeat unit of xyloglucan) from PCW-rich material of Anthoceros (a hornwort), mosses and both leafy and thalloid liverworts, as well as numerous vascular plants, showing xyloglucan to be a PCW component in all land plants tested. In contrast, charophycean green algae (Klebsormidium flaccidium, Coleochaete scutata and Chara corallina), thought to be closely related to land plants, did not contain xyloglucan. They did not yield isoprimeverose; additionally, charophyte material was not digestible with xyloglucan-specific endoglucanase or cellulase to give xyloglucan-derived oligosaccharides. (2) Uronic acids: acid hydrolysis of PCW-rich material from the charophytes, the hornwort, thalloid and leafy liverworts and a basal moss yielded higher concentrations of glucuronic acid than that from the remaining land plants including the less basal mosses and all vascular plants tested. Polysaccharides of the hornwort Anthoceros contained an unusual repeat-unit, glucuronic acid-alpha(1-->3)-galactose, not found in appreciable amounts in any other plants tested. Galacturonic acid was consistently the most abundant PCW uronic acid, but was present in higher concentrations in acid hydrolysates of bryophytes and charophytes than in those of any of the vascular plants. Mannuronic acid was not detected in any of the species surveyed. (3) Mannose: acid hydrolysis of charophyte and bryophyte PCW-rich material also yielded appreciably higher concentrations of mannose than are found in vascular plant PCWs. (4) Mixed-linkage glucan (MLG) was absent from all algae and bryophytes tested; however, upon digestion with licheninase, PCW-rich material from the alga Ulva lactuca and the leafy liverwort Lophocolea bidentata yielded penta- to decasaccharides, indicating the presence of MLG-related polysaccharides. Our

  6. Size, Shape, and Arrangement of Cellulose Microfibril in Higher Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Ding, S. Y.

    2013-01-01

    Plant cell walls from maize (Zea mays L.) are imaged using atomic force microscopy (AFM) at the sub-nanometer resolution. We found that the size and shape of fundamental cellulose elementary fibril (CEF) is essentially identical in different cell wall types, i.e., primary wall (PW), parenchyma secondary wall (pSW), and sclerenchyma secondary wall (sSW), which is consistent with previously proposed 36-chain model (Ding et al., 2006, J. Agric. Food Chem.). The arrangement of individual CEFs in these wall types exhibits two orientations. In PW, CEFs are horizontally associated through their hydrophilic faces, and the planar faces are exposed, forming ribbon-like macrofibrils. In pSW and sSW, CEFs are vertically oriented, forming layers, in which hemicelluloses are interacted with the hydrophobic faces of the CEF and serve as spacers between CEFs. Lignification occurs between CEF-hemicelluloses layers in secondary walls. Furthermore, we demonstrated quantitative analysis of plant cell wall accessibility to and digestibility by different cellulase systems at real-time using chemical imaging (e.g., stimulated Raman scattering) and fluorescence microscopy of labeled cellulases (Ding et al., 2012, Science, in press).

  7. The plant cell wall integrity maintenance mechanism-concepts for organization and mode of action.

    Science.gov (United States)

    Hamann, Thorsten

    2015-02-01

    One of the main differences between plant and animal cells are the walls surrounding plant cells providing structural support during development and protection like an adaptive armor against biotic and abiotic stress. During recent years it has become widely accepted that plant cells use a dedicated system to monitor and maintain the functional integrity of their walls. Maintenance of integrity is achieved by modifying the cell wall and cellular metabolism in order to permit tightly controlled changes in wall composition and structure. While a substantial amount of evidence supporting the existence of the mechanism has been reported, knowledge regarding its precise mode of action is still limited. The currently available evidence suggests similarities of the plant mechanism with respect to both design principles and molecular components involved to the very well characterized system active in the model organism Saccharomyces cerevisiae. There the system has been implicated in cell morphogenesis as well as response to abiotic stresses such as osmotic challenges. Here the currently available knowledge on the yeast system will be reviewed initially to provide a framework for the subsequent discussion of the plant cell wall integrity maintenance mechanism. The review will then end with a discussion on possible design principles for the cell wall integrity maintenance mechanism and the function of the plant turgor pressure in this context. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Beta-lactam antibiotics induce a lethal malfunctioning of the bacterial cell wall synthesis machinery

    Science.gov (United States)

    Cho, Hongbaek; Uehara, Tsuyoshi; Bernhardt, Thomas G.

    2014-01-01

    SUMMARY Penicillin and related beta-lactams comprise one of our oldest and most widely used antibiotic therapies. These drugs have long been known to target enzymes called penicillin-binding proteins (PBPs) that build the bacterial cell wall. Investigating the downstream consequences of target inhibition and how they contribute to the lethal action of these important drugs, we demonstrate that beta-lactams do more than just inhibit the PBPs as is commonly believed. Rather, they induce a toxic malfunctioning of their target biosynthetic machinery involving a futile cycle of cell wall synthesis and degradation, thereby depleting cellular resources and bolstering their killing activity. Characterization of this mode of action additionally revealed a quality-control function for enzymes that cleave bonds in the cell wall matrix. The results thus provide insight into the mechanism of cell wall assembly and suggest how best to interfere with the process for future antibiotic development. PMID:25480295

  9. Understanding the relationship between cotton fiber properties and non-cellulosic cell wall polysaccharides

    DEFF Research Database (Denmark)

    Rajasundaram, Dhivyaa; Runavot, Jean-Luc; Guo, Xiaoyuan;

    2014-01-01

    A detailed knowledge of cell wall heterogeneity and complexity is crucial for understanding plant growth and development. One key challenge is to establish links between polysaccharide-rich cell walls and their phenotypic characteristics. It is of particular interest for some plant material, like...... different cotton species were studied. The glycan array was generated by sequential extraction of cell wall polysaccharides from mature cotton fibers and screening samples against eleven extensively characterized cell wall probes. Also, phenotypic characteristics of cotton fibers such as length, strength...... and phenotypic traits. In addition, the analysis also identified specific polysaccharides which may play a major role during fiber development for the final fiber characteristics. Three different regression methods identified a negative correlation between micronaire and the xyloglucan and homogalacturonan...

  10. Genome-Wide Association Mapping for Cell Wall Composition and Properties in Temperate Grasses

    DEFF Research Database (Denmark)

    Bellucci, Andrea

    -glucans. Plant cell wall biosynthesis is regulated by a large number of genes and regulatory factors but very few of these are known and characterized. This PhD project aimed to the identification of putative candidate genes involved in plant cell wall composition and properties using a genome wide (GWAS......) approach. The species investigate were wheat, barley and B. distachyon, considered a model plant for temperate cereals. Agronomical traits as yield and plant height were also included in the analysis along with cell wall composition and saccharification properties. Several marker-trait associations were......Plant cell wall confers flexibility, support for the vital processes of the plant and resistance to abiotic stresses and pathogen. It is constituted by a complex matrix of cellulose, hemicellulose, pectins and polyphenolic compounds as lignin. These main components interact with each other...

  11. Regulation of auxin on secondary cell wall cellulose biosynthesis in developing cotton fibers

    Science.gov (United States)

    Cotton (Gossypium hirsutum L.) fibers are unicellular trichomes that differentiate from epidermal cells of developing cotton ovules. Mature fibers exhibit thickened secondary walls composed of nearly pure cellulose. Cotton fiber development is divided into four overlapping phases, 1) initiation sta...

  12. Variation in the Cell Wall Mechanical Properties of Dendrocalamus farinosus Bamboo by Nanoindentation

    National Research Council Canada - National Science Library

    Xi Yang; Genlin Tian; Lili Shang; Huangfei Lv; Shumin Yang; Xing'e Liu

    2014-01-01

    ... (Dendrocalamus farinosus) along the longitudinal direction of culms. The results indicated that among our four-sampled culm ages, the fiber cell wall had average values for the elastic modulus (MOE) and hardness (HL) of 18.56 GPa...

  13. Structure of ristocetin A in complex with a bacterial cell-wall mimetic

    OpenAIRE

    Nahoum, Virginie; Spector, Sherri; Loll, Patrick J.

    2009-01-01

    The crystal structure of the complex between ristocetin A and the cell-wall peptide mimetic N-acetyl-lysine-d-alanine-d-alanine has been solved. Structural details explaining the anticooperativity of the antibiotic have been identified.

  14. Arsenic interception by cell wall of bacteria observed with surface-enhanced Raman scattering.

    Science.gov (United States)

    Tian, Haixia; Zhuang, Guoqiang; Ma, Anzhou; Jing, Chuanyong

    2012-06-01

    The purpose of this study was to determine the interactions between arsenic (As) resistant bacteria and As, using surface-enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopy. According to our 16S rDNA results, eight bacteria isolated from the environment can be identified to four genera (Arthrobacter, Pseudomonas, Sphingomonas, and Acinetobacter). The bacteria were separated into cell wall and protoplast in the study to assess the As(V) attack. The As(V) stress on bacteria could be identified with SERS, but not with FTIR. The bacteria in our study primarily resist As(V) through sequestration of As(V) by the cell wall. The change in SERS peaks and their relationships with cell wall suggested that As(V) mainly interacts with functional groups on the cell wall including polysaccharides and flavin derivates.

  15. The Paracoccidioides cell wall: past and present layers towards understanding interaction with the host

    Directory of Open Access Journals (Sweden)

    Rosana ePuccia

    2011-12-01

    Full Text Available The cell wall of pathogenic fungi plays import roles in interaction with the host, so that its composition and structure may determine the course of infection. Here we present an overview of the current and past knowledge on the cell wall constituents of Paracoccidioides brasiliensis and P. lutzii. These are temperature-dependent dimorphic fungi that cause paracoccidioidomycosis, a systemic granulomatous and debilitating disease. Focus is given on cell wall carbohydrate and protein contents, their immune-stimulatory features, adhesion properties, drug target characteristics, and morphological phase specificity. We offer a journey towards the future understanding of the dynamic life that takes place in the cell wall and of the changes that it may suffer when living in the human host.

  16. 2012 PLANT CELL WALLS GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, AUGUST 4-10, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Jocelyn

    2012-08-10

    The sub-theme of this year’s meeting, ‘Cell Wall Research in a Post-Genome World’, will be a consideration of the dramatic technological changes that have occurred in the three years since the previous cell wall Gordon Conference in the area of DNA sequencing. New technologies are providing additional perspectives of plant cell wall biology across a rapidly growing number of species, highlighting a myriad of architectures, compositions, and functions in both "conventional" and specialized cell walls. This meeting will focus on addressing the knowledge gaps and technical challenges raised by such diversity, as well as our need to understand the underlying processes for critical applications such as crop improvement and bioenergy resource development.

  17. Understanding the relationship between cotton fiber properties and non-cellulosic cell wall polysaccharides

    DEFF Research Database (Denmark)

    Rajasundaram, Dhivyaa; Runavot, Jean-Luc; Guo, Xiaoyuan

    2014-01-01

    different cotton species were studied. The glycan array was generated by sequential extraction of cell wall polysaccharides from mature cotton fibers and screening samples against eleven extensively characterized cell wall probes. Also, phenotypic characteristics of cotton fibers such as length, strength......A detailed knowledge of cell wall heterogeneity and complexity is crucial for understanding plant growth and development. One key challenge is to establish links between polysaccharide-rich cell walls and their phenotypic characteristics. It is of particular interest for some plant material, like...... and phenotypic traits. In addition, the analysis also identified specific polysaccharides which may play a major role during fiber development for the final fiber characteristics. Three different regression methods identified a negative correlation between micronaire and the xyloglucan and homogalacturonan...

  18. Elevated Cell Wall Chitin in Candida albicans Confers Echinocandin Resistance In Vivo

    OpenAIRE

    Lee, K K; MacCallum, D.M; Jacobsen, M.D.; Walker, L A; Odds, F C; Gow, N. A. R.; Munro, C.A.

    2012-01-01

    Candida albicans cells with increased cell wall chitin have reduced echinocandin susceptibility in vitro. The aim of this study was to investigate whether C. albicans cells with elevated chitin levels have reduced echinocandin susceptibility in vivo. BALB/c mice were infected with C. albicans cells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully tre...

  19. Sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure

    OpenAIRE

    Coleman, Heather D.; Yan, Jimmy; Mansfield, Shawn D.

    2009-01-01

    Overexpression of the Gossypium hirsutum sucrose synthase (SuSy) gene under the control of 2 promoters was examined in hybrid poplar (Populus alba × grandidentata). Analysis of RNA transcript abundance, enzyme activity, cell wall composition, and soluble carbohydrates revealed significant changes in the transgenic lines. All lines showed significantly increased SuSy enzyme activity in developing xylem. This activity manifested in altered secondary cell wall cellulose content per dry weight in...

  20. Cell wall changes involved in the automorphic curvature of rice coleoptiles under microgravity conditions in space.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Mori, Ryuji; Saiki, Mizue; Nakamura, Yukiko; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro

    2004-12-01

    Seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) were cultivated on board the Space Shuttle STS-95 mission and changes in the morphology and the cell wall properties of coleoptiles were analyzed. In space, rice coleoptiles showed a spontaneous (automorphic) curvature toward the caryopsis in the elongating region. The angle of automorphic curvature was larger in Koshihikari than in a gibberellin-deficient dwarf cultivar, Tan-ginbozu, and the angle gradually decreased during the growth of coleoptiles in both cultivars. The more quickly expanding convex side of the bending region of the rice coleoptiles showed a greater extensibility of the cell wall than the opposite side. There was a significant correlation between the angle of curvature and the difference in the cell wall extensibility between the convex and the concave sides. Both the levels of the cell wall polysaccharides per unit length of coleoptile and the ratio of high-molecular-mass polysaccharides in the hemicellulose fraction were lower in the convex side than the concave one. Also, the activity of (1-->3),(1-->4)-beta-glucanases in the cell wall was higher in the convex side than the concave one. These results suggest that the uneven modifications of cell wall metabolism bring about the difference in the levels and the molecular size of the cell wall polysaccharides, thereby causing the difference in capacity of the cell wall to expand between the dorsal and the ventral sides, leading to the automorphic curvature of rice coleoptiles in space. The data also suggest the involvement of gibberellins in inducing the automorphic curvature under microgravity conditions.

  1. Isolation of diferulic bridges ester-linked to arabinan in sugar beet cell walls.

    Science.gov (United States)

    Levigne, Sébastien; Ralet, Marie-Christine; Quéméner, Bernard; Thibault, Jean-François

    2004-09-13

    After degradation of sugar beet cell walls with Driselase and fractionation of the solubilised products by hydrophobic interaction chromatography, a dehydrodiferuloylated oligoarabinan was isolated. Its structure was assigned to two dimers of (1-->5)-linked arabinose units esterified by a central 8-O-4' ferulic dimer. These results provide the first direct evidence that pectic arabinans in sugar beet cell walls may be covalently cross-linked through dehydrodiferulates.

  2. Formation of silica aggregates in sorghum root endodermis is predetermined by cell wall architecture and development.

    Science.gov (United States)

    Soukup, Milan; Martinka, Michal; Bosnic, Dragana; Caplovicová, Mária; Elbaum, Rivka; Lux, Alexander

    2017-06-22

    Deposition of silica in plant cell walls improves their mechanical properties and helps plants to withstand various stress conditions. Its mechanism is still not understood and silica-cell wall interactions are elusive. The objective of this study was to investigate the effect of silica deposition on the development and structure of sorghum root endodermis and to identify the cell wall components involved in silicification. Sorghum bicolor seedlings were grown hydroponically with (Si+) or without (Si-) silicon supplementation. Primary roots were used to investigate the transcription of silicon transporters by quantitative RT-PCR. Silica aggregation was induced also under in vitro conditions in detached root segments. The development and architecture of endodermal cell walls were analysed by histochemistry, microscopy and Raman spectroscopy. Water retention capability was compared between silicified and non-silicified roots. Raman spectroscopy analyses of isolated silica aggregates were also carried out. Active uptake of silicic acid is provided at the root apex, where silicon transporters Lsi1 and Lsi2 are expressed. The locations of silica aggregation are established during the development of tertiary endodermal cell walls, even in the absence of silicon. Silica aggregation takes place in non-lignified spots in the endodermal cell walls, which progressively accumulate silicic acid, and its condensation initiates at arabinoxylan-ferulic acid complexes. Silicification does not support root water retention capability; however, it decreases root growth inhibition imposed by desiccation. A model is proposed in which the formation of silica aggregates in sorghum roots is predetermined by a modified cell wall architecture and takes place as governed by endodermal development. The interaction with silica is provided by arabinoxylan-ferulic acid complexes and interferes with further deposition of lignin. Due to contrasting hydrophobicity, silicification and lignification

  3. Cytochemical location of urease in the cell wall of two different lichen phycobionts.

    Science.gov (United States)

    Millanes, A M; Fontaniella, B; García, M L; Solas, M T; Vicente, C; Legaz, M E

    2004-12-01

    The enzyme urease has been located in the cell wall of recently isolated phycobionts from Evernia prunastri and Xanthoria parietina lichens. Cytochemical detection is achieved by producing a black, electron-dense precipitate of cobalt sulfide proceeding from CO(2) evolved from urea in the presence of cobalt chloride. Cellular fractionation reveals that about 80% of total urease activity was associated to the cell wall on both phycobionts whereas only 20% was recovered as soluble protein.

