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  1. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  2. The Plant Cell Surface

    Institute of Scientific and Technical Information of China (English)

    Anne-Mie C.Emons; Kurt V.Fagerstedt

    2010-01-01

    @@ Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. Since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it.

  3. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  4. Organelle Extensions in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Jaideep Mathur; Alena Mammone; Kiah A.Barton

    2012-01-01

    Cell walls lock each cell in a specific position within the supraorganization of a plant.Despite its fixed location,each cell must be able to sense alterations in its immediate environment and respond rapidly to ensure the optimal functioning,continued growth and development,and eventual long-term survival of the plant.The ultra-structural detail that underlies our present understanding of the plant cell has largely been acquired from fixed and processed material that does not allow an appreciation of the dynamic nature of sub-cellular events in the cell.In recent years,fluorescent proteinaided imaging of living plant cells has added to our understanding of the dynamic nature of the plant cell.One of the major outcomes of live imaging of plant cells is the growing appreciation that organelle shapes are not fixed,and many organelles extend their surface transiently in rapid response to environmental stimuli.In many cases,the extensions appear as tubules extending from the main organelle.Specific terms such as stromules from plastids,matrixules from mitochondria,and peroxules from peroxisomes have been coined to describe the extensions.Here,we review our present understanding of organelle extensions and discuss how they may play potential roles in maintaining cellular homeostasis in plant cells.

  5. Celebrating Plant Cells: A Special Issue on Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ A special issue on plant cell biology is long overdue for JIPB! In the last two decades or so, the plant biology community has been thrilled by explosive discoveries regarding the molecular and genetic basis of plant growth, development, and responses to the environment, largely owing to recent maturation of model systems like Arabidopsis thaliana and the rice Oryza sativa, as well as the rapid development of high throughput technologies associated with genomics and proteomics.

  6. Nuclear lamina in plant cells

    Institute of Scientific and Technical Information of China (English)

    汪健; 杨澄; 翟中和

    1996-01-01

    By using selective extraction and diethylene glycol distearate (DGD) embedment and embedment-free electron microscopy, the nuclear lamina was demonstrated in carrot and Ginkgo male generative cells. Western blotting revealed that the nuclear lamina was composed of A-type and B-type lamins which contained at least 66-ku and 84-ku or 66-ku and 86-ku polypeptides, respectively. These lamin proteins were localized at the nudear periphery as shown by immunogold-labelling. In situ hybridization for light microscope and electron microscope showed that plant cells have the homologous sequences of animal lamin cDNA. The sorting site of lamin mRNA is mainly distributed in the cytoplasm near the nudear envelope. The data have verified that there indeed exists nudear lamina in plant cells.

  7. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.

    2005-01-01

    A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

  8. Regulation of Water in Plant Cells

    Science.gov (United States)

    Kowles, Richard V.

    2010-01-01

    Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

  9. Polynucleotide phosphorylase from plant cells.

    Science.gov (United States)

    Schumacher-Wittkopf, E; Richter, G; Schulze, S

    1984-06-01

    The isolation of polynucleotide phosphorylase (EC 2. 7. 7. 8) from suspension cultured plant cells of parsley (Petroselinum sativum) and from tomato seedlings (Lycopersicon esculentum) is described. The procedure includes an ultracentrifugation step, a glycerol density gradient centrifugation and preparative gel electrophoresis under nondenaturing conditions. Isoelectric focusing gives rise to a major component (pI ≈ 7.5) and to a minor one (pI ≈ 5). The enzyme contains five subunits with apparent Mr values of 160 000, 140 000, 70 000, 34 000 and 12 000, the 70 000-dalton one being a glycoprotein. PMID:24253429

  10. Refractive index of plant cell walls

    Science.gov (United States)

    Gausman, H. W.; Allen, W. A.; Escobar, D. E.

    1974-01-01

    Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants, and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the 500-2500-nm wavelength interval because cell wall-air interfaces were partly eliminated. Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1.425 approximates the refractive index of plant cell walls for the four plant genera.

  11. Morphological classification of plant cell deaths

    DEFF Research Database (Denmark)

    van Doorn, W.G.; Beers, E.P.; Dangl, J.L.;

    2011-01-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about...... the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death......, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during...

  12. Pathological modifications of plant stem cell destiny

    Science.gov (United States)

    In higher plants, the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai...

  13. Microtubule networks for plant cell division

    NARCIS (Netherlands)

    Keijzer, de Jeroen; Mulder, B.M.; Janson, M.E.

    2014-01-01

    During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called

  14. System Studies of Fuel Cell Power Plants

    OpenAIRE

    Kivisaari, Timo

    2001-01-01

    This thesis concerns system studies of power plants wheredifferent types of fuel cells accomplish most of the energyconversion. Ever since William Grove observed the fuel cell effect inthe late 1830s fuel cells have been the subject or more or lessintense research and development. Especially in the USA theseactivities intensified during the second part of the 1950s,resulting in the development of the fuel cells used in theApollo-program. Swedish fuel cell activities started in themid-1960s, w...

  15. Electron Tomography in Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This review focuses on the contribution of electron tomography-based techniques to our understanding of cellular processes in plant cells. Electron microscopy techniques have evolved to provide better three-dimensional resolution and improved preservation of the subcellular components. In particular, the combination of cryofixation/freeze substitution and electron tomography have allowed plant cell biologists to image organelles and macromolecular complexes in their native cellular context with unprecedented three-dimensional resolution (4-7 nm). Until now, electron tomography has been applied in plant cell biology for the study of cytokinesis, Golgi structure and trafficking, formation of plant endosome/prevacuolar compartments, and organization of photosynthetic membranes. We discuss in this review the new insights that these tomographic studies have brought to the plant biology field.

  16. Regulation of cell division in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, T.W.

    1992-01-01

    Cell division is arguably the most fundamental of all developmental processes. In higher plants, mitotic activity is largely confined to foci of patterned cell divisions called meristems. From these perpetually embryonic tissues arise the plant's essential organs of light capture, support, protection and reproduction. Once an adequate understanding of plant cell mitotic regulation is attained, unprecedented opportunities will ensue for analyzing and genetically controlling diverse aspects of development, including plant architecture, leaf shape, plant height, and root depth. The mitotic cycle in a variety of model eukaryotic systems in under the control of a regulatory network of striking evolutionary conservation. Homologues of the yeast cdc2 gene, its catalytic product, p34, and the cyclin regulatory subunits of the MPF complex have emerged as ubiquitous mitotic regulators. We have cloned cdc2-like and cyclin genes from pea. As in other eukaryotic model systems, p34 of Pisum sativum is a subunit of a high molecular weight complex which binds the fission yeast p13 protein and displays histone H1 kinase activity in vitro. Our primary objective in this study is to gain baseline information about the regulation of this higher plant cell division control complex in non-dividing, differentiated cells as well as in synchronous and asynchronous mitotic cells. We are investigating cdc2 and cyclin expression at the levels of protein abundance, protein phosphorylation and quaternary associations.

  17. Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

    Science.gov (United States)

    Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

    Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems. Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-L disposable bioreactor consisting of a bag containing a rigid plastic box ('Box-in-Bag' bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 L working volumes, validated with several plant species ('Wave and Undertow' and 'Slug Bubble' bioreactors). The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco.

  18. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G;

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways...... and their molecular components in plants are reviewed here....

  19. Microtubule networks for plant cell division.

    Science.gov (United States)

    de Keijzer, Jeroen; Mulder, Bela M; Janson, Marcel E

    2014-09-01

    During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called cell plate, which is constructed by localized deposition of membrane and cell wall material. Construction starts in the centre of the cell at the locus of the mitotic spindle and continues radially towards the existing plasma membrane. Finally the membrane of the cell plate and plasma membrane fuse to form two individual plasma membranes. Two microtubule-based cytoskeletal networks, the phragmoplast and the pre-prophase band (PPB), jointly control cytokinesis in plants. The bipolar microtubule array of the phragmoplast regulates cell plate deposition towards a cortical position that is templated by the ring-shaped microtubule array of the PPB. In contrast to most animal cells, plants do not use centrosomes as foci of microtubule growth initiation. Instead, plant microtubule networks are striking examples of self-organizing systems that emerge from physically constrained interactions of dispersed microtubules. Here we will discuss how microtubule-based activities including growth, shrinkage, severing, sliding, nucleation and bundling interrelate to jointly generate the required ordered structures. Evidence mounts that adapter proteins sense the local geometry of microtubules to locally modulate the activity of proteins involved in microtubule growth regulation and severing. Many of the proteins and mechanisms involved have roles in other microtubule assemblies as well, bestowing broader relevance to insights gained from plants. PMID:25136380

  20. Laser-mediated perforation of plant cells

    Science.gov (United States)

    Wehner, Martin; Jacobs, Philipp; Esser, Dominik; Schinkel, Helga; Schillberg, Stefan

    2007-07-01

    The functional analysis of plant cells at the cellular and subcellular levels requires novel technologies for the directed manipulation of individual cells. Lasers are increasingly exploited for the manipulation of plant cells, enabling the study of biological processes on a subcellular scale including transformation to generate genetically modified plants. In our setup either a picosecond laser operating at 1064 nm wavelength or a continuous wave laser diode emitting at 405 nm are coupled into an inverse microscope. The beams are focused to a spot size of about 1.5 μm and the tobacco cell protoplasts are irradiated. Optoporation is achieved when targeting the laser focal spot at the outermost edge of the plasma membrane. In case of the picosecond laser a single pulse with energy of about 0.4 μJ was sufficient to perforate the plasma membrane enabling the uptake of dye or DNA from the surrounding medium into the cytosol. When the ultraviolet laser diode at a power level of 17 mW is employed an irradiation time of 200 - 500 milliseconds is necessary to enable the uptake of macromolecules. In the presence of an EYFP encoding plasmid with a C-terminal peroxisomal signal sequence in the surrounding medium transient transformation of tobacco protoplasts could be achieved in up to 2% of the optoporated cells. Single cell perforation using this novel optoporation method shows that isolated plant cells can be permeabilized without direct manipulation. This is a valuable procedure for cell-specific applications, particularly where the import of specific molecules into plant cells is required for functional analysis.

  1. Characterization of Cellulose Synthesis in Plant Cells

    OpenAIRE

    Samaneh Sadat Maleki; Kourosh Mohammadi; Kong-shu Ji

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the...

  2. UV-Induced Cell Death in Plants

    Directory of Open Access Journals (Sweden)

    Chang Ho Kang

    2013-01-01

    Full Text Available Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm, plants are exposed to UV light, which is comprised of UV-C (below 280 nm, UV-B (280–320 nm and UV-A (320–390 nm. The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS. Arabidopsis metacaspase-8 (AtMC8 is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1 gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD.

  3. Osmosis in Poisoned Plant Cells.

    Science.gov (United States)

    Tatina, Robert

    1998-01-01

    Describes two simple laboratory exercises that allow students to test hypotheses concerning the requirement of cell energy for osmosis. The first exercise involves osmotically-caused changes in the length of potato tubers and requires detailed quantitative observations. The second exercise involves osmotically-caused changes in turgor of Elodea…

  4. Spectro-Microscopy of Living Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Klaus Harter; Alfred J. Meixner; Frank Schleifenbaum

    2012-01-01

    Spectro-microscopy,a combination of fluorescence microscopy with spatially resolved spectroscopic techniques,provides new and exciting tools for functional cell biology in living organisms.This review focuses on recent developments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context.The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassinosteroide receptor BRI1 in the plasma membrane of living plant cells.Moreover,the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime (FLT).Furthermore,a new spectro-microscopic technique,fluorescence intensity decay shape analysis microscopy (FIDSAM),has been developed.FIDSAM is capable of imaging lowexpressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts.In addition,FIDSAM provides a very effective and sensitive tool on the basis of F(o)rster resonance energy transfer (FRET) for the qualitative and quantitative determination of protein-protein interaction.Finally,we report on the quantitative analysis of the photosystem Ⅰ and Ⅱ (PSⅠ/PSⅡ) ratio in the chloroplasts of living Arabidopsis plants at room temperature,using high-resolution,spatially resolved fluorescence spectroscopy.With this technique,it was not only possible to measure PSⅠ/PSⅡ ratios,but also to demonstrate the differential competence of wild-type and carbohydrate-deficient plants to adapt the PSⅠ/PSⅡ ratio to different light conditions.In summary,the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches.Therefore,novel cell physiological and molecular topics can be addressed and valuable insights into molecular and

  5. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  6. Thermodynamics of irreversible plant cell growth

    Directory of Open Access Journals (Sweden)

    Mariusz Pietruszka

    2011-04-01

    Full Text Available The time-irreversible cell enlargement of plant cells at a constant temperature results from two independent physical processes, e.g. water absorption and cell wall yielding. In such a model cell growth starts with reduction in wall stress because of irreversible extension of the wall. The water absorption and physical expansion are spontaneous consequences of this initial modification of the cell wall (the juvenile cell vacuolate, takes up water and expands. In this model the irreversible aspect of growth arises from the extension of the cell wall. Such theory expressed quantitatively by time-dependent growth equation was elaborated by Lockhart in the 60's.The growth equation omit however a very important factor, namely the environmental temperature at which the plant cells grow. In this paper we put forward a simple phenomenological model which introduces into the growth equation the notion of temperature. Moreover, we introduce into the modified growth equation the possible influence of external growth stimulator or inhibitor (phytohormones or abiotic factors. In the presence of such external perturbations two possible theoretical solutions have been found: the linear reaction to the application of growth hormones/abiotic factors and the non-linear one. Both solutions reflect and predict two different experimental conditions, respectively (growth at constant or increasing concentration of stimulator/inhibitor. The non-linear solution reflects a common situation interesting from an environmental pollution point of view e.g. the influence of increasing (with time concentration of toxins on plant growth. Having obtained temperature modified growth equations we can draw further qualitative and, especially, quantitative conclusions about the mechanical properties of the cell wall itself. This also concerns a new and interesting result obtained in our model: We have calculated the magnitude of the cell wall yielding coefficient (T [m3 J-1•s-1] in

  7. Integrating transcriptional controls for plant cell expansion

    OpenAIRE

    Mockaitis, Keithanne; Estelle, Mark

    2004-01-01

    The plant hormones auxin and brassinosteroid promote cell expansion by regulating gene expression. In addition to independent transcriptional responses generated by the two signals, recent microarray analyses indicate that auxin and brassinosteroid also coordinate the expression of a set of shared target genes.

  8. Plant microbial fuel cell applied in wetlands

    NARCIS (Netherlands)

    Wetser, Koen; Liu, Jia; Buisman, Cees; Strik, David

    2015-01-01

    The plant microbial fuel cell (PMFC) has to be applied in wetlands to be able to generate electricity on a large scale. The objective of this PMFC application research is to clarify the differences in electricity generation between a Spartina anglica salt marsh and Phragmites australis peat soil

  9. Fluorescence activated cell sorting of plant protoplasts.

    Science.gov (United States)

    Bargmann, Bastiaan O R; Birnbaum, Kenneth D

    2010-02-18

    High-resolution, cell type-specific analysis of gene expression greatly enhances understanding of developmental regulation and responses to environmental stimuli in any multicellular organism. In situ hybridization and reporter gene visualization can to a limited extent be used to this end but for high resolution quantitative RT-PCR or high-throughput transcriptome-wide analysis the isolation of RNA from particular cell types is requisite. Cellular dissociation of tissue expressing a fluorescent protein marker in a specific cell type and subsequent Fluorescence Activated Cell Sorting (FACS) makes it possible to collect sufficient amounts of material for RNA extraction, cDNA synthesis/amplification and microarray analysis. An extensive set of cell type-specific fluorescent reporter lines is available to the plant research community. In this case, two marker lines of the Arabidopsis thaliana root are used: P(SCR;)::GFP (endodermis and quiescent center) and P(WOX5;)::GFP (quiescent center). Large numbers (thousands) of seedlings are grown hydroponically or on agar plates and harvested to obtain enough root material for further analysis. Cellular dissociation of plant material is achieved by enzymatic digestion of the cell wall. This procedure makes use of high osmolarity-induced plasmolysis and commercially available cellulases, pectinases and hemicellulases to release protoplasts into solution. FACS of GFP-positive cells makes use of the visualization of the green versus the red emission spectra of protoplasts excited by a 488 nm laser. GFP-positive protoplasts can be distinguished by their increased ratio of green to red emission. Protoplasts are typically sorted directly into RNA extraction buffer and stored for further processing at a later time. This technique is revealed to be straightforward and practicable. Furthermore, it is shown that it can be used without difficulty to isolate sufficient numbers of cells for transcriptome analysis, even for very scarce

  10. 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.

  11. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  12. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  13. Characterization of Cellulose Synthesis in Plant Cells.

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-Shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  14. Plant thin cell layers: update and perspectives

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime A.

    2015-12-01

    Full Text Available Thin cell layers (TCLs are small and versatile explants for the in vitro culture of plants. At face value, their morphogenic productivity may appear to be less than conventional explants, but once the plant growth correction factor and geometric factor have been applied, the true (potential productivity exceeds that of a conventional explant. It is for this reason that for almost 45 years, TCLs have been applied to the in vitro culture of almost 90 species or hybrids, mainly ornamentals and orchids, but also to field and vegetable crops and medicinal plants. Focusing on 12 new studies that have emerged in the recent past (2013-2015, this paper brings promise to other horticultural species that could benefit from the use of TCLs.

  15. Plant cell technologies in space: Background, strategies and prospects

    Science.gov (United States)

    Kirkorian, A. D.; Scheld, H. W.

    1987-01-01

    An attempt is made to summarize work in plant cell technologies in space. The evolution of concepts and the general principles of plant tissue culture are discussed. The potential for production of high value secondary products by plant cells and differentiated tissue in automated, precisely controlled bioreactors is discussed. The general course of the development of the literature on plant tissue culture is highlighted.

  16. How do plant cell walls extend?

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    This article briefly summarizes recent work that identifies the biophysical and biochemical processes that give rise to the extension of plant cell walls. I begin with the biophysical notion of stress relaxation of the wall and follow with recent studies of wall enzymes thought to catalyze wall extension and relaxation. Readers should refer to detailed reviews for more comprehensive discussion of earlier literature (Taiz, 1984; Carpita and Gibeaut, 1993; Cosgrove, 1993).

  17. Bio-based composites that mimic the plant cell wall

    OpenAIRE

    Li, Zhuo

    2009-01-01

    Nature creates high performance materials under modest conditions, i.e., neutral pH and ambient temperature and pressure. One of the most significant materials is the plant cell wall. The plant cell wall is a composite of oriented cellulose microfibrils reinforcing a lignin/hemicellulose matrix. In principle, the plant cell wall composite is designed much like a synthetic fiber-reinforced polymer composite. Unlike synthetic composites, the plant cell wall has an excellent combination of h...

  18. Functions of Xyloglucan in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Takahisa Hayashi; Rumi Kaida

    2011-01-01

    While an increase in the number of xyloglucan tethers between the cellulose microfibrils in plant cell walls increases the walls' rigidity, the degradation of these tethers causes the walls to loosen. Degradation can occur either through the integration of xyloglucan oligosaccharides due to the action of xyloglucan endotransglucosylase or through direct hydrolysis due to the action of xyloglucanase. This is why the addition of xyloglucan and its fragment oligosac-charides causes plant tissue tension to increase and decrease so dramatically. Experiments involving the overexpression of xyloglucanase and cellulase have revealed the roles of xyloglucans in the walls. The degradation of wall xyloglucan in poplar by the transgenic expression of xyloglucanase, for example, not only accelerated stem elongation in the primary wall, but also blocked upright-stem gravitropism in the secondary wall. Overexpression of cellulase also reduced xyloglucan content in the walls as cellulose microfibrils were trimmed at their amorphous region, resulting in increased cell volume in Arabidopsis leaves and in sengon with disturbed leaf movements. The hemicellulose xyloglucan, in its function as a tether, plays a key role in the loosening and tightening of cellulose microfibrils: it enables the cell to change its shape in growth and differentiation zones and to retain its final shape after cell maturation.

  19. 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.

  20. Roles of membrane trafficking in plant cell wall dynamics

    OpenAIRE

    Ebine, Kazuo; Ueda, Takashi

    2015-01-01

    The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transpor...

  1. 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.

  2. Plant and animal stem cells: similar yet different

    NARCIS (Netherlands)

    Heidstra, R.; Sabatini, S.

    2014-01-01

    The astonishingly long lives of plants and their regeneration capacity depend on the activity of plant stem cells. As in animals, stem cells reside in stem cell niches, which produce signals that regulate the balance between self-renewal and the generation of daughter cells that differentiate into n

  3. Dynamic simulation of a direct carbonate fuel cell power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  4. Homogenization of a viscoelastic model for plant cell wall biomechanics

    OpenAIRE

    Ptashnyk, Mariya; Seguin, Brian

    2015-01-01

    The microscopic structure of a plant cell wall is given by cellulose microfibrils embedded in a cell wall matrix. In this paper we consider a microscopic model for interactions between viscoelastic deformations of a plant cell wall and chemical processes in the cell wall matrix. We consider elastic deformations of the cell wall microfibrils and viscoelastic Kelvin--Voigt type deformations of the cell wall matrix. Using homogenization techniques (two-scale convergence and periodic unfolding me...

  5. 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.

  6. 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

  7. Auxin regulation of cell polarity in plants.

    Science.gov (United States)

    Pan, Xue; Chen, Jisheng; Yang, Zhenbiao

    2015-12-01

    Auxin is well known to control pattern formation and directional growth at the organ/tissue levels via the nuclear TIR1/AFB receptor-mediated transcriptional responses. Recent studies have expanded the arena of auxin actions as a trigger or key regulator of cell polarization and morphogenesis. These actions require non-transcriptional responses such as changes in the cytoskeleton and vesicular trafficking, which are commonly regulated by ROP/Rac GTPase-dependent pathways. These findings beg for the question about the nature of auxin receptors that regulate these responses and renew the interest in ABP1 as a cell surface auxin receptor, including the work showing auxin-binding protein 1 (ABP1) interacts with the extracellular domain of the transmembrane kinase (TMK) receptor-like kinases in an auxin-dependent manner, as well as the debate on this auxin binding protein discovered about 40 years ago. This review highlights recent work on the non-transcriptional auxin signaling mechanisms underscoring cell polarity and shape formation in plants. PMID:26599954

  8. Plant guard cell anion channel SLAC1 regulates stomatal closure

    OpenAIRE

    Vahisalu, Triin

    2010-01-01

    Plants are rooted to their growth place; therefore it is important that they react adequately to changes in environmental conditions. Stomatal pores, which are formed of a pair of guard cells in leaf epidermis, regulate plant gas-exchange. Importantly, guard cells protect the plant from desiccation in drought conditions by reducing the aperture of the stomatal pore. They serve also as the first barrier against the major air pollutant ozone, but the behaviour of guard cells during ozone expo...

  9. Using Tissue Culture To Investigate Plant Cell Differentiation and Dedifferentiation.

    Science.gov (United States)

    Bozzone, Donna M.

    1997-01-01

    Describes an experimental project that uses plant tissue culture techniques to examine cell differentiation in the carrot. Allows students to gain experience in some important techniques and to explore fundamental questions about cell differentiation. (DDR)

  10. 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...

  11. Formative cell divisions: principal determinants of plant morphogenesis.

    Science.gov (United States)

    Smolarkiewicz, Michalina; Dhonukshe, Pankaj

    2013-03-01

    Formative cell divisions utilizing precise rotations of cell division planes generate and spatially place asymmetric daughters to produce different cell layers. Therefore, by shaping tissues and organs, formative cell divisions dictate multicellular morphogenesis. In animal formative cell divisions, the orientation of the mitotic spindle and cell division planes relies on intrinsic and extrinsic cortical polarity cues. Plants lack known key players from animals, and cell division planes are determined prior to the mitotic spindle stage. Therefore, it appears that plants have evolved specialized mechanisms to execute formative cell divisions. Despite their profound influence on plant architecture, molecular players and cellular mechanisms regulating formative divisions in plants are not well understood. This is because formative cell divisions in plants have been difficult to track owing to their submerged positions and imprecise timings of occurrence. However, by identifying a spatiotemporally inducible cell division plane switch system applicable for advanced microscopy techniques, recent studies have begun to uncover molecular modules and mechanisms for formative cell divisions. The identified molecular modules comprise developmentally triggered transcriptional cascades feeding onto microtubule regulators that now allow dissection of the hierarchy of the events at better spatiotemporal resolutions. Here, we survey the current advances in understanding of formative cell divisions in plants in the context of embryogenesis, stem cell functionality and post-embryonic organ formation. PMID:23248201

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

    OpenAIRE

    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 wa...

  13. Cell Fate Switch during In Vitro Plant Organogenesis

    Institute of Scientific and Technical Information of China (English)

    Xiang Yu Zhao; Ying Hua Su; Zhi Juan Cheng; Xian Sheng Zhang

    2008-01-01

    Plant mature cells have the capability to reverse their state of differenUation and produce new organs under cultured conditions. Two phases, dedifferentiation and redifferentiation, are commonly characterized during in vitro organogenesis.In these processes, cells undergo fate switch several times regulated by both extrinsic and intrinsic factors, which are associated with reentry to the cell cycle, the balance between euchromatin and heterochromatin, reprogramming of gene expression, and so forth. This short article reviews the advances in the mechanism of organ regeneration from plant somatic cells in molecular, genomic and epigenetic aspects, aiming to provide important information on the mechanism underlying cell fate switch during in vitro plant organogenesis.

  14. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions

    OpenAIRE

    Daniela eBellincampi; Felice eCervone; Vincenzo eLionetti

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteri...

  15. The First Observation on Plant Cell Fossils in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; CUI Jinzhong

    2007-01-01

    For a long time, paleontologists have been focusing on hard parts of organisms during different geological periods while soft parts are rarely reported. Well-preserved plant cells, if found in fossils, are treated only as a rarity. Recent progress in research on fossil cytoplasm indicates that plant cytoplasm not only has excellent ultrastructures preserved but also may be a quite commonly seen fossil in strata. However, up to now there is no report of plant cell fossils in China yet. Here plant cell fossils are reported from Huolinhe Coal Mine (the early Cretaceous), Inner Mongolia, China. The presence of plant cytoplasm fossils in two cones on the same specimen not only provides further support for the recently proposed hypothesis on plant cytoplasm fossilization but also marks the first record of plant cytoplasm fossils in China, which suggests a great research potential in this new area.

  16. Progress and prospects for phosphoric acid fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J. [International Fuel Cells Corp., South Windsor, CT (United States)

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  17. Chemical- and pathogen-induced programmed cell death in plants

    NARCIS (Netherlands)

    Iakimova, E.T.; Atanassov, A.; Woltering, E.J.

    2005-01-01

    This review focuses on recent update in the understanding of programmed cell death regarding the differences and similarities between the diverse types of cell death in animal and plant systems and describes the morphological and some biochemical determinants. The role of PCD in plant development an

  18. Plant programmed cell death, ethylene and flower senescence

    NARCIS (Netherlands)

    Woltering, E.J.; Jong, de A.; Hoeberichts, F.A.; Iakimova, E.T.; Kapchina, V.

    2005-01-01

    Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD

  19. Dynamics and Regulation of Actin Cytoskeleton in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Ren Haiyun

    2007-01-01

    @@ The actin cytoskeleton constituted of globular actin (G-actin) is a ubiquitous component of eukaryotic cells and plays crucial roles in diverse physiological processes in plant cells, such as cytoplasmic streaming, organelle and nucleus positioning, cell morphogenesis, cell division, tip growth, etc.

  20. The role of root border cells in plant defense.

    Science.gov (United States)

    Hawes, M C; Gunawardena, U; Miyasaka, S; Zhao, X

    2000-03-01

    The survival of a plant depends upon the capacity of root tips to sense and move towards water and other nutrients in the soil. Perhaps because of the root tip's vital role in plant health, it is ensheathed by large populations of detached somatic cells - root 'border' cells - which have the ability to engineer the chemical and physical properties of the external environment. Of particular significance, is the production by border cells of specific chemicals that can dramatically alter the behavior of populations of soilborne microflora. Molecular approaches are being used to identify and manipulate the expression of plant genes that control the production and the specialized properties of border cells in transgenic plants. Such plants can be used to test the hypothesis that these unusual cells act as a phalanx of biological 'goalies', which neutralize dangers to newly generated root tissue as the root tip makes its way through soil.

  1. Cell wall integrity signaling and innate immunity in plants

    OpenAIRE

    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 ar...

  2. Super-resolution Microscopy in Plant Cell Imaging.

    Science.gov (United States)

    Komis, George; Šamajová, Olga; Ovečka, Miroslav; Šamaj, Jozef

    2015-12-01

    Although the development of super-resolution microscopy methods dates back to 1994, relevant applications in plant cell imaging only started to emerge in 2010. Since then, the principal super-resolution methods, including structured-illumination microscopy (SIM), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), and stimulated emission depletion microscopy (STED), have been implemented in plant cell research. However, progress has been limited due to the challenging properties of plant material. Here we summarize the basic principles of existing super-resolution methods and provide examples of applications in plant science. The limitations imposed by the nature of plant material are reviewed and the potential for future applications in plant cell imaging is highlighted.

  3. 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.

  4. Programmed cell death: a way of life for plants.

    OpenAIRE

    Greenberg, J T

    1996-01-01

    Cell death in higher plants has been widely observed in predictable patterns throughout development and in response to pathogenic infection. Genetic, biochemical, and morphological evidence suggests that these cell deaths occur as active processes and can be defined formally as examples of programmed cell death (PCD). Intriguingly, plants have at least two types of PCD, an observation that is also true of PCD in animals [Schwartz, L. M., Smith, W.W., Jones, M. E. E. & Osborne, B. A. (1993) Pr...

  5. Incorporation of mammalian actin into microfilaments in plant cell nucleus

    Directory of Open Access Journals (Sweden)

    Paves Heiti

    2004-04-01

    Full Text Available Abstract Background Actin is an ancient molecule that shows more than 90% amino acid homology between mammalian and plant actins. The regions of the actin molecule that are involved in F-actin assembly are largely conserved, and it is likely that mammalian actin is able to incorporate into microfilaments in plant cells but there is no experimental evidence until now. Results Visualization of microfilaments in onion bulb scale epidermis cells by different techniques revealed that rhodamine-phalloidin stained F-actin besides cytoplasm also in the nuclei whereas GFP-mouse talin hybrid protein did not enter the nuclei. Microinjection of fluorescently labeled actin was applied to study the presence of nuclear microfilaments in plant cells. Ratio imaging of injected fluorescent rabbit skeletal muscle actin and phalloidin staining of the microinjected cells showed that mammalian actin was able to incorporate into plant F-actin. The incorporation occurred preferentially in the nucleus and in the perinuclear region of plant cells whereas part of plant microfilaments, mostly in the periphery of cytoplasm, did not incorporate mammalian actin. Conclusions Microinjected mammalian actin is able to enter plant cell's nucleus, whereas incorporation of mammalian actin into plant F-actin occurs preferentially in the nucleus and perinuclear area.

  6. PECULIARITIES OF SECONDARY METABOLITES BIOSYNTHESIS IN PLANT CELL CULTURES

    Directory of Open Access Journals (Sweden)

    A.M. NOSOV

    2014-06-01

    Full Text Available metabolites formation in plant cell cultures of Panax spp., (ginsenosides; Dioscorea deltoidea (steroid glycosides; Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids; Polyscias spp., (triterpene glycosides, Taxus spp. (taxoids, Stevia rebaudiana (diterpene steviol-glycosides, Stephania glabra (alkaloids. They are some regular trends of secondary metabolites synthesis in the plant cell culture:It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass.Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides, the productivity of these compounds was up to 6.0 - 8.0% on dry biomass.By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only.Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactor-based production of isoprenoids using undifferentiated plant cell cultures. 

  7. [Transfer of T-DNA from agrobacteria into plant cells through cell walls and membranes].

    Science.gov (United States)

    Chumakov, M I

    2001-01-01

    Discusses probable routes of agrobacterial penetration through the plant integumental tissues, cell wall, and plant cell plasmodesma. Analyzes the contribution of extracellular structures of agrobacteria in penetration through barriers of a plant cell, primary contact (adhesion), and during DNA transfer from bacterial (E. coli, A. tumefaciens) to recipient (bacterial or plant) cells. Discusses the relationship between donor cell adhesion to recipient cell surface and the infectious and conjugation processes. Considers the probable role of piles in conjugative transfer of agrobacterial DNA through membranes of donor and recipient (bacterial and plant) cells. Analyzes the contribution of the plant cell cytoskeleton to T-DNA transfer. Suggests a model of transport of T-DNA-VirD2 complex and VirE2 proteins through independent channels consisting of vir-coded proteins. PMID:11236737

  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. Vital Autofluorescence: Application to the Study of Plant Living Cells

    OpenAIRE

    Roshchina, Victoria V.

    2012-01-01

    The application of various microscopy methods such as luminescence microscopy, microspectrofluorimetry and laser-scanning confocal microscopy has been considered as an approach to study the autofluorescence of plant living cells—from cell diagnostics up to modelling the cell-cell contacts and cell interactions with fluorescent biologically active substances. It bases on the direct observations of secretions released from allelopathic and medicinal species and the cell-donor interactions with ...

  10. Root Border Cells and Their Role in Plant Defense.

    Science.gov (United States)

    Hawes, Martha; Allen, Caitilyn; Turgeon, B Gillian; Curlango-Rivera, Gilberto; Minh Tran, Tuan; Huskey, David A; Xiong, Zhongguo

    2016-08-01

    Root border cells separate from plant root tips and disperse into the soil environment. In most species, each root tip can produce thousands of metabolically active cells daily, with specialized patterns of gene expression. Their function has been an enduring mystery. Recent studies suggest that border cells operate in a manner similar to mammalian neutrophils: Both cell types export a complex of extracellular DNA (exDNA) and antimicrobial proteins that neutralize threats by trapping pathogens and thereby preventing invasion of host tissues. Extracellular DNases (exDNases) of pathogens promote virulence and systemic spread of the microbes. In plants, adding DNase I to root tips eliminates border cell extracellular traps and abolishes root tip resistance to infection. Mutation of genes encoding exDNase activity in plant-pathogenic bacteria (Ralstonia solanacearum) and fungi (Cochliobolus heterostrophus) results in reduced virulence. The study of exDNase activities in plant pathogens may yield new targets for disease control. PMID:27215971

  11. Root Border Cells and Their Role in Plant Defense.

    Science.gov (United States)

    Hawes, Martha; Allen, Caitilyn; Turgeon, B Gillian; Curlango-Rivera, Gilberto; Minh Tran, Tuan; Huskey, David A; Xiong, Zhongguo

    2016-08-01

    Root border cells separate from plant root tips and disperse into the soil environment. In most species, each root tip can produce thousands of metabolically active cells daily, with specialized patterns of gene expression. Their function has been an enduring mystery. Recent studies suggest that border cells operate in a manner similar to mammalian neutrophils: Both cell types export a complex of extracellular DNA (exDNA) and antimicrobial proteins that neutralize threats by trapping pathogens and thereby preventing invasion of host tissues. Extracellular DNases (exDNases) of pathogens promote virulence and systemic spread of the microbes. In plants, adding DNase I to root tips eliminates border cell extracellular traps and abolishes root tip resistance to infection. Mutation of genes encoding exDNase activity in plant-pathogenic bacteria (Ralstonia solanacearum) and fungi (Cochliobolus heterostrophus) results in reduced virulence. The study of exDNase activities in plant pathogens may yield new targets for disease control.

  12. Guard cell protoplasts: isolation, culture, and regeneration of plants.

    Science.gov (United States)

    Tallman, Gary

    2006-01-01

    Guard cell protoplasts have been used extensively in short-term experiments designed to elucidate the signal transduction mechanisms that regulate stomatal movements. The utility of uard cell protoplasts for other types of longer-term signal transduction experiments is just now being realized. Because highly purified, primary isolates of guard cell protoplasts are synchronous initially, they are uniform in their responses to changes in culture conditions. Such isolates have demonstrated potential to reveal mechanisms that underlie hormonal signalling for plant cell survival, cell cycle re-entry, reprogramming of genes during dedifferentiation to an embryogenic state, and plant cell thermotolerance. Plants have been regenerated from cultured guard cell protoplasts of two species: Nicotiana glauca (Graham), tree tobacco, and Beta vulgaris, sugar beet. Plants genetically engineered for herbicide tolerance have been regenerated from cultured guard cell protoplasts of B. vulgaris. The method for isolating, culturing, and regenerating plants from guard cell protoplasts of N. glauca is described here. A recently developed procedure for large-scale isolation of these cells from as many as nine leaves per experiment is described. Using this protocol, yields of 1.5-2 x 10(7) per isolate may be obtained. Such yields are sufficient for standard methods of molecular, biochemical, and proteomic analysis.

  13. Plant programmed cell death and the point of no return

    NARCIS (Netherlands)

    Doorn, van W.G.

    2005-01-01

    The point of no return during programmed cell death (PCD) is defined as the step beyond which the cell is irreversibly committed to die. Some plant cells can be saved before this point by inducing the formation of functional chloroplasts. A visibly senescent tissue will then become green again and l

  14. Regulation of cell division in higher plants. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, T.W.

    1992-07-01

    Cell division is arguably the most fundamental of all developmental processes. In higher plants, mitotic activity is largely confined to foci of patterned cell divisions called meristems. From these perpetually embryonic tissues arise the plant`s essential organs of light capture, support, protection and reproduction. Once an adequate understanding of plant cell mitotic regulation is attained, unprecedented opportunities will ensue for analyzing and genetically controlling diverse aspects of development, including plant architecture, leaf shape, plant height, and root depth. The mitotic cycle in a variety of model eukaryotic systems in under the control of a regulatory network of striking evolutionary conservation. Homologues of the yeast cdc2 gene, its catalytic product, p34, and the cyclin regulatory subunits of the MPF complex have emerged as ubiquitous mitotic regulators. We have cloned cdc2-like and cyclin genes from pea. As in other eukaryotic model systems, p34 of Pisum sativum is a subunit of a high molecular weight complex which binds the fission yeast p13 protein and displays histone H1 kinase activity in vitro. Our primary objective in this study is to gain baseline information about the regulation of this higher plant cell division control complex in non-dividing, differentiated cells as well as in synchronous and asynchronous mitotic cells. We are investigating cdc2 and cyclin expression at the levels of protein abundance, protein phosphorylation and quaternary associations.

  15. Plant response to heavy metals and organic pollutants in cell culture and at whole plant level

    Energy Technology Data Exchange (ETDEWEB)

    Golan-Goldhirsh, A.; Barazani, O. [Ben-Gurion Univ. of The Negev, The Jacob Blaustein Inst. for Desert Research, Albert Katz Dept. of Dryland Biotechnologies, Desert Plant Biotechnology Lab., Sede Boqer Campus (Israel); Nepovim, A.; Soudek, P.; Vanek, T. [Inst. of Organic Chemistry and Biochemistry (Czech Republic); Smrcek, S.; Dufkova, L.; Krenkova, S. [Faculty of Natural Sciences, Charles Univ. (Czech Republic); Yrjala, K. [Univ. of Helsinki, Dept. of Biosciences, Div. of General Microbiology, Helsinki (Finland); Schroeder, P. [Inst. for Soil Ecology, GSF National Research Center for Environment and Health, Neuherberg, Oberschleissheim (Germany)

    2004-07-01

    Background. Increasing awareness in the last decade concerning environmental quality had prompted research into 'green solutions' for soil and water remediation, progressing from laboratory in vitro experiments to pot and field trials. In vitro cell culture experiments provide a convenient system to study basic biological processes, by which biochemical pathways, enzymatic activity and metabolites can be specifically studied. However, it is difficult to relate cell cultures, calli or even hydroponic experiments to the whole plant response to pollutant stress. In the field, plants are exposed to additional a-biotic and biotic factors, which complicate further plant response. Hence, we often see that in vitro selected species perform poorly under soil and field conditions. Soil physical and chemical properties, plant-mycorrhizal association and soil-microbial activity affect the process of contaminant degradation by plants and/or microorganisms, pointing to the importance of pot and field experiments. Objective. This paper is a joint effort of a group of scientists in COST action 837. It represents experimental work and an overview on plant response to environmental stress from in vitro tissue culture to whole plant experiments in soil. Results. Results obtained from in vitro plant tissue cultures and whole plant hydroponic experiments indicate the phytoremediation potential of different plant species and the biochemical mechanisms involved in plant tolerance. In pot experiments, several selected desert plant species, which accumulated heavy metal in hydroponic systems, succeeded in accumulating the heavy metal in soil conditions as well. Conclusions and recommendations. In vitro plant tissue cultures provide a useful experimental system for the study of the mechanisms involved in the detoxification of organic and heavy metal pollutants. However, whole plant experimental systems, as well as hydroponics followed by pot and field trials, are essential when

  16. Hormone Signaling Pathways in Plants: The Role of Jasmonic Acid in Plant Cell Signaling

    OpenAIRE

    TİRYAKİ, İskender

    2004-01-01

    Plant growth and metabolism are affected by various biotic and abiotic stimuli including microorganisms and insects attack as well as light and environmental stresses. Such a diverse plant response requires a communication system that uses a group of chemical messengers called hormones. Hormones promote, inhibit, or qualitatively modify plant growth and development. This complex process requires a signal transduction that defines a specific information pathway within a cell that translat...

  17. The Role of Plant Hormones in Nematode Feeding Cell Formation

    NARCIS (Netherlands)

    Goverse, A.; Bird, D.

    2011-01-01

    In this Chapter, we discuss recent advances in the role of plant hormones in the molecular mechanisms underlying feeding cell formation both by cyst (CN) and root-knot nematodes (RKN). Phytohormones are small signalling molecules that regulate plant growth and development, including the formation of

  18. Programmed cell death in plants: A chloroplastic connection

    OpenAIRE

    Ambastha, Vivek; Tripathy, Baishnab C; Tiwari, Budhi Sagar

    2015-01-01

    Programmed cell death (PCD) is an integral cellular program by which targeted cells culminate to demise under certain developmental and pathological conditions. It is essential for controlling cell number, removing unwanted diseased or damaged cells and maintaining the cellular homeostasis. The details of PCD process has been very well elucidated and characterized in animals but similar understanding of the process in plants has not been achieved rather the field is still in its infancy that ...

  19. 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.

  20. Extracellular ATP signaling and homeostasis in plant cells

    OpenAIRE

    Sun, Jian; Zhang, Chunlan; Zhang, Xuan; Deng, Shurong; Zhao, Rui; Shen, Xin; Chen, Shaoliang

    2012-01-01

    Extracellular ATP (eATP) is now recognized as an important signaling agent in plant growth and defense response to environmental stimuli. eATP has dual functions in plant cell signaling, which is largely dependent on its concentration in the extracellular matrix (ECM). A lethal level of eATP (extremely low or high) causes cell death, whereas a moderate level of eATP benefits plant growth and development. Ecto-apyrases (Nucleoside Triphosphate-Diphosphohydrolase) help control the eATP concentr...

  1. Plant Cell Cultures as Source of Cosmetic Active Ingredients

    Directory of Open Access Journals (Sweden)

    Ani Barbulova

    2014-04-01

    Full Text Available The last decades witnessed a great demand of natural remedies. As a result, medicinal plants have been increasingly cultivated on a commercial scale, but the yield, the productive quality and the safety have not always been satisfactory. Plant cell cultures provide useful alternatives for the production of active ingredients for biomedical and cosmetic uses, since they represent standardized, contaminant-free and biosustainable systems, which allow the production of desired compounds on an industrial scale. Moreover, thanks to their totipotency, plant cells grown as liquid suspension cultures can be used as “biofactories” for the production of commercially interesting secondary metabolites, which are in many cases synthesized in low amounts in plant tissues and differentially distributed in the plant organs, such as roots, leaves, flowers or fruits. Although it is very widespread in the pharmaceutical industry, plant cell culture technology is not yet very common in the cosmetic field. The aim of the present review is to focus on the successful research accomplishments in the development of plant cell cultures for the production of active ingredients for cosmetic applications.

  2. Confocal imaging of ionised calcium in living plant cells.

    Science.gov (United States)

    Williams, D A; Cody, S H; Gehring, C A; Parish, R W; Harris, P J

    1990-04-01

    Laser-scanning confocal microscopy has been used in conjunction with Fluo-3, a highly fluorescent visible wavelength probe for Ca2+, to visualize Ca2(+)-dynamics in the function of living plant cells. This combination has overcome many of the problems that have limited the use of fluorescence imaging techniques in the study of the role of cations (Ca2+ and H+) in plant cell physiology and enables these processes to be studied in single cells within intact plant tissue preparations. Maize coleoptiles respond to application of ionophores and plant growth hormones with elevations in cytosolic Ca2+ that can be resolved with a high degree of spatial resolution and can be interpreted quantitatively. PMID:2113832

  3. Space radiation effects on plant and mammalian cells

    Science.gov (United States)

    Arena, C.; De Micco, V.; Macaeva, E.; Quintens, R.

    2014-11-01

    The study of the effects of ionizing radiation on organisms is related to different research aims. The current review emphasizes the studies on the effects of different doses of sparsely and densely ionizing radiation on living organisms, with the final purpose of highlighting specific and common effects of space radiation in mammals and plants. This topic is extremely relevant in the context of radiation protection from space environment. The response of different organisms to ionizing radiation depends on the radiation quality/dose and/or the intrinsic characteristics of the living system. Macromolecules, in particular DNA, are the critical targets of radiation, even if there is a strong difference between damages encountered by plant and mammalian cells. The differences in structure and metabolism between the two cell types are responsible for the higher resistance of the plant cell compared with its animal counterpart. In this review, we report some recent findings from studies performed in Space or on Earth, simulating space-like levels of radiation with ground-based facilities, to understand the effect of ionizing radiation on mammalian and plant cells. In particular, our attention is focused on genetic alterations and repair mechanisms in mammalian cells and on structures and mechanisms conferring radioresistance to plant cells.

  4. Plant Micrometabolomics: The Analysis of Endogenous Metabolites Present in a Plant Cell or Tissue.

    NARCIS (Netherlands)

    Moco, S.I.A.; Schneider, B.; Vervoort, J.J.M.

    2009-01-01

    Identification and quantification of metabolites occurring within specific cell types or single cells of plants and other organisms is of particular interest for natural product chemistry, chemical ecology, and biochemistry in general. The integration of studies at the gene, transcript, protein and

  5. 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.

  6. Localization of muscarinic acetylcholine receptor in plant guard cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Acetylcholine (ACh), as an important neurotransmitter in animals, also plays a significant role in various kinds of physiological functions in plants. But relatively little is known about its receptors in plants. A green fluorescence BODIPY FL-labeled ABT, which is a high affinity ligand of muscarinic acetylcholine receptor (mAChR), was used to localize mAChR in plant guard cells. In Vicia faba L. and Pisum sativum L., mAChR was found both on the plasma membrane of guard cells. mAChR may also be distributed on guard cell chloroplast membrane of Vicia faba L. The evidence that mAChR localizes in the guard cells provides a new possible signal transduction pathway in ACh mediated stomata movement.

  7. Advanced coal gasifier-fuel cell power plant systems design

    Science.gov (United States)

    Heller, M. E.

    1983-01-01

    Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

  8. Polyphosphoinositides are present in plant tissue culture cells

    International Nuclear Information System (INIS)

    Polyphosphoinositides have been isolated from wild carrot cells grown in suspension culture. This is the first report of polyphosphoinositides in plant cells. The phospholipids were identified by comigration with known standards on thin-layer plates. After overnight labeling of the cells with myo-[2-3H] inositol, the phosphoinositides as percent recovered inositol were 93% phosphatidylinositol., 3.7% lysophosphatidylinositol, 1.7% phosphatidylinositol monophosphate, 0.8% phosphatidylinositol bisphosphate

  9. The market for utility-scale fuel cell plants

    Science.gov (United States)

    Watanabe, Yasuo; Matsumoto, Masaru; Takasu, Kazuhiko

    This paper is devoted to a survey of the current technology and future market for utility-scale fuel cell plants. The phosphoric acid fuel cell (PAFC) is entering into the stage where it is practically available for use with natural gas. Large capacity plants such as 11, 5 and 1 MW have been installed and operated in Italy and Japan. Their efficiency ranges from 36 to 42%. The molten carbonate fuel cell (MCFC) is in the demonstrating stage, both the fuel cell and the balance-of-plant (BOP) for natural gas. Demonstration plants of 2 and 1 MW have been under construction in the USA and Japan. Their efficiency will range from 40 to 50%. The solid oxide fuel cell (SOFC) is in the experimental stage around 100 kW for co-generation. Its conceptual system design has been conducted for both centralized and dispersed power plant in a cooperation with Westinghouse and NEDO. A market survey is now considered on the basis that future fuel cells will run for around 40 000 h in a stable manner with competitive performance. The market for fuel cells will be roughly at 2000 MW in Japan by the year 2010. Half of them will be installed for electric companies on the utility scale. The market will be shared between PAFC and MCFC by 10 and 90%, respectively. Current technologies have not reached the stage to precisely forecast when fuel cells will be entering into the market on a utility scale. At the present time, it is worthwhile to consider how the technological and economic requirements will be definitely achieved. After achieving these requirements, fuel cells will be positively introduced and socially accepted as the best energy converting option to save energy and environmental impact. Further efforts will be devoted to meeting the market from the technological and economic aspects.

  10. Cell-wall hemicelluloses as mobile carbon stores in plants

    OpenAIRE

    Schädel, Christina

    2009-01-01

    Hemicelluloses are the second most abundant polysaccharide in nature after cellulose. So far, the chemical heterogeneity of cell-wall hemicelluloses and the relatively large sample-volume required in existing methods represent major obstacles for large-scale, cross-species analyses of this important plant compounds. Here, we apply a new micro-extraction method to analyse hemicelluloses and the ratio of ‘cellulose and lignin’ to hemicelluloses in different tissues of 28 plant species comprisin...

  11. Nanosecond electric pulses trigger actin responses in plant cells

    International Nuclear Information System (INIS)

    We have analyzed the cellular effects of nanosecond pulsed electrical fields on plant cells using fluorescently tagged marker lines in the tobacco cell line BY-2 and confocal laser scanning microscopy. We observe a disintegration of the cytoskeleton in the cell cortex, followed by contraction of actin filaments towards the nucleus, and disintegration of the nuclear envelope. These responses are accompanied by irreversible permeabilization of the plasma membrane manifest as uptake of Trypan Blue. By pretreatment with the actin-stabilizing drug phalloidin, the detachment of transvacuolar actin from the cell periphery can be suppressed, and this treatment can also suppress the irreversible perforation of the plasma membrane. We discuss these findings in terms of a model, where nanosecond pulsed electric fields trigger actin responses that are key events in the plant-specific form of programmed cell death.

  12. The Endoplasmic Reticulum: A Social Network in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Jun Chen; Caitlin Doyle; Xingyun Qi; Huanquan Zheng

    2012-01-01

    The endoplasmic reticulum (ER) is an interconnected network comprised of ribosome-studded sheets and smooth tubules.The ER plays crucial roles in the biosynthesis and transport of proteins and lipids,and in calcium (Ca2+) regulation in compartmentalized eukaryotic cells including plant cells.To support its well-segregated functions,the shape of the ER undergoes notable changes in response to both developmental cues and outside influences.In this review,we will discuss recent findings on molecular mechanisms underlying the unique morphology and dynamics of the ER,and the importance of the interconnected ER network in cell polarity.In animal and yeast cells,two family proteins,the reticulons and DP1/Yop1,are required for shaping high-curvature ER tubules,while members of the atlastin family of dynamin-like GTPases are involved in the fusion of ER tubules to make an interconnected ER network.In plant cells,recent data also indicate that the reticulons are involved in shaping ER tubules,while RHD3,a plant member of the atlastin GTPases,is required for the generation of an interconnected ER network.We will also summarize the current knowledge on how the ER interacts with other membrane-bound organelles,with a focus on how the ER and Golgi interplay in plant cells.

  13. Oral Delivery of Protein Drugs Bioencapsulated in Plant Cells.

    Science.gov (United States)

    Kwon, Kwang-Chul; Daniell, Henry

    2016-08-01

    Plants cells are now approved by the FDA for cost-effective production of protein drugs (PDs) in large-scale current Good Manufacturing Practice (cGMP) hydroponic growth facilities. In lyophilized plant cells, PDs are stable at ambient temperature for several years, maintaining their folding and efficacy. Upon oral delivery, PDs bioencapsulated in plant cells are protected in the stomach from acids and enzymes but are subsequently released into the gut lumen by microbes that digest the plant cell wall. The large mucosal area of the human intestine offers an ideal system for oral drug delivery. When tags (receptor-binding proteins or cell-penetrating peptides) are fused to PDs, they efficiently cross the intestinal epithelium and are delivered to the circulatory or immune system. Unique tags to deliver PDs to human immune or nonimmune cells have been developed recently. After crossing the epithelium, ubiquitous proteases cleave off tags at engineered sites. PDs are also delivered to the brain or retina by crossing the blood-brain or retinal barriers. This review highlights recent advances in PD delivery to treat Alzheimer's disease, diabetes, hypertension, Gaucher's or ocular diseases, as well as the development of affordable drugs by eliminating prohibitively expensive purification, cold chain and sterile delivery. PMID:27378236

  14. Plant Cell Division Analyzed by Transient Agrobacterium-Mediated Transformation of Tobacco BY-2 Cells.

    Science.gov (United States)

    Buschmann, Henrik

    2016-01-01

    The continuing analysis of plant cell division will require additional protein localization studies. This is greatly aided by GFP-technology, but plant transformation and the maintenance of transgenic lines can present a significant technical bottleneck. In this chapter I describe a method for the Agrobacterium-mediated genetic transformation of tobacco BY-2 cells. The method allows for the microscopic analysis of fluorescence-tagged proteins in dividing cells in within 2 days after starting a coculture. This transient transformation procedure requires only standard laboratory equipment. It is hoped that this rapid method would aid researchers conducting live-cell localization studies in plant mitosis and cytokinesis.

  15. Do cancer cells in human and meristematic cells in plant exhibit similar responses toward plant extracts with cytotoxic activities?

    Science.gov (United States)

    Khalifa, Noha S; Barakat, Hoda S; Elhallouty, Salwa; Salem, Dina

    2015-01-01

    We examined the effect of water extracts of Persea americana fruit, and of the leaves of Tabernamontana divericata, Nerium oleander and Annona cherimolia (positive control) on Vicia faba root cells. We had confirmed in our previously published data the cytotoxicity of these plant extracts on four human cancer cell lines: liver (HepG-2), lung (A549), colon (HT-29) and breast (MCF-7). Vicia faba roots were soaked in plant extracts at dilutions of 100, 1,250, 2,500, 5,000, 10,000, 20,000 ppm for 4 and 24 h. All treatments resulted in a significant reduction in the mitotic index in a dose dependant manner. Root cells treated with T. divericata, N. oleander and A. cherimolia exhibited a decrease in prophase cell percentage, increase in micronuclei and chromosomal abnormalities as concentration increased. The P. americana treatment showed the highest cytotoxic effect on cancer cells, prophase cell percentage increased linearly with the applied concentration and no micronuclei were detected. This study shows that root tip assay of beans can be used in initial screening for new plant extracts to validate their use as candidates for containing active cytotoxic agents against malignant cells. This will greatly help in exploring new plant extracts as drugs for cancer treatment. PMID:24705601

  16. 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

  17. Synthesis and Application of Plant Cell Wall Oligogalactans

    DEFF Research Database (Denmark)

    Andersen, Mathias Christian Franch

    The plant cell walls represent almost 50% of the biomass found in plants and are therefore one of the main targets for biotechnological research. Major motivators are their potential as a renewable energy source for transport fuels, as functional foods, and as a source of raw materials to generate...... chemical building blocks for industrial processes. To achieve a sustainable development it is necessary to optimize plant production and utilization. This will require a better understanding of the cell wall structure and function at the molecular level. The cell wall is composed by an intricate network...... of the arabinogalactans series. The fragments were applied in the characterization of a glycosyl transferase, a hydrolase and to study the important cancer biomarker galectin-3. The work done during an external stay at University of Oxford is also presented. This concerns isolation and modification...

  18. 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...... features, others monitor physical changes caused by an infection attempt. Detection of microbes leads to activation of appropriate defense responses that then challenge the attack. Plant cell walls are formidable and dynamic barriers. They are constructed primarily of complex carbohydrates joined...... by numerous distinct connection types, and are subject to extensive post-synthetic modification to suit prevailing local requirements. Multiple changes can be triggered in cell walls in response to microbial attack. Some of these are well described, but many remain obscure. The study of the myriad of subtle...

  19. Phase-segregated model for plant cell culture: The effect of cell volume fraction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W. [Univ. of Adelaide, Adelaide (Australia). Dept. of Chemical Engineering]|[Tokyo Univ. (Japan)hinese Academy of Sciences, Dalian (China). Dalian Inst. of Chemical Physics; Furusaki, S. [Tokyo Univ. (Japan)] Middelberg, A. [Univ. of Adelaide, Adelaide (Australia). Dept. of Chemical Engineering

    1998-06-01

    Plant cells are characterized by low water content, so the fraction of cell volume (volume fraction) in a vessel is large compared with other cell systems, even if the cell concentrations are the same. Therefore, concentration of plant cells should preferably be expressed by the liquid volume basis rather than by the total vessel volume basis. In this paper, a new model is proposed to analyze behavior of a plant cell culture by dividing the cell suspension into the biotic- and abiotic-phases. Using this model, we analyzed the cell-growth and the alkaloid production by Catharanthus roseus. Large errors in the simulated results were observed if the phase-segregation was not considered. 12 refs., 3 figs.

  20. Plant Cell and Signaling Biology Blooms in the Wuyi Mountain

    Institute of Scientific and Technical Information of China (English)

    Jianping Hu

    2011-01-01

    @@ INTRODUCTION The Eighth International Conference on Plant Biology Fron-tiers, organized by Zhenbiao Yang, Chentao Lin, and Xing-wang Deng, was convened in the Wuyi Mountain Yeohwa Resort in Fujian, China, 23-27 September 2010.The meeting's main theme was Cells and Signals, featuring four keynote speeches, 45 plenary talks, and over 40 poster presentations that covered a wide range of topics, from dynamic cellular structures to how developmental and environmental signals control various plant processes at the juncture of cells.

  1. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  2. Phosphatidylinositol species of suspension cultured plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Heim, S.; Wagner, K.G.

    Suspension cultured Nicotiana tabacum and Catharanthus roseus cells were labeled with (/sup 3/H)inositol, the phospholipid fraction extracted and separated by thin layer chromatography. Three different solvent systems and reference compounds were used to assign the different /sup 3/H-labeled species by autoradiography. The ratio of (/sup 3/H)inositol incorporation into PI, PIP and PIP/sub 2/ was found to be 95:4:1; with some preparations a lyso-PI band was obtained which incorporated about a tenth of the label of the PIP band. With Catharanthus roseus cells a very faint band between PI and lyso-PI was detected which could not be assigned to a reference compound.

  3. Plastids: dynamic components of plant cell development

    Science.gov (United States)

    Guikema, J. A.; Gallegos, G. L.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The gravitropic bending of maize roots, as a response to reorientation of the root within a gravitational field, was examined for sensitivity to exogenous applications of the cytoskeletal inhibitor, cytochalasin D. Agar blocks were impregnated with this inhibitor, and were applied either to the root cap or to the zone of root cell elongation. Root growth was normal with either treatment, if the roots were not repositioned with respect to the gravitational vector. When untreated roots were placed in a horizontal position with respect to gravity, a 40 degree bending response was observed within one hour. This bending also occurred when cytochalasin D was applied at high concentrations to the zone of root cell elongation. However, when cytochalasin D above 40 micrograms/ml was applied to the root cap, roots lost the ability of directional reorientation within the gravitational field, causing a random bending.

  4. Mechanical Response of Single Plant Cells to Cell Poking: A Numerical Simulation Model

    Institute of Scientific and Technical Information of China (English)

    Rong Wang; Qun-Ying Jiao; De-Qiang Wei

    2006-01-01

    Cell poking is an experimental technique that is widely used to study the mechanical properties of plant cells. A full understanding of the mechanical responses of plant cells to poking force is helpful for experimental work. The aim of this study was to numerically investigate the stress distribution of the cell wall,cell turgor, and deformation of plant cells in response to applied poking force. Furthermore, the locations damaged during poking were analyzed. The model simulates cell poking, with the cell treated as a spherical,homogeneous, isotropic elastic membrane, filled with incompressible, highly viscous liquid. Equilibrium equations for the contact region and the non-contact regions were determined by using membrane theory.The boundary conditions and continuity conditions for the solution of the problem were found. The forcedeformation curve, turgor pressure and tension of the cell wall under cell poking conditions were obtained.The tension of the cell wall circumference was larger than that of the meridian. In general, maximal stress occurred at the equator around. When cell deformation increased to a certain level, the tension at the poker tip exceeded that of the equator. Breakage of the cell wall may start from the equator or the poker tip,depending on the deformation. A nonlinear model is suitable for estimating turgor, stress, and stiffness,and numerical simulation is a powerful method for determining plant cell mechanical properties.

  5. Mechanisms of Organelle Inheritance in Dividing Plant Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Organelles form essential compartments of all eukaryotic cells. Mechanisms that ensure the unbiased inheritance of organelles during cell division are therefore necessary to maintain the viability of future cell generations. Although inheritance of organelles represents a fundamental component of the cell cycle, surprisingly little is known about the underlying mechanisms that facilitate unbiased organelle inheritance. Evidence from a select number of studies, however,indicates that ordered organelle inheritance strategies exist in dividing cells of higher plants. The basic requirement for unbiased organelle inheritance is the duplication of organelle volume and distribution of the resulting organelle populations in a manner that facilitates unbiased partitioning of the organelle population to each daughter cell. Often, partitioning strategies are specific to the organelle, being influenced by the functional requirements of the organelle and whether the cells are mitotically active or re-entering into the cell cycle. Organelle partitioning mechanisms frequently depend on interactions with either the actin or microtubule cytoskeleton. In this focused review, we attempt to summarize key findings regarding organelle partitioning strategies in dividing cells of higher plants. We particularly concentrate on the role of the cytoskeleton in mediating unbiased organelle partitioning.