  4. Arabinose-rich polymers as an evolutionary strategy to plasticize resurrection plant cell walls against desiccation.

    Science.gov (United States)

    Moore, John P; Nguema-Ona, Eric E; Vicré-Gibouin, Mäite; Sørensen, Iben; Willats, William G T; Driouich, Azeddine; Farrant, Jill M

    2013-03-01

    A variety of Southern African resurrection plants were surveyed using high-throughput cell wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii, Xerophyta humilis and the resurrection grass Eragrostis nindensis, as well as a pteridophyte, the resurrection fern, Mohria caffrorum. Comparisons were made between hydrated and desiccated leaf and frond material, with respect to cell wall composition and polymer abundance, using monosaccharide composition analysis, FT-IR spectroscopy and comprehensive microarray polymer profiling in combination with multivariate data analysis. The data obtained suggest that three main functional strategies appear to have evolved to prepare plant cell walls for desiccation. Arabinan-rich pectin and arabinogalactan proteins are found in the resurrection fern M. caffrorum and the basal angiosperm M. flabellifolia where they appear to act as 'pectic plasticizers'. Dicotyledons with pectin-rich walls, such as C. plantagineum, seem to use inducible mechanisms which consist of up-regulating wall proteins and osmoprotectants. The hemicellulose-rich walls of the grass-like Xerophyta spp. and the resurrection grass E. nindensis were found to contain highly arabinosylated xylans and arabinogalactan proteins. These data support a general mechanism of 'plasticising' the cell walls of resurrection plants to desiccation and implicate arabinose-rich polymers (pectin-arabinans, arabinogalactan proteins and arabinoxylans) as the major contributors in ensuring flexibility is maintained and rehydration is facilitated in these plants.

  5. The cell walls of green algae: a journey through evolution and diversity

    Directory of Open Access Journals (Sweden)

    David eDomozych

    2012-05-01

    Full Text Available The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For example, the late divergent taxa of the Charophycean Green Algae possess cell walls containing assemblages of polymers with notable similarity to the cellulose, pectins, hemicelluloses, arabinogalactan proteins, extensin and lignin present in embryophyte walls. Ulvophycean seaweeds have cell wall components whose most abundant fibrillar constituents may change from cellulose to β-mannans to β-xylans and during different life cycle phases. Likewise, these algae produce complex sulfated polysaccharides, arabinogalactan proteins and extensin. Chlorophycean green algae produce a wide array of walls ranging from cellulose-pectin complexes to ones made of hydroxyproline-rich glycoproteins. Larger and more detailed surveys of the green algal taxa including incorporation of emerging genomic and transcriptomic data are required in order to more fully resolve evolutionary trends within the green algae and in relationship with higher plants as well as potential applications of wall components in the food and pharmaceutical industries.

  6. The Cell Walls of Green Algae: A Journey through Evolution and Diversity.

    Science.gov (United States)

    Domozych, David S; Ciancia, Marina; Fangel, Jonatan U; Mikkelsen, Maria Dalgaard; Ulvskov, Peter; Willats, William G T

    2012-01-01

    The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For example, the late divergent taxa of the Charophycean green algae possess cell walls containing assemblages of polymers with notable similarity to the cellulose, pectins, hemicelluloses, arabinogalactan proteins (AGPs), extensin, and lignin present in embryophyte walls. Ulvophycean seaweeds have cell wall components whose most abundant fibrillar constituents may change from cellulose to β-mannans to β-xylans and during different life cycle phases. Likewise, these algae produce complex sulfated polysaccharides, AGPs, and extensin. Chlorophycean green algae produce a wide array of walls ranging from cellulose-pectin complexes to ones made of hydroxyproline-rich glycoproteins. Larger and more detailed surveys of the green algal taxa including incorporation of emerging genomic and transcriptomic data are required in order to more fully resolve evolutionary trends within the green algae and in relationship with higher plants as well as potential applications of wall components in the food and pharmaceutical industries.

  7. The charophycean green algae provide insights into the early origins of plant cell walls.

    Science.gov (United States)

    Sørensen, Iben; Pettolino, Filomena A; Bacic, Antony; Ralph, John; Lu, Fachuang; O'Neill, Malcolm A; Fei, Zhangzhun; Rose, Jocelyn K C; Domozych, David S; Willats, William G T

    2011-10-01

    Numerous evolutionary innovations were required to enable freshwater green algae to colonize terrestrial habitats and thereby initiate the evolution of land plants (embryophytes). These adaptations probably included changes in cell-wall composition and architecture that were to become essential for embryophyte development and radiation. However, it is not known to what extent the polymers that are characteristic of embryophyte cell walls, including pectins, hemicelluloses, glycoproteins and lignin, evolved in response to the demands of the terrestrial environment or whether they pre-existed in their algal ancestors. Here we show that members of the advanced charophycean green algae (CGA), including the Charales, Coleochaetales and Zygnematales, but not basal CGA (Klebsormidiales and Chlorokybales), have cell walls that are comparable in several respects to the primary walls of embryophytes. Moreover, we provide both chemical and immunocytochemical evidence that selected Coleochaete species have cell walls that contain small amounts of lignin or lignin-like polymers derived from radical coupling of hydroxycinnamyl alcohols. Thus, the ability to synthesize many of the components that characterize extant embryophyte walls evolved during divergence within CGA. Our study provides new insight into the evolutionary window during which the structurally complex walls of embryophytes originated, and the significance of the advanced CGA during these events. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  8. Interaction and modulation of two antagonistic cell wall enzymes of mycobacteria.

    Directory of Open Access Journals (Sweden)

    Erik C Hett

    Full Text Available Bacterial cell growth and division require coordinated cell wall hydrolysis and synthesis, allowing for the removal and expansion of cell wall material. Without proper coordination, unchecked hydrolysis can result in cell lysis. How these opposing activities are simultaneously regulated is poorly understood. In Mycobacterium tuberculosis, the resuscitation-promoting factor B (RpfB, a lytic transglycosylase, interacts and synergizes with Rpf-interacting protein A (RipA, an endopeptidase, to hydrolyze peptidoglycan. However, it remains unclear what governs this synergy and how it is coordinated with cell wall synthesis. Here we identify the bifunctional peptidoglycan-synthesizing enzyme, penicillin binding protein 1 (PBP1, as a RipA-interacting protein. PBP1, like RipA, localizes both at the poles and septa of dividing cells. Depletion of the ponA1 gene, encoding PBP1 in M. smegmatis, results in a severe growth defect and abnormally shaped cells, indicating that PBP1 is necessary for viability and cell wall stability. Finally, PBP1 inhibits the synergistic hydrolysis of peptidoglycan by the RipA-RpfB complex in vitro. These data reveal a post-translational mechanism for regulating cell wall hydrolysis and synthesis through protein-protein interactions between enzymes with antagonistic functions.

  9. Neutrophil Attack Triggers Extracellular Trap-Dependent Candida Cell Wall Remodeling and Altered Immune Recognition.

    Directory of Open Access Journals (Sweden)

    Alex Hopke

    2016-05-01

    Full Text Available Pathogens hide immunogenic epitopes from the host to evade immunity, persist and cause infection. The opportunistic human fungal pathogen Candida albicans, which can cause fatal disease in immunocompromised patient populations, offers a good example as it masks the inflammatory epitope β-glucan in its cell wall from host recognition. It has been demonstrated previously that β-glucan becomes exposed during infection in vivo but the mechanism behind this exposure was unknown. Here, we show that this unmasking involves neutrophil extracellular trap (NET mediated attack, which triggers changes in fungal cell wall architecture that enhance immune recognition by the Dectin-1 β-glucan receptor in vitro. Furthermore, using a mouse model of disseminated candidiasis, we demonstrate the requirement for neutrophils in triggering these fungal cell wall changes in vivo. Importantly, we found that fungal epitope unmasking requires an active fungal response in addition to the stimulus provided by neutrophil attack. NET-mediated damage initiates fungal MAP kinase-driven responses, particularly by Hog1, that dynamically relocalize cell wall remodeling machinery including Chs3, Phr1 and Sur7. Neutrophil-initiated cell wall disruptions augment some macrophage cytokine responses to attacked fungi. This work provides insight into host-pathogen interactions during disseminated candidiasis, including valuable information about how the C. albicans cell wall responds to the biotic stress of immune attack. Our results highlight the important but underappreciated concept that pattern recognition during infection is dynamic and depends on the host-pathogen dialog.

  10. Selective degradation of the recalcitrant cell wall of Scenedesmus quadricauda CASA CC202.

    Science.gov (United States)

    Reshma, Ragini; Arumugam, Muthu

    2017-07-06

    An eco-friendly cell wall digestion strategy was developed to enhance the availability of nutritionally important bio molecules of edible microalgae and exploit them for cloning, transformation, and expression of therapeutic proteins. Microalgae are the source for many nutritionally important bioactive compounds and potential drugs. Even though edible microalgae are rich in nutraceutical, bioavailability of all these molecules is very less due to their rigid recalcitrant cell wall. For example, the cell wall of Scenedesmus quadricauda CASA CC202 is made up of three layers comprising of rigid outer pectin and inner cellulosic layer separated by a thin middle layer. In the present investigation, a comprehensive method has been developed for the selective degradation of S. quadricauda CASA CC202 cell wall, by employing both mechanical and enzymatic treatments. The efficiency of cell wall removal was evaluated by measuring total reducing sugar (TRS), tannic acid-ferric chloride staining, calcoflour white staining, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) analysis. It was confirmed that the yield of TRS increased from 129.82 mg/g in 14 h from pectinase treatment alone to 352.44 mg/g by combined sonication and enzymatic treatment within 12 h. As a result, the combination method was found to be effective for the selective degradation of S. quadricauda CASA CC202 cell wall. This study will form a base for our future works, where this will help to enhance the digestibility and availability of nutraceutically important proteins.

  11. Insights into cell wall structure of Sida hermaphrodita and its influence on recalcitrance.

    Science.gov (United States)

    Damm, Tatjana; Pattathil, Sivakumar; Günl, Markus; Jablonowski, Nicolai David; O'Neill, Malcolm; Grün, Katharina Susanne; Grande, Philipp Michael; Leitner, Walter; Schurr, Ulrich; Usadel, Björn; Klose, Holger

    2017-07-15

    The perennial plant Sida hermaphrodita (Sida) is attracting attention as potential energy crop. Here, the first detailed view on non-cellulosic Sida cell wall polysaccharide composition, structure and architecture is given. Cell walls were prepared from Sida stems and sequentially extracted with aqueous buffers and alkali. The structures of the quantitatively predominant polysaccharides present in each fraction were determined by biochemical characterization, glycome profiling and mass spectrometry. The amounts of glucose released by Accellerase-1500(®) treatment of the cell wall and the cell wall residue remaining after each extraction were used to assess the roles of pectin and hemicellulose in the recalcitrance of Sida biomass. 4-O-Methyl glucuronoxylan with a low proportion of side substitutions was identified as the major non-cellulosic glycan component of Sida stem cell walls. Pectic polysaccharides and xylans were found to be associated with lignin, suggesting that these polysaccharides have roles in Sida cell wall recalcitrance to enzymatic hydrolysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The changes of oil palm roots cell wall lipids during pathogenesis of Ganoderma boninense

    Science.gov (United States)

    Alexander, A.; Dayou, J.; Abdullah, S.; Chong, K. P.

    2017-07-01

    One of the first physical defences of plants against fungal infection is their cell wall. Interaction between combinations of metabolism enzymes known as the “weapons” of pathogen and the host cell wall probably determines the fate of possible invasion of the pathogen in the host. The present work aims to study the biochemical changes of cell wall lipids of oil palm roots and to determine novel information on root cell wall composition during pathogenesis of Ganoderma boninense by using Gas Chromatography Mass Spectrometry. Based on Total Ion Chromatogram analysis, 67 compounds were found more abundant in the roots infected with G. boninense compared to the healthy roots (60 compounds). Interestingly, nine new compounds were identified from the cell wall lipids of roots infected with G. boninense. These includes Cyclohexane, 1,2-dimethyl-, Methyl 2-hydroxy 16-methyl-heptadecanoate, 2-Propenoic acid, methyl ester, Methyl 9-oxohexacosanoate, 5-[(3,7,11,15-Tetramethylhexadecyl)oxy]thiophene-2carboxylic acid, Ergosta-5,7,22,24(28)-tetraen-3beta-ol, 7-Hydroxy-3',4'-methylenedioxyflavan, Glycine and (S)-4'-Hydroxy-4-methoxydalbergione, this may involve as response to pathogen invasion. This paper provides an original comparative lipidomic analysis of oil palm roots cell wall lipids in plant defence during pathogenesis of G. boninense.

  13. Monoclonal antibody-based analysis of cell wall remodeling during xylogenesis.

    Science.gov (United States)

    Shinohara, Naoki; Kakegawa, Koichi; Fukuda, Hiroo

    2015-11-01

    Xylogenesis, a process by which woody tissues are formed, entails qualitative and quantitative changes in the cell wall. However, the molecular events that underlie these changes are not completely understood. Previously, we have isolated two monoclonal antibodies, referred to as XD3 and XD27, by subtractive screening of a phage-display library of antibodies raised against a wall fraction of Zinnia elegans xylogenic culture cells. Here we report the biochemical and immunohistochemical characterization of those antibodies. The antibody XD3 recognized (1→4)-β-D-galactan in pectin fraction. During xylogenesis, the XD3 epitope was localized to the primary wall of tracheary-element precursor cells, which undergo substantial cell elongation, and was absent from mature tracheary elements. XD27 recognized an arabinogalactan protein that was bound strongly to a germin-like protein. The XD27 epitope was localized to pre-lignified secondary walls of tracheary elements. Thus these cell-wall-directed monoclonal antibodies revealed two molecular events during xylogenesis. The biological significance of these events is discussed in relation to current views of the plant cell wall.

  14. Participation of Candida albicans transcription factor RLM1 in cell wall biogenesis and virulence.

    Science.gov (United States)

    Delgado-Silva, Yolanda; Vaz, Catarina; Carvalho-Pereira, Joana; Carneiro, Catarina; Nogueira, Eugénia; Correia, Alexandra; Carreto, Laura; Silva, Sónia; Faustino, Augusto; Pais, Célia; Oliveira, Rui; Sampaio, Paula

    2014-01-01

    Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol), confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213%) and reduction in mannans (60%), in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.

  15. Participation of Candida albicans transcription factor RLM1 in cell wall biogenesis and virulence.

    Directory of Open Access Journals (Sweden)

    Yolanda Delgado-Silva

    Full Text Available Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol, confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213% and reduction in mannans (60%, in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.