  6. Quantification of plant cell coupling with live-cell microscopy

    DEFF Research Database (Denmark)

    Liesche, Johannes; Schulz, Alexander

    2015-01-01

    by confocal microscopy, loaded tracer is activated by UV illumination in a target cell and its spread to neighboring cells monitored. When combined with high-speed acquisition by resonant scanning or spinning disc confocal microscopy, the high signal-to-noise ratio of photoactivation allows collection...

  7. Quantification of Plant Cell Coupling with Live-Cell Microscopy

    DEFF Research Database (Denmark)

    Liesche, Johannes; Schulz, Alexander

    2015-01-01

    by confocal microscopy, loaded tracer is activated by UV illumination in a target cell and its spread to neighboring cells monitored. When combined with high-speed acquisition by resonant scanning or spinning disc confocal microscopy, the high signal-to-noise ratio of photoactivation allows collection...

  8. Patterns of Stem Cell Divisions Contribute to Plant Longevity.

    Science.gov (United States)

    Burian, Agata; Barbier de Reuille, Pierre; Kuhlemeier, Cris

    2016-06-01

    The lifespan of plants ranges from a few weeks in annuals to thousands of years in trees. It is hard to explain such extreme longevity considering that DNA replication errors inevitably cause mutations. Without purging through meiotic recombination, the accumulation of somatic mutations will eventually result in mutational meltdown, a phenomenon known as Muller's ratchet. Nevertheless, the lifespan of trees is limited more often by incidental disease or structural damage than by genetic aging. The key determinants of tree architecture are the axillary meristems, which form in the axils of leaves and grow out to form branches. The number of branches is low in annual plants, but in perennial plants iterative branching can result in thousands of terminal branches. Here, we use stem cell ablation and quantitative cell-lineage analysis to show that axillary meristems are set aside early, analogous to the metazoan germline. While neighboring cells divide vigorously, axillary meristem precursors maintain a quiescent state, with only 7-9 cell divisions occurring between the apical and axillary meristem. During iterative branching, the number of branches increases exponentially, while the number of cell divisions increases linearly. Moreover, computational modeling shows that stem cell arrangement and positioning of axillary meristems distribute somatic mutations around the main shoot, preventing their fixation and maximizing genetic heterogeneity. These features slow down Muller's ratchet and thereby extend lifespan. PMID:27161504

  9. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    OpenAIRE

    Truernit Elisabeth; Haseloff Jim

    2008-01-01

    Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy....

  10. Handbook of plant cell culture. Volume 2. Crop species

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, W.R.; Evans, D.A.; Ammirato, P.V.; Yamada, Y. (eds.)

    1984-01-01

    In this volume the state-of-the-art plant cell culture techniques described in the first volume are applied to several agricultural and horticultural crops. In 21 chapters, they include maize, oats, wheat, beans, red clover and other forage legumes, asparagus, celery, cassava, sweet potato, banana, pawpaw, apple, grapes, conifers, date palm, rubber, sugarcane and tobacco. Each chapter contains (1) detailed protocols to serve as the foundation for current research, (2) a critical review of the literature, and (3) in-depth evaluations of the potential shown by plant cell culture for crop improvement. The history and economic importance of each crop are discussed. This volume also includes an essay, ''Oil from plants'', by M. Calvin.

  11. Fluorescence Correlation Spectroscopy Applied to Living Plant Cells

    NARCIS (Netherlands)

    Hink, M.A.

    2002-01-01

    Keywords: Fluorescence correlation spectroscopy, photon counting histogram, intracellular, plant, AtSERK1In order to survive organisms have to be capable to adjust theirselves to changes in the environment. Cells, the building blocks of an organism react to these

  12. Engineering controlled mammalian type O-Glycosylation in plant cells

    DEFF Research Database (Denmark)

    Yang, Zhang; Drew, Damian Paul; Jørgensen, Bodil;

    2011-01-01

    Human mucins are large heavily O-glycosylated glycoproteins (>200 kDa), which account for the majority of proteins in mucus layers that e.g. hydrate, lubricate and protect cells from proteases as well as from pathogens. O-linked mucin glycans are truncated in many cancers, yielding truncated cancer...... specific glyco-peptide epitopes, such as the Tn epitope (GalNAc sugar attached to either Serine or Threonine), which are antigenic to the immune system. In the present study, we have identified plant cells as the only eukaryotic cells without mammalian type O-glycosylation or competing (for sites) O...

  13. Putting On The Breaks: Regulating Organelle Movements in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Julianna K.Vick; Andreas Nebenführ

    2012-01-01

    A striking characteristic of plant cells is that their organelles can move rapidly through the cell.This movement,commonly referred to as cytoplasmic streaming,has been observed for over 200 years,but we are only now beginning to decipher the mechanisms responsible for it.The identification of the myosin motor proteins responsible for these movements allows us to probe the regulatory events that coordinate organelle displacement with normal cell physiology.This review will highlight several recent developments that have provided new insight into the regulation of organelle movement,both at the cellular level and at the molecular level.

  14. Micrasterias as a model system in plant cell biology

    Directory of Open Access Journals (Sweden)

    Ursula Luetz-Meindl

    2016-07-01

    Full Text Available The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its extraordinary star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 µm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

  15. Micrasterias as a Model System in Plant Cell Biology

    Science.gov (United States)

    Lütz-Meindl, Ursula

    2016-01-01

    The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells. PMID:27462330

  16. Regulation of cell division in higher plants. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Thomas W.

    2000-02-29

    Research in the latter part of the grant period was divided into two parts: (1) expansion of the macromolecular tool kit for studying plant cell division; (2) experiments in which the roles played by plant cell cycle regulators were to be cast in the light of the emerging yeast and animal cell paradigm for molecular control of the mitotic cycle. The first objectives were accomplished to a very satisfactory degree. With regard to the second part of the project, we were driven to change our objectives for two reasons. First, the families of cell cycle control genes that we cloned encoded such closely related members that the prospects for success at raising distinguishing antisera against each were sufficiently dubious as to be impractical. Epitope tagging is not feasible in Pisum sativum, our experimental system, as this species is not realistically transformable. Therefore, differentiating the roles of diverse cyclins and cyclin-dependent kinases was problematic. Secondly, our procedure for generating mitotically synchronized pea root meristems for biochemical studies was far too labor intensive for the proposed experiments. We therefore shifted our objectives to identifying connections between the conserved proteins of the cell cycle engine and factors that interface it with plant physiology and development. In this, we have obtained some very exciting results.

  17. Determining the polysaccharide composition of plant cell walls.

    Science.gov (United States)

    Pettolino, Filomena A; Walsh, Cherie; Fincher, Geoffrey B; Bacic, Antony

    2012-09-01

    The plant cell wall is a chemically complex structure composed mostly of polysaccharides. Detailed analyses of these cell wall polysaccharides are essential for our understanding of plant development and for our use of plant biomass (largely wall material) in the food, agriculture, fabric, timber, biofuel and biocomposite industries. We present analytical techniques not only to define the fine chemical structures of individual cell wall polysaccharides but also to estimate the overall polysaccharide composition of cell wall preparations. The procedure covers the preparation of cell walls, together with gas chromatography-mass spectrometry (GC-MS)-based methods, for both the analysis of monosaccharides as their volatile alditol acetate derivatives and for methylation analysis to determine linkage positions between monosaccharide residues as their volatile partially methylated alditol acetate derivatives. Analysis time will vary depending on both the method used and the tissue type, and ranges from 2 d for a simple neutral sugar composition to 2 weeks for a carboxyl reduction/methylation linkage analysis. PMID:22864200

  18. Plant Cell Cancer: May Natural Phenolic Compounds Prevent Onset and Development of Plant Cell Malignancy? A Literature Review.

    Science.gov (United States)

    Rasouli, Hassan; Farzaei, Mohammad Hosein; Mansouri, Kamran; Mohammadzadeh, Sara; Khodarahmi, Reza

    2016-01-01

    Phenolic compounds (PCs) are known as a chemically diverse category of secondary and reactive metabolites which are produced in plants via the shikimate-phenylpropanoid pathways. These compounds-ubiquitous in plants-are an essential part of the human diet, and are of considerable interest due to their antioxidant properties. Phenolic compounds are essential for plant functions, because they are involved in oxidative stress reactions, defensive systems, growth, and development. A large body of cellular and animal evidence carried out in recent decades has confirmed the anticancer role of PCs. Phytohormones-especially auxins and cytokinins-are key contributors to uncontrolled growth and tumor formation. Phenolic compounds can prevent plant growth by the endogenous regulation of auxin transport and enzymatic performance, resulting in the prevention of tumorigenesis. To conclude, polyphenols can reduce plant over-growth rate and the development of tumors in plant cells by regulating phytohormones. Future mechanistic studies are necessary to reveal intracellular transcription and transduction agents associated with the preventive role of phenolics versus plant pathological malignancy cascades. PMID:27563858

  19. 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.

  20. 1000kW phosphoric acid fuel cell power plant. Outline of the plant

    Energy Technology Data Exchange (ETDEWEB)

    Shinobe, Kenji; Suzuki, Kazuo; Kaneko, Hideo

    1988-02-10

    The outline of the 1000KW phosphoric acid fuel cell power plant, developed as part of the Moonlight plan, was described. The plant was composed of 4 stacks of 260KW DC output. They were devided into two train with 680V and 765A. The generation efficiency of the plant was 40% and more. Steam reforming of natural gas was used. As the fuel, fuel cell exhaust gas was used in composition with the natural gas. The DC-AC inverter had an efficiency of 96%. The capacity of hot water generator and demineralized water plant for cell cooling were 2t/h and 1.6t/h, respectively, and air-system was incorporated. In September of 1987, the plant has succeeded in 1000KW power generation, and put in operation now. Under the 100% loaded condition, each cell had a voltage of 0.7V with little variation, and the current was 200mA/cm/sup 2/. No problems were found in cooling conditions and in the control of interpole differential pressure. The reformer has been operated for 1200h scince its commisioning, and had experiences of 100 times on start up-shut down operations, the reformer also indicated good performances in the gas compositions. The starting time of 8h and the load follow-up rate 10%/min remain as the subjects for shortening. DC-AC conversion was good. The concentration of NOx and the noise level satisfied the target values. (12 figs, 1 tab)

  1. Hydrogen peroxide homeostasis and signaling in plant cells

    Institute of Scientific and Technical Information of China (English)

    CHENG; Yanli; SONG; Chunpen

    2006-01-01

    The increases of H2O2 concentrations in plant cells often occur under biotic and abiotic stress conditions (e.g. light, environmental stresses and plant hormone abscisic acid).Atmospheric H2O2 as an ancient signal molecule not only plays the key role in inducing evolution of oxygenic photosynthesis, but also modulates many physiological events, such as stomatal movement, hypersensitive responses, programmed cell death and gene expressions. H2O2 levels in cells must sustain a fine equilibrium between production and scavenging. H2O2 enters cells from the apoplast or generated sources, and in turn is distributed in sub-cellular compartments.H2O2 can modulate the activities of many components in signaling, such as protein phosphatases,protein kinases, transcription factors (TFs), and calcium channels. Elevated cytosolic calcium concentrations will initiate further downstream responses, via the action of calcium-binding proteins. On the other hand, the research of H2O2 as a signal molecule is still in a comparatively juvenile stage, for example, little is known about how the cells sense H2O2, what the rate-limiting steps and most important cellular events are in cell signaling and what kind of genes is specific or necessary to H2O2 signaling. The answers to all the questions depend on the functional genomic and molecular genetics analysis.

  2. Plant Cell Cancer: May Natural Phenolic Compounds Prevent Onset and Development of Plant Cell Malignancy? A Literature Review

    Directory of Open Access Journals (Sweden)

    Hassan Rasouli

    2016-08-01

    Full Text Available Phenolic compounds (PCs are known as a chemically diverse category of secondary and reactive metabolites which are produced in plants via the shikimate-phenylpropanoid pathways. These compounds—ubiquitous in plants—are an essential part of the human diet, and are of considerable interest due to their antioxidant properties. Phenolic compounds are essential for plant functions, because they are involved in oxidative stress reactions, defensive systems, growth, and development. A large body of cellular and animal evidence carried out in recent decades has confirmed the anticancer role of PCs. Phytohormones—especially auxins and cytokinins—are key contributors to uncontrolled growth and tumor formation. Phenolic compounds can prevent plant growth by the endogenous regulation of auxin transport and enzymatic performance, resulting in the prevention of tumorigenesis. To conclude, polyphenols can reduce plant over-growth rate and the development of tumors in plant cells by regulating phytohormones. Future mechanistic studies are necessary to reveal intracellular transcription and transduction agents associated with the preventive role of phenolics versus plant pathological malignancy cascades.

  3. Thymoquinone causes multiple effects, including cell death, on dividing plant cells.

    Science.gov (United States)

    Hassanien, Sameh E; Ramadan, Ahmed M; Azeiz, Ahmed Z Abdel; Mohammed, Rasha A; Hassan, Sabah M; Shokry, Ahmed M; Atef, Ahmed; Kamal, Khalid B H; Rabah, Samar; Sabir, Jamal S M; Abuzinadah, Osama A; El-Domyati, Fotouh M; Martin, Gregory B; Bahieldin, Ahmed

    2013-01-01

    Thymoquinone (TQ) is a major constituent of Nigella sativa oil with reported anti-oxidative activity and anti-inflammatory activity in animal cells. It also inhibits proliferation and induces programmed cell death (apoptosis) in human skin cancer cells. The present study sought to detect the influence of TQ on dividing cells of three plant systems and on expression of Bcl2-associated athanogene-like (BAG-like) genes that might be involved during the process of cell death. BAG genes are known for the regulation of diverse physiological processes in animals, including apoptosis, tumorigenesis, stress responses, and cell division. Synthetic TQ at 0.1mg/mL greatly reduced wheat seed germination rate, whereas 0.2mg/mL completely inhibited germination. An Evans blue assay revealed moderate cell death in the meristematic zone of Glycine max roots after 1h of TQ treatment (0.2mg/mL), with severe cell death occurring in this zone after 2h of treatment. Light microscopy of TQ-treated (0.2mg/mL) onion hairy root tips for 1h revealed anti-mitotic activity and also cell death-associated changes, including nuclear membrane disruption and nuclear fragmentation. Transmission electron microscopy of TQ-treated cells (0.2mg/mL) for 1h revealed shrinkage of the plasma membrane, leakage of cell lysate, degradation of cell walls, enlargement of vacuoles and condensation of nuclei. Expression of one BAG-like gene, previously associated with cell death, was induced 20 min after TQ treatment in Glycine max root tip cells. Thus, TQ has multiple effects, including cell death, on dividing plant cells and plants may serve as a useful system to further investigate the mechanisms underlying the response of eukaryotic cells to TQ. PMID:24296078

  4. Plant Hormones Increase Efficiency of Reprogramming Mouse Somatic Cells to Induced Pluripotent Stem Cells and Reduce Tumorigenicity

    OpenAIRE

    Alvarez Palomo, Ana Belén; McLenachan, Samuel; Requena Osete, Jordi; Menchón, Cristina; Barrot, Carme; Chen, Fred; Munné-Bosch, Sergi; Michael J. Edel

    2013-01-01

    Reprogramming of somatic cells into induced pluripotent stem (iPS) cells by defined pluripotency and self-renewal factors has taken stem cell technology to the forefront of regenerative medicine. However, a number of challenges remain in the field including efficient protocols and the threat of cancer. Reprogramming of plant somatic cells to plant embryonic stem cells using a combination of two plant hormones was discovered in 1957 and has been a routine university laboratory practical for ov...

  5. Secondary Metabolite Localization by Autofluorescence in Living Plant Cells

    Directory of Open Access Journals (Sweden)

    Pascale Talamond

    2015-03-01

    Full Text Available Autofluorescent molecules are abundant in plant cells and spectral images offer means for analyzing their spectra, yielding information on their accumulation and function. Based on their fluorescence characteristics, an imaging approach using multiphoton microscopy was designed to assess localization of the endogenous fluorophores in living plant cells. This method, which requires no previous treatment, provides an effective experimental tool for discriminating between multiple naturally-occurring fluorophores in living-tissues. Combined with advanced Linear Unmixing, the spectral analysis extends the possibilities and enables the simultaneous detection of fluorescent molecules reliably separating overlapping emission spectra. However, as with any technology, the possibility for artifactual results does exist. This methodological article presents an overview of the applications of tissular and intra-cellular localization of these intrinsic fluorophores in leaves and fruits (here for coffee and vanilla. This method will provide new opportunities for studying cellular environments and the behavior of endogenous fluorophores in the intracellular environment.

  6. 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...... 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...... in horsetails (Equisetales order) was therefore significant and has prompted a re-evaluation of some of the current views on cell wall evolution and structural diversity. Addendum to: Sørensen I, Pettolino FA, Wilson SM, Doblin MS, Johansen B, Bacic A, Willats WGT. Mixed-linkage (1¿3),(1¿4)-ß...

  7. Integrating fuel cell power systems into building physical plants

    Energy Technology Data Exchange (ETDEWEB)

    Carson, J. [KCI Technologies, Inc., Hunt Valley, MD (United States)

    1996-12-31

    This paper discusses the integration of fuel cell power plants and absorption chillers to cogenerate chilled water or hot water/steam for all weather air conditioning as one possible approach to building system applications. Absorption chillers utilize thermal energy in an absorption based cycle to chill water. It is feasible to use waste heat from fuel cells to provide hydronic heating and cooling. Performance regimes will vary as a function of the supply and quality of waste heat. Respective performance characteristics of fuel cells, absorption chillers and air conditioning systems will define relationships between thermal and electrical load capacities for the combined systems. Specifically, this paper develops thermodynamic relationships between bulk electrical power and cooling/heating capacities for combined fuel cell and absorption chiller system in building applications.

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

    OpenAIRE

    Thygesen, Lisbeth G; Thybring, Emil E.; Johansen, Katja S.; Claus Felby

    2014-01-01

    Mechanical agitation during enzymatic hydrolysis of insoluble plant biomass at high dry matter contents is indispensable for the initial liquefaction step in biorefining. It is known that particle size reduction is an important part of liquefaction, but the mechanisms involved are poorly understood. 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 ...

  9. Penium margaritaceum as a model organism for cell wall analysis of expanding plant cells

    DEFF Research Database (Denmark)

    Rydahl, Maja Gro; Fangel, Jonatan Ulrik; Mikkelsen, Maria Dalgaard;

    2015-01-01

    have focused primarily upon late divergent multicellular land plants and specialized cell types (e.g., pollen tubes, root hairs). Here, we describe a unicellular green alga, Penium margaritaceum (Penium), which can serve as a valuable model organism for understanding cell expansion and the underlying...

  10. 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.

  11. ERC product improvement activities for direct fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C.; Carlson, G.; Doyon, J. [and others

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  12. Morphological Transformation of Plant Cells in vitro and Its Effect on Plant Growth

    Institute of Scientific and Technical Information of China (English)

    GUO Zhigang; ZENG Zhaolin; LIU Ruizhi; DENG Ying

    2005-01-01

    Enhancement of cell growth in suspension cultures is urgently needed in plant cell culture engineering. This study investigates the relationship between morphological transformation and cell growth in callus and suspension cultures of saffron cells belonging to the cell line C96 induced from Crocus sativus L. In the suspension culture, an unbalanced osmotic pressure between the intracell and extracell regions induced a large morphological transformation which affected normal division of the saffron cells. An increase in osmotic pressure caused by the addition of sucrose inhibits the vacuolation and shrinkage of cytoplasm in the cells. As the sucrose concentration increases, the total amount of accumulated biomass also increases. Besides the sucrose concentration, increased ionic strength and inoculation ratio also help restrain to a large extent the vacuolation and shrinkage of the cytoplasm in the suspended cells, which results in increased biomass. The conditions for optimal biomass are: Murashige and Skoog's (MS) medium with 40 g/L sucrose and 60% (v/v) inoculation ratio.

  13. Anhydrobiosis and programmed cell death in plants: Commonalities and Differences

    Directory of Open Access Journals (Sweden)

    Samer Singh

    2015-05-01

    Full Text Available Anhydrobiosis is an adaptive strategy of certain organisms or specialised propagules to survive in the absence of water while programmed cell death (PCD is a finely tuned cellular process of the selective elimination of targeted cell during developmental programme and perturbed biotic and abiotic conditions. Particularly during water stress both the strategies serve single purpose i.e., survival indicating PCD may also function as an adaptive process under certain conditions. During stress conditions PCD cause targeted cells death in order to keep the homeostatic balance required for the organism survival, whereas anhydrobiosis suspends cellular metabolic functions mimicking a state similar to death until reestablishment of the favourable conditions. Anhydrobiosis is commonly observed among organisms that have ability to revive their metabolism on rehydration after removal of all or almost all cellular water without damage. This feature is widely represented in terrestrial cyanobacteria and bryophytes where it is very common in both vegetative and reproductive stages of life-cycle. In the course of evolution, with the development of advanced vascular system in higher plants, anhydrobiosis was gradually lost from the vegetative phase of life-cycle. Though it is retained in resurrection plants that primarily belong to thallophytes and a small group of vascular angiosperm, it can be mostly found restricted in orthodox seeds of higher plants. On the contrary, PCD is a common process in all eukaryotes from unicellular to multicellular organisms including higher plants and mammals. In this review we discuss physiological and biochemical commonalities and differences between anhydrobiosis and PCD.

  14. Plant cell nucleolus as a hot spot for iron.

    Science.gov (United States)

    Roschzttardtz, Hannetz; Grillet, Louis; Isaure, Marie-Pierre; Conéjéro, Geneviève; Ortega, Richard; Curie, Catherine; Mari, Stéphane

    2011-08-12

    Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.

  15. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    Directory of Open Access Journals (Sweden)

    Truernit Elisabeth

    2008-06-01

    Full Text Available Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP fluorescence was possible. Conclusion The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy.

  16. Cloning and analysis of genes regulating plant cell growth

    International Nuclear Information System (INIS)

    The aims of this work are to identify, clone and analyze genes involved in the regulation of plant cell growth. To do this, we have induced tumors on Arabidopsis thaliana by exposing seed or germinating seedlings to ionizing radiation. The tumors which developed on the plants derived from these seed were excised and established in culture. Unlike normal tissue explants, the tumors are able to grow on hormone-free medium suggesting changes in growth control (either hormonal or other) induced by the radiation exposure. This progress report describes work aimed at characterizing these tumors at the physiological and cellular levels and at determining the molecular basis of the changes leading to the tumorous phenotype

  17. Genetic changes induced in higher plant cells by a laser microbeam

    International Nuclear Information System (INIS)

    Introducing foreign genes into higher plants has proved to be complicated, with the exception of transformation of protoplasts of some plants (Negrutiu et al. 1987). In particular, culture of protoplasts and regeneration to plants are difficult in many monocotyledonous crops. Therefore, it would be desirable to avoid extensive tissue culture by introducing cloned genes directly into cells. A laser microbeam can perforate plant cell walls, thus facilitating uptake of genes into cells

  18. A radioimmunoassay for lignin in plant cell walls

    International Nuclear Information System (INIS)

    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 β-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 ηg/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. 125I 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 NaClO2 delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed

  19. Actin based processes that could determine the cytoplasmic architecture of plant cells

    NARCIS (Netherlands)

    Honing, van der H.S.; Emons, A.M.C.; Ketelaar, M.J.

    2007-01-01

    Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells t

  20. Direct fuel cell power plants: the final steps to commercialization

    Science.gov (United States)

    Glenn, Donald R.

    Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each

  1. 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

    Mechanical agitation during enzymatic hydrolysis of insoluble plant biomass at high dry matter contents is indispensable for the initial liquefaction step in biorefining. It is known that particle size reduction is an important part of liquefaction, but the mechanisms involved are poorly understood....... 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...

  2. The Fluorescence Methods to Study Neurotransmitters (Biomediators) in Plant Cells.

    Science.gov (United States)

    Roshchina, Victoria V

    2016-05-01

    Fluorescence as a parameter for analysis of intracellular binding and localization of neurotransmitters also named biomediators (acetylcholine and biogenic amines such as catecholamines, serotonin, histamine) as well as their receptors in plant cells has been estimated basing on several world publications and own experiments of the author. The subjects of the consideration were 1. application of reagents forming fluorescent products (for catecholamines - glyoxylic acid, for histamine - formaldehyde or ortho-phthalic aldehyde) to show the presence and binding of the compounds in cells, 2. binding of their fluorescent agonists and antagonists with cell, 3. effects of the compounds, their agonists and antagonists on autofluorescence, 4. action of external factors on the accumulation of the compounds in cells. How neurotransmitters can bind to certain cellular compartments has been shown on intact individual cells (vegetative microspores, pollens, secretory cells) and isolated organelles. The staining with reagents on biogenic amines leads to the appearance blue or blue-green emission on the surface and excretions of intact cells as well in some DNA-containing organelles within cells. The difference between autofluorescence and histochemically induced fluorescence may reflect the occurrence and amount of biogenic amines in the cells studied. Ozone and salinity as external factors can regulate the emission of intact cells related to biogenic amines. After the treatment of isolated cellular organelles with glyoxylic acid blue emission with maximum 460-475 nm was seen in nuclei and chloroplasts (in control variants in this spectral region the noticeable emission was absent) and very expressive fluorescence (more than twenty times as compared to control) in the vacuoles. After exposure to ortho-phthalic aldehyde blue emission was more noticeable in nuclei and chloroplasts. Fluorescent agonists (muscarine, 6,7-diOHATN, BODIPY-dopamine or BODIPY-5HT) or antagonists (d

  3. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

    Directory of Open Access Journals (Sweden)

    Asako eUchiyama

    2014-11-01

    Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

  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. Information Technologies for Biology Education: Computerized Electrophysiology of Plant Cells

    Directory of Open Access Journals (Sweden)

    Vilma KISNIERIENE

    2008-04-01

    Full Text Available Biology has moved from a bench-based discipline to a bioinformational science in modern times but application of computational and analytical methods of informatics in it is still a problem for many researchers and students of biology. We suggest to integrate cost effective and practical combination of the real and the virtual laboratories into the undergraduate biological science curriculum. This laboratory work illustrates passive and active electrical properties of plant cell membranes while introducing basic principles of electrophysiological recording, data acquisition and analysis. As the object for investigation in this laboratory work large cells of starry stonewort (Nitellopsis obtusa were used. The simple program for experiment control and express visualization of recorded data was developed. Experiment proposed in this paper is easy implemented with a minimum of laboratory equipment, materials and gives an experience of computerized biological experiment.

  6. Consolidated pretreatment and hydrolysis of plant biomass expressing cell wall degrading enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Raab, R. Michael; Zhang, Dongcheng; Bougri, Oleg

    2016-02-02

    Methods for consolidated pretreatment and hydrolysis of genetically engineered plants expressing cell wall degrading enzymes are provided. Expression cassettes and vectors for making transgenic plants are described. Plants engineered to express one or more cell wall degrading enzymes using expression cassettes and vectors of the invention are also provided.

  7. CYCLODEXTRINS AS A USEFUL TOOL FOR BIOCONVERSIONS IN PLANT-CELL BIOTECHNOLOGY

    NARCIS (Netherlands)

    VANUDEN, W; WOERDENBAG, HJ; PRAS, N

    1994-01-01

    The application of cyclodextrins as precursor solubilizers in biotechnological processes, in which plant cells are involved, is new. In this paper the possibilities for cyclodextrin facilitated bioconversions by freely suspended and/or immobilized plant cells or plant enzymes are demonstrated. After

  8. Long-term performance of a plant microbial fuel cell with Spartina anglica

    NARCIS (Netherlands)

    Timmers, R.A.; Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2010-01-01

    The plant microbial fuel cell is a sustainable and renewable way of electricity production. The plant is integrated in the anode of the microbial fuel cell which consists of a bed of graphite granules. In the anode, organic compounds deposited by plant roots are oxidized by electrochemically active

  9. Green electricity production with living plants and bacteria in a fuel cell

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Hamelers, H.V.M.; Snel, J.F.H.; Buisman, C.J.N.

    2008-01-01

    The world needs sustainable, efficient, and renewable energy production. We present the plant microbial fuel cell (plant-MFC), a concept that exploits a bioenergy source in situ. In the plant-MFC, plants and bacteria were present to convert solar energy into green electricity. The principal idea is

  10. Measuring NO Production by Plant Tissues and Suspension Cultured Cells

    Institute of Scientific and Technical Information of China (English)

    Jan Vitecek; Vilem Reinohl; Russell L.Jones

    2008-01-01

    We describe an inexpensive and reliable detector for measuring NO emitted in the gas phase from plants.The method relies on the use of a strong oxidizer to convert NO to NO2 and subsequent capture of NO2 by a Griess reagent trap.The set-up approaches the sensitivity for NO comparable to that of instruments based on chemiluminescence and photoacoustic detectors.We demonstrate the utility of our set-up by measuring NO produced by a variety of well established plant sources.NO produced by nitrate reductase (NR) in tobacco leaves and barley aleurone was readily detected,as was the production of NO from nitrite by the incubation medium of barley aleurone.Arabidopsis mutants that overproduce NO or lack NO-synthase (AtNOS1) also displayed the expected NO synthesis phenotype when assayed by our set-up.We could also measure NO production from elicitor-treated suspension cultured cells using this set-up.Further,we have focused on the detection of NO by a widely used fluorescent probe 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM).Our work points to the pitfalls that must be avoided when using DAF-FM to detect the production of NO by plant tissues.In addition to the dramatic effects that pH can have on fluorescence from DAF-FM,the widely used NO scavengers 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (PTIO) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) can produce anomalous and unexpected results.Perhaps the most serious drawback of DAF-FM is its ability to bind to dead cells and remain NO-sensitive.

  11. Exocytosis and polarity in plant cells: insights by studying cellulose synthase complexes and the exocyst

    NARCIS (Netherlands)

    Ying Zhang, Ying

    2012-01-01

    The work presented in this thesis covers aspects of exocytosis, plant cell growth and cell wall formation. These processes are strongly linked as cell growth and cell wall formation occur simultaneously and exocytosis is the process that delivers cell wall components to the existing cell wall and in

  12. Nanobiotechnology meets plant cell biology: Carbon nanotubes as organelle targeting nanocarriers

    KAUST Repository

    Bayoumi, Maged Fouad

    2013-01-01

    For years, nanotechnology has shown great promise in the fields of biomedical and biotechnological sciences and medical research. In this review, we demonstrate its versatility and applicability in plant cell biology studies. Specifically, we discuss the ability of functionalized carbon nanotubes to penetrate the plant cell wall, target specific organelles, probe protein-carrier activity and induce organelle recycling in plant cells. We also, shed light on prospective applications of carbon nanomaterials in cell biology and plant cell transformation. © 2013 The Royal Society of Chemistry.

  13. Guiding plant virus particles to integrin-displaying cells

    Science.gov (United States)

    Hovlid, Marisa L.; Steinmetz, Nicole F.; Laufer, Burkhardt; Lau, Jolene L.; Kuzelka, Jane; Wang, Qian; Hyypiä, Timo; Nemerow, Glen R.; Kessler, Horst; Manchester, Marianne; Finn, M. G.