  16. Effects of wall shear stress and its gradient on tumor cell adhesion in curved microvessels.

    Science.gov (United States)

    Yan, W W; Cai, B; Liu, Y; Fu, B M

    2012-05-01

    Tumor cell adhesion to vessel walls in the microcirculation is one critical step in cancer metastasis. In this paper, the hypothesis that tumor cells prefer to adhere at the microvessels with localized shear stresses and their gradients, such as in the curved microvessels, was examined both experimentally and computationally. Our in vivo experiments were performed on the microvessels (post-capillary venules, 30-50 μm diameter) of rat mesentery. A straight or curved microvessel was cannulated and perfused with tumor cells by a glass micropipette at a velocity of ~1mm/s. At less than 10 min after perfusion, there was a significant difference in cell adhesion to the straight and curved vessel walls. In 60 min, the averaged adhesion rate in the curved vessels (n = 14) was ~1.5-fold of that in the straight vessels (n = 19). In 51 curved segments, 45% of cell adhesion was initiated at the inner side, 25% at outer side, and 30% at both sides of the curved vessels. To investigate the mechanical mechanism by which tumor cells prefer adhering at curved sites, we performed a computational study, in which the fluid dynamics was carried out by the lattice Boltzmann method , and the tumor cell dynamics was governed by the Newton's law of translation and rotation. A modified adhesive dynamics model that included the influence of wall shear stress/gradient on the association/dissociation rates of tumor cell adhesion was proposed, in which the positive wall shear stress/gradient jump would enhance tumor cell adhesion while the negative wall shear stress/gradient jump would weaken tumor cell adhesion. It was found that the wall shear stress/gradient, over a threshold, had significant contribution to tumor cell adhesion by activating or inactivating cell adhesion molecules. Our results elucidated why the tumor cell adhesion prefers to occur at the positive curvature of curved microvessels with very low Reynolds number (in the order of 10(-2)) laminar flow.

  17. Changes in inositol phosphates in wild carrot cells upon initiation of cell wall digestion

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, M.; Boss, W.F.

    1987-04-01

    Previous studies have shown that inositol trisphosphate (IP/sub 3/) stimulated /sup 45/Ca/sup +2/ efflux from fusogenic carrot protoplasts and it was suggested that IP/sub 3/ may serve as a second messenger for the mobilization of intracellular Ca/sup +2/ in higher plant cells. To determine whether or not inositol phosphate metabolism changes in response to external stimuli, the cells were labeled with myo-(2-/sup 3/H) inositol for 18 h and exposed to cell wall digestion enzymes, Driselase. The inositol phosphates were extracted with ice cold 10% TCA and separated by anion exchange chromatography. The radioactivity of the fraction that contained IP/sub 3/ increased 2-3.8 fold and that which contained inositol bisphosphate increased 1.9-2.6 fold within 1.5 min of exposure to Driselase. After 6 min, the radioactivity of both fractions increased 6-7.7 fold and an increase in inositol monophosphate was observed. These data indicate that inositol phosphate metabolism is stimulated by Driselase and suggest polyphosphoinositide hydrolysis occurs upon initiation of cell wall digestion.

  18. Disturbance of the bacterial cell wall specifically interferes with biofilm formation.

    Science.gov (United States)

    Bucher, Tabitha; Oppenheimer-Shaanan, Yaara; Savidor, Alon; Bloom-Ackermann, Zohar; Kolodkin-Gal, Ilana

    2015-12-01

    In nature, bacteria communicate via chemical cues and establish complex communities referred to as biofilms, wherein cells are held together by an extracellular matrix. Much research is focusing on small molecules that manipulate and prevent biofilm assembly by modifying cellular signalling pathways. However, the bacterial cell envelope, presenting the interface between bacterial cells and their surroundings, is largely overlooked. In our study, we identified specific targets within the biosynthesis pathways of the different cell wall components (peptidoglycan, wall teichoic acids and teichuronic acids) hampering biofilm formation and the anchoring of the extracellular matrix with a minimal effect on planktonic growth. In addition, we provide convincing evidence that biofilm hampering by transglycosylation inhibitors and D-Leucine triggers a highly specific response without changing the overall protein levels within the biofilm cells or the overall levels of the extracellular matrix components. The presented results emphasize the central role of the Gram-positive cell wall in biofilm development, resistance and sustainment.

  19. Ethanolic rhizome extract from Kaempferia parviflora Wall. ex. Baker induces apoptosis in HL-60 cells.

    Science.gov (United States)

    Banjerdpongchai, Ratana; Suwannachot, Kittiphan; Rattanapanone, Viboon; Sripanidkulchai, Bungorn

    2008-01-01

    Kaempferia parviflora Wall. ex. Baker is a Thai herb containing many flavonoids that have anti-inflammatory, anti-allergic and antioxidant activities. The objective of this study was to demonstrate apoptotic effects of Kaempferia parviflora Wall. ex. Baker rhizome ethanolic extract on HL-60 cells in vitro. The extract suppressed HL-60 cell growth and decreased cell viability in a dose- and time-dependent manner. Apoptotic cell death was demonstrated by changes in cell morphology, externalization of phosphatidylserine on the cell surface, loss in mitochondrial transmembrane potential and activation of caspase 3. Apoptosis induced by K. parviflora Wall. ex. Baker rhizome ethanolic extract was enhanced by treatment with paclitaxel or doxorubicin, and inhibitors of Akt, PI3-K and MEK.

  20. Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans.

    NARCIS (Netherlands)

    Klis, F.M.; de Koster, C.G.; Brul, S.

    2014-01-01

    Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell p

  1. The Structure of Plant Cell Walls: I. The Macromolecular Components of the Walls of Suspension-cultured Sycamore Cells with a Detailed Analysis of the Pectic Polysaccharides.

    Science.gov (United States)

    Talmadge, K W; Keegstra, K; Bauer, W D; Albersheim, P

    1973-01-01

    This is the first in a series of papers dealing with the structure of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus). These studies have been made possible by the availability of purified hydrolytic enzymes and by recent improvements in the techniques of methylation analysis. These techniques have permitted us to identify and quantitate the macromolecular components of sycamore cell walls. These walls are composed of 10% arabinan, 2% 3,6-linked arabinogalactan, 23% cellulose, 9% oligo-arabinosides (attached to hydroxyproline), 8% 4-linked galactan, 10% hydroxyproline-rich protein, 16% rhamnogalacturonan, and 21% xyloglucan.The structures of the pectic polymers (the neutral arabinan, the neutral galactan, and the acidic rhamnogalacturonan) were obtained, in part, by methylation analysis of fragments of these polymers which were released from the sycamore walls by the action of a highly purified endopolygalacturonase. The data suggest a branched arabinan and a linear 4-linked galactan occurring as side chains on the rhamnogalacturonan. Small amounts or pieces of a xyloglucan, the wall hemicellulose, appear to be covalently linked to some of the galactan chains. Thus, the galactan appears to serve as a bridge between the xyloglucan and rhamnogalacturonan components of the wall.The rhamnogalacturonan consists of an alpha-(1 --> 4)-linked galacturonan chain which is interspersed with 2-linked rhamnosyl residues. The rhamnosyl residues are not randomly distributed in the chain but probably occur in units of rhamnosyl- (1 --> 4)-galacturonosyl- (1 --> 2)-rhamnosyl. This sequence appears to alternate with a homogalacturonan sequence containing approximately 8 residues of 4-linked galacturonic acid. About half of the rhamnosyl residues are branched, having a substituent attached to carbon 4. This is likely to be the site of attachment of the 4-linked galactan.The hydroxyprolyl oligo-arabinosides of the hydroxyproline-rich glycoprotein

  2. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens.

    Science.gov (United States)

    Reem, Nathan T; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A; Bellincampi, Daniela; Zabotina, Olga A

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens.

  3. A new diterpene glycoside from Stevia rebaudiana

    National Research Council Canada - National Science Library

    Chaturvedula, Venkata Sai Prakash; Prakash, Indra

    2011-01-01

    From the commercial extract of the leaves of Stevia rebaudiana, a new diterpene glycoside was isolated besides the known steviol glycosides including stevioside, rebaudiosides A-F, rubusoside and dulcoside...

  4. Enhancement of beta-sitosterol transformation in Mycobacterium vaccae with increased cell wall permeability.

    Science.gov (United States)

    Korycka-Machała, M; Rumijowska-Galewicz, A; Lisowska, K; Ziolkowskit, A; Sedlacze, L

    2001-01-01

    Mycobacterium vaccae exposed to compounds which are known to disorganise the cell wall composition and architecture (protamine, glycine) showed increased specific activity in beta-sitosterol biotransformation to androstene derivatives, intennediates in the production of most medical steroids. GC/MS analysis of free lipid fatty acids revealed higher content of unsaturated compounds, mainly C16:1 and C18:1 in protamine- and glycine-treated cells than that in control cells, which seems to change the permeability features of the cell wall barrier, facilitating hydrophobic beta-sitosterol diffusion.

  5. Efficiency of cellular growth when creating small pockets of electric current along the walls of cells.

    Science.gov (United States)

    Kletetschka, Gunther; Zila, Vojtech; Klimova, Lucie

    2014-04-01

    Pulses up to 11 Tesla magnetic fields may generate pockets of currents along the walls of cellular material and may interfere with the overall ability of cell division. We used prokaryotic cells (Escherichia coli) and eukaryotic cells (murine fibroblasts) and exposed them to magnetic pulses of intensities ranging from 1 millitesla (mT) to 11,000 mT. We found prokaryotic cells to be more sensitive to magnetic field pulses than eukaryotic cells.

  6. Efficiency of Cellular Growth When Creating Small Pockets of Electric Current Along the Walls of Cells

    OpenAIRE

    Kletetschka, Gunther; Zila, Vojtech; Klimova, Lucie

    2014-01-01

    Pulses up to 11 Tesla magnetic fields may generate pockets of currents along the walls of cellular material and may interfere with the overall ability of cell division. We used prokaryotic cells (Escherichia coli) and eukaryotic cells (murine fibroblasts) and exposed them to magnetic pulses of intensities ranging from 1 millitesla (mT) to 11,000 mT. We found prokaryotic cells to be more sensitive to magnetic field pulses than eukaryotic cells.

  7. Endo-b-1,4-glucanases impact plant cell wall development by influencing cellulose crystallization

    Institute of Scientific and Technical Information of China (English)

    Magdalena Glass; Sarah Barkwill; Faride Unda; Shawn D. Mansfield

    2015-01-01

    Cell walls are vital to the normal growth and development of plants as they protect the protoplast and provide rigidity to the stem. Here, two poplar and Arabidopsis orthologous endoglucanases, which have been proposed to play a role in secondary cell wall development, were examined. The class B endoglucanases, PtGH9B5 and AtGH9B5, are secreted enzymes that have a predicted glycosylphosphatidylinositol anchor, while the class C endo-glucanases, PtGH9C2 and AtGH9C2, are also predicted to be secreted but instead contain a carbohydrate-binding module. The poplar endoglucanases were expressed in Arabidopsis using both a 35S promoter and the Arabidopsis secondary cell wall-specific CesA8 promoter. Additionally, Arabidopsis t-DNA insertion lines and an RNAi construct was created to downregulate AtGH9C2 in Arabidopsis. All of the plant lines were examined for changes in cell morphology and pattern-ing, growth and development, cell wall crystallinity, microfibril angle, and proportion of cell wall carbohydrates. Misregula-tion of PtGH9B5/AtGH9B5 resulted in changes in xylose content, while misregulation of PtGH9C2/AtGH9C2 resulted in changes in crystallinity, which was inversely correlated with changes in plant height and rosette diameter. Together, these results suggest that these endoglucanases affect secondary cell wall development by contributing to the cell wall crystallization process.

  8. Inorganic polyphosphate occurs in the cell wall of Chlamydomonas reinhardtii and accumulates during cytokinesis

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    Freimoser Florian M

    2007-09-01

    Full Text Available Abstract Background Inorganic polyphosphate (poly P, linear chains of phosphate residues linked by energy rich phosphoanhydride bonds, is found in every cell and organelle and is abundant in algae. Depending on its localization and concentration, poly P is involved in various biological functions. It serves, for example, as a phosphate store and buffer against alkali, is involved in energy metabolism and regulates the activity of enzymes. Bacteria defective in poly P synthesis are impaired in biofilm development, motility and pathogenicity. PolyP has also been found in fungal cell walls and bacterial envelopes, but has so far not been measured directly or stained specifically in the cell wall of any plant or alga. Results Here, we demonstrate the presence of poly P in the cell wall of Chlamydomonas reinhardtii by staining with specific poly P binding proteins. The specificity of the poly P signal was verified by various competition experiments, by staining with different poly P binding proteins and by correlation with biochemical quantification. Microscopical investigation at different time-points during growth revealed fluctuations of the poly P signal synchronous with the cell cycle: The poly P staining peaked during late cytokinesis and was independent of the high intracellular poly P content, which fluctuated only slightly during the cell cycle. Conclusion The presented staining method provides a specific and sensitive tool for the study of poly P in the extracellular matrices of algae and could be used to describe the dynamic behaviour of cell wall poly P during the cell cycle. We assume that cell wall poly P and intracellular poly P are regulated by distinct mechanisms and it is suggested that cell wall bound poly P might have important protective functions against toxic compounds or pathogens during cytokinesis, when cells are more vulnerable.

  9. Interactions of the cell-wall glycopolymers of lactic acid bacteria with their bacteriophages

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    Marie-Pierre eChapot-Chartier

    2014-05-01

    Full Text Available Lactic acid bacteria (LAB are Gram positive bacteria widely used in the production of fermented food in particular cheese and yoghurts. Bacteriophage infections during fermentation processes have been for many years a major industrial concern and have stimulated numerous research efforts. Better understanding of the molecular mechanisms of bacteriophage interactions with their host bacteria is required for the development of efficient strategies to fight against infections. The bacterial cell wall plays key roles in these interactions. First, bacteriophages must adsorb at the bacterial surface through specific interactions with receptors that are cell wall components. At next step, phages must overcome the barrier constituted by cell wall peptidoglycan to inject DNA inside bacterial cell. Also at the end of the infection cycle, phages synthesize endolysins able to hydrolyze peptidoglycan and lyse bacterial cells to release phage progeny. In the last decade, concomitant development of genomics and structural analysis of cell wall components allowed considerable advances in the knowledge of their structure and function in several model LAB. Here, we describe the present knowledge on the structure of the cell wall glycopolymers of the best characterized LAB emphasizing their structural variations and we present the available data regarding their role in bacteria-phage specific interactions at the different steps of the infection cycle.

  10. Characterization of Cell Wall Proteins in Saccharomyces cerevisiae Clinical Isolates Elucidates Hsp150p in Virulence.

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    Pang-Hung Hsu

    Full Text Available The budding yeast Saccharomyces cerevisiae has recently been described as an emerging opportunistic fungal pathogen. Fungal cell wall mannoproteins have been demonstrated to be involved in adhesion to inert surfaces and might be engaged in virulence. In this study, we observed four clinical isolates of S. cerevisiae with relatively hydrophobic cell surfaces. Yeast cell wall subproteome was evaluated quantitatively by liquid chromatography/tandem mass spectrometry. We identified totally 25 cell wall proteins (CWPs from log-phase cells, within which 15 CWPs were quantified. The abundance of Scw10p, Pst1p, and Hsp150p/Pir2p were at least 2 folds higher in the clinical isolates than in S288c lab strain. Hsp150p is one of the members in Pir family conserved in pathogenic fungi Candida glabrata and Candida albicans. Overexpression of Hsp150p in lab strain increased cell wall integrity and potentially enhanced the virulence of yeast. Altogether, these results demonstrated that quantitative cell wall subproteome was analyzed in clinical isolates of S. cerevisiae, and several CWPs, especially Hsp150p, were found to be expressed at higher levels which presumably contribute to strain virulence and fungal pathogenicity.

  11. Effect of marine glycosides on adenosinetriphosphatase activity.

    Science.gov (United States)

    Gorshkov, B A; Gorshkova, I A; Stonik, V A; Elyakov, G B

    1982-01-01

    Marine glycosides from the sea cucumbers Actinopyga agassizi, Holothuria atra, Bohadschia argus, Cucumaria fraudatrix, Astichopus multifidus and Thelenota ananas inhibit both Na+-K+ ATPase and Mg2+-ATPase of rat brain in vitro. The glycoside-cholesterol complex of these compounds does not influence ATPase activity. Asterosaponins from starfishes Linckia guildingi and Linckia laevigata possess a slight inhibiting effect. The triterpene glycosides from sea cucumbers are more powerful inhibitors than steroidal glycosides from starfishes.