    2012-05-01

    Viral nanoparticles (VNPs) are structurally regular, highly stable, tunable nanomaterials that can be conveniently produced in high yields. Unmodified VNPs from plants and bacteria generally do not show tissue specificity or high selectivity in binding to or entry into mammalian cells. They are, however, malleable by both genetic and chemical means, making them useful scaffolds for the display of large numbers of cell- and tissue-targeting ligands, imaging moieties, and/or therapeutic agents in a well-defined manner. Capitalizing on this attribute, we modified the genetic sequence of the Cowpea mosaic virus (CPMV) coat protein to display an RGD oligopeptide sequence derived from human adenovirus type 2 (HAdV-2). Concurrently, wild-type CPMV was modified via NHS acylation and Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry to attach an integrin-binding cyclic RGD peptide. Both types of particles showed strong and selective affinity for several different cancer cell lines that express RGD-binding integrin receptors.Viral nanoparticles (VNPs) are structurally regular, highly stable, tunable nanomaterials that can be conveniently produced in high yields. Unmodified VNPs from plants and bacteria generally do not show tissue specificity or high selectivity in binding to or entry into mammalian cells. They are, however, malleable by both genetic and chemical means, making them useful scaffolds for the display of large numbers of cell- and tissue-targeting ligands, imaging moieties, and/or therapeutic agents in a well-defined manner. Capitalizing on this attribute, we modified the genetic sequence of the Cowpea mosaic virus (CPMV) coat protein to display an RGD oligopeptide sequence derived from human adenovirus type 2 (HAdV-2). Concurrently, wild-type CPMV was modified via NHS acylation and Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry to attach an integrin-binding cyclic RGD peptide. Both types of particles showed strong and selective affinity

  14. Microtubules in Plant Cells: Strategies and Methods for Immunofluorescence, Transmission Electron Microscopy and Live Cell Imaging

    Science.gov (United States)

    Celler, Katherine; Fujita, Miki; Kawamura, Eiko; Ambrose, Chris; Herburger, Klaus; Wasteneys, Geoffrey O.

    2016-01-01

    Microtubules are required throughout plant development for a wide variety of processes, and different strategies have evolved to visualize and analyze them. This chapter provides specific methods that can be used to analyze microtubule organization and dynamic properties in plant systems and summarizes the advantages and limitations for each technique. We outline basic methods for preparing samples for immunofluorescence labelling, including an enzyme-based permeabilization method, and a freeze-shattering method, which generates microfractures in the cell wall to provide antibodies access to cells in cuticle-laden aerial organs such as leaves. We discuss current options for live cell imaging of MTs with fluorescently tagged proteins (FPs), and provide chemical fixation, high pressure freezing/freeze substitution, and post-fixation staining protocols for preserving MTs for transmission electron microscopy and tomography. PMID:26498784

  15. Imaging Nuclear Morphology and Organization in Cleared Plant Tissues Treated with Cell Cycle Inhibitors.

    Science.gov (United States)

    de Souza Junior, José Dijair Antonino; de Sa, Maria Fatima Grossi; Engler, Gilbert; Engler, Janice de Almeida

    2016-01-01

    Synchronization of root cells through chemical treatment can generate a large number of cells blocked in specific cell cycle phases. In plants, this approach can be employed for cell suspension cultures and plant seedlings. To identify plant cells in the course of the cell cycle, especially during mitosis in meristematic tissues, chemical inhibitors can be used to block cell cycle progression. Herein, we present a simplified and easy-to-apply protocol to visualize mitotic figures, nuclei morphology, and organization in whole Arabidopsis root apexes. The procedure is based on tissue clearing, and fluorescent staining of nuclear DNA with DAPI. The protocol allows carrying out bulk analysis of nuclei and cell cycle phases in root cells and will be valuable to investigate mutants like overexpressing lines of genes disturbing the plant cell cycle.

  16. Aspects of plant cell growth and the actin cytoskeleton: lessons from root hairs

    NARCIS (Netherlands)

    Ruijter, de N.C.A.

    1999-01-01

    The main topic the thesis addresses is the role of the actin cytoskeleton in the growth process of plant cells. Plant growth implies a combination of cell division and cell expansion. The cytoskeleton, which exists of microtubules and actin filaments, plays a major role in both processes. Before cel

  17. Assembly and enlargement of the primary cell wall in plants

    Science.gov (United States)

    Cosgrove, D. J.

    1997-01-01

    Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1-->4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.

  18. Effect of Thai medicinal plant extracts on cell aggregation of Escherichia coli O157: H7.

    OpenAIRE

    Limsuwan, S.; Vanmanee, S.; Voravuthikunchai, S.

    2005-01-01

    Medicinal plants have been used for treating diarrhoea but the interference mechanisms are not clearly understood. One possible hypothesis is that of an effect on cell surface hydrophobicity of microbial cells. In this study, we examined cell aggregation affected by crude extracts of Thai medicinal plants on cell surface hydrophobicity of Escherichia coli strains by salt aggregation test. Correlation between minimal inhibitory concentration and cell aggregation was performed. Aqueous and etha...

  19. Determination of the pore size of cell walls of living plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, N.; Sabularse, D.; Montezinos, D.; Delmer, D.P.

    1979-09-14

    The limiting diameter of pores in the walls of living plant cells through which molecules can freely pass has been determined by a solute exclusion technique to be 35 to 38 angstroms for hair cells of Raphanus sativus roots and fibers of Gossypium hirsutum, 38 to 40 angstroms for cultured cells of Acer pseudoplatanus, and 45 to 52 angstroms for isolated palisade parenchyma cells of the leaves of Xanthium strumarium and Commelina communis. These results indicate that molecules with diameters larger than these pores would be restricted in their ability to penetrate such a cell wall, and that such a wall may represent a more significant barrier to cellular communication than has been previously assumed.

  20. 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.

  1. 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)

    2016-08-22

    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.

  2. Cytotoxicity of Selected Medicinal and Nonmedicinal Plant Extracts to Microbial and Cervical Cancer Cells

    OpenAIRE

    Gary M. Booth; Malmstrom, Robert D.; Erica Kipp; Alexandra Paul

    2012-01-01

    This study investigated the cytotoxicity of 55 species of plants. Each plant was rated as medicinal, or nonmedicinal based on the existing literature. About 79% of the medicinal plants showed some cytotoxicity, while 75% of the nonmedicinal plants showed bioactivity. It appears that Asteraceae, Labiatae, Pinaceae, and Chenopodiaceae were particularly active against human cervical cancer cells. Based on the literature, only three of the 55 plants have been significantly investigated for cytoto...

  3. Unleashing the potential of the root hair cell as a single plant cell type model in root systems biology

    OpenAIRE

    Zhenzhen eQiao; Marc eLibault

    2013-01-01

    Plant root is an organ composed of multiple cell types with different functions. This multicellular complexity limits our understanding of root biology because –omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i....

  4. Fusion and metabolism of plant cells as affected by microgravity.

    Science.gov (United States)

    Hampp, R; Hoffmann, E; Schönherr, K; Johann, P; De Filippis, L

    1997-01-01

    Plant cell protoplasts derived from leaf tissue of two different tobacco species (Nicotiana tabacum., N. rustica L.) were exposed to short-term (sounding rocket experiments) and long-term (spacelab) microgravity environments in order to study both (electro) cell fusion and cell metabolism during early and later stages of tissue regeneration. The period of exposure to microgravity varied from 10 min (sounding rocket) to 10 d (space shuttle). The process of electro fusion of protoplasts was improved under conditions of microgravity: the time needed to establish close membrane contact between protoplasts (alignment time) was reduced (5 as compared to 15 s under 1 g) and numbers of fusion products between protoplasts of different specific density were increased by a factor of about 10. In addition, viability of fusion products, as shown by the ability to form callus, increased from about 60% to more than 90%. Regenerated fusion products obtained from both sounding-rocket and spacelab experiments showed a wide range of intermediate properties between the two parental plants. This was verified by isozyme analysis and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). In order to address potential metabolic responses, more general markers such as the overall energy state (ATP/ADP ratio), the redox charge of the diphosphopyridine nucleotide system (NADH/NAD ratio), and the pool size of fructose-2,6-bisphosphate (Fru 2,6 bisp), a regulator of the balance between glycolysis and gluconeogenesis, were determined. Responses of these parameters were different with regard to short-term and long-term exposure. Shortly after transition to reduced gravitation (sounding rocket) ratios of ATP/ADP exhibited strong fluctuation while the pool size of NAD decreased (indicating an increased NADH/NAD ratio) and that of Fru 2,6 bisp increased. As similar changes can be observed under stress conditions, this response is probably indicative of a metabolic stress

  5. Fusion and metabolism of plant cells as affected by microgravity.

    Science.gov (United States)

    Hampp, R; Hoffmann, E; Schönherr, K; Johann, P; De Filippis, L

    1997-01-01

    Plant cell protoplasts derived from leaf tissue of two different tobacco species (Nicotiana tabacum., N. rustica L.) were exposed to short-term (sounding rocket experiments) and long-term (spacelab) microgravity environments in order to study both (electro) cell fusion and cell metabolism during early and later stages of tissue regeneration. The period of exposure to microgravity varied from 10 min (sounding rocket) to 10 d (space shuttle). The process of electro fusion of protoplasts was improved under conditions of microgravity: the time needed to establish close membrane contact between protoplasts (alignment time) was reduced (5 as compared to 15 s under 1 g) and numbers of fusion products between protoplasts of different specific density were increased by a factor of about 10. In addition, viability of fusion products, as shown by the ability to form callus, increased from about 60% to more than 90%. Regenerated fusion products obtained from both sounding-rocket and spacelab experiments showed a wide range of intermediate properties between the two parental plants. This was verified by isozyme analysis and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). In order to address potential metabolic responses, more general markers such as the overall energy state (ATP/ADP ratio), the redox charge of the diphosphopyridine nucleotide system (NADH/NAD ratio), and the pool size of fructose-2,6-bisphosphate (Fru 2,6 bisp), a regulator of the balance between glycolysis and gluconeogenesis, were determined. Responses of these parameters were different with regard to short-term and long-term exposure. Shortly after transition to reduced gravitation (sounding rocket) ratios of ATP/ADP exhibited strong fluctuation while the pool size of NAD decreased (indicating an increased NADH/NAD ratio) and that of Fru 2,6 bisp increased. As similar changes can be observed under stress conditions, this response is probably indicative of a metabolic stress

  6. Programmed cell cycle arrest is required for infection of corn plants by the fungus Ustilago maydis.

    Science.gov (United States)

    Castanheira, Sónia; Mielnichuk, Natalia; Pérez-Martín, José

    2014-12-01

    Ustilago maydis is a plant pathogen that requires a specific structure called infective filament to penetrate the plant tissue. Although able to grow, this filament is cell cycle arrested on the plant surface. This cell cycle arrest is released once the filament penetrates the plant tissue. The reasons and mechanisms for this cell cycle arrest are unknown. Here, we have tried to address these questions. We reached three conclusions from our studies. First, the observed cell cycle arrest is the result of the cooperation of at least two distinct mechanisms: one involving the activation of the DNA damage response (DDR) cascade; and the other relying on the transcriptional downregulation of Hsl1, a kinase that modulates the G2/M transition. Second, a sustained cell cycle arrest during the infective filament step is necessary for the virulence in U. maydis, as a strain unable to arrest the cell cycle was severely impaired in its ability to infect corn plants. Third, production of the appressorium, a structure required for plant penetration, is incompatible with an active cell cycle. The inability to infect plants by strains defective in cell cycle arrest seems to be caused by their failure to induce the appressorium formation process. In summary, our findings uncover genetic circuits to arrest the cell cycle during the growth of this fungus on the plant surface, thus allowing the penetration into plant tissue.

  7. Plasma membrane protein trafficking in plant-microbe interactions: a plant cell point of view

    Directory of Open Access Journals (Sweden)

    Nathalie eLeborgne-Castel

    2014-12-01

    Full Text Available In order to ensure their physiological and cellular functions, plasma membrane (PM proteins must be properly conveyed from their site of synthesis, i.e. the endoplasmic reticulum, to their final destination, the PM, through the secretory pathway. PM protein homeostasis also relies on recycling and/or degradation, two processes that are initiated by endocytosis. Vesicular membrane trafficking events to and from the PM have been shown to be altered when plant cells are exposed to mutualistic or pathogenic microbes. In this review, we will describe the fine-tune regulation of such alterations, and their consequence in PM protein activity. We will consider the formation of intracellular perimicrobial compartments, the PM protein trafficking machinery of the host, and the delivery or retrieval of signaling and transport proteins such as pattern-recognition receptors, producers of reactive oxygen species, and sugar transporters.

  8. Towards high-yield production of pharmaceutical proteins with plant cell suspension cultures.

    Science.gov (United States)

    Xu, Jianfeng; Ge, Xumeng; Dolan, Maureen C

    2011-01-01

    "Molecular farming" in plants with significant advantages in cost and safety is touted as a promising platform for the production of complex pharmaceutical proteins. While whole-plant produced biopharmaceuticals account for a significant portion of the preclinical and clinical pipeline, plant cell suspension culture, which integrates the merits of whole-plant systems with those of microbial fermentation, is emerging as a more compliant alternative "factory". However, low protein productivity remains a major obstacle that limits extensive commercialization of plant cell bioproduction platform. This review highlights the advantages and recent progress in plant cell culture technology and outlines viable strategies at both the biological and process engineering levels for advancing the economic feasibility of plant cell-based protein production. Approaches to overcome and solve the associated challenges of this culture system that include non-mammalian glycosylation and genetic instability will also be discussed. PMID:21236330

  9. Towards high-yield production of pharmaceutical proteins with plant cell suspension cultures.

    Science.gov (United States)

    Xu, Jianfeng; Ge, Xumeng; Dolan, Maureen C

    2011-01-01

    "Molecular farming" in plants with significant advantages in cost and safety is touted as a promising platform for the production of complex pharmaceutical proteins. While whole-plant produced biopharmaceuticals account for a significant portion of the preclinical and clinical pipeline, plant cell suspension culture, which integrates the merits of whole-plant systems with those of microbial fermentation, is emerging as a more compliant alternative "factory". However, low protein productivity remains a major obstacle that limits extensive commercialization of plant cell bioproduction platform. This review highlights the advantages and recent progress in plant cell culture technology and outlines viable strategies at both the biological and process engineering levels for advancing the economic feasibility of plant cell-based protein production. Approaches to overcome and solve the associated challenges of this culture system that include non-mammalian glycosylation and genetic instability will also be discussed.

  10. Roles of the plasma membrane and the cell wall in the responses of plant cells to freezing.

    Science.gov (United States)

    Yamada, Tomoyoshi; Kuroda, Katsushi; Jitsuyama, Yutaka; Takezawa, Daisuke; Arakawa, Keita; Fujikawa, Seizo

    2002-09-01

    In an effort to clarify the responses of a wide range of plant cells to freezing, we examined the responses to freezing of the cells of chilling-sensitive and chilling-resistant tropical and subtropical plants. Among the cells of the plants that we examined, those of African violet ( Saintpaulia grotei Engl.) leaves were most chilling-sensitive, those of hypocotyls in mungbean [ Vigna radiata (L.) R. Wilcz.] seedlings were moderately chilling-sensitive, and those of orchid [ Paphiopedilum insigne (Wallich ex Lindl.) Pfitz.] leaves were chilling-resistant, when all were chilled at -2 degrees C. By contrast, all these plant cells were freezing-sensitive and suffered extensive damage when they were frozen at -2 degrees C. Cryo-scanning electron microscopy (Cryo-SEM) confirmed that, upon chilling at -2 degrees C, both chilling-sensitive and chilling-resistant plant cells were supercooled. Upon freezing at -2 degrees C, by contrast, intracellular freezing occurred in Saintpaulia leaf cells, frost plasmolysis followed by intracellular freezing occurred in mungbean seedling cells, and extracellular freezing (cytorrhysis) occurred in orchid leaf cells. We postulate that chilling-related destabilization of membranes might result in the loss of the ability of the plasma membrane to act as a barrier against the propagation of extracellular ice in chilling-sensitive plant cells. We also examined the role of cell walls in the response to freezing using cells in which the plasma membrane had been disrupted by repeated freezing and thawing. In chilling-sensitive Saintpaulia and mungbean cells, the cells with a disrupted plasma membrane responded to freezing at -2 degrees C by intracellular freezing. By contrast, in chilling-resistant orchid cells, as well as in other cells of chilling-resistant and freezing-resistant plant tissues, including leaves of orchard grass ( Dactylis glomerata L.), leaves of Arabidopsis thaliana (L.) Heynh. and cortical tissues of mulberry ( Morus

  11. Multiple host-cell recombination pathways act in Agrobacterium-mediated transformation of plant cells.

    Science.gov (United States)

    Mestiri, Imen; Norre, Frédéric; Gallego, Maria E; White, Charles I

    2014-02-01

    Using floral-dip, tumorigenesis and root callus transformation assays of both germline and somatic cells, we present here results implicating the four major non-homologous and homologous recombination pathways in Agrobacterium-mediated transformation of Arabidopsis thaliana. All four single mutant lines showed similar mild reductions in transformability, but knocking out three of four pathways severely compromised Agrobacterium-mediated transformation. Although integration of T-DNA into the plant genome is severely compromised in the absence of known DNA double-strand break repair pathways, it does still occur, suggesting the existence of other pathways involved in T-DNA integration. Our results highlight the functional redundancy of the four major plant recombination pathways in transformation, and provide an explanation for the lack of strong effects observed in previous studies on the roles of plant recombination functions in transformation.

  12. Involvement of Plant Stem Cells or Stem Cell-Like Cells in Dedifferentiation

    OpenAIRE

    Jiang, Fangwei; Feng, Zhenhua; Liu, Hailiang; Zhu, Jian

    2015-01-01

    Dedifferentiation is the transformation of cells from a given differentiated state to a less differentiated or stem cell-like state. Stem cell-related genes play important roles in dedifferentiation, which exhibits similar histone modification and DNA methylation features to stem cell maintenance. Hence, stem cell-related factors possibly synergistically function to provide a specific niche beneficial to dedifferentiation. During callus formation in Arabidopsis petioles, cells adjacent to pro...

  13. 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.

  14. 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. PMID:27107260

  15. 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.

  16. Navigating the plant cell: intracellular transport logistics in the green kingdom.

    Science.gov (United States)

    Geitmann, Anja; Nebenführ, Andreas

    2015-10-01

    Intracellular transport in plant cells occurs on microtubular and actin arrays. Cytoplasmic streaming, the rapid motion of plant cell organelles, is mostly driven by an actin-myosin mechanism, whereas specialized functions, such as the transport of large cargo or the assembly of a new cell wall during cell division, are performed by the microtubules. Different modes of transport are used, fast and slow, to either haul cargo over long distances or ascertain high-precision targeting, respectively. Various forms of the actin-specific motor protein myosin XI exist in plant cells and might be involved in different cellular functions.

  17. Plant cell wall dynamics and wall-related susceptibility in plant–pathogen interactions

    OpenAIRE

    Bellincampi, Daniela; Cervone, Felice; Lionetti, Vincenzo

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteri...

  18. Catalysts of plant cell wall loosening [version 1; referees: 2 approved

    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...

  19. Actin based processes that could determine the cytoplasmic architecture of plant cells

    OpenAIRE

    Honing; Emons, A.M.C.; Ketelaar, M.J.

    2007-01-01

    Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells that is likely to depend on actin-based force generation is the organisation of the cytoplasm. We compare the function of actin binding proteins of three well-studied mammalian models that depend on...

  20. Intact plant MRI for the study of cell water relations, membrane permeability, cell-to-cell and long distance water transport

    NARCIS (Netherlands)

    As, van H.

    2007-01-01

    Water content and hydraulic conductivity, including transport within cells, over membranes, cell-to-cell, and long-distance xylem and phloem transport, are strongly affected by plant water stress. By being able to measure these transport processes non-invasely in the intact plant situation in relati

  1. Im"plant"ing of Mammalian Glycosyltransferase Gene into Plant Suspension-Cultured Cells Using Agrobacterium-Mediated Transformation.

    Science.gov (United States)

    Kajiura, Hiroyuki; Fujiyama, Kazuhito

    2015-01-01

    Enzymatic activity assay of exogenous glycosyltransferase (GT) and glycosylhydrolase (GH) expressed in plants is an important analysis for determination of the expression of the gene of interest. However, generations and establishment of in planta transgenic lines are time-consuming. Furthermore, the expression levels and the activities of the exogenous GTs and GHs are quite low and weak, the radiolabeled donor substrate had to be used to analyze the enzymatic activity. Here, we describe a protocol for the generation of transgenic plants using suspension-cultured cells and a high sensitive assay for GT, especially β1,4-galactosyltransferase, using microsomal fraction from plant cells and fluorescent-labeled sugar chains as an acceptor substrate. This method enables less-time-consuming preparation of stable transgenic plants, non-radiolabeled, high-throughput detail analysis which includes mass spectrometric analysis and exo-glycosidase digestions.

  2. Foaming and cell flotation in suspended plant cell cultures and the effect of chemical antifoams.

    Science.gov (United States)

    Wongsamuth, R; Doran, P M

    1994-08-01

    Foam development and stability in Atropa belladonna suspensions were investigated as a function of culture conditions. Foaming was due mainly to properties of the cell-free broth and was correlated with protein content; effects due to presence of cells increased towards the end of batch culture. Highest foam levels were measured 11 days after inoculation. Air flow rate was of major importance in determining foam volume; foam volume and stability were also strongly dependent on pH. Foam flotation of plant cells was very effective. After 30 min foaming, ca. 55% of cells were found in the foam; this increased to ca. 75% after 90 min. Polypropylene glycol 1025 and 2025, Pluronic PE 6100, and Antifoam-C emulsion were tested as chemical antifoams. Polypropylene glycol 1025 and Antifoam C at concentrations up to 600 ppm had no adverse effect on growth in shake flasks; Pluronic PE 6100 has an inhibitory effect at all levels tested. Concentrations of polypropylene glycol 2025 and Pluronic PE 6100 as low as 20 ppm reduced foam volumes by a factor of ca. 10. Addition of antifoam reduced k(L)a values in bubble-column and stirred-tank bioreactors. After operation of a stirred reactor for 2 days using Antifoam C for foam control, cell production was limited by oxygen due to the effect of antifoam on mass transfer. Theoretical analysis showed that maximum cell concentrations and biomass levels decline with increasing reactors working volume due to greater consumption of antifoam to prevent foam overflow. The results indicate that when chemical foam control is used in plant cell cultures, head-space volume and tolerable foam levels must be considered to optimize biomass production. (c) 1994 John Wiley & Sons, Inc.

  3. Foaming and cell flotation in suspended plant cell cultures and the effect of chemical antifoams.

    Science.gov (United States)

    Wongsamuth, R; Doran, P M

    1994-08-01

    Foam development and stability in Atropa belladonna suspensions were investigated as a function of culture conditions. Foaming was due mainly to properties of the cell-free broth and was correlated with protein content; effects due to presence of cells increased towards the end of batch culture. Highest foam levels were measured 11 days after inoculation. Air flow rate was of major importance in determining foam volume; foam volume and stability were also strongly dependent on pH. Foam flotation of plant cells was very effective. After 30 min foaming, ca. 55% of cells were found in the foam; this increased to ca. 75% after 90 min. Polypropylene glycol 1025 and 2025, Pluronic PE 6100, and Antifoam-C emulsion were tested as chemical antifoams. Polypropylene glycol 1025 and Antifoam C at concentrations up to 600 ppm had no adverse effect on growth in shake flasks; Pluronic PE 6100 has an inhibitory effect at all levels tested. Concentrations of polypropylene glycol 2025 and Pluronic PE 6100 as low as 20 ppm reduced foam volumes by a factor of ca. 10. Addition of antifoam reduced k(L)a values in bubble-column and stirred-tank bioreactors. After operation of a stirred reactor for 2 days using Antifoam C for foam control, cell production was limited by oxygen due to the effect of antifoam on mass transfer. Theoretical analysis showed that maximum cell concentrations and biomass levels decline with increasing reactors working volume due to greater consumption of antifoam to prevent foam overflow. The results indicate that when chemical foam control is used in plant cell cultures, head-space volume and tolerable foam levels must be considered to optimize biomass production. (c) 1994 John Wiley & Sons, Inc. PMID:18618782

  4. Phospholipase D activation correlates with microtubule reorganization in living plant cells

    NARCIS (Netherlands)

    P.B. Dhonukshe; A.M. Laxalt; J. Goedhart; Th.W.J. Gadella; T. Munnik

    2003-01-01

    A phospholipase D (PLD) was shown recently to decorate microtubules in plant cells. Therefore, we used tobacco BY-2 cells expressing the microtubule reporter GFP-MAP4 to test whether PLD activation affects the organization of plant microtubules. Within 30 min of adding n-butanol, a potent activator

  5. Bioproduction of therapeutic proteins in the 21st century and the role of plants and plant cells as production platforms.

    Science.gov (United States)

    Boehm, Robert

    2007-04-01

    In the last decade, the technique to genetically modify crop plants has gained more and more interest in terms of bioproduction of heterologous proteins. Plants have been discovered as a possible source for large amounts of cost effective recombinant protein. Main application fields are therapeutics for use in animal and human health, diagnostics, and technical enzymes. This review is focused on the recent progress in this field of molecular farming. After a comparison with hitherto established protein production systems, the advantages of plants as an alternative production system are discussed. An overview about the different host plants and possible expression strategies is given and the progress in commercialization of the techniques is highlighted. Finally, the role of plant cell cultures for the production of recombinant proteins is discussed.

  6. Cyanobacteria as Cell Factories to Produce Plant Secondary Metabolites

    OpenAIRE

    Xue, Yong; He, Qingfang

    2015-01-01

    Cyanobacteria represent a promising platform for the production of plant secondary metabolites. Their capacity to express plant P450 proteins, which have essential functions in the biosynthesis of many plant secondary metabolites, makes cyanobacteria ideal for this purpose, and their photosynthetic capability allows cyanobacteria to grow with simple nutrient inputs. This review summarizes the advantages of using cyanobacteria to transgenically produce plant secondary metabolites. Some techniq...

  7. Dye-sensitized solar cells based on dyes extracted from dried plant leaves

    OpenAIRE

    Sofyan A. Taya; Taher M. El-Agez; ELREFI, Kamal S.

    2015-01-01

    In this work, natural dyes were extracted from dried plant leaves of plant cream, apricot, figs, apples, sage, thyme, mint, Ziziphus jujuba, orange, shade tree, basil, berry, Mirabelle plum, Victoria plum, peach, mango, pomegranate, banana, guava, and fluoridation-treated plant. The extracts were used as photosensitizers for dye-sensitized solar cells (DSSCs). The cells were assembled using nanostructured TiO2 films. The best performance was observed for the DSSC sensitized with Ziziphus juju...

  8. Structure, function, and biosynthesis of plant cell walls: proceedings of the seventh annual symposium in botany

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, W.M.; Bartnicki-Garcia, S. (eds.)

    1984-01-01

    Papers in the following areas were included in these symposium proceedings: (1) cell wall chemistry and biosynthesis; (2) cell wall hydrolysis and associated physiology; (3) cellular events associated with cell wall biosynthesis; and (4) interactions of plant cell walls with pathogens and related responses. Papers have been individually abstracted for the data base. (ACR)

  9. Improving Plant Transformation Using Zygote as the Recipient Cell

    Institute of Scientific and Technical Information of China (English)

    Y.H. Yang; H.Q. Tian

    2007-01-01

    @@ Since the first transgenic plant was obtained from tobacco in the 1980's, the transformation of higher plants has been a vigorous field of study using applications of molecular biology. To date, transgenic methods of introducing foreign genes into higher plants include techniques of electrofusion, eletroporation, microinjection and transformation mediated by PEG and Agrobacterium.

  10. Cytotoxicity of Selected Medicinal and Nonmedicinal Plant Extracts to Microbial and Cervical Cancer Cells

    Directory of Open Access Journals (Sweden)

    Gary M. Booth

    2012-01-01

    Full Text Available This study investigated the cytotoxicity of 55 species of plants. Each plant was rated as medicinal, or nonmedicinal based on the existing literature. About 79% of the medicinal plants showed some cytotoxicity, while 75% of the nonmedicinal plants showed bioactivity. It appears that Asteraceae, Labiatae, Pinaceae, and Chenopodiaceae were particularly active against human cervical cancer cells. Based on the literature, only three of the 55 plants have been significantly investigated for cytotoxicity. It is clear that there is much toxicological work yet to be done with both medicinal and nonmedicinal plants.

  11. Function of root border cells in plant health: pioneers in the rhizosphere.

    Science.gov (United States)

    Hawes, M C; Brigham, L A; Wen, F; Woo, H H; Zhu, Y

    1998-01-01

    Plants dedicate a large amount of energy to the regulated production of living cells programmed to separate from roots into the external environment. This unusual process may be worth the cost because it enables the plant to dictate which species will share its ecological niche. For example, border cells can rapidly attract and stimulate growth in some microorganisms and repel and inhibit the growth of others. Such specificity may provide a way to control the dynamics of adjacent microbial populations in the soil to foster beneficial associations and inhibit pathogenic invasion. Plant genes controlling the delivery of border cells and the expression of their unique properties provide tools to genetically engineer plants with altered border cell quality and quantity. Such variants are being used to test the hypothesis that the function of border cells is to protect plant health by controlling the ecology of the root system.

  12. Eduard Strasburger (1844-1912): founder of modern plant cell biology.

    Science.gov (United States)

    Volkmann, Dieter; Baluška, František; Menzel, Diedrik

    2012-10-01

    Eduard Strasburger, director of the Botany Institute and the Botanical Garden at the University of Bonn from 1881 to 1912, was one of the most admirable scientists in the field of plant biology, not just as the founder of modern plant cell biology but in addition as an excellent teacher who strongly believed in "education through science." He contributed to plant cell biology by discovering the discrete stages of karyokinesis and cytokinesis in algae and higher plants, describing cytoplasmic streaming in different systems, and reporting on the growth of the pollen tube into the embryo sac and guidance of the tube by synergides. Strasburger raised many problems which are hot spots in recent plant cell biology, e.g., structure and function of the plasmodesmata in relation to phloem loading (Strasburger cells) and signaling, mechanisms of cell plate formation, vesicle trafficking as a basis for most important developmental processes, and signaling related to fertilization.

  13. 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.

  14. Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis

    OpenAIRE

    Sano Toshio; Kutsuna Natsumaro; Higaki Takumi; Hasezawa Seiichiro

    2008-01-01

    Abstract Background Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs) and actin microfilaments (MFs). Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials...

  15. Mechanics of Cellulose Synthase Complexes in Living Plant Cells

    Science.gov (United States)

    Zehfroosh, Nina; Liu, Derui; Ramos, Kieran P.; Yang, Xiaoli; Goldner, Lori S.; Baskin, Tobias I.

    The polymer cellulose is one of the major components of the world's biomass with unique and fascinating characteristics such as its high tensile strength, renewability, biodegradability, and biocompatibility. Because of these distinctive aspects, cellulose has been the subject of enormous scientific and industrial interest, yet there are still fundamental open questions about cellulose biosynthesis. Cellulose is synthesized by a complex of transmembrane proteins called ``Cellulose Synthase A'' (CESA) in the plasma membrane. Studying the dynamics and kinematics of the CESA complex will help reveal the mechanism of cellulose synthesis and permit the development and validation of models of CESA motility. To understand what drives these complexes through the cell membrane, we used total internal reflection fluorescence microscopy (TIRFM) and variable angle epi-fluorescence microscopy to track individual, fluorescently-labeled CESA complexes as they move in the hypocotyl and root of living plants. A mean square displacement analysis will be applied to distinguish ballistic, diffusional, and other forms of motion. We report on the results of these tracking experiments. This work was funded by NSF/PHY-1205989.