  12. The best time of cytotoxicity for extracted cell wall from Lactobacillus casei and paracasei in K562 cell line

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    Riki M

    2013-02-01

    Full Text Available Background: The aim of this study was to evaluate the effect of extracted cell walls from Lactobacillus casei and Lactobacillus paracasei as probiotic bacteria (isolated from common carp intestine on K562 and the role of cell concentration on the results of MTT [3-(4,5-Dimethylthiazol-2-yl2,5- Diphenyl tetrazolium Bromide] test.Methods: For this purpose, bacteria were cultured in specific medium (MRS broth at anaerobic condition for 24-48 hour. After incubation period culture medium was centri-fuged, then the cells were washed twice with PBS buffer to remove additional medium. Finally, collected bacterial cell disrupted by Sonication and cell walls were separated from other components by centrifugation. After that, different concentrations of cell walls (500, 1000, 2000 and 4000 µg/ml were prepared in RPMI medium for each bacteria, separately. Then anticancer properties of the cell walls were determined in vitro at 12, 24, 48 and 72 h, also the effect of K562 concentration was assayed with MTT technique.Results: The results showed extracted cell wall from both probiotic statistically (P=0.098 have anti turmeric properties in K562 and their properties will arise in relation with concentration. As well as, we found that the number of cell had not any affect on the result of MTT assay.Conclusion: We conclude that the cytotoxicity property of extracted cell wall is related in the type of bacteria, but this anticancer property would warrant further study on the clinical application of extracted cell wall.

  13. 2009 Plant Cell Walls Gordon Research Conference-August 2-7,2009

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    Debra Mohnen

    2009-08-07

    Plant cell walls are a complex cellular compartment essential for plant growth, development and response to biotic and abiotic stress and a major biological resource for meeting our future bioenergy and natural product needs. The goal of the 2009 Plant Cell Walls Gordon Research Conference is to summarize and critically evaluate the current level of understanding of the structure, synthesis and function of the whole plant extracellular matrix, including the polysaccharides, proteins, lignin and waxes that comprise the wall, and the enzymes and regulatory proteins that drive wall synthesis and modification. Innovative techniques to study how both primary and secondary wall polymers are formed and modified throughout plant growth will be emphasized, including rapid advances taking place in the use of anti-wall antibodies and carbohydrate binding proteins, comparative and evolutionary wall genomics, and the use of mutants and natural variants to understand and identify wall structure-function relationships. Discussions of essential research advances needed to push the field forward toward a systems biology approach will be highlighted. The meeting will include a commemorative lecture in honor of the career and accomplishments of the late Emeritus Professor Bruce A. Stone, a pioneer in wall research who contributed over 40 years of outstanding studies on plant cell wall structure, function, synthesis and remodeling including emphasis on plant cell wall beta-glucans and arabinogalactans. The dwindling supply of fossil fuels will not suffice to meet our future energy and industrial product needs. Plant biomass is the renewable resource that will fill a large part of the void left by vanishing fossil fuels. It is therefore critical that basic research scientists interact closely with industrial researchers to critically evaluate the current state of knowledge regarding how plant biomass, which is largely plant cell walls, is synthesized and utilized by the plant. A final

  14. Differential actions of chlorhexidine on the cell wall of Bacillus subtilis and Escherichia coli.

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    Hon-Yeung Cheung

    Full Text Available Chlorhexidine is a chlorinated phenolic disinfectant used commonly in mouthwash for its action against bacteria. However, a comparative study of the action of chlorhexidine on the cell morphology of gram-positive and gram-negative bacteria is lacking. In this study, the actions of chlorhexidine on the cell morphology were identified with the aids of electron microscopy. After exposure to chlorhexidine, numerous spots of indentation on the cell wall were found in both Bacillus subtilis and Escherichia coli. The number of indentation spots increased with time of incubation and increasing chlorhexidine concentration. Interestingly, the dented spots found in B. subtilis appeared mainly at the hemispherical caps of the cells, while in E. coli the dented spots were found all over the cells. After being exposed to chlorhexidine for a prolonged period, leakage of cellular contents and subsequent ghost cells were observed, especially from B subtilis. By using 2-D gel/MS-MS analysis, five proteins related to purine nucleoside interconversion and metabolism were preferentially induced in the cell wall of E. coli, while three proteins related to stress response and four others in amino acid biosynthesis were up-regulated in the cell wall materials of B. subtilis. The localized morphological damages together with the biochemical and protein analysis of the chlorhexidine-treated cells suggest that chlorhexidine may act on the differentially distributed lipids in the cell membranes/wall of B. subtilis and E. coli.

  15. Human psychometric and taste receptor responses to steviol glycosides.

    Science.gov (United States)

    Hellfritsch, Caroline; Brockhoff, Anne; Stähler, Frauke; Meyerhof, Wolfgang; Hofmann, Thomas

    2012-07-11

    Steviol glycosides, the sweet principle of Stevia Rebaudiana (Bertoni) Bertoni, have recently been approved as a food additive in the EU. The herbal non-nutritive high-potency sweeteners perfectly meet the rising consumer demand for natural food ingredients in Europe. We have characterized the organoleptic properties of the most common steviol glycosides by an experimental approach combining human sensory studies and cell-based functional taste receptor expression assays. On the basis of their potency to elicit sweet and bitter taste sensations, we identified glycone chain length, pyranose substitution, and the C16 double bond as the structural features giving distinction to the gustatory profile of steviol glycosides. A comprehensive screening of 25 human bitter taste receptors revealed that two receptors, hTAS2R4 and hTAS2R14, mediate the bitter off-taste of steviol glycosides. For some test substances, e.g., stevioside, we observed a decline in sweet intensity at supra-maximum concentrations. This effect did not arise from allosteric modulation of the hTAS1R2/R3 sweet taste receptor but might be explained by intramolecular cross-modal suppression between the sweet and bitter taste component of steviol glycosides. These results might contribute to the production of preferentially sweet and least bitter tasting Stevia extracts by an optimization of breeding and postharvest downstream processing.

  16. Sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure.

    Science.gov (United States)

    Coleman, Heather D; Yan, Jimmy; Mansfield, Shawn D

    2009-08-04

    Overexpression of the Gossypium hirsutum sucrose synthase (SuSy) gene under the control of 2 promoters was examined in hybrid poplar (Populus alba x grandidentata). Analysis of RNA transcript abundance, enzyme activity, cell wall composition, and soluble carbohydrates revealed significant changes in the transgenic lines. All lines showed significantly increased SuSy enzyme activity in developing xylem. This activity manifested in altered secondary cell wall cellulose content per dry weight in all lines, with increases of 2% to 6% over control levels, without influencing plant growth. The elevated concentration of cellulose was associated with an increase in cell wall crystallinity but did not alter secondary wall microfibril angle. This finding suggests that the observed increase in crystallinity is a function of altered carbon partitioning to cellulose biosynthesis rather than the result of tension wood formation. Furthermore, the augmented deposition of cellulose in the transgenic lines resulted in thicker xylem secondary cell wall and consequently improved wood density. These findings clearly implicate SuSy as a key regulator of sink strength in poplar trees and demonstrate the tight association of SuSy with cellulose synthesis and secondary wall formation.

  17. Faster fermentation of cooked carrot cell clusters compared to cell wall fragments in vitro by porcine feces.

    Science.gov (United States)

    Day, Li; Gomez, Justine; Øiseth, Sofia K; Gidley, Michael J; Williams, Barbara A

    2012-03-28

    Plant cell walls are the major structural component of fruits and vegetables, which break down to cell wall particles during ingestion (oral mastication) or food processing. The major health-promoting effect of cell walls occurs when they reach the colon and are fermented by the gut microbiota. In this study, the fermentation kinetics of carrot cell wall particle dispersions with different particle size and microstructure were investigated in vitro using porcine feces. The cumulative gas production and short-chain fatty acids (SCFAs) produced were measured at time intervals up to 48 h. The results show that larger cell clusters with an average particle size (d(0.5)) of 298 and 137 μm were more rapidly fermented and produced more SCFAs and gas than smaller single cells (75 μm) or cell fragments (50 μm), particularly between 8 and 20 h. Confocal microscopy suggests that the junctions between cells provides an environment that promotes bacterial growth, outweighing the greater specific surface area of smaller particles as a driver for more rapid fermentation. The study demonstrates that it may be possible, by controlling the size of cell wall particles, to design plant-based foods for fiber delivery and promotion of colon fermentation to maximize the potential for human health.

  18. Structural relationships in the lysozyme superfamily: significant evidence for glycoside hydrolase signature motifs.

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    Alexandre Wohlkönig

    Full Text Available BACKGROUND: Chitin is a polysaccharide that forms the hard, outer shell of arthropods and the cell walls of fungi and some algae. Peptidoglycan is a polymer of sugars and amino acids constituting the cell walls of most bacteria. Enzymes that are able to hydrolyze these cell membrane polymers generally play important roles for protecting plants and animals against infection with insects and pathogens. A particular group of such glycoside hydrolase enzymes share some common features in their three-dimensional structure and in their molecular mechanism, forming the lysozyme superfamily. RESULTS: Besides having a similar fold, all known catalytic domains of glycoside hydrolase proteins of lysozyme superfamily (families and subfamilies GH19, GH22, GH23, GH24 and GH46 share in common two structural elements: the central helix of the all-α domain, which invariably contains the catalytic glutamate residue acting as general-acid catalyst, and a β-hairpin pointed towards the substrate binding cleft. The invariant β-hairpin structure is interestingly found to display the highest amino acid conservation in aligned sequences of a given family, thereby allowing to define signature motifs for each GH family. Most of such signature motifs are found to have promising performances for searching sequence databases. Our structural analysis further indicates that the GH motifs participate in enzymatic catalysis essentially by containing the catalytic water positioning residue of inverting mechanism. CONCLUSIONS: The seven families and subfamilies of the lysozyme superfamily all have in common a β-hairpin structure which displays a family-specific sequence motif. These GH β-hairpin motifs contain potentially important residues for the catalytic activity, thereby suggesting the participation of the GH motif to catalysis and also revealing a common catalytic scheme utilized by enzymes of the lysozyme superfamily.

  19. Early evolution of polyisoprenol biosynthesis and the origin of cell walls

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    Jonathan Lombard

    2016-10-01

    Full Text Available After being a matter of hot debate for years, the presence of lipid membranes in the last common ancestor of extant organisms (i.e., the cenancestor now begins to be generally accepted. By contrast, cenancestral cell walls have attracted less attention, probably owing to the large diversity of cell walls that exist in the three domains of life. Many prokaryotic cell walls, however, are synthesized using glycosylation pathways with similar polyisoprenol lipid carriers and topology (i.e., orientation across the cell membranes. Here, we provide the first systematic phylogenomic report on the polyisoprenol biosynthesis pathways in the three domains of life. This study shows that, whereas the last steps of the polyisoprenol biosynthesis are unique to the respective domain of life of which they are characteristic, the enzymes required for basic unsaturated polyisoprenol synthesis can be traced back to the respective last common ancestor of each of the three domains of life. As a result, regardless of the topology of the tree of life that may be considered, the most parsimonious hypothesis is that these enzymes were inherited in modern lineages from the cenancestor. This observation supports the presence of an enzymatic mechanism to synthesize unsaturated polyisoprenols in the cenancestor and, since these molecules are notorious lipid carriers in glycosylation pathways involved in the synthesis of a wide diversity of prokaryotic cell walls, it provides the first indirect evidence of the existence of a hypothetical unknown cell wall synthesis mechanism in the cenancestor.

  20. Early evolution of polyisoprenol biosynthesis and the origin of cell walls

    Science.gov (United States)

    2016-01-01

    After being a matter of hot debate for years, the presence of lipid membranes in the last common ancestor of extant organisms (i.e., the cenancestor) now begins to be generally accepted. By contrast, cenancestral cell walls have attracted less attention, probably owing to the large diversity of cell walls that exist in the three domains of life. Many prokaryotic cell walls, however, are synthesized using glycosylation pathways with similar polyisoprenol lipid carriers and topology (i.e., orientation across the cell membranes). Here, we provide the first systematic phylogenomic report on the polyisoprenol biosynthesis pathways in the three domains of life. This study shows that, whereas the last steps of the polyisoprenol biosynthesis are unique to the respective domain of life of which they are characteristic, the enzymes required for basic unsaturated polyisoprenol synthesis can be traced back to the respective last common ancestor of each of the three domains of life. As a result, regardless of the topology of the tree of life that may be considered, the most parsimonious hypothesis is that these enzymes were inherited in modern lineages from the cenancestor. This observation supports the presence of an enzymatic mechanism to synthesize unsaturated polyisoprenols in the cenancestor and, since these molecules are notorious lipid carriers in glycosylation pathways involved in the synthesis of a wide diversity of prokaryotic cell walls, it provides the first indirect evidence of the existence of a hypothetical unknown cell wall synthesis mechanism in the cenancestor.

  1. Early evolution of polyisoprenol biosynthesis and the origin of cell walls.

    Science.gov (United States)

    Lombard, Jonathan

    2016-01-01

    After being a matter of hot debate for years, the presence of lipid membranes in the last common ancestor of extant organisms (i.e., the cenancestor) now begins to be generally accepted. By contrast, cenancestral cell walls have attracted less attention, probably owing to the large diversity of cell walls that exist in the three domains of life. Many prokaryotic cell walls, however, are synthesized using glycosylation pathways with similar polyisoprenol lipid carriers and topology (i.e., orientation across the cell membranes). Here, we provide the first systematic phylogenomic report on the polyisoprenol biosynthesis pathways in the three domains of life. This study shows that, whereas the last steps of the polyisoprenol biosynthesis are unique to the respective domain of life of which they are characteristic, the enzymes required for basic unsaturated polyisoprenol synthesis can be traced back to the respective last common ancestor of each of the three domains of life. As a result, regardless of the topology of the tree of life that may be considered, the most parsimonious hypothesis is that these enzymes were inherited in modern lineages from the cenancestor. This observation supports the presence of an enzymatic mechanism to synthesize unsaturated polyisoprenols in the cenancestor and, since these molecules are notorious lipid carriers in glycosylation pathways involved in the synthesis of a wide diversity of prokaryotic cell walls, it provides the first indirect evidence of the existence of a hypothetical unknown cell wall synthesis mechanism in the cenancestor.

  2. Cell wall alterations in the leaves of fusariosis-resistant and susceptible pineapple cultivars.

    Science.gov (United States)

    de Farias Viégas Aquije, Glória Maria; Zorzal, Poliana Belisário; Buss, David Shaun; Ventura, José Aires; Fernandes, Patricia Machado Bueno; Fernandes, Antonio Alberto Ribeiro

    2010-10-01

    Fusariosis, caused by the fungus Fusarium subglutinans f. sp. ananas (Syn. F. guttiforme), is one of the main phytosanitary threats to pineapple (Ananas comosus var. comosus). Identification of plant cell responses to pathogens is important in understanding the plant-pathogen relationship and establishing strategies to improve and select resistant cultivars. Studies of the structural properties and phenolic content of cell walls in resistant (Vitoria) and susceptible (Perola) pineapple cultivars, related to resistance to the fungus, were performed. The non-chlorophyll base of physiologically mature leaves was inoculated with a conidia suspension. Analyses were performed post-inoculation by light, atomic force, scanning and transmission electron microscopy, and measurement of cell wall-bound phenolic compounds. Non-inoculated leaves were used as controls to define the constitutive tissue characteristics. Analyses indicated that morphological differences, such as cell wall thickness, cicatrization process and lignification, were related to resistance to the pathogen. Atomic force microscopy indicated a considerable difference in the mechanical properties of the resistant and susceptible cultivars, with more structural integrity, associated with higher levels of cell wall-bound phenolics, found in the resistant cultivar. p-Coumaric and ferulic acids were shown to be the major phenolics bound to the cell walls and were found in higher amounts in the resistant cultivar. Leaves of the resistant cultivar had reduced fungal penetration and a faster and more effective cicatrization response compared to the susceptible cultivar.