  16. Methods and compositions for regulating gene expression in plant cells

    Science.gov (United States)

    Beachy, Roger N. (Inventor); Luis, Maria Isabel Ordiz (Inventor); Dai, Shunhong (Inventor)

    2010-01-01

    Novel chimeric plant promoter sequences are provided, together with plant gene expression cassettes comprising such sequences. In certain preferred embodiments, the chimeric plant promoters comprise the BoxII cis element and/or derivatives thereof. In addition, novel transcription factors are provided, together with nucleic acid sequences encoding such transcription factors and plant gene expression cassettes comprising such nucleic acid sequences. In certain preferred embodiments, the novel transcription factors comprise the acidic domain, or fragments thereof, of the RF2a transcription factor. Methods for using the chimeric plant promoter sequences and novel transcription factors in regulating the expression of at least one gene of interest are provided, together with transgenic plants comprising such chimeric plant promoter sequences and novel transcription factors.

  17. Programmed cell death in plants and caspase-like activities

    NARCIS (Netherlands)

    Gaussand, Gwénael Martial Daniel Jean-Marie

    2007-01-01

    The development of multicellular organisms involves an important balance between cell growth, cell division and cell death. In animals, programmed cell death (PCD) plays a key role by forming and deleting structures, controlling cell numbers and eliminating abnormal damaged cells. Caspases were foun

  18. Behind the lines–actions of bacterial type III effector proteins in plant cells

    Science.gov (United States)

    Büttner, Daniela

    2016-01-01

    Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed. PMID:27526699

  19. In situ isolation of mRNA from individual plant cells: creation of cell-specific cDNA libraries

    NARCIS (Netherlands)

    Karrer, E.E.; Lincoln, J.E.; Hogenhout, S.A.; Bennett, A.B.; Bostock, R.M.; Martineau, B.; Lucas, W.J.; Gilchrist, D.G.; Alexander, D.

    1995-01-01

    A method for isolating and cloning mRNA populations from individual cells in living, intact plant tissues is described. The contents of individual cells were aspirated into micropipette tips filled with RNA extraction buffer. The mRNA from these cells was purified by binding to oligo(dT)-linked magn

  20. Application of the comet assay in studies of programmed cell death (PCD in plants

    Directory of Open Access Journals (Sweden)

    Maria Charzyńska

    2014-02-01

    Full Text Available Programmed cell death (PCD in plants is an intensively investigated process. One of the main characteristics of PCD in both animal and plant organisms is the non-random, internucleosomal fragmentation of nuclear DNA, usually analysed using total DNA gel electrophoresis or TUNEL method. In this paper we present application of the "comet assay" (Single Cell Gel Electrophoresis for detection of nDNA degradation in studies of PCD during plant life cycle. We analyzed three types of tissue: anther tapetum, endosperm and mesophyll which were prepared in different ways to obtain a suspension of viable cells (without cell walls. The comet assay gives a possibility of examination of the nDNA degradation in individual cell. This method is significant for studies of the plant tissue differentiation and senescence especially in the cases when it is not possible to isolate large number of cells at the same developmental stage.

  1. Penium margaritaceum: A Unicellular Model Organism for Studying Plant Cell Wall Architecture and Dynamics

    OpenAIRE

    Domozych, David S

    2014-01-01

    Penium margaritaceum is a new and valuable unicellular model organism for studying plant cell wall structure and developmental dynamics. This charophyte has a cell wall composition remarkably similar to the primary cell wall of many higher plants and clearly-defined inclusive zones containing specific polymers. Penium has a simple cylindrical phenotype with a distinct region of focused wall synthesis. Specific polymers, particularly pectins, can be identified using monoclonal antibodies rais...

  2. Apoptosis-Inducing Effect of Three Medicinal Plants on Oral Cancer Cells KB and ORL-48

    OpenAIRE

    Mohd Zabidi Majid; Zuraiza Mohamad Zaini; Fathilah Abdul Razak

    2014-01-01

    Brucea javanica, Azadirachta indica, and Typhonium flagelliforme are medicinal plants commonly used to treat conditions associated with tumour formation. This study aimed to determine the antiproliferative activity of these plants extracts on KB and ORL-48 oral cancer cell lines and to suggest their mode of cell death. The concentration producing 50% cell inhibition (IC50) was determined and the activity was examined under an inverted microscope. Immunohistochemistry fluorescent staining meth...

  3. Expression of Functional Human Coagulation Factor XIII A-domain in Plant Cell Suspensions and Whole Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Johnway; Hooker, Brian S.; Anderson, Daniel B.

    2004-09-01

    Coagulation factor XIII, a zymogen present in blood as a tetramer (A2B2) of A- and B-domains, is one of the components of many ''wound sealants'' which are proposed for use or currently in use as effective hemostatic agents, sealants and tissue adhesives in surgery. After activation by ?-thrombin cleavage, coagulation factor XIII A-domain, a transglutaminase, is formed and catalyzes the covalent crosslinking of the ?- and ?-chains of linear fibrin to form homopolymers, which can quickly stop bleeding. We have successfully expressed the A-domain of factor XIII in both plant cell cultures and whole plants. Transgenic plant cell culture allows a rapid method for testing production feasibility while expression in whole plants demonstrates an economic production system for recombinant human plasma-based proteins. The expressed factor XIII A-domain had a similar size as that of human plasma-derived factor XIII. Crude plant extract containing recombinant factor XIII A-domain showed transglutaminase activity with monodansylcadaverine and casein as substrates and crosslinking activity in the presence of linear fibrin. The expression of factor XIII A-domain was not affected by plant leaf position.

  4. 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.

  5. 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

    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...

  6. Induction and selection of mutants from in vitro cultured plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yung Il; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-07-01

    Mutant cell lines are useful for biochemical, physiological and genetical material for marker in various genetic manipulation experiments and for the direct use in crop plant improvement. Mutant selection may lead to the production of plants showing resistance or tolerance to specific environmental stress, such as solinity, drought, toxed metals, herbicides, pathogens and low temperature. In this review, these included the production of the somatic variation, the selection process itself and stability of the selected characters in cell culture and regenerated plant. Which would seem to be useful for improving plants and securring genetic resources. 45 refs. (Author).

  7. DCD – a novel plant specific domain in proteins involved in development and programmed cell death

    Directory of Open Access Journals (Sweden)

    Doerks Tobias

    2005-07-01

    Full Text Available Abstract Background Recognition of microbial pathogens by plants triggers the hypersensitive reaction, a common form of programmed cell death in plants. These dying cells generate signals that activate the plant immune system and alarm the neighboring cells as well as the whole plant to activate defense responses to limit the spread of the pathogen. The molecular mechanisms behind the hypersensitive reaction are largely unknown except for the recognition process of pathogens. We delineate the NRP-gene in soybean, which is specifically induced during this programmed cell death and contains a novel protein domain, which is commonly found in different plant proteins. Results The sequence analysis of the protein, encoded by the NRP-gene from soybean, led to the identification of a novel domain, which we named DCD, because it is found in plant proteins involved in development and cell death. The domain is shared by several proteins in the Arabidopsis and the rice genomes, which otherwise show a different protein architecture. Biological studies indicate a role of these proteins in phytohormone response, embryo development and programmed cell by pathogens or ozone. Conclusion It is tempting to speculate, that the DCD domain mediates signaling in plant development and programmed cell death and could thus be used to identify interacting proteins to gain further molecular insights into these processes.

  8. 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.

  9. 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.

  10. NAC-MYB-based transcriptional regulation of secondary cell wall biosynthesis in land plants

    OpenAIRE

    Nakano, Yoshimi; Yamaguchi, Masatoshi; Endo, Hitoshi; Rejab, Nur Ardiyana; Ohtani, Misato

    2015-01-01

    Plant cells biosynthesize primary cell walls (PCW) in all cells and produce secondary cell walls (SCWs) in specific cell types that conduct water and/or provide mechanical support, such as xylem vessels and fibers. The characteristic mechanical stiffness, chemical recalcitrance, and hydrophobic nature of SCWs result from the organization of SCW-specific biopolymers, i.e., highly ordered cellulose, hemicellulose, and lignin. Synthesis of these SCW-specific biopolymers requires SCW-specific enz...

  11. Actin based processes that could determine the cytoplasmic architecture of plant cells.

    Science.gov (United States)

    van der Honing, Hannie S; Emons, Anne Mie C; Ketelaar, Tijs

    2007-05-01

    Actin polymerisation can generate forces that are necessary for cell movement, such as the propulsion of a class of bacteria, including Listeria, and the protrusion of migrating animal cells. Force generation by the actin cytoskeleton in plant cells has not been studied. One process in plant cells that is likely to depend on actin-based force generation is the organisation of the cytoplasm. We compare the function of actin binding proteins of three well-studied mammalian models that depend on actin-based force generation with the function of their homologues in plants. We predict the possible role of these proteins, and thus the role of actin-based force generation, in the production of cytoplasmic organisation in plant cells.

  12. Microfluidic monitoring of programmed cell death in living plant seed tissue

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Zor, Kinga;

    Programmed cell death (PCD) is a highly regulated process in which cells are dismantled. Reactive oxygen species (ROS) are involved in PCD in plants, but the relationship between and mechanisms behind ROS and PCD are only poorly understood in plant cells compared to in animal cells (Gechev, Tsanko......, et al., (2006), BioEssays, 28, p. 1091). Microfluidic cell culture enables in vitro experiments to approach in vivo conditions. Combining microfluidics with the Lab-On-a-Chip concept allows implementing a wide range of assays for real-time monitoring of effects in a biological system of factors......, 126, p. 156; Finnie, Christine, et al., (2011), Proteomics, 11, p. 1595). The potential of microfluidics real-time monitoring is relatively unexplored within plant biology, and the barley aleurone layer system will thus enable new ground to be broken in the field of plant science and microfluidics....

  13. Ceratopteris richardii (C-fern: A model for investigating adaptive modification of vascular plant cell walls

    Directory of Open Access Journals (Sweden)

    Olivier eLeroux

    2013-09-01

    Full Text Available Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterising cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they not yet available this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.

  14. The Role of Plant Cell Wall Proteins in Response to Salt Stress

    Directory of Open Access Journals (Sweden)

    Lyuben Zagorchev

    2014-01-01

    Full Text Available Contemporary agriculture is facing new challenges with the increasing population and demand for food on Earth and the decrease in crop productivity due to abiotic stresses such as water deficit, high salinity, and extreme fluctuations of temperatures. The knowledge of plant stress responses, though widely extended in recent years, is still unable to provide efficient strategies for improvement of agriculture. The focus of study has been shifted to the plant cell wall as a dynamic and crucial component of the plant cell that could immediately respond to changes in the environment. The investigation of plant cell wall proteins, especially in commercially important monocot crops revealed the high involvement of this compartment in plants stress responses, but there is still much more to be comprehended. The aim of this review is to summarize the available data on this issue and to point out the future areas of interest that should be studied in detail.

  15. The nucleus of differentiated root plant cells: modifications induced by arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    G Lingua

    2009-12-01

    Full Text Available The nuclei of plant cells show marked differences in chromatin organisation, related to their DNA content, which ranges from the type with large strands of condensed chromatin (reticulate or chromonematic nuclei to one with mostly decondensed chromatin (chromocentric or diffuse nuclei. A loosening of the chromatin structure generally occurs in actively metabolising cells, such as differentiating and secretory cells, in relation to their high transcriptional activity. Endoreduplication may occur, especially in plants with a small genome, which increases the availability of nuclear templates, the synthesis of DNA, and probably regulates gene expression. Here we describe structural and quantitative changes of the chromatin and their relationship with transcription that occur in differentiated cells following an increase of their metabolism. The nuclei of root cortical cells of three plants with different 2C DNA content (Allium porrum, Pisum sativum and Lycopersicon esculentm and their modifications induced by arbuscular mycorrhization, which strongly increase the metabolic activity of colonised cells, are taken as examples.

  16. Glow in the Dark: Fluorescent Proteins as Cell and Tissue-Specific Markers in Plants

    Institute of Scientific and Technical Information of China (English)

    Wenzislava Ckurshumova; Adriana E. Caragea; Rochelle S. Goldstein; Thomas Berleth

    2011-01-01

    Since the hallmark discovery of Aequorea victoria's Green Fluorescent Protein (GFP) and its adaptation for efficient use in plants,fluorescent protein tags marking expression profiles or genuine proteins of interest have been used to recognize plant tissues and cell types,to monitor dynamic cell fate selection processes,and to obtain cell type-specific transcriptomes.Fluorescent tagging enabled visualization in living tissues and the precise recordings of dynamic expression pattern changes.The resulting accurate recording of cell fate acquisition kinetics in space and time has strongly stimulated mathematical modeling of self-organizing feedback mechanisms.In developmental studies,the use of fluorescent proteins has become critical,where morphological markers of tissues,cell types,or differentiation stages are either not known or not easily recognizable.In this review,we focus on the use of fluorescent markers to identify and illuminate otherwise invisible cell states in plant development.

  17. Redefining plant systems biology: from cell to ecosystem

    NARCIS (Netherlands)

    Keurentjes, J.J.B.; Angenent, G.C.; Dicke, M.; Martins Dos Santos, V.A.P.; Molenaar, J.; Putten, van der W.H.; Ruiter, de P.C.; Struik, P.C.; Thomma, B.

    2011-01-01

    Molecular biologists typically restrict systems biology to cellular levels. By contrast, ecologists define biological systems as communities of interacting individuals at different trophic levels that process energy, nutrient and information flows. Modern plant breeding needs to increase agricultura

  18. 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...

  19. BIOCONVERSION OF NATURALLY-OCCURRING PRECURSORS AND RELATED SYNTHETIC COMPOUNDS USING PLANT-CELL CULTURES

    NARCIS (Netherlands)

    PRAS, N

    1992-01-01

    The nearly unlimited enzymatic potential of cultured plant cells can basically be employed for bioconversion purposes. Plant enzymes are able to catalyze regio- and stereospecific reactions and can therefore be applied to the production of compounds of pharmaceutical interest. Naturally occurring as

  20. Bleomycin resistance : a new dominant selectable marker for plant cell transformation

    NARCIS (Netherlands)

    Hille, Jacques; Verheggen, Frank; Roelvink, Peter; Franssen, Henk; Kammen, Ab van; Zabel, Pim

    1986-01-01

    Plant cells are sensitive to the antibiotic bleomycin, a DNA damaging glycopeptide. A bleomycin resistance determinant, located on transposon Tn5 and functional in bacteria, has been cloned in a plant expression vector and introduced into Nicotiana plumbaginifolia using Agrobacterium tumefaciens. Th

  1. Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier hyd...

  2. Global Analysis of FRET-FLIM Data in Live Plant Cells

    NARCIS (Netherlands)

    Laptenok, S.; Snellenburg, J.J.; Bücherl, C.A.; Konrad, K.R.; Borst, J.W.

    2014-01-01

    This chapter describes the procedure for globally analyzing fluorescence lifetime imaging (FLIM) data for the observation and quantification of Förster resonance energy transfer (FRET) in live plant cells. The procedure is illustrated by means of a case study, for which plant protoplasts were transf

  3. A Case for Distributed Control of Local Stem Cell Behavior in Plants.

    Science.gov (United States)

    Rahni, Ramin; Efroni, Idan; Birnbaum, Kenneth D

    2016-09-26

    The root meristem has a centrally located group of mitotically quiescent cells, to which current models assign a stem cell organizer function. However, evidence is emerging for decentralized control of stem cell activity, whereby self-renewing behavior emerges from the lack of cell displacement at the border of opposing differentiation gradients. We term this a "stagnation" model due to its reliance on passive mechanics. The position of stem cells is established by two opposing axes that reciprocally control each other's differentiation. Such broad tissue organization programs would allow plants, like some animal systems, to rapidly reconstitute stem cells from non-stem-cell tissues. PMID:27676436

  4. Primary observations of the existence of Fas-like cytoplasmic death factor in plant cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The main activity of Fas is to trigger cytoplasm death program in animal cells. In G2 pea, vacuole plays a pivotal role in inducing cell death in the cytoplasm of longday (LD) grown apical meristem cells. Expression patterns of the Fas in G2 pea cells revealed that the Fas is mainly localized in the vacuole of cells undergoing programmed cell death (PCD). The Fas expression is corresponding to the initiation of menadione-induced PCD in tobacco protoplasts.The results suggest the existence of the Fas-like mediated cytoplasmic death pathway in plant cells.``

  5. 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. PMID:27242834

  6. 4-Methylthiobutyl isothiocyanate (Erucin) from rocket plant dichotomously affects the activity of human immunocompetent cells.

    Science.gov (United States)

    Gründemann, Carsten; Garcia-Käufer, Manuel; Lamy, Evelyn; Hanschen, Franziska S; Huber, Roman

    2015-03-15

    Isothiocyanates (ITC) from the Brassicaceae plant family are regarded as promising for prevention and treatment of cancer. However, experimental settings consider their therapeutic action without taking into account the risk of unwanted effects on healthy tissues. In the present study we investigated the effects of Eruca sativa seed extract containing MTBITC (Erucin) and pure Erucin from rocket plant on healthy cells of the human immune system in vitro. Hereby, high doses of the plant extract as well as of Erucin inhibited cell viability of human lymphocytes via induction of apoptosis to comparable amounts. Non-toxic low concentrations of the plant extract and pure Erucin altered the expression of the interleukin (IL)-2 receptor but did not affect further T cell activation, proliferation and the release of the effector molecules interferon (IFN)-gamma and IL-2 of T-lymphocytes. However, the activity of NK-cells was significantly reduced by non-toxic concentrations of the plant extract and pure Erucin. These results indicate that the plant extract and pure Erucin interfere with the function of human T lymphocytes and decreases the activity of NK-cells in comparable concentrations. Long-term clinical studies with ITC-enriched plant extracts from Brassicaceae should take this into account.

  7. 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.

  8. 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. PMID:27242834

  9. The effect of Translationally Controlled Tumour Protein (TCTP) on programmed cell death in plants

    OpenAIRE

    Hoepflinger, Marion Christine; Reitsamer, Johannes; Geretschlaeger, Anja Maria; Mehlmer, Norbert; Tenhaken, Raimund

    2013-01-01

    Background: Translationally controlled tumour protein (TCTP), a well known protein of the animal kingdom, was shown to be a Ca2+-binding protein with important functions in many different cellular processes (e.g. protection against stress and apoptosis, cell growth, cell cycle progression, and microtubule organization). However, only little is known about TCTP in plants. Transcript and protein levels of plant TCTPs were shown to be altered by various stress conditions (e.g. cold, salt, draugh...

  10. Reversal of an immunity associated plant cell death program by the growth regulator auxin

    Directory of Open Access Journals (Sweden)

    Gopalan Suresh

    2008-12-01

    Full Text Available Abstract Background One form of plant immunity against pathogens involves a rapid host programmed cell death at the site of infection accompanied by the activation of local and systemic resistance to pathogens, termed the hypersensitive response (HR. In this work it was tested (i if the plant growth regulator auxin can inhibit the cell death elicited by a purified proteinaceous HR elicitor, (ii how far down the process this inhibition can be achieved, and (iii if the inhibition affects reporters of immune response. The effect of constitutive modulation of endogenous auxin levels in transgenic plants on this cell death program was also evaluated. Results The HR programmed cell death initiated by a bacterial type III secretion system dependent proteinaceous elicitor harpin (from Erwinia amylovora can be reversed till very late in the process by the plant growth regulator auxin. Early inhibition or late reversal of this cell death program does not affect marker genes correlated with local and systemic resistance. Transgenic plants constitutively modulated in endogenous levels of auxin are not affected in ability or timing of cell death initiated by harpin. Conclusion These data indicate that the cell death program initiated by harpin can be reversed till late in the process without effect on markers strongly correlated with local and systemic immunity. The constitutive modulation of endogenous auxin does not affect equivalent signaling processes affecting cell death or buffers these signals. The concept and its further study has utility in choosing better strategies for treating mammalian and agricultural diseases.

  11. Cell wall assembly and intracellular trafficking in plant cells are directly affected by changes in the magnitude of gravitational acceleration.

    Directory of Open Access Journals (Sweden)

    Youssef Chebli

    Full Text Available Plants are able to sense the magnitude and direction of gravity. This capacity is thought to reside in selected cell types within the plant body that are equipped with specialized organelles called statoliths. However, most plant cells do not possess statoliths, yet they respond to changes in gravitational acceleration. To understand the effect of gravity on the metabolism and cellular functioning of non-specialized plant cells, we investigated a rapidly growing plant cell devoid of known statoliths and without gravitropic behavior, the pollen tube. The effects of hyper-gravity and omnidirectional exposure to gravity on intracellular trafficking and on cell wall assembly were assessed in Camellia pollen tubes, a model system with highly reproducible growth behavior in vitro. Using an epi-fluorescence microscope mounted on the Large Diameter Centrifuge at the European Space Agency, we were able to demonstrate that vesicular trafficking is reduced under hyper-gravity conditions. Immuno-cytochemistry confirmed that both in hyper and omnidirectional gravity conditions, the characteristic spatial profiles of cellulose and callose distribution in the pollen tube wall were altered, in accordance with a dose-dependent effect on pollen tube diameter. Our findings suggest that in response to gravity induced stress, the pollen tube responds by modifying cell wall assembly to compensate for the altered mechanical load. The effect was reversible within few minutes demonstrating that the pollen tube is able to quickly adapt to changing stress conditions.

  12. WallProtDB, a database resource for plant cell wall proteomics

    OpenAIRE

    San Clemente, Hélène; Jamet, Elisabeth

    2015-01-01

    Background During the last fifteen years, cell wall proteomics has become a major research field with the publication of more than 50 articles describing plant cell wall proteomes. The WallProtDB database has been designed as a tool to facilitate the inventory, the interpretation of cell wall proteomics data and the comparisons between cell wall proteomes. Results WallProtDB (http://www.polebio.lrsv.ups-tlse.fr/WallProtDB/) presently contains 2170 proteins and ESTs identified experimentally i...

  13. Homogenization of a system of elastic and reaction-diffusion equations modelling plant cell wall biomechanics

    OpenAIRE

    Ptashnyk, Mariya; Seguin, Brian

    2014-01-01

    In this paper we present a derivation and multiscale analysis of a mathematical model for plant cell wall biomechanics that takes into account both the microscopic structure of a cell wall coming from the cellulose microfibrils and the chemical reactions between the cell wall's constituents. Particular attention is paid to the role of pectin and the impact of calcium-pectin cross-linking chemistry on the mechanical properties of the cell wall. We prove the existence and uniqueness of the stro...

  14. Extracellular Trapping of Soil Contaminants by Root Border Cells: New Insights into Plant Defense

    Directory of Open Access Journals (Sweden)

    Martha C. Hawes

    2016-01-01

    Full Text Available Soil and water pollution by metals and other toxic chemicals is difficult to measure and control, and, as such, presents an ongoing global threat to sustainable agriculture and human health. Efforts to remove contaminants by plant-mediated pathways, or “phytoremediation”, though widely studied, have failed to yield consistent, predictable removal of biological and chemical contaminants. Emerging research has revealed that one major limitation to using plants to clean up the environment is that plants are programmed to protect themselves: Like white blood cells in animals, border cells released from plant root tips carry out an extracellular trapping process to neutralize threats and prevent injury to the host. Variability in border cell trapping has been found to be correlated with variation in sensitivity of roots to aluminum, and removal of border cell results in increased Al uptake into the root tip. Studies now have implicated border cells in responses of diverse plant roots to a range of heavy metals, including arsenic, copper, cadmium, lead, mercury, iron, and zinc. A better understanding of border cell extracellular traps and their role in preventing toxin uptake may facilitate efforts to use plants as a nondestructive approach to neutralize environmental threats.

  15. Time-resolved NMR metabolomics of plant cells based on a microfluidic chip.

    Science.gov (United States)

    Maisch, Jan; Kreppenhofer, Kristina; Büchler, Silke; Merle, Christian; Sobich, Shukhrat; Görling, Benjamin; Luy, Burkhard; Ahrens, Ralf; Guber, Andreas E; Nick, Peter

    2016-08-01

    The plant secondary metabolism generates numerous compounds harbouring pharmaceutical activity. In plants, these compounds are typically formed by different and specialised cell types that have to interact constituting a metabolic process chain. This interactivity impedes biotechnological production of secondary compounds, because cell differentiation is suppressed under the conditions of a batch bio-fermenter. We present a novel strategy to address this limitation using a biomimetic approach, where we simulate the situation in a real tissue by a microfluidic chamber system, where plant cells can be integrated into a process flow. We show that walled cells of the plant model tobacco BY-2 can be successfully cultivated in this system and that physiological parameters (such as cell viability, mitotic index and division synchrony) can be preserved over several days. The microfluidic design allows to resolve dynamic changes of specific metabolites over different stages of culture development. These results serve as proof-of-principle that a microfluidic organisation of cultivated plant cells can mimic the metabolic flows in a real plant tissue. PMID:27318870

  16. Time-resolved NMR metabolomics of plant cells based on a microfluidic chip.

    Science.gov (United States)

    Maisch, Jan; Kreppenhofer, Kristina; Büchler, Silke; Merle, Christian; Sobich, Shukhrat; Görling, Benjamin; Luy, Burkhard; Ahrens, Ralf; Guber, Andreas E; Nick, Peter

    2016-08-01

    The plant secondary metabolism generates numerous compounds harbouring pharmaceutical activity. In plants, these compounds are typically formed by different and specialised cell types that have to interact constituting a metabolic process chain. This interactivity impedes biotechnological production of secondary compounds, because cell differentiation is suppressed under the conditions of a batch bio-fermenter. We present a novel strategy to address this limitation using a biomimetic approach, where we simulate the situation in a real tissue by a microfluidic chamber system, where plant cells can be integrated into a process flow. We show that walled cells of the plant model tobacco BY-2 can be successfully cultivated in this system and that physiological parameters (such as cell viability, mitotic index and division synchrony) can be preserved over several days. The microfluidic design allows to resolve dynamic changes of specific metabolites over different stages of culture development. These results serve as proof-of-principle that a microfluidic organisation of cultivated plant cells can mimic the metabolic flows in a real plant tissue.

  17. A simple and efficient method for the long-term preservation of plant cell suspension cultures

    Directory of Open Access Journals (Sweden)

    Boisson Anne-Marie

    2012-01-01

    Full Text Available Abstract Background The repeated weekly subculture of plant cell suspension is labour intensive and increases the risk of variation from parental cells lines. Most of the procedures to preserve cultures are based on controlled freezing/thawing and storage in liquid nitrogen. However, cells viability after unfreezing is uncertain. The long-term storage and regeneration of plant cell cultures remains a priority. Results Sycamore (Acer pseudoplatanus and Arabidopsis cell were preserved over six months as suspensions cultures in a phosphate-free nutrient medium at 5°C. The cell recovery monitored via gas exchange measurements and metabolic profiling using in vitro and in vivo 13C- and 31P-NMR took a couple of hours, and cell growth restarted without appreciable delay. No measurable cell death was observed. Conclusion We provide a simple method to preserve physiologically homogenous plant cell cultures without subculture over several months. The protocol based on the blockage of cell growth and low culture temperature is robust for heterotrophic and semi-autotrophic cells and should be adjustable to cell lines other than those utilised in this study. It requires no specialized equipment and is suitable for routine laboratory use.

  18. A suitable model plant for control of the set fuel cell-DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)

    2008-04-15

    In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)

  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. Cell death mechanisms of plant-derived anticancer drugs: beyond apoptosis.

    Science.gov (United States)

    Gali-Muhtasib, Hala; Hmadi, Raed; Kareh, Mike; Tohme, Rita; Darwiche, Nadine

    2015-12-01

    Despite remarkable progress in the discovery and development of novel cancer therapeutics, cancer remains the second leading cause of death in the world. For many years, compounds derived from plants have been at the forefront as an important source of anticancer therapies and have played a vital role in the prevention and treatment of cancer because of their availability, and relatively low toxicity when compared with chemotherapy. More than 3000 plant species have been reported to treat cancer and about thirty plant-derived compounds have been isolated so far and have been tested in cancer clinical trials. The mechanisms of action of plant-derived anticancer drugs are numerous and most of them induce apoptotic cell death that may be intrinsic or extrinsic, and caspase and/or p53-dependent or independent mechanisms. Alternative modes of cell death by plant-derived anticancer drugs are emerging and include mainly autophagy, necrosis-like programmed cell death, mitotic catastrophe, and senescence leading to cell death. Considering that the non-apoptotic cell death mechanisms of plant-derived anticancer drugs are less reviewed than the apoptotic ones, this paper attempts to focus on such alternative cell death pathways for some representative anticancer plant natural compounds in clinical development. In particular, emphasis will be on some promising polyphenolics such as resveratrol, curcumin, and genistein; alkaloids namely berberine, noscapine, and colchicine; terpenoids such as parthenolide, triptolide, and betulinic acid; and the organosulfur compound sulforaphane. The understanding of non-apoptotic cell death mechanisms induced by these drugs would provide insights into the possibility of exploiting novel molecular pathways and targets of plant-derived compounds for future cancer therapeutics. PMID:26362468

  1. Programmed Cell Death in Relation to Petal Senescence in Ornamental Plants

    Institute of Scientific and Technical Information of China (English)

    Yuan ZHOU; Cai-Yun WANG; Hong GE; Frank A. HOEBERICHTS; Peter B. VISSER

    2005-01-01

    Cell death is a common event in all types of plant organisms. Understanding the phenomenon of programmed cell death (PCD) is an important area of research for plant scientists because of its role in senescence and the post-harvest quality of ornamentals, fruits, and vegetables. In the present paper, PCD in relation to petal senescence in ornamental plants is reviewed. Morphological, anatomical, physiological,and biochemical changes that are related to PCD in petals, such as water content, sink-source relationships,hormones, genes, and signal transduction pathways, are discussed. Several approaches to improving the quality of post-harvest ornamentals are reviewed and some prospects for future research are given.

  2. Integration of A Solid Oxide Fuel Cell into A 10 MW Gas Turbine Power Plant

    Directory of Open Access Journals (Sweden)

    Denver F. Cheddie

    2010-04-01

    Full Text Available Power generation using gas turbine power plants operating on the Brayton cycle suffers from low efficiencies. In this work, a solid oxide fuel cell (SOFC is proposed for integration into a 10 MW gas turbine power plant, operating at 30% efficiency. The SOFC system utilizes four heat exchangers for heat recovery from both the turbine outlet and the fuel cell outlet to ensure a sufficiently high SOFC temperature. The power output of the hybrid plant is 37 MW at 66.2% efficiency. A thermo-economic model predicts a payback period of less than four years, based on future projected SOFC cost estimates.

  3. 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

    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...... analysis of mutant and wild-type plants, as demonstrated here for the Arabidopsis thaliana mutants fra8, mur1 and mur3. CoMPP was also applied to Physcomitrella patens cell walls and was validated by carbohydrate linkage analysis. These data provide new insights into the structure and functions of plant...