  3. Demonstration of pectic polysaccharides in cork cell wall from Quercus suber L.

    Science.gov (United States)

    Rocha, S M; Coimbra, M A; Delgadillo, I

    2000-06-01

    Scanning electron microscopy (SEM) and chemical analysis were used to observe the cell wall changes that occur in cork with "mancha amarela", when compared to a standard cork. To mimic the microbial attack exhibited in cork with mancha amarela, the standard cork was treated enzymatically with commercial pectinase and hemicellulase preparations. The tissues treated with pectinase were comparable with those attacked with mancha amarela. Both were composed by deformed and wrinkly cells and exhibited cell wall separation at the middle lamella level, which suggests solubilization/removal of the pectic polysaccharides. The cork cell wall material, prepared as alcohol-insoluble residue, was fractionated by hot water (Pect(H)()2(O)) and hot dilute acid (Pect(acid)). The relatively large amount of hexuronic acid and the occurrence of Ara in the SPect(H)()2(O) and SPect(acid) allow to confirm, as far as we know, for the first time the presence of pectic polysaccharides in the cell walls of cork from Quercus suber L. They accounted for ca. 1.5% of the cork and may consist of polymers with long side chains of arabinosyl residues. These polymers have to be taken into account in any realistic model of the cork cell wall. Cork with mancha amarela contained a smaller amount of pectic polysaccharides (ca. 0.5%), which confirms that the cellular separation observed by SEM is related to the degradation/removal of the middle lamella pectic polysaccharides.

  4. Aleurone Cell Walls of Wheat Grain: High Spatial Resolution Investigation Using Synchrotron Infrared Microspectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jamme, F.; Robert, R; Bouchet, B; Saulnier, L; Dumas, P; Guillon, F

    2008-01-01

    Infrared microspectroscopy and immunolabeling techniques were employed in order to obtain deeper insight into the biochemical nature of aleurone cell walls of wheat grain. The use of a synchrotron source, thanks to its intrinsic brightness, has provided unprecedented information at the level of a few micrometers and has allowed the discrimination of various polysaccharides in cell walls. The high spectral quality obtained in the small analyzed domain has been beneficial in estimating the relative proportions of {Beta}-glucan and arabinoxylan, through the use of principal component analysis (PCA). The highest amount of {Beta}-glucan is found in periclinal cell walls close to the starchy endosperm. The junction regions between aleurone cells are enriched in arabinoxylan. At the early stage of wheat grain development (271 degrees D), the chemical composition along the cell walls is more heterogeneous than at the mature stage. Both synchrotron infrared microspectroscopy and immunolabeling experiments made it possible to reveal the spatial heterogeneity of the various chemical compositions of aleurone cell walls.

  5. [Revealing the chemical changes of tea cell wall induced by anthracnose with confocal Raman microscopy].

    Science.gov (United States)

    Li, Xiao-li; Luo, Liu-bin; Hu, Xiao-qian; Lou, Bing-gan; He, Yong

    2014-06-01

    Healthy tea and tea infected by anthracnose were first studied by confocal Raman microscopy to illustrate chemical changes of cell wall in the present paper. Firstly, Raman spectra of both healthy and infected sample tissues were collected with spatial resolution at micron-level, and ultrastructure of healthy and infected tea cells was got from scanning electron microscope. These results showed that there were significant changes in Raman shift and Raman intensity between healthy and infected cell walls, indicating that great differences occurred in chemical compositions of cell walls between healthy and infected samples. In details, intensities at many Raman bands which were closely associated with cellulose, pectin, esters were reduced after infection, revealing that the content of chemical compounds such as cellulose, pectin, esters was decreased after infection. Subsequently, chemical imaging of both healthy and infected tea cell walls were realized based on Raman fingerprint spectra of cellulose and microscopic spatial structure. It was found that not only the content of cellulose was reduced greatly after infection, but also the ordered structure of cellulose was destroyed by anthracnose infection. Thus, confocal Raman microscopy was shown to be a powerful tool to detect the chemical changes in cell wall of tea caused by anthracnose without any chemical treatment or staining. This research firstly applied confocal Raman microscopy in phytopathology for the study of interactive relationship between host and pathogen, and it will also open a new way for intensive study of host-pathogen at cellular level.

  6. Metabolic changes in elicitor-treated bean cells. Enzymic responses associated with rapid changes in cell wall components.

    Science.gov (United States)

    Bolwell, G P; Robbins, M P; Dixon, R A

    1985-05-02

    Treatment of cell suspension cultures of bean (Phaseolus vulgaris c.v. Immuna) with an elicitor preparation heat-released from the cell walls of the phytopathogenic fungus Colletotrichum lindemuthianum resulted in rapid changes in the composition of the bean cell walls. These consisted of (a) increases in phenolic material bound to the cellulosic and hemicellulosic fractions of the wall, (b) loss of material (mainly glucose) from the hemicellulosic fraction and (c) an increase in wall-associated hydroxyproline. The increases in wall-bound phenolics were preceded by (a) rapid decreases in the intracellular levels of free hydroxycinnamic acids and (b) transient increases in the extractable activities of L-phenylalanine ammonia-lyase and cinnamic acid 4-hydroxylase. 4-Hydroxycinnamic acid 3-hydroxylase activity was present at a high level in control cultures and was not induced by elicitor. Changes in the levels of cytochrome P-450, as determined by dot blot assays utilising an anti-(P-450) monoclonal antibody, paralleled the changes in cinnamic acid 4-hydroxylase activity. The accumulation of cell wall hydroxyproline was associated with rapid transient increases in the extractable activities of proline 2-oxoglutarate dioxygenase and a protein arabinosyl transferase. An hydroxyproline-rich acceptor protein of Mr 42 500 was the major protein to incorporate [3H]arabinose following elicitation of the bean cells, and the kinetics of the extent of labelling of this protein paralleled the accumulation of hydroxyproline protein in the endomembrane system. The above metabolic changes associated with cell wall components followed rapid kinetics similar to those involved in the formation of the phytoalexin kievitone in the elicited cultures [Robbins, M. P. et al. (1985) Eur. J. Biochem. 148, 563-569]. It is therefore concluded that increased 5-hydroxy-substituted isoflavonoid biosynthesis, wall-bound phenolic synthesis and synthesis of arabinosylated hydroxyproline-rich protein

  7. Xyloglucan oligosaccharides cause cell wall loosening by enhancing xyloglucan endotransglucosylase/hydrolase activity in azuki bean epicotyls.

    Science.gov (United States)

    Kaku, Tomomi; Tabuchi, Akira; Wakabayashi, Kazuyuki; Hoson, Takayuki

    2004-01-01

    Addition of xyloglucan-derived oligosaccharides shifted the wall-bound xyloglucans to a lower molecular mass distribution and increased the cell wall extensibility of the native epidermal tissue strips isolated from azuki bean (Vigna angularis) epicotyls. To ascertain the mechanism of oligosaccharide function, we examined the action of a xyloglucan endotransglucosylase/hydrolase (XTH) showing both endotransglucosylase and endohydrolase activities, isolated from azuki bean epicotyl cell walls, in the presence of xyloglucan oligosaccharides. The addition of xyloglucan oligosaccharides enhanced the xyloglucan-degrading activity of XTH against isolated xyloglucan substrates. When the methanol-fixed epidermal tissue strips were incubated with XTH, the molecular mass of wall-bound xyloglucans was decreased and the cell wall extensibility increased markedly in the presence of the oligosaccharides. These results suggest that xyloglucan oligosaccharides stimulate the degradation of xyloglucans by enhancing the XTH activity within the cell wall architecture, thereby increasing the cell wall extensibility in azuki bean epicotyls.

  8. We’re good to grow: Dynamic integration of cell wall architecture with the machinery of growth

    Directory of Open Access Journals (Sweden)

    Matheus R Benatti

    2012-08-01

    Full Text Available Despite differences in cell wall composition between the type I cell walls of dicots and most monocots and the type II walls of commelinid monocots, all flowering plants respond to the same classes of growth regulators in the same tissue-specific way and exhibit the same growth physics. Substantial progress has been made in defining gene families and identifying mutants in cell wall-related genes, but our understanding of the biochemical basis of wall extensibility during growth is still rudimentary. In this review, we highlight insights into the physiological control of cell expansion emerging from genetic functional analyses, mostly in Arabidopsis and other dicots, and a few examples of genes of potential orthologous function in grass species. We discuss examples of cell wall architectural features that impact growth independent of composition, and progress in identifying proteins involved in transduction of growth signals and integrating their outputs in the molecular machinery of wall expansion.

  9. Atkinesin-13A modulates cell-wall synthesis and cell expansion in Arabidopsis thaliana via the THESEUS1 pathway.

    Directory of Open Access Journals (Sweden)

    Ushio Fujikura

    2014-09-01

    Full Text Available Growth of plant organs relies on cell proliferation and expansion. While an increasingly detailed picture about the control of cell proliferation is emerging, our knowledge about the control of cell expansion remains more limited. We demonstrate here that the internal-motor kinesin AtKINESIN-13A (AtKIN13A limits cell expansion and cell size in Arabidopsis thaliana, with loss-of-function atkin13a mutants forming larger petals with larger cells. The homolog, AtKINESIN-13B, also affects cell expansion and double mutants display growth, gametophytic and early embryonic defects, indicating a redundant role of the two genes. AtKIN13A is known to depolymerize microtubules and influence Golgi motility and distribution. Consistent with this function, AtKIN13A interacts genetically with ANGUSTIFOLIA, encoding a regulator of Golgi dynamics. Reduced AtKIN13A activity alters cell wall structure as assessed by Fourier-transformed infrared-spectroscopy and triggers signalling via the THESEUS1-dependent cell-wall integrity pathway, which in turn promotes the excess cell expansion in the atkin13a mutant. Thus, our results indicate that the intracellular activity of AtKIN13A regulates cell expansion and wall architecture via THESEUS1, providing a compelling case of interplay between cell wall integrity sensing and expansion.

  10. Strong adhesion of Saos-2 cells to multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Makoto, E-mail: matsuoka@den.hokudai.ac.jp [Department of Oral and Maxillofacial Surgery, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Akasaka, Tsukasa [Department of Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Totsuka, Yasunori [Department of Oral and Maxillofacial Surgery, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Watari, Fumio [Department of Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan)

    2010-10-15

    In recent years, carbon nanotubes (CNTs) have been considered potential biomedical materials because of their unique character. The aim of this study was to investigate the response of a human osteoblast-like cell line - Saos-2 - on single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs). The surface of a culture dish was coated with CNTs, and Saos-2 cells were cultured for three days. Cell morphology, viability, alkaline phosphatase (ALP) activity, adhesion, and vinculin expression were evaluated. The result showed high cell viability and strong adhesion to MWCNTs. Saos-2 cultured on MWCNTs exhibited vinculin expression throughout the cell body, while the cells attached to SWCNTs and glass were mostly limited to their periphery. Our results suggest that CNT coatings promote cell activity and adhesiveness. These findings indicate that MWCNTs could be used as surface coating materials to promote cell adhesion.

  11. Inhibition of Nuclear Transcription Factor-κB and Activation of Peroxisome Proliferator-Activated Receptors in HepG2 Cells by Cucurbitane-Type Triterpene Glycosides from Momordica charantia

    Science.gov (United States)

    Nhiem, Nguyen Xuan; Yen, Pham Hai; Ngan, Nguyen Thi Thanh; Quang, Tran Hong; Kiem, Phan Van; Minh, Chau Van; Tai, Bui Huu; Cuong, Nguyen Xuan; Song, Seok Bean

    2012-01-01

    Abstract Momordica charantia: is used to treat various diseases, including inflammatory conditions. Previous reports indicated that the extract of this plant inhibits activation of nuclear transcription factor-κB (NF-κB) but activates peroxisome proliferator-activated receptor (PPAR). Additionally, cucurbitane-type triterpene glycosides are the main bioactive components of the fruit of M. charantia. Therefore, we investigated the anti-inflammatory activity of 17 cucurbitane-type triterpene glycosides (1–17) isolated from this plant. Their inhibition of NF-κB and activation of PPAR activities in HepG2 cells were measured using luciferase reporter and PPAR subtype transactivation assays. Compounds 6 and 8 were found to inhibit NF-κB activation stimulated by tumor necrosis factor-α (TNFα) in a dose-dependent manner. With 50% inhibition concentration (IC50) values of 0.4 μM, compounds 6 and 8 were more potent inhibitors than the positive control, sulfasalazine (IC50=0.9 μM). Compounds 4, 6, and 8 also inhibited TNFα-induced expressions of inducible nitric oxide synthase and cyclooxygenase-2 mRNA. However, only compound 13 significantly increased PPARγ transactivation. PMID:22248180

  12. Inhibition of nuclear transcription factor-κB and activation of peroxisome proliferator-activated receptors in HepG2 cells by cucurbitane-type triterpene glycosides from Momordica charantia.

    Science.gov (United States)

    Nhiem, Nguyen Xuan; Yen, Pham Hai; Ngan, Nguyen Thi Thanh; Quang, Tran Hong; Kiem, Phan Van; Minh, Chau Van; Tai, Bui Huu; Cuong, Nguyen Xuan; Song, Seok Bean; Kim, Young Ho

    2012-04-01

    Momordica charantia is used to treat various diseases, including inflammatory conditions. Previous reports indicated that the extract of this plant inhibits activation of nuclear transcription factor-κB (NF-κB) but activates peroxisome proliferator-activated receptor (PPAR). Additionally, cucurbitane-type triterpene glycosides are the main bioactive components of the fruit of M. charantia. Therefore, we investigated the anti-inflammatory activity of 17 cucurbitane-type triterpene glycosides (1-17) isolated from this plant. Their inhibition of NF-κB and activation of PPAR activities in HepG2 cells were measured using luciferase reporter and PPAR subtype transactivation assays. Compounds 6 and 8 were found to inhibit NF-κB activation stimulated by tumor necrosis factor-α (TNFα) in a dose-dependent manner. With 50% inhibition concentration (IC(50)) values of 0.4 μM, compounds 6 and 8 were more potent inhibitors than the positive control, sulfasalazine (IC(50)=0.9 μM). Compounds 4, 6, and 8 also inhibited TNFα-induced expressions of inducible nitric oxide synthase and cyclooxygenase-2 mRNA. However, only compound 13 significantly increased PPARγ transactivation.

  13. Plant cell wall-degrading enzymes and their secretion in plant-pathogenic fungi.

    Science.gov (United States)

    Kubicek, Christian P; Starr, Trevor L; Glass, N Louise

    2014-01-01

    Approximately a tenth of all described fungal species can cause diseases in plants. A common feature of this process is the necessity to pass through the plant cell wall, an important barrier against pathogen attack. To this end, fungi possess a diverse array of secreted enzymes to depolymerize the main structural polysaccharide components of the plant cell wall, i.e., cellulose, hemicellulose, and pectin. Recent advances in genomic and systems-level studies have begun to unravel this diversity and have pinpointed cell wall-degrading enzyme (CWDE) families that are specifically present or enhanced in plant-pathogenic fungi. In this review, we discuss differences between the CWDE arsenal of plant-pathogenic and non-plant-pathogenic fungi, highlight the importance of individual enzyme families for pathogenesis, illustrate the secretory pathway that transports CWDEs out of the fungal cell, and report the transcriptional regulation of expression of CWDE genes in both saprophytic and phytopathogenic fungi.

  14. The innate immune protein Nod2 binds directly to MDP, a bacterial cell wall fragment.

    Science.gov (United States)

    Grimes, Catherine Leimkuhler; Ariyananda, Lushanti De Zoysa; Melnyk, James E; O'Shea, Erin K

    2012-08-22

    Mammalian Nod2 is an intracellular protein that is implicated in the innate immune response to the bacterial cell wall and is associated with the development of Crohn's disease, Blau syndrome, and gastrointestinal cancers. Nod2 is required for an immune response to muramyl dipeptide (MDP), an immunostimulatory fragment of bacterial cell wall, but it is not known whether MDP binds directly to Nod2. We report the expression and purification of human Nod2 from insect cells. Using novel MDP self-assembled monolayers (SAMs), we provide the first biochemical evidence for a direct, high-affinity interaction between Nod2 and MDP.