  4. Integration of a municipal solid waste gasification plant with solid oxide fuel cell and gas turbine

    DEFF Research Database (Denmark)

    Bellomare, Filippo; Rokni, Masoud

    2013-01-01

    it reacts with air and produces electricity. The exhausted gases out of the SOFC enter a burner for further fuel combusting and finally the off-gases are sent to a gas turbine to produce additional electricity. Different plant configurations have been studied and the best one found to be a regenerative gas...... in landfills. A Municipal Solid Waste Gasification Plant Integrated with Solid Oxide Fuel Cell (SOFC) and Gas Turbine (GT) has been studied and the plant is called IGSG (Integrated Gasification SOFC and GT). Gasification plant is fed by MSW to produce syngas by which the anode side of an SOFC is fed wherein...

  5. Stem-Cell-Triggered Immunity Safeguards Cytokinin Enriched Plant Shoot Apexes from Pathogen Infection

    Directory of Open Access Journals (Sweden)

    Thomas eDandekar

    2014-10-01

    Full Text Available Intricate mechanisms discriminate between friends and foes in plants. Plant organs deploy overlapping and distinct protection strategies. Despite vulnerability to a plethora of pathogens, the growing tips of plants grow bacteria free. The shoot apical meristem (SAM is among three stem cells niches, a self-renewable reservoir for the future organogenesis of leaf, stem and flowers. How plants safeguard this high value growth target from infections was not known until now. Recent reports find the stem cell secreted 12-amino acid peptide CLV3p (CLAVATA3 peptide is perceived by FLS2 (FLAGELLIN SENSING 2 receptor and activates the transcription of immunity and defense marker genes. No infection in the SAM of wild type plants and bacterial infection in clv3 and fls2 mutants illustrate this natural protection against infections. Cytokinins are enriched in the SAM and regulate meristem activities by their involvement in stem cell signaling networks. Auxin mediates plant susceptibility to pathogen infections while cytokinins boost plant immunity. Here, in addition to the stem-cell-triggered immunity we also highlight a potential link between cytokinin signaling and CLV3p mediated immune response in the SAM.

  6. COMPARATIVE ASPECTS OF PLANT-CELL WALL DIGESTION IN INSECTS

    NARCIS (Netherlands)

    PRINS, RA; KREULEN, DA

    1991-01-01

    Although many phytophagous and wood-eating invertibrates form their own cellulases, there is an overwhelming variety of symbioses between plant- and wood-utilising insects and microorganisms. In one type of symbiosis (endosymbiosis), insects (rhinoceros beetle, cockroach, lower termites) host cellul

  7. Solid Oxide Fuel Cell – Gas Turbine Hybrid Power Plant

    OpenAIRE

    Henke, Moritz; Willich, Caroline; Steilen, Mike; Kallo, Josef; Friedrich, K. Andreas

    2013-01-01

    A model of a hybrid power plant consisting of SOFC and a gas turbine is presented. Simulations are carried out for a different number of SOFC stacks while keeping the output power of the SOFC constant. Results show that the effect of stack number on system performance is only marginal within the investigated range. Operating conditions of the SOFC, however, are strongly influenced.

  8. A novel approach for studying programmed cell death in living plant tissues

    DEFF Research Database (Denmark)

    Mark, Christina

    insight by determining both the intra- and extracellular reducing capacity in living cells rather than using cell extracts. The reducing capacity of aleurone cells was shown to increase over time in parallel with the increase in cell death. Use of the flavoenzyme inhibitor diphenyleneiodonium chloride......, and enabled a higher throughput. The system wasused for parallel time course studies of cell viability, intracellular reducing capacity and transient expression profiles in immobilised tissue under multiple incubation conditions. Immobilisation resulted in decreased rates of cell death due to the lower......Programmed cell death (PCD) is a highly regulated process in which cells are killed as part of developmental programmes or as defence mechanisms against pathogens, but the process is less well understood in plant cells compared to animal cells. Reactive oxygen species (ROS) are involved in PCD...

  9. Induction and characterization of micronuclei in plant cells. Perspectives for micronucleus-mediated chromosome transfer.

    NARCIS (Netherlands)

    Verhoeven, H.A.

    1989-01-01

    In this thesis, micronucleation in plant cells has been investigated and systems for isolation and transfer of organelles have been established.The discovery, described in chapter two, that the phosphoric amide herbicide amiprophos-methyl induced micronuclei at a high frequency in cell suspensions o

  10. A single-cell bioluminescence imaging system for monitoring cellular gene expression in a plant body.

    Science.gov (United States)

    Muranaka, Tomoaki; Kubota, Saya; Oyama, Tokitaka

    2013-12-01

    Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescent reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive [Cauliflower mosaic virus 35S (CaMV35S)] and a rhythmic [Arabidopsis thaliana CIRCADIAN CLOCK ASSOCIATED 1 (AtCCA1)] promoter. Bioluminescence images were captured using an EM-CCD (electron multiply charged couple device) camera. Luminescent spots of the transfected cells in the plant body were quantitatively measured at the single-cell level. Luminescence intensities varied over a 1,000-fold range among CaMV35S::luc+-transfected cells in the same plant body and showed a log-normal-like frequency distribution. We monitored cellular gene expression under light-dark conditions by capturing bioluminescence images every hour. Luminescence traces of ≥50 individual cells in a frond were successfully obtained in each monitoring procedure. Rhythmic and constitutive luminescence behaviors were observed in cells transfected with AtCCA1::luc+ and CaMV35S::luc+, respectively. Diurnal rhythms were observed in every AtCCA1::luc+-introduced cell with traceable luminescence, and slight differences were detected in their rhythmic waveforms. Thus the single-cell bioluminescence monitoring system was useful for the characterization of cellular gene expression in a plant body.

  11. Production and excretion of secondary metabolites by plant cell cultures of Tagetes.

    NARCIS (Netherlands)

    Buitelaar, R.M.

    1991-01-01

    In this thesis, the results are presented of several approaches to improve the production and excretion of thiophenes by cell cultures or hairy roots of Tagetes spp.In chapter one, most of the techniques to improve the production and/or excretion of secondary metabolites with plant cell cultures are

  12. Preparation of labelled lipids by the use of plant cell cultures

    International Nuclear Information System (INIS)

    The preparation of some radioacitvely labelled lipids by the use of plant cell cultures is discussed and further applications of the new method are suggested. Cell suspension cultures of rape (Brassica napus) and soya (Glycine max) have been used for the preparation of lipids labelled with radioisotopes. Radioactive acetic acid as well as various long-chain fatty acids are readily incorporated into the neutral and ionic lipids of plant cell cultures. In addition, 14C-labelled glycerol, ethanolamine and choline are well utilized by the cells. Randomly labelled lipids have been obtained by incubating cell suspension cultures of rape and soya with [1-14C] acetic acid, and uniformly labelled lipids have been isolated from cultures that had been incubated with a mixture of [1-14C] acetic acid plus [2-14C] acetic acid. The use of techniques of plant cell cultures for the preparation of lipds labelled with stable or radioactive isotopesappears particularly rewarding because the uptake of precursors by the cells and their incorporation into various lipid compounds proceeds rapidly and often quanitatively.This new approach should be useful also for the biosynthesis of lipids whose acyl moieties contain a spn radical, a fluorescent group, or a light-sensitive label. Thus, plant cell cultures constitute valuable new tools for the biosynthetic preparation of a great variety of labelled lipids. (A.G.)

  13. A single-cell bioluminescence imaging system for monitoring cellular gene expression in a plant body.

    Science.gov (United States)

    Muranaka, Tomoaki; Kubota, Saya; Oyama, Tokitaka

    2013-12-01

    Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescent reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive [Cauliflower mosaic virus 35S (CaMV35S)] and a rhythmic [Arabidopsis thaliana CIRCADIAN CLOCK ASSOCIATED 1 (AtCCA1)] promoter. Bioluminescence images were captured using an EM-CCD (electron multiply charged couple device) camera. Luminescent spots of the transfected cells in the plant body were quantitatively measured at the single-cell level. Luminescence intensities varied over a 1,000-fold range among CaMV35S::luc+-transfected cells in the same plant body and showed a log-normal-like frequency distribution. We monitored cellular gene expression under light-dark conditions by capturing bioluminescence images every hour. Luminescence traces of ≥50 individual cells in a frond were successfully obtained in each monitoring procedure. Rhythmic and constitutive luminescence behaviors were observed in cells transfected with AtCCA1::luc+ and CaMV35S::luc+, respectively. Diurnal rhythms were observed in every AtCCA1::luc+-introduced cell with traceable luminescence, and slight differences were detected in their rhythmic waveforms. Thus the single-cell bioluminescence monitoring system was useful for the characterization of cellular gene expression in a plant body. PMID:24058151

  14. Induction of Apoptosis in Protoplasts and Suspension Cultures of Plant Cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Many studies have showed that apoptosis exists in plants. Our study shows that (1) menadione(VK3) induces apoptosis in suspension cultures of carrot cells; (2) heat shock induces apoptosis in suspension cultures of tobacco cells; and (3) ethrel induces apoptosis in carrot protoplasts. Some important indications of apoptosis were observed, including DNA laddering, TUNEL-positive reaction, condensation and degradation of nuclei.

  15. The invention of WUS-like stem cell-promoting functions in plants predates leptosporangiate ferns.

    Science.gov (United States)

    Nardmann, Judith; Werr, Wolfgang

    2012-01-01

    The growth of land plants depends on stem cell-containing meristems which show major differences in their architecture from basal to higher plant species. In Arabidopsis, the stem cell niches in the shoot and root meristems are promoted by WUSCHEL (WUS) and WOX5, respectively. Both genes are members of a non-ancestral clade of the WUS-related homeobox (WOX) gene family, which is absent in extant bryophytes and lycophytes. Our analyses of five fern species suggest that a single WUS orthologue was present in the last common ancestor (LCA) of leptosporangiate ferns and seed plants. In the extant fern Ceratopteris richardii, the WUS pro-orthologue marks the pluripotent cell fate of immediate descendants of the root apical initial, so-called merophytes, which undergo a series of stereotypic cell divisions and give rise to all cell types of the root except the root cap. The invention of a WUS-like function within the WOX gene family in an ancestor of leptosporangiate ferns and seed plants and its amplification and sub-functionalisation to different stem cell niches might relate to the success of seed plants, especially angiosperms.

  16. The role of the cell wall compartment in mutualistic symbioses of plants

    Directory of Open Access Journals (Sweden)

    Mélanie K. Rich

    2014-06-01

    Full Text Available Plants engage in mutualistic interactions with microbes that improve their mineral nutrient supply. The most wide-spread symbiotic association is arbuscular mycorrhiza (AM, in which fungi of the order Glomeromycota invade roots and colonize the cellular lumen of cortical cells. The establishment of this interaction requires a dedicated molecular-genetic program and a cellular machinery of the plant host. This program is partially shared with the root nodule symbiosis (RNS, which involves prokaryotic partners collectively referred to as rhizobia. Both, AM and RNS are endosymbioses that involve intracellular accommodation of the microbial partner in the cells of the plant host. Since plant cells are surrounded by sturdy cell walls, root penetration and cell invasion requires mechanisms to overcome this barrier while maintaining the cytoplasm of the two partners separate during development of the symbiotic association. Here, we discuss the diverse functions of the cell wall compartment in establishment and functioning of plant symbioses with the emphasis on AM and RNS, and we describe the stages of the AM association between the model organisms Petunia hybrida and Rhizophagus irregularis.

  17. Biosynthesis and biotransformation of lipids in plant cell cultures and algae

    International Nuclear Information System (INIS)

    The biosynthesis and metabolism of lipids in plant cell cultures grown photoautotrophically, has been studied since 1970. The most prominently occuring lipids in cell cultures and whole plants are phospholipids, glycolipids, triglycerides and glycosides. Radioactively labelled lipids have been produced from soybean cell cultures incubated with 14C-linoleic acid, and the fate of the phospholipid formed was investigated. Freshwater and marine algae cultured under different conditions of light, temperature and nutrient media have also been investigated for their lipid and fatty acid content. The exploitation of biotechnological processes for producing valuable lipids is encouraged. (U.K.)

  18. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Svensson, Birte;

    Programmed cell death (PCD) in plants can influence the outcome of yield and quality of crops through its important role in seed germination and the defence process against pathogens. The main scope of the project is to apply microfluidic cell culture for the measurement of electrochemically...... or optically detectable events during PCD in barley aleurone layer, a cell model for living plant tissues, for a better understanding of the underlying mechanisms of PCD in plants. Microfluidic cell culture enables in vitro experiments to approach in vivo conditions. The major advantage of electrochemical...... sensors and detection systems is that they can be miniaturized, multiplexed and automated without losing their performance making them suitable for integration with microfluidic devices1,2. Combining microfluidics with electrochemical and optical detection allows implementation of a wide range of assays...

  19. Plant cells in the context of climate change

    Directory of Open Access Journals (Sweden)

    Marcelo Rubens Machado

    2014-02-01

    Full Text Available Global warming and its origins triggered the beginning to considerable discussion in the last century. Studies of climate models presented in multidisciplinary scientific reports suggest that anthropogenic activities, particularly the emission of gases from the greenhouse effect, are greatly responsible for the current climate changes. The increase of carbon dioxide (CO2 atmospheric concentration has been in discussion in the news, scientific meetings and in public policy debates in several countries. Apart from its impact on global warming, the rising atmospheric CO2 has alerted the scientific community to the need to investigate any morpho-physiological alterations in the plants, given their direct influence on photosynthesis. This article aims to discuss cellular aspects related to plant growth, their behavior of cuticular waxes and the responses of the stomatal development arising from the chemical change to the atmosphere, which are the causes of serious concern and discussion.

  20. Perception of Plant Steroid Hormones at the Cell Surface

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianming

    2013-03-25

    The proposed research had two main objectives: 1) investigating the molecular mechanism by which BRs activate the BRI1-containing steroid receptor; and 2) to investigate the molecular mechanism of BRI1 function. During the course of this project, several research papers were published from other laboratories, which reported studies similar to our proposed experiments. We therefore changed our research direction and focused our research efforts on 1) molecular genetic studies of several extragenic suppressors of a weak bri1-9 mutant (which were named as EMS-mutagenized bri1 suppressor or ebs) and 2) biochemical characterization of the protein products of the cloned EBS genes. This switch turned out to be extremely successful and led to a surprising discovery that the dwarf phenotype of the well-studied bri1-9 mutant is not due to the failure of the bri1 receptor to bind the plant steroid hormone but rather caused by the retention of a structurally-imperfect but biochemically-competent bri1-9 and its subsequent degradation in the endoplasmic reticulum. This initial discovery coupled with subsequent cloning and further studies of additional EBS genes significantly increased our understanding of the protein quality control mechanisms in plants, a severely under-studied research topic in plant biology.

  1. Effects of Plants on Osteogenic Differentiation and Mineralization of Periodontal Ligament Cells: A Systematic Review.

    Science.gov (United States)

    Costa, Cláudio Rodrigues Rezende; Amorim, Bruna Rabelo; de Magalhães, Pérola; De Luca Canto, Graziela; Acevedo, Ana Carolina; Guerra, Eliete Neves Silva

    2016-04-01

    This systematic review aimed to evaluate the effects of plants on osteogenic differentiation and mineralization of human periodontal ligament cells. The included studies were selected using five different electronic databases. The reference list of the included studies was crosschecked, and a partial gray literature search was undertaken using Google Scholar and ProQuest. The methodology of the selected studies was evaluated using GRADE. After a two-step selection process, eight studies were identified. Six different types of plants were reported in the selected studies, which were Morinda citrifolia, Aloe vera, Fructus cnidii, Zanthoxylum schinifolium, Centella asiatica, and Epimedium species. They included five types of isolated plant components: acemannan, osthole, hesperetin, asiaticoside, and icariin. In addition, some active substances of these components were identified as polysaccharides, coumarins, flavonoids, and triterpenes. The studies demonstrated the potential effects of plants on osteogenic differentiation, cell proliferation, mineral deposition, and gene and protein expression. Four studies showed that periodontal ligament cells induce mineral deposition after plant treatment. Although there are few studies on the subject, current evidence suggests that plants are potentially useful for the treatment of periodontal diseases. However, further investigations are required to confirm the promising effect of these plants in regenerative treatments. PMID:26822584

  2. Effects of Plants on Osteogenic Differentiation and Mineralization of Periodontal Ligament Cells: A Systematic Review.

    Science.gov (United States)

    Costa, Cláudio Rodrigues Rezende; Amorim, Bruna Rabelo; de Magalhães, Pérola; De Luca Canto, Graziela; Acevedo, Ana Carolina; Guerra, Eliete Neves Silva

    2016-04-01

    This systematic review aimed to evaluate the effects of plants on osteogenic differentiation and mineralization of human periodontal ligament cells. The included studies were selected using five different electronic databases. The reference list of the included studies was crosschecked, and a partial gray literature search was undertaken using Google Scholar and ProQuest. The methodology of the selected studies was evaluated using GRADE. After a two-step selection process, eight studies were identified. Six different types of plants were reported in the selected studies, which were Morinda citrifolia, Aloe vera, Fructus cnidii, Zanthoxylum schinifolium, Centella asiatica, and Epimedium species. They included five types of isolated plant components: acemannan, osthole, hesperetin, asiaticoside, and icariin. In addition, some active substances of these components were identified as polysaccharides, coumarins, flavonoids, and triterpenes. The studies demonstrated the potential effects of plants on osteogenic differentiation, cell proliferation, mineral deposition, and gene and protein expression. Four studies showed that periodontal ligament cells induce mineral deposition after plant treatment. Although there are few studies on the subject, current evidence suggests that plants are potentially useful for the treatment of periodontal diseases. However, further investigations are required to confirm the promising effect of these plants in regenerative treatments.

  3. A new tool for plant cell biology: in vivo antibody uptake in plant protoplasts.

    Science.gov (United States)

    Brière, C; Barthou, H; Petitprez, M

    2004-07-01

    We report on the in vivo uptake of antibodies into plant protoplasts. When protoplasts of sunflower, Arabidopsis or tobacco were incubated in vivo with an antibody, this antibody was detected by immunofluorescence in the cytoplasm and/or the nucleus, depending on the location of the target protein. Furthermore, when protoplasts were cultured in the presence of antibodies, specific effects were observed. Incubation with antibodies raised against p34cdc2 led to a strong inhibition of the division rate, and a decrease in the average DNA content of protoplasts. With antibodies against HaWLIM1, a LIM domain protein of the CRP type, a negative effect on actin organisation was observed. We conclude that antibodies can penetrate plant protoplasts in vivo, and thus may be used as powerful tools for the study of protein function.

  4. Thermodynamic optimization of solid oxide fuel cell based combined cycle cogeneration plant

    Energy Technology Data Exchange (ETDEWEB)

    Odukoya, A.; Reddy, B.V. [University of Ontario Inst. of Technology, Oshawa, ON (Canada). Dept. of Mechanical Engineering; Carretero, J.A. [New Brunswick Univ., Fredericton, NB (Canada). Dept. of Mechanical Engineering

    2010-07-01

    Although coal has the highest greenhouse gas emission of all fossil fuels it is the most abundant of all the fuels. Optimization of new and existing power plant designs will help increase the operational efficiency of power generation. In particular, there is a need to optimize the design and operating parameters of power plants using integrated gasification combined cycle cogeneration technology. This study investigated the optimal operating condition of a co-fired combined cycle cogeneration power plant with solid oxide fuel cell (SOFC) combination fuelled with coal and natural gas. It examined the macroscopic detail of the plant while optimizing the operating parameters of individual components such as the gasifier, the consumption of methane and carbon monoxide in the fuel cell and the consumption of fuel in the combustion chamber of the gas turbine. The optimization of the entire plant was used to determine the best mode of operating the plant for a set of conditions within suggested limits. The study also found efficient ways to perform iterative processes to find exit conditions from the gasifier, fuel cell, gas turbine combustion chamber and exit condition from the gas turbine. The maximum fuel cell net work output, combined cycle net work output, combined cycle thermal efficiency and cogeneration efficiency were determined. The optimal pressure ratio, temperature of operation of the SOFC and, gas turbine inlet temperature were determined using a sequential quadratic program solver based on the Quasi-Newton algorithm. 18 refs., 5 tabs., 2 figs.

  5. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Skok, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); Abueg, R.Z. [Basic Measuring Instruments, Santa Clara, CA (United States); Schwartz, P. [Fluor Daniel, Inc., Irvine, CA (United States)] [and others

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  6. Selectively Structural Determination of Cellulose and Hemicellulose in Plant Cell Wall

    Science.gov (United States)

    Huang, Shih-Chun; Park, Yong; Cosgrove, Daniel; Maranas, Janna; Janna Maranas Team; Daniel Cosgrove Team

    2013-03-01

    Primary plant cell walls support the plant body, and regulate cell size, and plant growth. It contains several biopolymers that can be categorized into three groups: cellulose, hemicellulose and pectin. To determine the structure of plant cell wall, we use small angle neutron scattering in combination with selective deuteration and contrast matching method. We compare the structure between wild Arabidopsis thaliana and its xyloglucan-deficient mutant. Hemicellulose in both samples forms coil with similar radii of gyration, and weak scattering from the mutant suggests a limited amount of hemicellulose in the xyloglucan-deficient mutant. We observe good amount of hemicellulose coating on cellulose microfibrils only in wild Arabidopsis. The absence of coating in its xyloglucan-deficient mutation suggests the other polysaccharides do not have comparable interaction with cellulose. This highlights the importance of xyloglucan in plant cell wall. At larger scale, the average distance between cellulose fibril is found smaller than reported value, which directly reflects on their smaller matured plant size. U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Center for LignoCellulose Structure and Formation

  7. MANUFACTURE OF PHOTOVOLTAIC SOLAR CELL USING PLANT CHLOROPHYLL

    Science.gov (United States)

    To date, we have successfully manufactured working chlorophyll sensitized solar cells using chlorophyll (and b mixture) from spinach leaves. We have evaluated the electronic characteristics (voltage, current, and power outputs using different loading resistors) of this solar c...

  8. Thermoeconomic analysis of large solid oxide fuel cell plants: Atmospheric vs. pressurized performance

    International Nuclear Information System (INIS)

    A detailed thermoeconomic analysis of two large solid oxide fuel cell-based power plants operating at atmospheric pressure and 20 bar, respectively, is assessed in this work. The analyzed systems employ SOFC-GT (gas turbine) modules as main power generators; a bottom HRSC (heat recovery steam cycle) to generate additional electricity from the SOFC-GT exhaust hot gases is also included. The thermodynamic and economic performance of the two plant configurations are studied in detail: the exergy analysis shows an enhanced exergetic performance for the pressurized cycle that features components with higher efficiency and consequently a lower rate of exergy destruction (∼20% less than the atmospheric plant). The economic analysis considers the capital cost of each component within the system and is developed aiming at estimating the levelized cost of electricity. In order to match both exergetic and economic parts, a rigorous thermoeconomic analysis following the theory of Valero and Bejan [1,2] is implemented. A well-defined set of rules for the exergoeconomic balance around each plant component is specified and specific cost balance equations are thus derived. Results show how pressurized plant outperforms the atmospheric one, with a (on exergo-economic base) cost of electricity of 47.7 $/MWh instead of 64.2 $/MWh. Therefore, both exergetic and economic advantages result from the adoption of a pressurized SOFC-GT cycle in the framework of future advance power plants based on high-temperature fuel cells. - Highlights: • Exergy analysis of atmospheric and pressurized SOFC plants. • Exergy destruction in a fuel cell hybrid power plant. • Rigorous thermoeconomic methodology to assess the performance of different power generation plants. • Economic performance of SOFC plants

  9. Mechanistic Framework for Establishment, Maintenance, and Alteration of Cell Polarity in Plants

    Directory of Open Access Journals (Sweden)

    Pankaj Dhonukshe

    2012-01-01

    Full Text Available Cell polarity establishment, maintenance, and alteration are central to the developmental and response programs of nearly all organisms and are often implicated in abnormalities ranging from patterning defects to cancer. By residing at the distinct plasma membrane domains polar cargoes mark the identities of those domains, and execute localized functions. Polar cargoes are recruited to the specialized membrane domains by directional secretion and/or directional endocytic recycling. In plants, auxin efflux carrier PIN proteins display polar localizations in various cell types and play major roles in directional cell-to-cell transport of signaling molecule auxin that is vital for plant patterning and response programs. Recent advanced microscopy studies applied to single cells in intact plants reveal subcellular PIN dynamics. They uncover the PIN polarity generation mechanism and identified important roles of AGC kinases for polar PIN localization. AGC kinase family members PINOID, WAG1, and WAG2, belonging to the AGC-3 subclass predominantly influence the polar localization of PINs. The emerging mechanism for AGC-3 kinases action suggests that kinases phosphorylate PINs mainly at the plasma membrane after initial symmetric PIN secretion for eventual PIN internalization and PIN sorting into distinct ARF-GEF-regulated polar recycling pathways. Thus phosphorylation status directs PIN translocation to different cell sides. Based on these findings a mechanistic framework evolves that suggests existence of cell side-specific recycling pathways in plants and implicates AGC3 kinases for differential PIN recruitment among them for eventual PIN polarity establishment, maintenance, and alteration.

  10. The fusarium mycotoxin deoxynivalenol can inhibit plant apoptosis-like programmed cell death.

    Directory of Open Access Journals (Sweden)

    Mark Diamond

    Full Text Available The Fusarium genus of fungi is responsible for commercially devastating crop diseases and the contamination of cereals with harmful mycotoxins. Fusarium mycotoxins aid infection, establishment, and spread of the fungus within the host plant. We investigated the effects of the Fusarium mycotoxin deoxynivalenol (DON on the viability of Arabidopsis cells. Although it is known to trigger apoptosis in animal cells, DON treatment at low concentrations surprisingly did not kill these cells. On the contrary, we found that DON inhibited apoptosis-like programmed cell death (PCD in Arabidopsis cells subjected to abiotic stress treatment in a manner independent of mitochondrial cytochrome c release. This suggested that Fusarium may utilise mycotoxins to suppress plant apoptosis-like PCD. To test this, we infected Arabidopsis cells with a wild type and a DON-minus mutant strain of F. graminearum and found that only the DON producing strain could inhibit death induced by heat treatment. These results indicate that mycotoxins may be capable of disarming plant apoptosis-like PCD and thereby suggest a novel way that some fungi can influence plant cell fate.

  11. Subamolide B Isolated from Medicinal Plant Cinnamomum subavenium Induces Cytotoxicity in Human Cutaneous Squamous Cell Carcinoma Cells through Mitochondrial and CHOP-Dependent Cell Death Pathways

    OpenAIRE

    Shu-Yi Yang; Hui-Min Wang; Tai-Wen Wu; Yi-Ju Chen; Jeng-Jer Shieh; Ju-Hwa Lin; Tsing-Fen Ho; Ren-Jie Luo; Chung-Yi Chen; Chia-Che Chang

    2013-01-01

    Subamolide B is a butanolide isolated from Cinnamomum subavenium, a medicinal plant traditionally used to treat various ailments including carcinomatous swelling. We herein reported for the first time that subamolide B potently induced cytotoxicity against diverse human skin cancer cell lines while sparing nonmalignant cells. Mechanistic studies on human cutaneous squamous cell carcinoma (SCC) cell line SCC12 highlighted the involvement of apoptosis in subamolide B-induced cytotoxicity, as ev...

  12. 2009 Plant Cell Walls Gordon Research Conference-August 2-7,2009

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. Delivering DNA into Plant Cell by Gene Carriers of ZnS Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    FU Yu-qin; LI Lu-hua; WANG Pi-wu; QU Jing; FU Yong-ping; WANG Hui; SUN Jing-ran; L(U) Chang-li

    2012-01-01

    The development.of nanotechnology provides a new method for genetic engineering.However,the nanoparticles as gene carriers have been mainly used in the mammalian cells so far.We observed that ZnS nanoparticles modified with positively charged poly-L-lysine(PLL) successfully delivered GUS-encoding plasmid DNA into tobacco cells by means of ultrasound-assisted method.Polymerase chain reaction(PCR) detection,Southern blot analysis and GUS histochemical staining were carried out for the regenerated plants.The stable genetic modified plants mediated by ZnS nanoparticles can be obtained.This article demonstrates the great potential of nanoparticles as gene carrier in plant transformation and proves a novel approach for plant genetic decoration.

  14. Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass

    OpenAIRE

    Pattathil, Sivakumar; Hahn, Michael G.; Dale, Bruce E; Chundawat, Shishir P. S.

    2015-01-01

    Cell walls, which constitute the bulk of plant biomass, vary considerably in their structure, composition, and architecture. Studies on plant cell walls can be conducted on both native and pre-treated plant biomass samples, allowing an enhanced understanding of these structural and compositional variations. Here glycome profiling was employed to determine the relative abundance of matrix polysaccharides in several phylogenetically distinct native and pre-treated plant biomasses. Eight distinc...

  15. 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

    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......Relax, that deduces relaxation spectra from appropriate rheological measurements is presented and made accessible through a Web interface. BayesRelax models the cell wall as a continuum of relaxing elements, and the ability of the method to resolve small differences in cell wall mechanical properties is demonstrated...

  16. Multiwalled carbon nanotubes enter broccoli cells enhancing growth and water uptake of plants exposed to salinity

    OpenAIRE

    Martínez-Ballesta, Mª Carmen; Zapata, Lavinia; Chalbi, Najla; Carvajal, Micaela

    2016-01-01

    Background Carbon nanotubes have been shown to improve the germination and growth of some plant species, extending the applicability of the emerging nano-biotechnology field to crop science. Results In this work, exploitation of commercial multiwalled carbon nanotubes (MWCNTs) in control and 100 mM NaCl-treated broccoli was performed. Transmission electron microscopy demonstrated that MWCNTs can enter the cells in adult plants with higher accumulation under salt stress. Positive effect of MWC...

  17. Mechanisms and effective control of physiological browning phenomena in plant cell cultures.

    Science.gov (United States)

    Dong, Yan-Shan; Fu, Chun-Hua; Su, Peng; Xu, Xiang-Ping; Yuan, Jie; Wang, Sheng; Zhang, Meng; Zhao, Chun-Fang; Yu, Long-Jiang

    2016-01-01

    Browning phenomena are ubiquitous in plant cell cultures that severely hamper scientific research and widespread application of plant cell cultures. Up to now, this problem still has not been well controlled due to the unclear browning mechanisms in plant cell cultures. In this paper, the mechanisms were investigated using two typical materials with severe browning phenomena, Taxus chinensis and Glycyrrhiza inflata cells. Our results illustrated that the browning is attributed to a physiological enzymatic reaction, and phenolic biosynthesis regulated by sugar plays a decisive role in the browning. Furthermore, to confirm the specific compounds which participate in the enzymatic browning reaction, transcriptional profile and metabolites of T. chinensis cells, and UV scanning and high-performance liquid chromatography-mass spectrometry (HPLC-MS) profile of the browning compounds extracted from the brown-turned medium were analyzed, flavonoids derived from phenylpropanoid pathway were found to be the main compounds, and myricetin and quercetin were deduced to be the main substrates of the browning reaction. Inhibition of flavonoid biosynthesis can prevent the browning occurrence, and the browning is effectively controlled via blocking flavonoid biosynthesis by gibberellic acid (GA3 ) as an inhibitor, which further confirms that flavonoids mainly contribute to the browning. On the basis above, a model elucidating enzymatic browning mechanisms in plant cell cultures was put forward, and effective control approaches were presented.