  15. Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

    Energy Technology Data Exchange (ETDEWEB)

    Allgaier, M.; Reddy, A.; Park, J. I.; Ivanova, N.; D' haeseleer, P.; Lowry, S.; Sapra, R.; Hazen, T.C.; Simmons, B.A.; VanderGheynst, J. S.; Hugenholtz, P.

    2009-11-15

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  16. Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Amitha; Allgaier, Martin; Park, Joshua I.; Ivanoval, Natalia; Dhaeseleer, Patrik; Lowry, Steve; Sapra, Rajat; Hazen, Terry C.; Simmons, Blake A.; VanderGheynst, Jean S.; Hugenholtz, Philip

    2011-05-11

    Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence data from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.

  17. Development of a High Throughput Platform for Screening Glycoside Hydrolases Based on Oxime-NIMS

    Science.gov (United States)

    Deng, Kai; Guenther, Joel M.; Gao, Jian; Bowen, Benjamin P.; Tran, Huu; Reyes-Ortiz, Vimalier; Cheng, Xiaoliang; Sathitsuksanoh, Noppadon; Heins, Richard; Takasuka, Taichi E.; Bergeman, Lai F.; Geertz-Hansen, Henrik; Deutsch, Samuel; Loqué, Dominique; Sale, Kenneth L.; Simmons, Blake A.; Adams, Paul D.; Singh, Anup K.; Fox, Brian G.; Northen, Trent R.

    2015-01-01

    Cost-effective hydrolysis of biomass into sugars for biofuel production requires high-performance low-cost glycoside hydrolase (GH) cocktails that are active under demanding process conditions. Improving the performance of GH cocktails depends on knowledge of many critical parameters, including individual enzyme stabilities, optimal reaction conditions, kinetics, and specificity of reaction. With this information, rate- and/or yield-limiting reactions can be potentially improved through substitution, synergistic complementation, or protein engineering. Given the wide range of substrates and methods used for GH characterization, it is difficult to compare results across a myriad of approaches to identify high performance and synergistic combinations of enzymes. Here, we describe a platform for systematic screening of GH activities using automatic biomass handling, bioconjugate chemistry, robotic liquid handling, and nanostructure-initiator mass spectrometry (NIMS). Twelve well-characterized substrates spanning the types of glycosidic linkages found in plant cell walls are included in the experimental workflow. To test the application of this platform and substrate panel, we studied the reactivity of three engineered cellulases and their synergy of combination across a range of reaction conditions and enzyme concentrations. We anticipate that large-scale screening using the standardized platform and substrates will generate critical datasets to enable direct comparison of enzyme activities for cocktail design. PMID:26528471

  18. Swelling of root cell walls as an indicator of their functional state.

    Science.gov (United States)

    Meychik, N R; Yermakov, I P

    2001-02-01

    The swelling capacity of cell walls isolated from different parts of lupine root was investigated. The water content in fragments of intact roots (Q) and swelling coefficient of standardized samples of cell walls (Kcw) were determined, and the dependences of Q and Kcw on the distance from the root tip (L) were plotted. It was shown that the change in Q value along the stretch of the lupine root reaches its maximum at distances of 1.5-6 cm or 7-12 cm from the root tip in 7-day-old and 14-day-old seedlings, respectively, whereas the Kcw value distribution over the root length is virtually invariable. In the radial direction, both the Q and Kcw values in cortex tissues are about twice higher than in the central cylinder. In our opinion, the changes of both Q and Kcw in the radial direction are associated with different degrees of cross-linking between polymer chains in cell wall structures of root cortex and central cylinder. The results of measurement of the Kcw value are consistent with the widely accepted mechanisms of water transport in roots in the radial direction. These data show that water transport through apoplast to the border between the cortex and central cylinder is accompanied by an increase in the resistance to water flow. Among other factors, this increase is due to a greater degree of cross-linking between cell wall polymers in the central cylinder. The results of measurement of the swelling coefficient of standardized cell wall samples in water and in 10 mM KCl at different pH values show that the swelling capacity of root cell walls varies according to the physicochemical properties of synthetic ion exchangers. Cell walls shrink (cell wall volume decreases) as ion concentration in solution increases and pH decreases. This causes an increase in the hydraulic resistance (or a decrease in the hydraulic conductivity) of apoplast. It was concluded that swelling is determined by the physicochemical properties of the cell wall, whereas the change in the

  19. TRITERPENE GLYCOSIDE FROM TERMINALIA ARJUNA

    Institute of Scientific and Technical Information of China (English)

    R. K. UPADHYAY; M. B. PANDEY; R. N. JHA; V. P. SINGH; V. B. PANDEY

    2001-01-01

    A new triterpene glycoside, arjunetoside, together with oleanolic and arjunic acids has been isolated from the root bark of Terminalia arjuna. The structure of arjunetoside has been established as 3-O-β-D-glucopyranosyl-2α,3β, 19α-trihydroxyolean-12-en-28-oic acid, 28-O-β-D-glucopyranoside by chemical and spectral data.

  20. Neolignan glycoside from Angelica dahurica

    Institute of Scientific and Technical Information of China (English)

    Xing Zeng Zhao; Xu Feng; Xiao Dong Jia; Yun Fa Dong; Ming Wang

    2007-01-01

    A new neolignan glycoside, 4-O-β-D-glucopyranosyl-9-O-β-D-glucopyranosyl-(7R, 8S)-dehydrodiconiferyl alcohol was isolated from the fresh roots of Angelica dahurica. The structure of the new compound was elucidated on the basis of spectral analysis.

  1. Al-induced root cell wall chemical components differences of wheat ...

    African Journals Online (AJOL)

    Jane

    2011-07-13

    Jul 13, 2011 ... Environment, Ministry of Agriculture, Department of Plant Nutrition, ... in cell wall chemical components of root tip cell between wheat lines with different Al tolerances induce ..... the highly significant interaction between cultivar × con- .... formation is a sensitive marker for genotypic aluminium sensitivity in.

  2. Positive role of cell wall anchored proteinase PrtP in adhesion of lactococci

    NARCIS (Netherlands)

    Habimana, Olivier; Le Goff, Carine; Juillard, Vincent; Bellon-Fontaine, Marie-Noelle; Buist, Girbe; Kulakauskas, Saulius; Briandet, Romain

    2007-01-01

    Background: The first step in biofilm formation is bacterial attachment to solid surfaces, which is dependent on the cell surface physico-chemical properties. Cell wall anchored proteins (CWAP) are among the known adhesins that confer the adhesive properties to pathogenic Gram-positive bacteria. To

  3. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Science.gov (United States)

    Yuan, Hengguang; Hu, Shanglian; Huang, Peng; Song, Hua; Wang, Kan; Ruan, Jing; He, Rong; Cui, Daxiang

    2011-12-01

    Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  4. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    Directory of Open Access Journals (Sweden)

    Huang Peng

    2011-01-01

    Full Text Available Abstract Herein we are the first to report that single-walled carbon nanotubes (SWCNTs exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  5. Hydroxycinnamate Conjugates as Potential Monolignol Replacements: In vitro Lignification and Cell Wall Studies with Rosmarinic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Yuki, Tobimatsu; Sasikumar, Elumalai; Grabber, John H.; Davidson, Christy L.; Xuejun, Pan; John, Ralph

    2012-04-01

    The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers, such as rosmarinic acid (RA) and analogous catechol derivatives, into cell-wall lignins that are consequently less recalcitrant to biomass processing. In vitro lignin polymerization experiments revealed that RA readily underwent peroxidase-catalyzed copolymerization with monolignols and lignin oligomers to form polymers with new benzodioxane inter-unit linkages. Incorporation of RA permitted extensive depolymerization of synthetic lignins by mild alkaline hydrolysis, presumably by cleavage of ester intra-unit linkages within RA. Copolymerization of RA with monolignols into maize cell walls by in situ peroxidases significantly enhanced alkaline lignin extractability and promoted subsequent cell wall saccharification by fungal enzymes. Incorporating RA also improved cell wall saccharification by fungal enzymes and by rumen microflora even without alkaline pretreatments, possibly by modulating lignin hydrophobicity and/or limiting cell wall cross-linking. Consequently, we anticipate that bioengineering approaches for partial monolignol substitution with RA and analogous plant hydroxycinnamates would permit more efficient utilization of plant fiber for biofuels or livestock production.

  6. Detection of Cell Wall Chemical Variation in Zea Mays Mutants Using Near-Infrared Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Buyck, N.; Thomas, S.

    2001-01-01

    Corn stover is regarded as the prime candidate feedstock material for commercial biomass conversion in the United States. Variations in chemical composition of Zea mays cell walls can affect biomass conversion process yields and economics. Mutant lines were constructed by activating a Mu transposon system. The cell wall chemical composition of 48 mutant families was characterized using near-infrared (NIR) spectroscopy. NIR data were analyzed using a multivariate statistical analysis technique called Principal Component Analysis (PCA). PCA of the NIR data from 349 maize leaf samples reveals 57 individuals as outliers on one or more of six Principal Components (PCs) at the 95% confidence interval. Of these, 19 individuals from 16 families are outliers on either PC3 (9% of the variation) or PC6 (1% of the variation), the two PCs that contain information about cell wall polymers. Those individuals for which altered cell wall chemistry is confirmed with wet chemical analysis will then be subjected to fermentation analysis to determine whether or not biomass conversion process kinetics, yields and/or economics are significantly affected. Those mutants that provide indications for a decrease in process cost will be pursued further to identify the gene(s) responsible for the observed changes in cell wall composition and associated changes in process economics. These genes will eventually be incorporated into maize breeding programs directed at the development of a truly dual use crop.

  7. Systems and synthetic biology approaches to alter plant cell walls and reduce biomass recalcitrance.

    Science.gov (United States)

    Kalluri, Udaya C; Yin, Hengfu; Yang, Xiaohan; Davison, Brian H

    2014-12-01

    Fine-tuning plant cell wall properties to render plant biomass more amenable to biofuel conversion is a colossal challenge. A deep knowledge of the biosynthesis and regulation of plant cell wall and a high-precision genome engineering toolset are the two essential pillars of efforts to alter plant cell walls and reduce biomass recalcitrance. The past decade has seen a meteoric rise in use of transcriptomics and high-resolution imaging methods resulting in fresh insights into composition, structure, formation and deconstruction of plant cell walls. Subsequent gene manipulation approaches, however, commonly include ubiquitous mis-expression of a single candidate gene in a host that carries an intact copy of the native gene. The challenges posed by pleiotropic and unintended changes resulting from such an approach are moving the field towards synthetic biology approaches. Synthetic biology builds on a systems biology knowledge base and leverages high-precision tools for high-throughput assembly of multigene constructs and pathways, precision genome editing and site-specific gene stacking, silencing and/or removal. Here, we summarize the recent breakthroughs in biosynthesis and remodelling of major secondary cell wall components, assess the impediments in obtaining a systems-level understanding and explore the potential opportunities in leveraging synthetic biology approaches to reduce biomass recalcitrance. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Gene Mining for Proline Based Signaling Proteins in Cell Wall of Arabidopsis thaliana

    Science.gov (United States)

    Ihsan, Muhammad Z.; Ahmad, Samina J. N.; Shah, Zahid Hussain; Rehman, Hafiz M.; Aslam, Zubair; Ahuja, Ishita; Bones, Atle M.; Ahmad, Jam N.

    2017-01-01

    The cell wall (CW) as a first line of defense against biotic and abiotic stresses is of primary importance in plant biology. The proteins associated with cell walls play a significant role in determining a plant's sustainability to adverse environmental conditions. In this work, the genes encoding cell wall proteins (CWPs) in Arabidopsis were identified and functionally classified using geneMANIA and GENEVESTIGATOR with published microarrays data. This yielded 1605 genes, out of which 58 genes encoded proline-rich proteins (PRPs) and glycine-rich proteins (GRPs). Here, we have focused on the cellular compartmentalization, biological processes, and molecular functioning of proline-rich CWPs along with their expression at different plant developmental stages. The mined genes were categorized into five classes on the basis of the type of PRPs encoded in the cell wall of Arabidopsis thaliana. We review the domain structure and function of each class of protein, many with respect to the developmental stages of the plant. We have then used networks, hierarchical clustering and correlations to analyze co-expression, co-localization, genetic, and physical interactions and shared protein domains of these PRPs. This has given us further insight into these functionally important CWPs and identified a number of potentially new cell-wall related proteins in A. thaliana. PMID:28289422

  9. Zinc adsorption and desorption characteristics in root cell wall involving zinc hyperaccumulation in Sedum alfredii Hance.

    Science.gov (United States)

    Li, Ting-qiang; Yang, Xiao-e; Meng, Fan-hua; Lu, Ling-li

    2007-02-01

    Radiotracer techniques were employed to characterize (65)Zn adsorption and desorption in root-cell-wall of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) species of Sedum alfredii Hance. The results indicated that at the end of a 30 min short time radioisotope loading period, comparable amounts of (65)Zn were accumulated in the roots of the two ecotypes Sedum alfredii, whereas 2.1-fold more (65)Zn remains in NHE root after 45-min desorption. At the end of 60 min uptake period, no difference of (65)Zn accumulation was observed in undesorbed root-cell-wall of Sedum alfredii. However, 3.0-fold more (65)Zn accumulated in desorbed root-cell-wall of NHE. Zn(2+) binding in root-cell-wall preparations of NHE was greater than that in HE under high Zn(2+) concentration. All these results suggested that root-cell-wall of the two ecotypes Sedum alfredii had the same ability to adsorb Zn(2+), whereas the desorption characteristics were different, and with most of (65)Zn binding on root of HE being available for loading into the xylem, as a result, more (65)Zn was translocated to the shoot.

  10. WD40-repeat proteins in plant cell wall formation: current evidence and research prospects

    Directory of Open Access Journals (Sweden)

    Gea eGuerriero

    2015-12-01

    Full Text Available The metabolic complexity of living organisms relies on supramolecular protein structures which ensure vital processes, such as signal transduction, transcription, translation and cell wall synthesis. In eukaryotes WD40-repeat (WDR proteins often function as molecular hubs mediating supramolecular interactions. WDR proteins may display a variety of interacting partners and participate in the assembly of complexes involved in distinct cellular functions. In plants, the formation of lignocellulosic biomass involves extensive synthesis of cell wall polysaccharides, a process that requires the assembly of large transmembrane enzyme complexes, intensive vesicle trafficking, interactions with the cytoskeleton, and coordinated gene expression. Because of their function as supramolecular hubs, WDR proteins could participate in each or any of these steps, although to date only few WDR proteins have been linked to the cell wall by experimental evidence. Nevertheless, several potential cell wall-related WDR proteins were recently identified using in silico aproaches, such as analyses of co-expression, interactome and conserved gene neighbourhood. Notably, some WDR genes are frequently genomic neighbours of genes coding for GT2-family polysaccharide synthases in eukaryotes, and this WDR-GT2 collinear microsynteny is detected in diverse taxa. In angiosperms, two WDR genes are collinear to cellulose synthase genes, CESAs, whereas in ascomycetous fungi several WDR genes are adjacent to chitin synthase genes, chs. In this Perspective we summarize and discuss experimental and in silico studies on the possible involvement of WDR proteins in plant cell wall formation. The prospects of biotechnological engineering for enhanced biomass production are discussed.