  18. When supply does not meet demand-ER stress and plant programmed cell death

    Science.gov (United States)

    Williams, Brett; Verchot, Jeanmarie; Dickman, Martin B.

    2014-01-01

    The endoplasmic reticulum (ER) is the central organelle in the eukaryotic secretory pathway. The ER functions in protein synthesis and maturation and is crucial for proper maintenance of cellular homeostasis and adaptation to adverse environments. Acting as a cellular sentinel, the ER is exquisitely sensitive to changing environments principally via the ER quality control machinery. When perturbed, ER-stress triggers a tightly regulated and highly conserved, signal transduction pathway known as the unfolded protein response (UPR) that prevents the dangerous accumulation of unfolded/misfolded proteins. In situations where excessive UPR activity surpasses threshold levels, cells deteriorate and eventually trigger programmed cell death (PCD) as a way for the organism to cope with dysfunctional or toxic signals. The programmed cell death that results from excessive ER stress in mammalian systems contributes to several important diseases including hypoxia, neurodegeneration, and diabetes. Importantly, hallmark features and markers of cell death that are associated with ER stress in mammals are also found in plants. In particular, there is a common, conserved set of chaperones that modulate ER cell death signaling. Here we review the elements of plant cell death responses to ER stress and note that an increasing number of plant-pathogen interactions are being identified in which the host ER is targeted by plant pathogens to establish compatibility. PMID:24926295

  19. Detection of the plant parasite Cuscuta reflexa by a tomato cell surface receptor.

    Science.gov (United States)

    Hegenauer, Volker; Fürst, Ursula; Kaiser, Bettina; Smoker, Matthew; Zipfel, Cyril; Felix, Georg; Stahl, Mark; Albert, Markus

    2016-07-29

    Parasitic plants are a constraint on agriculture worldwide. Cuscuta reflexa is a stem holoparasite that infests most dicotyledonous plants. One exception is tomato, which is resistant to C. reflexa We discovered that tomato responds to a small peptide factor occurring in Cuscuta spp. with immune responses typically activated after perception of microbe-associated molecular patterns. We identified the cell surface receptor-like protein CUSCUTA RECEPTOR 1 (CuRe1) as essential for the perception of this parasite-associated molecular pattern. CuRe1 is sufficient to confer responsiveness to the Cuscuta factor and increased resistance to parasitic C. reflexa when heterologously expressed in otherwise susceptible host plants. Our findings reveal that plants recognize parasitic plants in a manner similar to perception of microbial pathogens.

  20. Cytotoxic activity of Thai medicinal plants against human cholangiocarcinoma, laryngeal and hepatocarcinoma cells in vitro

    Directory of Open Access Journals (Sweden)

    Itharat Arunporn

    2010-09-01

    Full Text Available Abstract Background Cholangiocarcinoma is a serious public health in Thailand with increasing incidence and mortality rates. The present study aimed to investigate cytotoxic activities of crude ethanol extracts of a total of 28 plants and 5 recipes used in Thai folklore medicine against human cholangiocarcinoma (CL-6, human laryngeal (Hep-2, and human hepatocarcinoma (HepG2 cell lines in vitro. Methods Cytotoxic activity of the plant extracts against the cancerous cell lines compared with normal cell line (renal epithelial cell: HRE were assessed using MTT assay. 5-fluorouracil was used as a positive control. The IC50 (concentration that inhibits cell growth by 50% and the selectivity index (SI were calculated. Results The extracts from seven plant species (Atractylodes lancea, Kaempferia galangal, Zingiber officinal, Piper chaba, Mesua ferrea, Ligusticum sinense, Mimusops elengi and one folklore recipe (Pra-Sa-Prao-Yhai exhibited promising activity against the cholangiocarcinoma CL-6 cell line with survival of less than 50% at the concentration of 50 μg/ml. Among these, the extracts from the five plants and one recipe (Atractylodes lancea, Kaempferia galangal, Zingiber officinal, Piper chaba, Mesua ferrea, and Pra-Sa-Prao-Yhai recipe showed potent cytotoxic activity with mean IC50 values of 24.09, 37.36, 34.26, 40.74, 48.23 and 44.12 μg/ml, respectively. All possessed high activity against Hep-2 cell with mean IC50 ranging from 18.93 to 32.40 μg/ml. In contrast, activity against the hepatoma cell HepG2 varied markedly; mean IC50 ranged from 9.67 to 115.47 μg/ml. The only promising extract was from Zingiber officinal (IC50 = 9.67 μg/ml. The sensitivity of all the four cells to 5-FU also varied according to cell types, particularly with CL-6 cell (IC50 = 757 micromolar. The extract from Atractylodes lancea appears to be both the most potent and most selective against cholangiocarcinoma (IC50 = 24.09 μg/ml, SI = 8.6. Conclusions The

  1. 2-Fluoro-L-Fucose Is a Metabolically Incorporated Inhibitor of Plant Cell Wall Polysaccharide Fucosylation.

    Science.gov (United States)

    Villalobos, Jose A; Yi, Bo R; Wallace, Ian S

    2015-01-01

    The monosaccharide L-fucose (L-Fuc) is a common component of plant cell wall polysaccharides and other plant glycans, including the hemicellulose xyloglucan, pectic rhamnogalacturonan-I (RG-I) and rhamnogalacturonan-II (RG-II), arabinogalactan proteins, and N-linked glycans. Mutations compromising the biosynthesis of many plant cell wall polysaccharides are lethal, and as a result, small molecule inhibitors of plant cell wall polysaccharide biosynthesis have been developed because these molecules can be applied at defined concentrations and developmental stages. In this study, we characterize novel small molecule inhibitors of plant fucosylation. 2-fluoro-L-fucose (2F-Fuc) analogs caused severe growth phenotypes when applied to Arabidopsis seedlings, including reduced root growth and altered root morphology. These phenotypic defects were dependent upon the L-Fuc salvage pathway enzyme L-Fucose Kinase/ GDP-L-Fucose Pyrophosphorylase (FKGP), suggesting that 2F-Fuc is metabolically converted to the sugar nucleotide GDP-2F-Fuc, which serves as the active inhibitory molecule. The L-Fuc content of cell wall matrix polysaccharides was reduced in plants treated with 2F-Fuc, suggesting that this molecule inhibits the incorporation of L-Fuc into these polysaccharides. Additionally, phenotypic defects induced by 2F-Fuc treatment could be partially relieved by the exogenous application of boric acid, suggesting that 2F-Fuc inhibits RG-II biosynthesis. Overall, the results presented here suggest that 2F-Fuc is a metabolically incorporated inhibitor of plant cellular fucosylation events, and potentially suggest that other 2-fluorinated monosaccharides could serve as useful chemical probes for the inhibition of cell wall polysaccharide biosynthesis.

  2. Control of the meiotic cell division program in plants

    NARCIS (Netherlands)

    Wijnker, T.G.; Schnittger, A.

    2013-01-01

    While the question of why organisms reproduce sexually is still a matter of controversy, it is clear that the foundation of sexual reproduction is the formation of gametes with half the genomic DNA content of a somatic cell. This reduction in genomic content is accomplished through meiosis that, in

  3. Influence of decenylsuccinic Acid on water permeability of plant cells.

    Science.gov (United States)

    Lee, O Y; Stadelmann, E J; Weiser, C J

    1972-11-01

    Decenylsuccinic acid altered permeability to water of epidermal cells of bulb scales of Allium cepa and of the leaf midrib of Rhoeo discolor. Water permeability, as determined by deplasmolysis time measurements, was related to the dose of undissociated decenylsuccinic acid (mm undissociated decenylsuccinic acid x minute). No relationship was found between permeability and total dose of decenylsuccinic acid, or dose of dissociated decenylsuccinic acid, suggesting that the undissociated molecule was the active factor in permeability changes and injury.At doses which did not damage cells (0.0008 to 0.6 [mm of the undissociated molecule x minute]) decenylsuccinic acid decreased water permeability. At higher doses (e.g., 4 to 8 [mm x minute]) injury to cells was common and decenylsuccinic acid increased permeability. Doses above the 10 to 20 (mm x minute) range were generally lethal. The plasmolysis form of uninjured cells was altered and protoplasmic swelling occasionally was observed. The dose-dependent reversal of water permeability changes (decreased to increased permeability) may reflect decenylsuccinic acid-induced changes in membrane structure. Reported effects of decenylsuccinic acid on temperature dependence of permeability and frost resistance were not verified. PMID:16658227

  4. RhizoFlowCell system reveals early effects of micropollutants on aquatic plant rhizosphere.

    Science.gov (United States)

    Mynampati, Kalyan Chakravarthy; Lee, Yong Jian; Wijdeveld, Arjan; Reuben, Sheela; Samavedham, Lakshminarayanan; Kjelleberg, Staffan; Swarup, Sanjay

    2015-12-01

    In aquatic systems, one of the non-destructive ways to quantify toxicity of contaminants to plants is to monitor changes in root exudation patterns. In aquatic conditions, monitoring and quantifying such changes are currently challenging because of dilution of root exudates in water phase and lack of suitable instrumentation to measure them. Exposure to pollutants would not only change the plant exudation, but also affect the microbial communities that surround the root zone, thereby changing the metabolic profiles of the rhizosphere. This study aims at developing a device, the RhizoFlowCell, which can quantify metabolic response of plants, as well as changes in the microbial communities, to give an estimate of the stress to which the rhizosphere is exposed. The usefulness of RhizoFlowCell is demonstrated using naphthalene as a test pollutant. Results show that RhizoFlowCell system is useful in quantifying the dynamic metabolic response of aquatic rhizosphere to determine ecosystem health. PMID:26386206

  5. Bacterial conjugation protein MobA mediates integration of complex DNA structures into plant cells.

    Science.gov (United States)

    Bravo-Angel, A M; Gloeckler, V; Hohn, B; Tinland, B

    1999-09-01

    Agrobacterium tumefaciens transfers T-DNA to plant cells, where it integrates into the genome, a property that is ensured by bacterial proteins VirD2 and VirE2. Under natural conditions, the protein MobA mobilizes its encoding plasmid, RSF1010, between different bacteria. A detailed analysis of MobA-mediated DNA mobilization by Agrobacterium to plants was performed. We compared the ability of MobA to transfer DNA and integrate it into the plant genome to that of pilot protein VirD2. MobA was found to be about 100-fold less efficient than VirD2 in conducting the DNA from the pTi plasmid to the plant cell nucleus. However, interestingly, DNAs transferred by the two proteins were integrated into the plant cell genome with similar efficiencies. In contrast, most of the integrated DNA copies transferred from a MobA-containing strain were truncated at the 5' end. Isolation and analysis of the most conserved 5' ends revealed patterns which resulted from the illegitimate integration of one transferred DNA within another. These complex integration patterns indicate a specific deficiency in MobA. The data conform to a model according to which efficiency of T-DNA integration is determined by plant enzymes and integrity is determined by bacterial proteins. PMID:10482518

  6. The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

    KAUST Repository

    Neumann, Christina

    2014-10-17

    Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6), thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

  7. To Stretch the Boundary of Secondary Metabolite Production in Plant Cell-Based Bioprocessing: Anthocyanin as a Case Study

    OpenAIRE

    Wei Zhang; Chris Franco; Chris Curtin; Simon Conn

    2004-01-01

    Plant cells and tissue cultures hold great promise for controlled production of a myriad of useful secondary metabolites on demand. The current yield and productivity cannot fulfill the commercial goal of a plant cell-based bioprocess for the production of most secondary metabolites. In order to stretch the boundary, recent advances, new directions and opportunities in plant cell-based bioprocessing, have been critically examined for the 10 years from 1992 to 2002. A review of the literature ...

  8. The biochemical control of the cell cycle by growth regulators in higher plants

    Institute of Scientific and Technical Information of China (English)

    TANGWei; LatoyaHarris; RonaldJ.Newton

    2004-01-01

    The cell cycle is an important research field in cell biology and it is genetically and developmentally regulated in animals and plants. The aim of this study was to review knowledge about the biochemical regulation of the cell cycle by plant growth regulators through molecular checkpoints that regulate the transition from G0-G1-S-phase and G2-M in higher plants.Recent research has shown that zeatin treatment led to the up-regulation of CycD3 in Arabidopsis. Benzyladenine treatment can also shorten the duration of S-phase through recruitment of latent origins of DNA replication. Kinetin is involved in the phosphoregulation of the G2-M checkpoint; the major cyclin-dependent kinase (Cdk) at this checkpoint has recently shown to be dephosphorylated as a result of cytokinin treatment, an effect that can also be mimicked by the fission yeast Cdc25 phosphatase. Gibberellic acid (GA) treatment induces internode elongation in deepwater rice, this response is mediated by a GA-induced up-regulation of a cyclin-Cdk at the G2-M checkpoint. Recent evidence has also linked abscisic acid to a cyclin-dependent kinase inhibitor. A new D-type cyclin, recently discovered in Arabidopsis may have a key role in this process. A brief review on plant growth regulator-cell cycle interfacing during development and a cytokinin-induced continuum of cell cycle activation through the up-regulation of a plant D-type cyclin at the G1 checkpoint and the phosphoregulation of the Cdk at the G2/M checkpoint had been concluded. This review could be valuable to research on cell and developmental biology in plants.

  9. Special considerations on operating a fuel cell power plant using natural gas with marginal heating value

    Energy Technology Data Exchange (ETDEWEB)

    Moses, L. Ng; Chien-Liang Lin [Industrial Technology Research Institute, Taiwan (China); Ya-Tang Cheng [Power Research Institute, Taiwan (China)

    1996-12-31

    In realizing new power generation technologies in Taiwan, a phosphoric acid fuel cell power plant (model PC2513, ONSI Corporation) has been installed in the premises of the Power Research Institute of the Taiwan Power Company in Taipei County of Taiwan. The pipeline gas supplying to the site of this power plant has a high percentage of carbon dioxide and thus a slightly lower heating value than that specified by the manufacturer. Because of the lowering of heating value of input gas, the highest Output power from the power plant is understandably less than the rated power of 200 kW designed. Further, the transient response of the power plant as interrupted from the Grid is also affected. Since this gas is also the pipeline gas supplying to the heavily populated Taipei Municipal area, it is conceivable that the success of the operations of fuel cells using this fuel is of vital importance to the promotion of the use of this power generation technology in Taiwan. Hence, experiments were set up to assess the feasibility of this fuel cell power plant using the existing pipeline gas in this part of Taiwan where fuel cells would most likely find useful.

  10. Low cost delivery of proteins bioencapsulated in plant cells to human non-immune or immune modulatory cells.

    Science.gov (United States)

    Xiao, Yuhong; Kwon, Kwang-Chul; Hoffman, Brad E; Kamesh, Aditya; Jones, Noah T; Herzog, Roland W; Daniell, Henry

    2016-02-01

    Targeted oral delivery of GFP fused with a GM1 receptor binding protein (CTB) or human cell penetrating peptide (PTD) or dendritic cell peptide (DCpep) was investigated. Presence of GFP(+) intact plant cells between villi of ileum confirm their protection in the digestive system from acids/enzymes. Efficient delivery of GFP to gut-epithelial cells by PTD or CTB and to M cells by all these fusion tags confirm uptake of GFP in the small intestine. PTD fusion delivered GFP more efficiently to most tissues or organs than the other two tags. GFP was efficiently delivered to the liver by all fusion tags, likely through the gut-liver axis. In confocal imaging studies of human cell lines using purified GFP fused with different tags, GFP signal of DCpep-GFP was only detected within dendritic cells. PTD-GFP was only detected within kidney or pancreatic cells but not in immune modulatory cells (macrophages, dendritic, T, B, or mast cells). In contrast, CTB-GFP was detected in all tested cell types, confirming ubiquitous presence of GM1 receptors. Such low-cost oral delivery of protein drugs to sera, immune system or non-immune cells should dramatically lower their cost by elimination of prohibitively expensive fermentation, protein purification cold storage/transportation and increase patient compliance. PMID:26706477

  11. New insights on plant cell elongation: a role for acetylcholine.

    Science.gov (United States)

    Di Sansebastiano, Gian-Pietro; Fornaciari, Silvia; Barozzi, Fabrizio; Piro, Gabriella; Arru, Laura

    2014-01-01

    We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response. PMID:24642879

  12. New Insights on Plant Cell Elongation: A Role for Acetylcholine

    Directory of Open Access Journals (Sweden)

    Gian-Pietro Di Sansebastiano

    2014-03-01

    Full Text Available We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response.

  13. Targeting and Regulation of Cell Wall Synthesis During Tip Growth in Plants

    Institute of Scientific and Technical Information of China (English)

    Fangwei Gu; Erik Nielsen

    2013-01-01

    Root hairs and pollen tubes are formed through tip growth, a process requiring synthesis of new cell wall material and the precise targeting and integration of these components to a selected apical plasma membrane domain in the growing tips of these cells. Presence of a tip-focused calcium gradient, control of actin cytoskeleton dynamics, and formation and targeting of secretory vesicles are essential to tip growth. Similar to cells undergoing diffuse growth, cellulose, hemi-celluloses, and pectins are also deposited in the growing apices of tip-growing cells. However, differences in the manner in which these cell wall components are targeted and inserted in the expanding portion of tip-growing cells is reflected by the identification of elements of the plant cell wall synthesis machinery which have been shown to play unique roles in tip-growing cells. In this review, we summarize our current understanding of the tip growth process, with a particular focus on the subcellular targeting of newly synthesized cell wall components, and their roles in this form of plant cell expansion.

  14. Apoptosis-Inducing Effect of Three Medicinal Plants on Oral Cancer Cells KB and ORL-48

    Directory of Open Access Journals (Sweden)

    Mohd Zabidi Majid

    2014-01-01

    Full Text Available Brucea javanica, Azadirachta indica, and Typhonium flagelliforme are medicinal plants commonly used to treat conditions associated with tumour formation. This study aimed to determine the antiproliferative activity of these plants extracts on KB and ORL-48 oral cancer cell lines and to suggest their mode of cell death. The concentration producing 50% cell inhibition (IC50 was determined and the activity was examined under an inverted microscope. Immunohistochemistry fluorescent staining method (TUNEL was performed to indicate the mechanism of cell death and the fragmented DNA band pattern produced was obtained for verification. Compared to Azadirachta sp. and Typhonium sp., the antiproliferative activity of Brucea sp. extract was the most potent on both KB and ORL-48 cells with IC50 of 24.37 ± 1.75 and 6.67 ± 1.15 µg/mL, respectively. Signs of cell attrition were observed 24 hr after treatment. Green fluorescent spots indicating cell death by apoptosis were observed in images of both cells following treatment with all the three extracts. DNA fragments harvested from Brucea-treated cells produced bands in a ladder pattern suggesting the apoptotic effect of the extract. It is thus concluded that Brucea sp. extract exhibited cytotoxic activity on ORL-48 cells and their action mechanism is via apoptosis.

  15. From microgravity to osmotic conditions: mechanical integration of plant cells in response to stress

    Science.gov (United States)

    Wojtaszek, Przemyslaw; Kasprowicz, Anna; Michalak, Michal; Janczara, Renata; Volkmann, Dieter; Baluska, Frantisek

    Chemical reactions and interactions between molecules are commonly thought of as being at the basis of Life. Research of recent years, however, is more and more evidently indicating that physical forces are profoundly affecting the functioning of life at all levels of its organiza-tion. To detect and to respond to such forces, plant cells need to be integrated mechanically. Cell walls are the outermost functional zone of plant cells. They surround the individual cells, and also form a part of the apoplast. In cell suspensions, cell walls are embedded in the cul-ture medium which can be considered as a superapoplast. Through physical and chemical interactions they provide a basis for the structural and functional cell wall-plasma membrane-cytoskeleton (WMC) continuum spanning the whole cell. Here, the working of WMC contin-uum, and the participation of signalling molecules, like NO, would be presented in the context of plant responses to stress. In addition, the effects of the changing composition of WMC continuum will be considered, with particular attention paid to the modifications of the WMC components. Plant cells are normally adapted to changing osmotic conditions, resulting from variable wa-ter availability. The appearance of the osmotic stress activates adaptory mechanisms. If the strength of osmotic stress grows relatively slowly over longer period of time, the cells are able to adapt to conditions that are lethal to non-adapted cells. During stepwise adaptation of tobacco BY-2 suspension cells to the presence of various osmotically active agents, cells diverged into independent, osmoticum type-specific lines. In response to ionic agents (NaCl, KCl), the adhe-sive properties were increased and randomly dividing cells formed clumps, while cells adapted to nonionic osmotica (mannitol, sorbitol, PEG) revealed ordered pattern of precisely positioned cell divisions, resulting in the formation of long cell files. Changes in the growth patterns were accompanied by

  16. Binary co-generation power plant with night-temperature (SOFC) fuel cells of natural gas, v. 15(57)

    International Nuclear Information System (INIS)

    Binary co-generation power plant with height-temperature SOFC fuel cells of natural gas are presented in this paper. Based on before optimization calculations for this type of power plants is made: basic measures, number of modules, electric power and fuel cell efficiency; gas turbine electric power and efficiency; co-generation steam turbine electric and heat power efficiency. Compare analysis of binary co-generation power plant with SOFC fuel cells and co-generative power plant without fuel cells in relation of efficiency, ecological benefits and profitability (economy analysis) is given. (Author)

  17. [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.

  18. Inhibition of proliferation by agricultural plant extracts in seven human adult T-cell leukaemia (ATL)-related cell lines.

    Science.gov (United States)

    Kai, Hisahiro; Akamatsu, Ena; Torii, Eri; Kodama, Hiroko; Yukizaki, Chizuko; Sakakibara, Yoichi; Suiko, Masahito; Morishita, Kazuhiro; Kataoka, Hiroaki; Matsuno, Koji

    2011-07-01

    Adult T-cell leukaemia (ATL) is caused by human T-cell leukaemia virus type I (HTLV-I) infection and is resistant to conventional chemotherapy. We evaluated the inhibitory effects of agricultural plants on the proliferation of seven ATL-related human leukaemia cells, using three ATL cell lines (ED, Su9T01 and S1T), two human T-cell lines transformed by HTLV-I infection (HUT-102 and MT-2) and two HTLV-I-negative human T-cell acute lymphoblastic leukaemia cell lines (Jurkat and MOLT-4). A total of 52 samples of 80% ethanol extracts obtained from 30 types of agricultural plants were examined. On the basis of IC(50) values, we selected samples with greater activity than genistein, which was used as a positive control. The highest inhibitory effect was observed with extracts from leaves of Vaccinium virgatum Aiton (blueberry) on four cell lines (ED, Su9T01, HUT-102 and Jurkat); seeds of Momordica charantia L. (bitter gourd) exhibited the second highest activity. The bitter gourd seeds suppressed the proliferation of three cell lines (Su9T01, HUT-102 and Jurkat). The extracts from edible parts of Ipomea batatas LAM. (sweet potato), edible parts of Colocasia esculenta (L.) Schott (taro), skin of taro and seeds of Prunus mume Sieb. et Zucc. (mume) showed markedly greater inhibitory effects on Su9T01 than genistein. These findings suggest that ATL-preventative bioactive compounds may exist in these agricultural plants, which are considered to be functional foods. PMID:21293936

  19. Induction of murine embryonic stem cell differentiation by medicinal plant extracts

    Energy Technology Data Exchange (ETDEWEB)

    Reynertson, Kurt A. [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Charlson, Mary E. [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Gudas, Lorraine J., E-mail: ljgudas@med.cornell.edu [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States)

    2011-01-01

    Epidemiological evidence indicates that diets high in fruits and vegetables provide a measure of cancer chemoprevention due to phytochemical constituents. Natural products are a rich source of cancer chemotherapy drugs, and primarily target rapidly cycling tumor cells. Increasing evidence indicates that many cancers contain small populations of resistant, stem-like cells that have the capacity to regenerate tumors following chemotherapy and radiation, and have been linked to the initiation of metastases. Our goal is to discover natural product-based clinical or dietary interventions that selectively target cancer stem cells, inducing differentiation. We adapted an alkaline phosphatase (AP) stain to assay plant extracts for the capacity to induce differentiation in embryonic stem (ES) cells. AP is a characteristic marker of undifferentiated ES cells, and this represents a novel approach to screening medicinal plant extracts. Following a survey of approximately 100 fractions obtained from 12 species of ethnomedically utilized plants, we found fractions from 3 species that induced differentiation, decreasing AP and transcript levels of pluripotency markers (Nanog, Oct-4, Rex-1). These fractions affected proliferation of murine ES, and human embryonal, prostate, and breast carcinoma cells in a dose-dependent manner. Several phytochemical constituents were isolated; the antioxidant phytochemicals ellagic acid and gallic acid were shown to affect viability of cultured breast carcinoma cells.

  20. Turnover of galactans and other cell wall polysaccharides during development of flax plants

    International Nuclear Information System (INIS)

    We investigated the synthesis and turnover of cell wall polysaccharides of the flax (Linum usitatissimum L.) plant during development of the phloem fibers. One-month-old flax plants were exposed to a 40-min pulse with 14CO2 followed by 8-h, 24-h, and 1-month periods of chase with ambient CO2, and radioactivity in cell wall sugars was determined in various plant parts. The relative radioactivity of glucose in noncellulosic polysaccharides was the highest compared with all other cell wall sugars immediately after the pulse and decreased substantially during the subsequent chase. The relative radioactivities of the other cell wall sugars changed with differing rates, indicating turnover of specific polysaccharides. Notably, after 1 month of chase there was a marked decrease in the proportional mass and total radioactivity in cell wall galactose, indicating a long-term turnover of the galactans enriched in the fiber-containing tissues. The ratio of radiolabeled xylose to arabinose also increased during the chase, indicating a turnover of arabinose-containing polymers and interconversion to xylose. The pattern of label redistribution differed between organs, indicating that the cell wall turnover processes are tissue- and cell-specific

  1. Startup, testing, and operation of the Santa Clara 2MW direct carbonate fuel cell demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Skok, A.J.; Leo, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); O`Shea, T.P. [Santa Clara Demonstration Project, CA (United States)

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is a collaboration between several utility organizations, Fuel Cell Engineering Corporation (FCE), and the U.S. Dept. Of Energy aimed at the demonstration of Energy Research Corporation`s (ERC) direct carbonate fuel cell (DFC) technology. ERC has been pursuing the development of the DFC for commercialization near the end of this decade, and this project is an integral part of the ERC commercialization effort. The objective of the Santa Clara Demonstration Project is to provide the first full, commercial scale demonstration of this technology. The approach ERC has taken in the commercialization of the DFC is described in detail elsewhere. An aggressive core technology development program is in place which is focused by ongoing interaction with customers and vendors to optimize the design of the commercial power plant. ERC has selected a 2.85 MW power plant unit for initial market entry. Two ERC subsidiaries are supporting the commercialization effort: the Fuel Cell Manufacturing Corporation (FCMC) and the Fuel Cell Engineering Corporation (FCE). FCMC manufactures carbonate stacks and multi-stack modules, currently from its production facility in Torrington, CT. FCE is responsible for power plant design, integration of all subsystems, sales/marketing, and client services. FCE is serving as the prime contractor for the design, construction, and testing of the SCDP Plant. FCMC has manufactured the multi-stack submodules used in the DC power section of the plant. Fluor Daniel Inc. (FDI) served as the architect-engineer subcontractor for the design and construction of the plant and provided support to the design of the multi-stack submodules. FDI is also assisting the ERC companies in commercial power plant design.

  2. Human cultured cells are capable to incorporate isolated plant mitochondria loaded with exogenous DNA

    Directory of Open Access Journals (Sweden)

    Laktionov P. P.

    2012-07-01

    Full Text Available Aim. To investigate the possibility of human cultured cells to incorporate isolated mitochondria together with exogenous DNA introduced into organelles. Methods. Two approaches were used for this purpose, fluorescent labelling of mitochondria and/or DNA with subsequent analysis of the cells subjected to incubation by microscopy or by quantitative PCR. Results. We have shown that human cultured cells lines, HeLa and HUVEC, are capable to uptake isolated plant mitochondria and that this process depends on the incubation time and concentration of organelles present in medium. The incorporated mitochondria can serve as vehicles to deliver exogenous DNA into human cells, this DNA is then distributed in different cell compartments. Conclusions. These results are preliminary and need further investigations, including testing the possibility of human cells to incorporate the mitochondria of human or animal origin and creating genetic construction which could provide certain selectivity or stability of the transferred exogenous DNA upon cell uptake of the mitochondria as vectors.

  3. Among plant lignans, pinoresinol has the strongest antiinflammatory properties in human intestinal Caco-2 cells.

    Science.gov (United States)

    During, Alexandrine; Debouche, Céline; Raas, Thomas; Larondelle, Yvan

    2012-10-01

    Dietary lignans show some promising health benefits, but little is known about their fate and activities in the small intestine. The purpose of this study was thus to investigate whether plant lignans are taken up by intestinal cells and modulate the intestinal inflammatory response using the Caco-2 cell model. Six lignan standards [secoisolariciresinol diglucoside (SDG), secoisolariciresinol (SECO), pinoresinol (PINO), lariciresinol, matairesinol (MAT), and hydroxymatairesinol] and their colonic metabolites [enterolactone (ENL) and enterodiol] were studied. First, differentiated cells were exposed to SDG, SECO, PINO, or ENL at increasing concentrations for 4 h, and their cellular contents (before and after deconjugation) were determined by HPLC. Second, in IL-1β-stimulated confluent and/or differentiated cells, lignan effects were tested on different soluble proinflammatory mediators quantified by enzyme immunoassays and on the NF-κB activation pathway by using cells transiently transfected. SECO, PINO, and ENL, but not SDG, were taken up and partly conjugated by cells, which is a saturable conjugation process. PINO was the most efficiently conjugated (75% of total in cells). In inflamed cells, PINO significantly reduced IL-6 by 65% and 30% in confluent and differentiated cells, respectively, and cyclooxygenase (COX)-2-derived prostaglandin E(2) by 62% in confluent cells. In contrast, MAT increased significantly COX-2-derived prostaglandin E(2) in confluent cells. Moreover, PINO dose-dependently decreased IL-6 and macrophage chemoattractant protein-1 secretions and NF-κB activity. Our findings suggest that plant lignans can be absorbed and metabolized in the small intestine and, among the plant lignans tested, PINO exhibited the strongest antiinflammatory properties by acting on the NF-κB signaling pathway, possibly in relation to its furofuran structure and/or its intestinal metabolism.

  4. Dracocephalum: Novel Anticancer Plant Acting on Liver Cancer Cell Mitochondria

    Directory of Open Access Journals (Sweden)

    Mojtaba Talari

    2014-01-01

    Full Text Available Dracocephalum kotschyi Boiss. (Labiatae is a native Iranian medicinal plant which has been used in combination with Peganum harmala L. as a remedy for many forms of human cancer especially leukemia and gastrointestinal malignancies. Hepatocellular carcinoma (HCC is the third leading cause of cancer-related death worldwide. In this investigation HCC was induced by a single intraperitoneal injection of diethylnitrosamine (DEN in corn oil at 200 mg/kg body weight to rats. Two weeks after DEN administration, cancer development was promoted with dietary 2-acetylaminofluorene (2-AAF (0.02%, w/w for 2 weeks. Serum alpha-fetoprotein (AFP concentration, serum alanine transaminase (ALT, aspartate transaminase (AST, and alkaline phosphatase (ALP activities were also determined for confirmation of hepatocellular carcinoma induction. Then rat hepatocytes were isolated with collagen perfusion technique and tumoral hepatocytes were sorted by flow cytometry. Finally isolated mitochondria obtained from both tumoral and nontumoral hepatocytes were used for any probable toxic effect of Dracocephalum kotschyi ethanolic extract. Our results showed that D. kotschyi extract (250 µg/mL induced reactive oxygen species (ROS formation, mitochondrial membrane permeabilization (MMP, and mitochondrial swelling and cytochrome c release only in tumoral but not nontumoral hepatocyte. These findings propose Dracocephalum kotschyi as a promising candidate for future anticancer research.