  11. Effects of hypergravity on growth and cell wall properties of cress hypocotyls.

    Science.gov (United States)

    Hoson, T; Nishitani, K; Miyamoto, K; Ueda, J; Kamisaka, S; Yamamoto, R; Masuda, Y

    1996-04-01

    Elongation growth of etiolated hypocotyls of cress (Lepidium sativum L.) was suppressed when they were exposed to basipetal hypergravity at 35 x g and above. Acceleration at 135 x g caused a decrease in the mechanical extensibility and an increase in the minimum stress-relaxation time of the cell wall. Such changes in the mechanical properties of the cell wall were prominent in the lower regions of hypocotyls. The amounts of cell wall polysaccharides per unit length of hypocotyls increased under the hypergravity condition and, in particular, the increase in the amount of cellulose in the lower regions was conspicuous. Hypergravity did not influence the neutral sugar composition of either the pectin or the hemicellulose fraction. The amount of lignin was also increased by hypergravity treatment, although the level was low. The data suggest that hypergravity modifies the metabolism of cell wall components and thus makes the cell wall thick and rigid, thereby inhibiting elongation growth of cress hypocotyls. These changes may contribute to the plants' ability to sustain their structures against hypergravity.

  12. The bulk elastic modulus and the reversible properties of cell walls in developing Quercus leaves.

    Science.gov (United States)

    Saito, Takami; Soga, Kouichi; Hoson, Takayuki; Terashima, Ichiro

    2006-06-01

    We examined the relationship between the bulk elastic modulus (epsilon) of an individual leaf obtained by the pressure-volume (P-V) technique and the mechanical properties of cell walls in the leaf. The plants used were Quercus glauca and Q. serrata, an evergreen and a deciduous broad-leaved tree species, respectively. We compared epsilon and Young's modulus of leaf specimens determined by the stretch technique at various stages of their leaf development. The results showed that epsilon increased from approximately 5 to 20 MPa during leaf development, although other potential determinants of epsilon such as the apoplastic water content in the leaf and the diameter of a palisade tissue cells remained almost constant. epsilon in these two species was similar at every developmental stages, although the apparent mechanical strength of the leaf lamina and thickness of mesophyll cell walls were greater in Q. glauca. There were significant linear relationships between Young's modulus and epsilon (P < 0.01; R (2) = 0.78 and 0.84 in Q. glauca and Q. serrata, respectively) with small y-intercepts. From these results, we conclude that epsilon is closely related to the reversible properties of the cell walls. From the estimation of epsilon based on a physical model, we suggest that the effective thickness of cell walls responsible for epsilon is smaller than the observed wall thickness.

  13. Two new benzofuran lignan glycosides from Gelsemium elegans

    Institute of Scientific and Technical Information of China (English)

    Wei Hua; Qing Chun Zhao; Jia Yang; Guo Bing Shi; Li Jun Wu; Tao Guo

    2008-01-01

    Two new benzofuran lignan glycosides,gelsemiunoside A and B,were isolated from the whole plant of Gelsemium elegans Benth.Their structures were elucidated on the basis of spectroscopic evidence.Furthermore,gelsemiunoside A and B were shown a potent cytotoxic activity by suppressing the proliferation of A375-S2 cells.

  14. Triterpenoid glycosides from the leaves of Meliosma henryi.

    Science.gov (United States)

    Alabdul Magid, Abdulmagid; Morjani, Hamid; Harakat, Dominique; Madoulet, Claudie; Dumontet, Vincent; Lavaud, Catherine

    2015-01-01

    Seven triterpenoid glycosides, named meliosmosides A-G, were isolated from the leaves of Meliosma henryi Diels (Sabiaceae). Their structures were elucidated by different spectroscopic methods including 1D and 2D NMR experiments as well as HRESIMS analysis. Isolated compounds were evaluated for their cytotoxic activity against KB cell line.

  15. A new phenolic glycoside from the stem of Dendrobium nobile.

    Science.gov (United States)

    Zhou, Xue-Ming; Zheng, Cai-Juan; Wu, Jia-Ting; Chen, Guang-Ying; Zhang, Bin; Sun, Chong-Ge

    2017-05-01

    A new phenolic glycoside dendroside (1), together with seven known compounds (2-8) were isolated from the stems of Dendrobium nobile. The structures of these compounds were elucidated using comprehensive spectroscopic methods. The inhibitory activities of all compounds against three cancer cell lines HeLa, MCF-7 and A549 were evaluated.

  16. Soulieoside R : A New Cycloartane Triterpenoid Glycoside from Souliea vaginata

    Directory of Open Access Journals (Sweden)

    Qiongyu Zou

    2018-01-01

    Full Text Available A new cycloartane triterpenoid glycoside, named soulieoside R, was isolated from the rhizomes of Souliea vaginata. Its structure was characterized by comprehensive analyses of 1H, 13C NMR, COSY, HSQC, HMBC, NOESY spectroscopic, and HRESIMS mass spectrometric data, as well as chemical methods. The new compound showed weak inhibitory activity against three human cancer cell lines.

  17. Characterization of pentasaccharide glycosides from the roots of Ipomoea arborescens.

    Science.gov (United States)

    León, Ismael; Mirón, Gumersindo; Alonso, Daniel

    2006-06-01

    Ten new pentasaccharide glycosides, arboresins 1-6 (1-6) and murucins 6-9 (8-11), along with five known glycolipids, were isolated from the roots of Ipomoea arborescens, and their structures were elucidated by spectroscopic and chemical methods. Compounds 1-6 and 8-11 were evaluated for cytotoxicity against a small panel of cancer cell lines.

  18. A new modified sesquiterpene glycoside from Cupressus chengiana.

    Science.gov (United States)

    Lin, Yan; Li, Rong-Jiao; Li, Yan; McGarvey, Brian D; Wu, Hai-Feng; Wang, Xiao-Ling

    2014-01-01

    A new sesquiterpene glycoside, cupressusoside (1), and five known compounds were isolated from the 70% aqueous ethanol extract of the branches and leaves of Cupressus chengiana. Their structures were elucidated by using spectroscopic methods. All the isolates expressed no remarkable cytotoxic activity against colon carcinoma (HCT-8) and breast cancer (MCF-7) cell lines, with IC50>40 mg/mL.

  19. Disruption of Protein Mannosylation Affects Candida guilliermondii Cell Wall, Immune Sensing, and Virulence

    Science.gov (United States)

    Navarro-Arias, María J.; Defosse, Tatiana A.; Dementhon, Karine; Csonka, Katalin; Mellado-Mojica, Erika; Dias Valério, Aline; González-Hernández, Roberto J.; Courdavault, Vincent; Clastre, Marc; Hernández, Nahúm V.; Pérez-García, Luis A.; Singh, Dhirendra K.; Vizler, Csaba; Gácser, Attila; Almeida, Ricardo S.; Noël, Thierry; López, Mercedes G.; Papon, Nicolas; Mora-Montes, Héctor M.

    2016-01-01

    The fungal cell wall contains glycoproteins that interact with the host immune system. In the prominent pathogenic yeast Candida albicans, Pmr1 acts as a Golgi-resident ion pump that provides cofactors to mannosyltransferases, regulating the synthesis of mannans attached to glycoproteins. To gain insight into a putative conservation of such a crucial process within opportunistic yeasts, we were particularly interested in studying the role of the PMR1 homolog in a low-virulent species that rarely causes candidiasis, Candida guilliermondii. We disrupted C. guilliermondii PMR1 and found that loss of Pmr1 affected cell growth and morphology, biofilm formation, susceptibility to cell wall perturbing agents, mannan levels, and the wall composition and organization. Despite the significant increment in the amount of β1,3-glucan exposed at the wall surface, this positively influenced only the ability of the mutant to stimulate IL-10 production by human monocytes, suggesting that recognition of both mannan and β1,3-glucan, is required to stimulate strong levels of pro-inflammatory cytokines. Accordingly, our results indicate C. guilliermondii sensing by monocytes was critically dependent on the recognition of N-linked mannans and β1,3-glucan, as reported in other Candida species. In addition, chemical remotion of cell wall O-linked mannans was found to positively influence the recognition of C. guilliermondii by human monocytes, suggesting that O-linked mannans mask other cell wall components from immune cells. This observation contrasts with that reported in C. albicans. Finally, mice infected with C. guilliermondii pmr1Δ null mutant cells had significantly lower fungal burdens compared to animals challenged with the parental strain. Accordingly, the null mutant showed inability to kill larvae in the Galleria mellonella infection model. This study thus demonstrates that mannans are relevant for the C. guilliermondii-host interaction, with an atypical role for O

  20. Physical and Mechanical Characterization of Fiber Cell Wall in Castor (Ricinus communis L. Stalk

    Directory of Open Access Journals (Sweden)

    Xiaoping Li

    2014-02-01

    Full Text Available Castor (Ricinus communis L. stalk is a byproduct of the production of castor oil. As a natural material, castor stalk has great potential in the production of bio-composites as reinforcement materials. To provide more information about the castor stalk for using it better, the structure, microfibril angle (MFA, relative degree of crystallinity (%, and mechanical properties of castor fiber cell walls were investigated using X-ray diffraction (XRD and nanoindentation. The influence of chemical composition and MFA on the mechanical properties of fiber cell wall was studied as well. The cortex of castor stalks primarily contains long fibers, while the xylem of castor stalk, an excellent wood-type material, comprises most of the castor stalk (83.95% by weight; the pith of the stalk is composed of parenchyma cells. The average elastic modulus of fiber cell wall in lower, upper, and branch parts are 16.0 GPa, 18.6 GPa, and 13.2 GPa, respectively. The average hardness of fiber cell wall in lower, upper, and branch parts are 0.50 GPa, 0.54 GPa, and 0.43 GPa, respectively. As lignin content increases from 15.57% to 17.41% and MFA decreases from 21.3˚ to 15.4˚, the elastic modulus increases from 13.2 GPa to 18.6 GPa and the hardness increases from 0.43 GPa to 0.54 GPa. The mechanical properties, including the elastic modulus and the hardness of the fiber cell wall in the upper region of the castor stalk, are higher than those in the lower region, while the mechanical properties of the fiber cell wall in the branches are lower than those in either the upper or lower regions.

  1. Disruption of Protein Mannosylation Affects Candida guilliermondii Cell Wall, Immune Sensing, and Virulence

    Directory of Open Access Journals (Sweden)

    María J. Navarro-Arias

    2016-12-01

    Full Text Available The fungal cell wall contains glycoproteins that interact with the host immune system. In the prominent pathogenic yeast Candida albicans, Pmr1 acts as a Golgi-resident ion pump that provides cofactors to mannosyltransferases, regulating the synthesis of mannans attached to glycoproteins. To gain insight into a putative conservation of such a crucial process within opportunistic yeasts, we were particularly interested in studying the role of the PMR1 homolog in a low-virulent species that rarely causes candidiasis, Candida guilliermondii. We disrupted C. guilliermondii PMR1 and found that loss of Pmr1 affected cell growth and morphology, biofilm formation, susceptibility to cell wall perturbing agents, mannan levels, and the wall composition and organization. Despite there was a significant increment in the amount of β1,3-glucan exposed at the wall surface, this positively influenced only the ability of the mutant to stimulate IL-10 production by human monocytes, suggesting that recognition of both mannan and β1,3-glucan, is required to stimulate strong levels of pro-inflammatory cytokines. Accordingly, our results indicate C. guilliermondii sensing by monocytes was critically dependent on the recognition of N-linked mannans and β1,3-glucan, as reported in other Candida species. In addition, chemical remotion of cell wall O-linked mannans was found to positively influence the recognition of C. guilliermondii by human monocytes, suggesting that O-linked mannans mask other cell wall components from immune cells. This observation contrasts with that reported in C. albicans. Finally, mice infected with C. guilliermondii pmr1 null mutant cells had significantly lower fungal burdens compared to animals challenged with the parental strain. Accordingly, the null mutant showed inability to kill larvae in the Galleria mellonella infection model. This study thus demonstrates that mannans are relevant for the C. guilliermondii-host interaction, with

  2. Cell wall polysaccharides hydrolysis of malting barley (Hordeum vulgare L.: a review

    Directory of Open Access Journals (Sweden)

    Jamar, C.

    2011-01-01

    Full Text Available Malting quality results from the different steps of the malting process. Malting uses internal changes of the seed occurring during germination, such as enzymes synthesis, to obtain a good hydrolysis process and the components required. Among the three main hydrolytic events observed, that are namely starch degradation, cell wall breakdown and protein hydrolysis, an efficient cell wall polysaccharides hydrolysis is an essential condition for a final product of quality. Indeed, because of the physical barrier of the cell wall, cell wall polysaccharides hydrolysis is one of the first steps expected from the process to gain access to the cell components. Moreover, viscosity problem and haze formation in malting industry are related to their presence during the process when inefficient degradation occurs, leading to increased production time and cost. Understanding the key elements in cell wall degradation is important for a better control. (1-3,1-4-β-glucans and arabinoxylans are the main constituents of cell wall. (1-3,1-4-β-glucans are unbranched chains of β-D-glucopyranose residues with β-(1,3 linkages and β-(1,4 linkages. Arabinoxylan consists in a backbone of D-xylanopyranosyl units linked by β-(1-4 bonds connected to single L-arabinofuranose by α-(1→2 or α-(1→3-linkages. Degradation of (1-3,1-4-β-glucans is processed by the (1-3,1-4-β-glucanases, the β-glucosidases and the β-glucane exohydrolases. It seems that the (1-3-β-glucanases are also involved. Arabinoxylans are mainly decomposed by (1-4-β-xylan endohydrolase, arabinofuranosidase and β-xylosidase.

  3. Some ultrastructural information on intact, living bacterial cells and related cell-wall fragments as given by FTIR

    Science.gov (United States)

    Naumann, D.

    1984-05-01

    Living bacterial cells of Staphylococcus aureus have been measured from aqueous suspensions taking advantage of the solvent subtraction capabilities of FTIR. All spectral features, between 1800-800 cm -1, of the intact cells could be measured with a reproducibility of better than ±5% when applying strict metabolic control of cell growth and a highly standardized experimental procedure prior to IR measurements. IR bands near 1745, 1656, 1547, 1240 and 1200-1000 cm -1were tentatively assigned to: CO stretching of ester groups, amide I and amide II bands of the various peptides and proteins, asymmetric stretching of phosphate groups and complex vibrational modes resulting from polysaccharidal compounds, respectively. Absorbance subtraction of IR spectra of different intact baterial cells and cell-wall preparations yielded reasonable results on structural variations accompanying: (i) cell growth, (ii) use of different growth media, (iii) chemical treatment of cells and (iv) biochemical isolation processes of cell walls from the intact cells.

  4. Assessing adsorption of polycyclic aromatic hydrocarbons on Rhizopus oryzae cell wall components with water-methanol cosolvent model.

    Science.gov (United States)

    Ma, Bin; Lv, Xiaofei; He, Yan; Xu, Jianming

    2016-03-01

    The contribution of different fungal cell wall components in adsorption of polycyclic aromatic hydrocarbons (PAHs) is still unclear. We isolated Rhizopus oryzae cell walls components with sequential extraction, characterized functional groups with NEXAFS spectra, and determined partition coefficients of PAHs on cell walls and cell wall components with cosolvent model. Spectra of NEXAFS indicated that isolated cell walls components were featured with peaks at ~532.7 and ~534.5eV energy. The lipid cosolvent partition coefficients were approximately one order of magnitude higher than the corresponding carbohydrate cosolvent partition coefficients. The partition coefficients for four tested carbohydrates varied at approximate 0.5 logarithmic units. Partition coefficients between biosorbents and water calculated based cosolvent models ranged from 0.8 to 4.2. The present study proved the importance of fungal cell wall components in adsorption of PAHs, and consequently the role of fungi in PAHs bioremediation.

  5. Plasmolysis and cell wall deposition in wheat root hairs under osmotic stress.

    Science.gov (United States)

    Volgger, Michael; Lang, Ingeborg; Ovecka, Miroslav; Lichtscheidl, Irene

    2010-07-01

    We analysed cell wall formation in rapidly growing root hairs of Triticum aestivum under reduced turgor pressure by application of iso- and hypertonic mannitol solutions. Our experimental series revealed an osmotic value of wheat root hairs of 150 mOsm. In higher concentrations (200-650 mOsm), exocytosis of wall material and its deposition, as well as callose synthesis, still occurred, but the elongation of root hairs was stopped. Even after strong plasmolysis when the protoplast retreated from the cell wall, deposits of wall components were observed. Labelling with DiOC(6)(3) and FM1-43 revealed numerous Hechtian strands that spanned the plasmolytic space. Interestingly, the Hechtian strands also led towards the very tip of the root hair suggesting strong anchoring sites that are readily incorporated into the new cell wall. Long-term treatments of over 24 h in mannitol solutions (150-450 mOsm) resulted in reduced growth and concentration-dependent shortening of root hairs. However, the formation of new root hairs does occur in all concentrations used. This reflects the extraordinary potential of wheat root cells to adapt to environmental stress situations.

  6. Arabinose-rich polymers as an evolutionary strategy to plasticize resurrection plant cell walls against desiccation

    DEFF Research Database (Denmark)

    Moore, John P.; Nguema-Ona, Eric E.; Vicré-Gibouin, Mäite

    2013-01-01

    A variety of Southern African resurrection plants were surveyed using high-throughput cell wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii, Xerophyta humilis...... and comprehensive microarray polymer profiling in combination with multivariate data analysis. The data obtained suggest that three main functional strategies appear to have evolved to prepare plant cell walls for desiccation. Arabinan-rich pectin and arabinogalactan proteins are found in the resurrection fern M......-like Xerophyta spp. and the resurrection grass E. nindensis were found to contain highly arabinosylated xylans and arabinogalactan proteins. These data support a general mechanism of ‘plasticising’ the cell walls of resurrection plants to desiccation and implicate arabinose-rich polymers (pectin...

  7. Role of proline in cell wall synthesis and plant development and its implications in plant ontogeny

    Directory of Open Access Journals (Sweden)

    POLAVARAPU BILHAN KAVI KISHOR

    2015-07-01

    Full Text Available Proline is a proteogenic amino acid and accumulates both under stress and non-stress conditions as a beneficial solute in plants. Recent discoveries point out that proline plays an important role in plant growth and differentiation across life cycle. It is a key determinant of many cell wall proteins that plays important roles in plant development. The role of extensins (EXTs, arabinogalactan proteins (AGPs and hydroxyproline- and proline-rich proteins (H/PRPs as important components of cell wall proteins that play pivotal roles in cell wall signal transduction cascades, plant development and stress tolerance is discussed in this review. Molecular insights are also provided here into the plausible roles of proline transporters modulating key events in plant development. In addition, the roles of proline during seed developmental transitions including storage protein synthesis are discussed.

  8. Cell-Wall Carbohydrates of the Endosperm of the Seed of Gleditsia triacanthos.

    Science.gov (United States)

    Manzi, A E; Ancibor, E; Cerezo, A S

    1990-04-01

    The endosperm of the seed of Gleditsia triacanthos L. contains 18.55% of its dry weight as nonreserve, cell-wall carbohydrates. Of this carbohydrate material, comprising mainly mannose, galactose, and glucose, 76.1% was of low-molecular weight or highly hydrophilic. Mannose, galactose, and glucose were also the major sugar components of the polysaccharides extracted with alkali (23.1% of the cell-wall), while the same sugars, with minor amounts of arabinose, form the residues. Methylation analysis of the polysaccharides and the borate-sodium hydroxide residue indicate that the cell walls are built up on a network of galactomannans, with high Man/Gal ratios, reinforced with minor amounts of cellulose.

  9. Cell-Wall Carbohydrates of the Endosperm of the Seed of Gleditsia triacanthos1

    Science.gov (United States)

    Manzi, Adriana E.; Ancibor, Elena; Cerezo, Alberto S.

    1990-01-01

    The endosperm of the seed of Gleditsia triacanthos L. contains 18.55% of its dry weight as nonreserve, cell-wall carbohydrates. Of this carbohydrate material, comprising mainly mannose, galactose, and glucose, 76.1% was of low-molecular weight or highly hydrophilic. Mannose, galactose, and glucose were also the major sugar components of the polysaccharides extracted with alkali (23.1% of the cell-wall), while the same sugars, with minor amounts of arabinose, form the residues. Methylation analysis of the polysaccharides and the borate-sodium hydroxide residue indicate that the cell walls are built up on a network of galactomannans, with high Man/Gal ratios, reinforced with minor amounts of cellulose. Images Figure 2 Figure 2 PMID:16667408

  10. Assembly of MOF Microcapsules with Size-Selective Permeability on Cell Walls.

    Science.gov (United States)

    Li, Wanbin; Zhang, Yufan; Xu, Zehai; Meng, Qin; Fan, Zheng; Ye, Shuaiju; Zhang, Guoliang

    2016-01-18

    The assembly of metal-organic frameworks (MOFs) into microcapsules has attracted great interest because of their unique properties. However, it remains a challenge to obtain MOF microcapsules with size selectivity at the molecular scale. In this report, we used cell walls from natural biomaterials as non-toxic, stable, and inexpensive support materials to assemble MOF/cell wall (CW) microcapsules with size-selective permeability. By making use of the hollow structure, small pores, and high density of heterogeneous nucleation sites of the cell walls, uniform and continuous MOF layers could be easily obtained by inside/outside interfacial crystallization. The prepared MOF/CW microcapsules have excellent stability and enable the steady, slow, and size-selective release of small molecules. Moreover, the size selectivity of the microcapsules can be adjusted by changing the type of deposited MOF.

  11. Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

    Directory of Open Access Journals (Sweden)

    E Santin

    2006-12-01

    Full Text Available This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb and ochratoxin (500 or 250 ppb, and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

  12. Saccharomyces Cerevisiae Cell Wall Components as Tools for Ochratoxin A Decontamination

    Directory of Open Access Journals (Sweden)

    Małgorzata Piotrowska

    2015-04-01

    Full Text Available The aim of this study was to evaluate the usefulness of Saccharomyces cerevisiae cell wall preparations in the adsorption of ochratoxin A (OTA. The study involved the use of a brewer’s yeast cell wall devoid of protein substances, glucans obtained by water and alkaline extraction, a glucan commercially available as a dietary supplement for animals and, additionally, dried brewer’s yeast for comparison. Fourier Transform Infrared (FTIR analysis of the obtained preparations showed bands characteristic for glucans in the resulting spectra. The yeast cell wall preparation, water-extracted glucan and the commercial glucan bound the highest amount of ochratoxin A, above 55% of the initial concentration, and the alkaline-extracted glucan adsorbed the lowest amount of this toxin. It has been shown that adsorption is most effective at a close-to-neutral pH, while being considerably limited in alkaline conditions.

  13. Cell Wall Regeneration by Protoplasts in the Weak Combined Magnetic Field

    Science.gov (United States)

    Nedukha, Olena; Bogatina, Nina; Kordyum, Elizabeth; Ovcharenko, Yu.; Vorobyeva, T.

    2008-06-01

    Role of gravity on growth of high plants has been studied for many years, but many questions on biogenesis of plant cell wall are investigated insufficiently, and require new experiments. We have studied regeneration of cell wall in the fused and separate protoplasts of tobacco and soyabean in the presence of the weak, alternating magnetic field that consisted of frequency of 32 Hz (for Ca2+ ; F=40 μT) or 75 Hz (for Mg2+; F=60 μT) in side μ-metal shield. We discovered that the combined magnetic field that was adjusted to the cyclotron frequency of Ca2+ or Mg2+ is changed the rate of cell wall regeneration. Light and confocal laser microscopy were used for the investigations.

  14. The Role of Pectin Acetylation in the Organization of Plant Cell Walls

    DEFF Research Database (Denmark)

    Fimognari, Lorenzo

    adopt defined 3D organization to allow their composition/interactions to be tweaked upon developmental need. Failure to build functional cell wall architecture will affect plant growth and resistance to stresses. In this PhD dissertation I explored the role of pectin acetylation in controlling...... reduction in pectin and hemicellulose acetylation. We found that the increased resistance to pathogens in this mutant was due to the constitutive upregulation of defenses responses and the concomitant loss of integrity in the cell wall. Based on the results obtained in Manuscript I, we hypothesized...... that the loss of structural integrity in the cell wall was the underlying cause for triggering defenses response. This hypothesis was tested in Manuscript II. Through a suppressor screen of 30.000 Arabidopsis rwa2 plants and mapping of mutations by next generation sequencing, we pinpointed pectin deacetylation...

  15. Plant metabolism and cell wall formation in space (microgravity) and on Earth

    Science.gov (United States)

    Lewis, Norman G.

    1994-01-01

    Variations in cell wall chemistry provide vascular plants with the ability to withstand gravitational forces, as well as providing facile mechanisms for correctional responses to various gravitational stimuli, e.g., in reaction wood formation. A principal focus of our current research is to precisely and systematically dissect the essentially unknown mechanism(s) of vascular plant cell wall assembly, particularly with respect to formation of its phenolic constituents, i.e., lignins and suberins, and how gravity impacts upon these processes. Formation of these phenolic polymers is of particular interest, since it appears that elaboration of their biochemical pathways was essential for successful land adaptation. By extrapolation, we are also greatly intrigued as to how the microgravity environment impacts upon 'normal' cell wall assembly mechanisms/metabolism.

  16. Fourier transform mid infrared spectroscopy applications for monitoring the structural plasticity of plant cell walls

    Science.gov (United States)

    Largo-Gosens, Asier; Hernández-Altamirano, Mabel; García-Calvo, Laura; Alonso-Simón, Ana; Álvarez, Jesús; Acebes, José L.

    2014-01-01

    Fourier transform mid-infrared (FT-MIR) spectroscopy has been extensively used as a potent, fast and non-destructive procedure for analyzing cell wall architectures, with the capacity to provide abundant information about their polymers, functional groups, and in muro entanglement. In conjunction with multivariate analyses, this method has proved to be a valuable tool for tracking alterations in cell walls. The present review examines recent progress in the use of FT-MIR spectroscopy to monitor cell wall changes occurring in muro as a result of various factors, such as growth and development processes, genetic modifications, exposition or habituation to cellulose biosynthesis inhibitors and responses to other abiotic or biotic stresses, as well as its biotechnological applications. PMID:25071791

  17. Knockdown of a Laccase in Populus deltoides Confers Altered Cell Wall Chemistry and Increased Sugar Release

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Anthony C.; Jawdy, Sara; Gunter, Lee; Gjersing, Erica; Sykes, Robert; Hinchee, Maud A. W.; Winkeler, Kimberly A.; Collins, Cassandra M.; Engle, Nancy; Tschaplinski, Timothy J.; Yang, Xiaohan; Tuskan, Gerald A.; Muchero, Wellington; Chen, Jin-Gui

    2016-10-01

    Plant laccases are thought to function in the oxidation of monolignols which leads to higher order lignin formation. Only a hand-full of laccases in plants have been functionally evaluated and as such little is known about the breadth of their impact on cell wall chemistry or structure. Here we describe a previously uncharacterized laccase from Populus, encoded by locus Potri.008G064000, whose reduced expression resulted in transgenic Populus trees with changes in syringyl/guaiacyl (S/G) ratios as well as altered sugar release phenotypes. These phenotypes are consistent with plant biomass exhibiting reduced recalcitrance. Interestingly, the transgene effect on recalcitrance is dependent on a mild pretreatment prior to chemical extraction of sugars. Metabolite profiling suggests the transgene modulates phenolics that are associated with the cell wall structure. We propose that this particular laccase has a range of functions related to oxidation of phenolics and conjugation of flavonoids that interact with lignin in the cell wall.

  18. Knockdown of a laccase in Populus deltoides confers altered cell wall chemistry and increased sugar release.

    Science.gov (United States)

    Bryan, Anthony C; Jawdy, Sara; Gunter, Lee; Gjersing, Erica; Sykes, Robert; Hinchee, Maud A W; Winkeler, Kimberly A; Collins, Cassandra M; Engle, Nancy; Tschaplinski, Timothy J; Yang, Xiaohan; Tuskan, Gerald A; Muchero, Wellington; Chen, Jin-Gui

    2016-10-01

    Plant laccases are thought to function in the oxidation of monolignols which leads to higher order lignin formation. Only a hand-full of laccases in plants have been functionally evaluated, and as such little is known about the breadth of their impact on cell wall chemistry or structure. Here, we describe a previously uncharacterized laccase from Populus, encoded by locus Potri.008G064000, whose reduced expression resulted in transgenic Populus trees with changes in syringyl/guaiacyl ratios as well as altered sugar release phenotypes. These phenotypes are consistent with plant biomass exhibiting reduced recalcitrance. Interestingly, the transgene effect on recalcitrance is dependent on a mild pretreatment prior to chemical extraction of sugars. Metabolite profiling suggests the transgene modulates phenolics that are associated with the cell wall structure. We propose that this particular laccase has a range of functions related to oxidation of phenolics and conjugation of flavonoids that interact with lignin in the cell wall.

  19. Cell-wall disruption and lipid/astaxanthin extraction from microalgae: Chlorella and Haematococcus.

    Science.gov (United States)

    Kim, Dong-Yeon; Vijayan, Durairaj; Praveenkumar, Ramasamy; Han, Jong-In; Lee, Kyubock; Park, Ji-Yeon; Chang, Won-Seok; Lee, Jin-Suk; Oh, You-Kwan

    2016-01-01

    Recently, biofuels and nutraceuticals produced from microalgae have emerged as major interests, resulting in intensive research of the microalgal biorefinery process. In this paper, recent developments in cell-wall disruption and extraction methods are reviewed, focusing on lipid and astaxanthin production from the biotechnologically important microalgae Chlorella and Haematococcus, respectively. As a common, critical bottleneck for recovery of intracellular components such as lipid and astaxanthin from these microalgae, the composition and structure of rigid, thick cell-walls were analyzed. Various chemical, physical, physico-chemical, and biological methods applied for cell-wall breakage and lipid/astaxanthin extraction from Chlorella and Haematococcus are discussed in detail and compared based on efficiency, energy consumption, type and dosage of solvent, biomass concentration and status (wet/dried), toxicity, scalability, and synergistic combinations. This report could serve as a useful guide to the implementation of practical downstream processes for recovery of valuable products from microalgae including Chlorella and Haematococcus.

  20. Thaxtomin A affects CESA-complex density, expression of cell wall genes, cell wall composition, and causes ectopic lignification in Arabidopsis thaliana seedlings.

    Science.gov (United States)

    Bischoff, Volker; Cookson, Sarah Jane; Wu, Shuang; Scheible, Wolf-Rüdiger

    2009-01-01

    Thaxtomin A, a phytotoxin produced by Streptomyces eubacteria, is suspected to act as a natural cellulose synthesis inhibitor. This view is confirmed by the results obtained from new chemical, molecular, and microscopic analyses of Arabidopsis thaliana seedlings treated with thaxtomin A. Cell wall analysis shows that thaxtomin A reduces crystalline cellulose, and increases pectins and hemicellulose in the cell wall. Treatment with thaxtomin A also changes the expression of genes involved in primary and secondary cellulose synthesis as well as genes associated with pectin metabolism and cell wall remodelling, in a manner nearly identical to isoxaben. In addition, it induces the expression of several defence-related genes and leads to callose deposition. Defects in cellulose synthesis cause ectopic lignification phenotypes in A. thaliana, and it is shown that lignification is also triggered by thaxtomin A, although in a pattern different from isoxaben. Spinning disc confocal microscopy further reveals that thaxtomin A depletes cellulose synthase complexes from the plasma membrane and results in the accumulation of these particles in a small microtubule-associated compartment. The results provide new and clear evidence for thaxtomin A having a strong impact on cellulose synthesis, thus suggesting that this is its primary mode of action.

  1. Cell Wall Growth and Modulation Dynamics in a Model Unicellular Green Alga—Penium margaritaceum: Live Cell Labeling with Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    David S. Domozych

    2011-01-01

    Full Text Available Penium margaritaceum is a unicellular charophycean green alga that possesses cell wall polymers similar to those of land plants. Several wall macromolecules of this alga are recognized by monoclonal antibodies specific for wall polymer epitopes of land plants. Immunofluorescence protocols using these antibodies may be employed to label specific cell wall constituents of live cells. Fluorescent labeling persists for several days, and this attribute allows for tracing of wall epitopes in both long- and short-term studies of cell development. Quantitative analysis of surface area covered by cell wall polymers is also easily performed. We show that significant cell expansion caused by incubation of cells in low levels of osmotically active agents like mannitol, glucose,