  5. Antiproliferative effects of some medicinal plants on HeLa cells

    Directory of Open Access Journals (Sweden)

    Cenić-Milošević Desanka

    2013-01-01

    Full Text Available Medicinal plants maintain the health and vitality of individuals, and also have potential curative effect on various diseases, including cancer. In this study were investigated the antiproliferative effects of water extracts of previously obtained ethanolic dry extracts of three different medicinal plants (Echinacea angustifolia, Salvia officinalis and Melissa officinalis on cell lines derived from human cervix adenocarcinoma (HeLa cells. The best cytotoxic activity (IC50 = 43.52 μg/ml on HeLa cell lines was exhibited by Echinacea angustifolia. The extract of Salvia officinalis also showed a good cytotoxic activity against HeLa cell lines; the IC50 value was 70.41 μg/ml. Melissa officinalis manifested a slightly weaker cytotoxic activity and an IC50 value of 122.22 μg/ml. [Projekat Ministarstva nauke Republike Srbije, br. 34021 i br. 175011

  6. Quantitative analysis of changes in actin microfilament contribution to cell plate development in plant cytokinesis

    Directory of Open Access Journals (Sweden)

    Sano Toshio

    2008-07-01

    Full Text Available Abstract Background Plant cells divide by the formation of new cross walls, known as cell plates, from the center to periphery of each dividing cell. Formation of the cell plate occurs in the phragmoplast, a complex structure composed of membranes, microtubules (MTs and actin microfilaments (MFs. Disruption of phragmoplast MTs was previously found to completely inhibit cell plate formation and expansion, indicative of their crucial role in the transport of cell plate membranes and materials. In contrast, disruption of MFs only delays cell plate expansion but does not completely inhibit cell plate formation. Despite such findings, the significance and molecular mechanisms of MTs and MFs remain largely unknown. Results Time-sequential changes in MF-distribution were monitored by live imaging of tobacco BY-2 cells stably expressing the GFP-actin binding domain 2 (GFP-ABD2 fusion protein, which vitally co-stained with the endocytic tracer, FM4-64, that labels the cell plate. During cytokinesis, MFs accumulated near the newly-separated daughter nuclei towards the emerging cell plate, and subsequently approached the expanding cell plate edges. Treatment with an actin polymerization inhibitor caused a decrease in the cell plate expansion rate, which was quantified using time-lapse imaging and regression analysis. Our results demonstrated time-sequential changes in the contribution of MFs to cell plate expansion; MF-disruption caused about a 10% decrease in the cell plate expansion rate at the early phase of cytokinesis, but about 25% at the late phase. MF-disruption also caused malformation of the emerging cell plate at the early phase, indicative of MF involvement in early cell plate formation and expansion. The dynamic movement of endosomes around the cell plate was also inhibited by treatment with an actin polymerization inhibitor and a myosin ATPase inhibitor, respectively. Furthermore, time-lapse imaging of the endoplasmic reticulum (ER revealed

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

    OpenAIRE

    Cécile Albenne; Hervé Canut; Laurent Hoffmann; Elisabeth Jamet

    2014-01-01

    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 ...

  8. Omics and modeling approaches approaches for understanding regulation of asymmetric cell divisions in Arabidopsis and other angiosperm plants.

    NARCIS (Netherlands)

    Kajala, K.; Ramakrishna, A.; Fisher, A.; Bergmann, D.C.; Smet, De I.; Sozzani, R.; Weijers, D.; Brady, S.M.

    2014-01-01

    Background Asymmetric cell divisions are formative divisions that generate daughter cells of distinct identity. These divisions are coordinated by either extrinsic (‘niche-controlled’) or intrinsic regulatory mechanisms and are fundamentally important in plant development. Scope This review describe

  9. Glyoxylate Reductase Isoform 1 is Localized in the Cytosol and Not Peroxisomes in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Steven L. K. Ching; Satinder K. Gidda; Amanda Rochon; Owen R. van Cauwenberghe; Barry J. Shelp; Robert T. Mullen

    2012-01-01

    Glyoxylate reductase (GLYR) is a key enzyme in plant metabolism which catalyzes the detoxification of both photorespiratory glyoxylate and succinic semialdehdye,an intermediate of the γ-aminobutyrate (GABA) pathway.Two isoforms of GLYR exist in plants,GLYR1 and GLYR2,and while GLYR2 is known to be localized in plastids,GLYR1 has been reported to be localized in either peroxisomes or the cytosol.Here,we reappraised the intracellular localization of GLYR1 in Arabidopsis thaliana L.Heynh (ecotype Lansberg erecta) using both transiently-transformed suspension cells and stably-transformed plants,in combination with fluorescence microscopy.The results indicate that GLYR1 is localized exclusively to the cytosol regardless of the species,tissue and/or cell type,or exposure of plants to environmental stresses that would increase flux through the GABA pathway.Moreover,the C-terminal tripeptide sequence of GLYR1,-SRE,despite its resemblance to a type 1 peroxisomal targeting signal,is not sufficient for targeting to peroxisomes.Collectively,these results define the cytosol as the intracellular location of GLYR1 and provide not only important insight to the metabolic roles of GLYR1 and the compartmentation of the GABA and photorespiratory pathways in plant cells,but also serve as a useful reference for future studies of proteins proposed to be localized to peroxisomes and/or the cytosol.

  10. Candidate Effector Proteins of the Rust Pathogen Melampsora larici-populina Target Diverse Plant Cell Compartments.

    Science.gov (United States)

    Petre, Benjamin; Saunders, Diane G O; Sklenar, Jan; Lorrain, Cécile; Win, Joe; Duplessis, Sébastien; Kamoun, Sophien

    2015-06-01

    Rust fungi are devastating crop pathogens that deliver effector proteins into infected tissues to modulate plant functions and promote parasitic growth. The genome of the poplar leaf rust fungus Melampsora larici-populina revealed a large catalog of secreted proteins, some of which have been considered candidate effectors. Unraveling how these proteins function in host cells is a key to understanding pathogenicity mechanisms and developing resistant plants. In this study, we used an effectoromics pipeline to select, clone, and express 20 candidate effectors in Nicotiana benthamiana leaf cells to determine their subcellular localization and identify the plant proteins they interact with. Confocal microscopy revealed that six candidate effectors target the nucleus, nucleoli, chloroplasts, mitochondria, and discrete cellular bodies. We also used coimmunoprecipitation (coIP) and mass spectrometry to identify 606 N. benthamiana proteins that associate with the candidate effectors. Five candidate effectors specifically associated with a small set of plant proteins that may represent biologically relevant interactors. We confirmed the interaction between the candidate effector MLP124017 and TOPLESS-related protein 4 from poplar by in planta coIP. Altogether, our data enable us to validate effector proteins from M. larici-populina and reveal that these proteins may target multiple compartments and processes in plant cells. It also shows that N. benthamiana can be a powerful heterologous system to study effectors of obligate biotrophic pathogens.

  11. Plant adaptation to fluctuating environment and biomass production are strongly dependent on guard cell potassium channels

    Science.gov (United States)

    Lebaudy, Anne; Vavasseur, Alain; Hosy, Eric; Dreyer, Ingo; Leonhardt, Nathalie; Thibaud, Jean-Baptiste; Véry, Anne-Aliénor; Simonneau, Thierry; Sentenac, Hervé

    2008-01-01

    At least four genes encoding plasma membrane inward K+ channels (Kin channels) are expressed in Arabidopsis guard cells. A double mutant plant was engineered by disruption of a major Kin channel gene and expression of a dominant negative channel construct. Using the patch-clamp technique revealed that this mutant was totally deprived of guard cell Kin channel (GCKin) activity, providing a model to investigate the roles of this activity in the plant. GCKin activity was found to be an essential effector of stomatal opening triggered by membrane hyperpolarization and thereby of blue light-induced stomatal opening at dawn. It improved stomatal reactivity to external or internal signals (light, CO2 availability, and evaporative demand). It protected stomatal function against detrimental effects of Na+ when plants were grown in the presence of physiological concentrations of this cation, probably by enabling guard cells to selectively and rapidly take up K+ instead of Na+ during stomatal opening, thereby preventing deleterious effects of Na+ on stomatal closure. It was also shown to be a key component of the mechanisms that underlie the circadian rhythm of stomatal opening, which is known to gate stomatal responses to extracellular and intracellular signals. Finally, in a meteorological scenario with higher light intensity during the first hours of the photophase, GCKin activity was found to allow a strong increase (35%) in plant biomass production. Thus, a large diversity of approaches indicates that GCKin activity plays pleiotropic roles that crucially contribute to plant adaptation to fluctuating and stressing natural environments. PMID:18367672

  12. Chloride regulates leaf cell size and water relations in tobacco plants.

    Science.gov (United States)

    Franco-Navarro, Juan D; Brumós, Javier; Rosales, Miguel A; Cubero-Font, Paloma; Talón, Manuel; Colmenero-Flores, José M

    2016-02-01

    Chloride (Cl(-)) is a micronutrient that accumulates to macronutrient levels since it is normally available in nature and actively taken up by higher plants. Besides a role as an unspecific cell osmoticum, no clear biological roles have been explicitly associated with Cl(-) when accumulated to macronutrient concentrations. To address this question, the glycophyte tobacco (Nicotiana tabacum L. var. Habana) has been treated with a basal nutrient solution supplemented with one of three salt combinations containing the same cationic balance: Cl(-)-based (CL), nitrate-based (N), and sulphate+phosphate-based (SP) treatments. Under non-saline conditions (up to 5 mM Cl(-)) and no water limitation, Cl(-) specifically stimulated higher leaf cell size and led to a moderate increase of plant fresh and dry biomass mainly due to higher shoot expansion. When applied in the 1-5 mM range, Cl(-) played specific roles in regulating leaf osmotic potential and turgor, allowing plants to improve leaf water balance parameters. In addition, Cl(-) also altered water relations at the whole-plant level through reduction of plant transpiration. This was a consequence of a lower stomatal conductance, which resulted in lower water loss and greater photosynthetic and integrated water-use efficiency. In contrast to Cl(-), these effects were not observed for essential anionic macronutrients such as nitrate, sulphate, and phosphate. We propose that the abundant uptake and accumulation of Cl(-) responds to adaptive functions improving water homeostasis in higher plants.

  13. 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. PMID:27269671

  14. Intracellular Transport of Plant Viruses: Finding the Door out of the Cell

    Institute of Scientific and Technical Information of China (English)

    James E. Schoelz; Phillip A. Harries; Richard S. Nelson

    2011-01-01

    Plant viruses are a class of plant pathogens that specialize in movement from cell to cell.As part of their arsenal for infection of plants,every virus encodes a movement protein (MP),a protein dedicated to enlarging the pore size of plasmodesmata (PD) and actively transporting the viral nucleic acid into the adjacent cell.As our knowledge of intercellular transport has increased,it has become apparent that viruses must also use an active mechanism to target the virus from their site of replication within the cell to the PD.Just as viruses are too large to fit through an unmodified plasmodesma,they are also too large to be freely diffused through the cytoplasm of the cell.Evidence has accumulated now for the involvement of other categories of viral proteins in intracellular movement in addition to the MP,including viral proteins originally associated with replication or gene expression.In this review,we will discuss the strategies that viruses use for intracellular movement from the replication site to the PD,in particular focusing on the role of host membranes for intracellular transport and the coordinated interactions between virus proteins within cells that are necessary for successful virus spread.

  15. 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.

  16. Upconversion nanoparticles for differential imaging of plant cells and detection of fluorescent dyes

    Institute of Scientific and Technical Information of China (English)

    吴笑峰; 刘云新; 胡盼; 胡仕刚; 陈增辉; 严焕元; 唐志军; 席在芳; 余意; 戴港涛

    2016-01-01

    Upconversion NaLuF4 nanoparticles were synthesized by the solvothermal method which could emit multicolor visible light under the excitation of 980 nm near-infrared (NIR) photons. These upconversion nanoparticles (UCNPs) with an acidic ligand could rapidly capture the basic rhodamine-B (RB) in plant cells to generate a close UCNPs@RB system. RB could efficiently absorb the green fluorescence from NaLuF4:18 mol.%Yb3+,2 mol.%Er3+ UCNPs and then emitted red light in the UCNPs@RB system by a robust luminescence resonance energy transfer (LRET) from UCNPs to RB. The detection limit of RB with these upconversion fluo-rescent nanoprobes could reach 0.25μg/cm3 in plant cell even under an ultra low excitation power source of 0.2 W/mm2. This LRET phenomenon was also extended to NaLuF4:18 mol.%Yb3+,0.5 mol.%Tm3+@Sodium fluorescein (SF) system. In addition, the differ-ential imaging could be achieved by successively incubating plant cells with fluorescent dyes and UCNPs. The fluorescent dyes ag-gregated in cell wall while UCNPs with surface modification distributed both in cell wall and cytoplasm, so that UCNPs@Dyes formed in cell walls which could emit multicolor light by LRET which was different from the emission in cytoplasm with only UCNPs.

  17. Assessment and comparison of 100-MW coal gasification phosphoric acid fuel cell power plants

    Science.gov (United States)

    Lu, Cheng-Yi

    1988-01-01

    One of the advantages of fuel cell (FC) power plants is fuel versatility. With changes only in the fuel processor, the power plant will be able to accept a variety of fuels. This study was performed to design process diagrams, evaluate performance, and to estimate cost of 100 MW coal gasifier (CG)/phosphoric acid fuel cell (PAFC) power plant systems utilizing coal, which is the largest single potential source of alternate hydrocarbon liquids and gases in the United States, as the fuel. Results of this study will identify the most promising integrated CG/PAFC design and its near-optimal operating conditions. The comparison is based on the performance and cost of electricity which is calculated under consistent financial assumptions.

  18. Plant regeneration from protoplasts of hydroxyproline resistant cell line in Onobrychis viciaefolia

    Institute of Scientific and Technical Information of China (English)

    XUZIQIN; JINGFENJIA

    1995-01-01

    An efficient protocol for plant regeneration from protoplasts of hydroxyproline(HYP)resistant cell line of Onobrychis viciaefolia was established.In SH medium supplemented with 1mg/L2,4-dichlorophenoxy-acetic acid(2,4-D),0.5mg/L kinetin(KT)and 0.2mg/L naphthalene acetic acid(NAA),the division frequency of protoplastderived cells reached up to over 60%,and microcalli were obtained in 5-6wk.Upon transferring them on agar solidified MS medium plus 2mg/L indole-3-acetic acid (IAA),shoots were induced.After cultivating them on MS medium with or without IAA,roots were regenerated.Chromosome number of all protoplast-regenerated plants examined were normal(2n=28).The protoplast-derived calli and plants grew vigorously on the medium containing 10 mmol/L HYP.

  19. Quantitative proteome changes in Arabidopsis thaliana suspension-cultured cells in response to plant natriuretic peptides

    KAUST Repository

    Turek, Ilona

    2015-06-30

    Proteome changes in the Arabidopsis thaliana suspension cells in response to the A. thaliana plant natriuretic peptide (PNP), AtPNP-A (At2g18660) were assessed using quantitative proteomics employing tandem mass tag (TMT) labeling and tandem mass spectrometry (LC–MS/MS). In this study, we characterized temporal responses of suspension-cultured cells to 1 nM and 10 pM AtPNP-A at 0, 10 and 30 min post-treatment. Both concentrations we found to yield a distinct differential proteome signature. The data shown in this article are associated with the article “Plant natriuretic peptides induce a specific set of proteins diagnostic for an adaptive response to abiotic stress” by Turek et al. (Front. Plant Sci. 5 (2014) 661) and have been deposited to the ProteomeXchange with identifier PXD001386.

  20. Quantitative proteome changes in Arabidopsis thaliana suspension-cultured cells in response to plant natriuretic peptides

    Directory of Open Access Journals (Sweden)

    Ilona Turek

    2015-09-01

    Full Text Available Proteome changes in the Arabidopsis thaliana suspension cells in response to the A. thaliana plant natriuretic peptide (PNP, AtPNP-A (At2g18660 were assessed using quantitative proteomics employing tandem mass tag (TMT labeling and tandem mass spectrometry (LC–MS/MS. In this study, we characterized temporal responses of suspension-cultured cells to 1 nM and 10 pM AtPNP-A at 0, 10 and 30 min post-treatment. Both concentrations we found to yield a distinct differential proteome signature. The data shown in this article are associated with the article “Plant natriuretic peptides induce a specific set of proteins diagnostic for an adaptive response to abiotic stress” by Turek et al. (Front. Plant Sci. 5 (2014 661 and have been deposited to the ProteomeXchange with identifier PXD001386.

  1. Probing cytoplasmic organization and the actin cytoskeleton of plant cells with optical tweezers

    NARCIS (Netherlands)

    Ketelaar, T.; Honing, van der H.S.; Emons, A.M.C.

    2010-01-01

    In interphase plant cells, the actin cytoskeleton is essential for intracellular transport and organization. To fully understand how the actin cytoskeleton functions as the structural basis for cytoplasmic organization, both molecular and physical aspects of the actin organization have to be conside

  2. Layered Double Hydroxide Nanotransporter for Molecule Delivery to Intact Plant Cells

    Science.gov (United States)

    Bao, Wenlong; Wang, Junya; Wang, Qiang; O’Hare, Dermot; Wan, Yinglang

    2016-01-01

    Here we report a powerful method that facilitates the transport of biologically active materials across the cell wall barrier in plant cells. Positively charged delaminated layered double hydroxide lactate nanosheets (LDH-lactate-NS) with a 0.5‒2 nm thickness and 30‒60 nm diameter exhibit a high adsorptive capacity for negatively charged biomolecules, including fluorescent dyes such as tetramethyl rhodamine isothiocyanate (TRITC), fluorescein isothiocyanate isomer I(FITC) and DNA molecules, forming neutral LDH-nanosheet conjugates. These neutral conjugates can shuttle the bound fluorescent dye into the cytosol of intact plant cell very efficiently. Furthermore, typical inhibitors of endocytosis and low temperature incubation did not prevent LDH-lactate-NS internalization, suggesting that LDH-lactate-NS penetrated the plasma membrane via non-endocytic pathways, which will widen the applicability to a variety of plant cells. Moreover, the absence of unwanted side effects in our cytological studies, and the nuclear localization of ssDNA-FITC suggest that nano-LDHs have potential application as a novel gene carrier to plants. PMID:27221055

  3. Molecular and genetics approaches for investigation of phospholipase D role in plant cells

    Directory of Open Access Journals (Sweden)

    Volotovsky I. D.

    2010-04-01

    Full Text Available The review is devoted to the analysis of publications ñoncerning the role of phospholipase D (PLD in regulation of metabolism in plant cells. Analysis of molecular and genetic studies suggest that PLD is an important component of various hormonal and stress signaling pathways

  4. Turkish Student Teachers' Ideas about Diagrams of a Flower and a Plant Cell

    Science.gov (United States)

    Topsakal, Unsal Umdu; Oversby, John

    2012-01-01

    In the present study, the understandings of student teachers (training for the primary phase and Master's degree students from a primary science and technology education department) about flowers and plant cells using the method of drawing in combination with interviews are explored. The data were gathered from 116 student teachers and 10 Master's…

  5. Image segmentation of em bryonic plant cell using pulse-coupled neural networks

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Traditional image segmentation algorithms exhibit weak performance for plant cells which have complex structure. On the other hand, pulse-coupled neural network (PCNN) based on Eckhorn's model of the cat visual cortex should be suitable to the segmentation of plant cell image.But the present theories cannot explain the relationship between the parameters of PCNN mathematical model and the effect of segmentation. Satisfactory results usually require time-consuming selection of experimental parameters. Meanwhile, in a proper, selected parametric model, the number of iteration determines the segmented effect evaluated by visual judgment, which decreases the efficiency of image segmentation. To avoid these flaws, this note proposes a new PCNN algorithm for automatically segmenting plant embryonic cell image based on the maximum entropy principle. The algorithm produces a desirable result. In addition, a model with proper parameters can automatically determine the number of iteration, avoid visual judgment, enhance the speed of segmentation and will be utilized subsequently by accurate quantitative analysis of micro-molecules of plant cell. So this algorithm is valuable for theoretical investigation and application of PCNN.``

  6. 8th Annual Glycoscience Symposium: Integrating Models of Plant Cell Wall Structure, Biosynthesis and Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Azadi, Paratoo [Univ. of Georgia, Athens, GA (United States)

    2015-09-24

    The Complex Carbohydrate Research Center (CCRC) of the University of Georgia holds a symposium yearly that highlights a broad range of carbohydrate research topics. The 8th Annual Georgia Glycoscience Symposium entitled “Integrating Models of Plant Cell Wall Structure, Biosynthesis and Assembly” was held on April 7, 2014 at the CCRC. The focus of symposium was on the role of glycans in plant cell wall structure and synthesis. The goal was to have world leaders in conjunction with graduate students, postdoctoral fellows and research scientists to propose the newest plant cell wall models. The symposium program closely followed the DOE’s mission and was specifically designed to highlight chemical and biochemical structures and processes important for the formation and modification of renewable plant cell walls which serve as the basis for biomaterial and biofuels. The symposium was attended by both senior investigators in the field as well as students including a total attendance of 103, which included 80 faculty/research scientists, 11 graduate students and 12 Postdoctoral students.

  7. Central Cell-Derived Peptides Regulate Early Embryo Patterning in Flowering Plants

    NARCIS (Netherlands)

    Costa, L.M.; Marshall, E.; Tesfaye, M.; Silverstein, K.A.T.; Mori, M.; Umetsu, Y.; Otterbach, S.L.; Papareddy, R.; Dickinson, H.G.; Boutilier, K.A.; VandenBosch, K.A.; Ohki, S.; Gutierrez-Marcos, J.F.

    2014-01-01

    Plant embryogenesis initiates with the establishment of an apical-basal axis; however, the molecular mechanisms accompanying this early event remain unclear. Here, we show that a small cysteine-rich peptide family is required for formation of the zygotic basal cell lineage and proembryo patterning i

  8. Treatment of endosulfan contaminated water with in vitro plant cell cultures.

    Science.gov (United States)

    Lucero, Patricia A; Ferrari, Mónica M; Orden, Alejandro A; Cañas, Irene; Nassetta, Mirtha; Kurina-Sanz, Marcela

    2016-03-15

    Endosulfan is a Persistent Organic Pollutant insecticide still used in many countries. It is commercially available as mixtures of two diastereomers, α- and β-endosulfan, known as technical grade endosulfan (TGE). A laboratory model based on the use of axenic plant cell cultures to study the removal and metabolization of both isomers from contaminated water matrixes was established. No differences were recorded in the removal of the two individual isomers with the two tested endemic plants, Grindelia pulchella and Tessaria absinthioides. Undifferentiated cultures of both plant species were very efficient to lower endosulfan concentration in spiked solutions. Metabolic fate of TGE was evaluated by analyzing the time course of endosulfan metabolites accumulation in both plant biomass and bioremediation media. While in G. pulchella we only detected endosulfan sulfate, in T. absinthioides the non-toxic endosulfan alcohol was the main metabolite at 48h, giving the possibility of designing phytoremediation approaches. PMID:26685061

  9. Plant Cell Protolytic Enzymes Activity under Exposure to Lectins of Endophytic and Epiphytic Azospirillum Strains

    Directory of Open Access Journals (Sweden)

    S.A. Alen’kina

    2016-05-01

    Full Text Available We studied the ability of lectins isolated from the surface of the two strains of nitrogen-fixing soil bacteria of the genus Azospirillum, A. brasilense Sp7 (epiphytic and A. brasilense Sp245 (endophytic, to show have a regulating effect on the activity of pectinolytic enzymes in the roots of wheat seedlings. Research results showed that the lectins under study can cause the induction of the activity of polygalacturonase, pectinesterase, pectatlyase from the plant cell wall, thereby ensuring the bacteria penetration in the plant tissues, as well as the induction of plants responses which, being combined with growth-stimulating effect of bacteria, contributes to the formation of plants stability and productivity.

  10. Genomic characterization of plant cell wall degrading enzymes and in silico analysis of xylanses and polygalacturonases of Fusarium virguliforme

    Science.gov (United States)

    Plant cell wall degrading enzymes (PCWDEs) are important effectors for plant pathogens to invade plants. In this study, the composition of PCWDEs in Fusarium virguliforme that were grown for 5-days and 20 days in liquid medium was determined by RNA-Seq. Differential expression analysis showed more P...

  11. Defined plant extracts can protect human cells against combined xenobiotic effects

    Directory of Open Access Journals (Sweden)

    Clair Emilie

    2011-01-01

    Full Text Available Abstract Background Pollutants representative of common environmental contaminants induce intracellular toxicity in human cells, which is generally amplified in combinations. We wanted to test the common pathways of intoxication and detoxification in human embryonic and liver cell lines. We used various pollutants such as Roundup residues, Bisphenol-A and Atrazine, and five precise medicinal plant extracts called Circ1, Dig1, Dig2, Sp1, and Uro1 in order to understand whether specific molecular actions took place or not. Methods Kidney and liver are major detoxification organs. We have studied embryonic kidney and hepatic human cell lines E293 and HepG2. The intoxication was induced on the one hand by a formulation of one of the most common herbicides worldwide, Roundup 450 GT+ (glyphosate and specific adjuvants, and on the other hand by a mixture of Bisphenol-A and Atrazine, all found in surface waters, feed and food. The prevention and curative effects of plant extracts were also measured on mitochondrial succinate dehydrogenase activity, on the entry of radiolabelled glyphosate (in Roundup in cells, and on cytochromes P450 1A2 and 3A4 as well as glutathione-S-transferase. Results Clear toxicities of pollutants were observed on both cell lines at very low sub-agricultural dilutions. The prevention of such phenomena took place within 48 h with the plant extracts tested, with success rates ranging between 25-34% for the E293 intoxicated by Roundup, and surprisingly up to 71% for the HepG2. By contrast, after intoxication, no plant extract was capable of restoring E293 viability within 48 h, however, two medicinal plant combinations did restore the Bisphenol-A/Atrazine intoxicated HepG2 up to 24-28%. The analysis of underlying mechanisms revealed that plant extracts were not capable of preventing radiolabelled glyphosate from entering cells; however Dig2 did restore the CYP1A2 activity disrupted by Roundup, and had only a mild preventive effect

  12. A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells.

    Science.gov (United States)

    Higaki, Takumi; Kutsuna, Natsumaro; Akita, Kae; Takigawa-Imamura, Hisako; Yoshimura, Kenji; Miura, Takashi

    2016-04-01

    Plant leaf epidermal cells exhibit a jigsaw puzzle-like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo.

  13. Radiation effects and radioprotection by Thai medicinal plants in mouse macrophage cell line

    Institute of Scientific and Technical Information of China (English)

    Cheeraratana Cheeramakara; Kriyaporn Songmueng; Wanyarat Nakosiri; Montri Chairojana; Arag Vitittheeranon; Nopchai Suthisai; Nongnuch Jangsawang; Channarong Sanghiran; Apichart Nontprasert

    2009-01-01

    Objective:To investigate the effects of radiation on growth-arrested (GA)and micronucleus-production (MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitro.Methods:Mouse macrophage cell line (RAW264.7)was cultured in vitro.Various radiation expo-sures,growth-arrested rate assay,micronucleus production assay,and radioprotection by Thai medicinal plants were performed.Results:The results showed that GA and MP rates for γ-rays and UV were dose-dependent. The 50%-affected dose of γand UV radiation for the GA rate was 10 Gy and 159 microwatt/cm2 for 0.5 sec-onds,respectively.After X-ray exposure,there was no apparent effect on RAW264.7 cells,even with a forty-fold human diagnostic dose.Two exposures to γradiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control (P <0.05).The Thai medicinal plants (Kamin-chun capsules,Curcu-ma longa Linn;Hed lingeu,Ganoderma lucidum;Ya Pakking capsule,Murdannia loriformis)could not pre-vent cell damage,but epigallocatechin gallate and L-cysteine could provide protection from 2 Gy γ-ray expo-sure.Conclusion:γradiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe.The radioprotective effects of Thai medicinal plants,Kamin-chun,Hed lingeu, and Ya Pakking,could not prevent cell damage in this study.

  14. Gravity resistance, another graviresponse in plants - role of microtubule-membrane-cell wall continuum

    Science.gov (United States)

    Hoson, T.; Saito, Y.; Usui, S.; Soga, K.; Wakabayashi, K.

    Resistance to the gravitational force has been a serious problem for plants to survive on land, after they first went ashore more than 400 million years ago. Thus, gravity resistance is the principal graviresponse in plants comparable to gravitropism. Nevertheless, only limited information has been obtained for this second gravity response. We have examined the mechanism of gravity resistance using hypergravity conditions produced by centrifugation. The results led a hypothesis on the mechanism of plant resistance to the gravitational force that the plant constructs a tough body by increasing the cell wall rigidity, which are brought about by modification of the cell wall metabolism and cell wall environment, especially pH. The hypothesis was further supported by space experiments during the Space Shuttle STS-95 mission. On the other hand, we have shown that gravity signal may be perceived by mechanoreceptors (mechanosensitive ion channels) on the plasma membrane and amyloplast sedimentation in statocytes is not involved in gravity resistance. Moreover, hypergravity treatment increased the expression levels of genes encoding alpha-tubulin, a component of microtubules and 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of terpenoids such as membrane sterols. The expression of HMGR and alpha- and beta-tubulin genes increased within several hours after hypergravity treatment, depending on the magnitude of gravity. The determination of levels of gene products as well as the analysis with knockout mutants of these genes by T-DNA insertions in Arabidopsis supports the involvement of both membrane sterols and microtubules in gravity resistance. These results suggest that structural or physiological continuum of microtubule-cell membrane-cell wall is responsible for plant resistance to the gravitational force.

  15. 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

  16. The degradation of potato virus M (PVM particles in plant cells

    Directory of Open Access Journals (Sweden)

    Anna Rudzińska-Langwald

    2014-02-01

    Full Text Available Degradation of potato virus M particles was observed in the cells of Solanum tuberosum, Solanum rostratum, Lycopersicon esculentum and Lycopersicon chilense plants infected with this virus. PVM particles found in the cytoplasm of infected parenchyma cells grouped together in the form of inclusions, often found near the tonoplast. The ends of the virus particles and the tonoplast came into close contact. Cytoplasmic protrusions containing PVM particles, reaching into vacuoles were formed in those places. In addition to a large central vacuole, small vacuoles were observed in cells containing PVM particles. Various stages of degradation of cytoplasmic protrusions were observed both in the large and small vacuoles.

  17. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Svensson, Birte;

    Programmed cell death (PCD) in plants can influence the outcome of yield and quality of crops through its important role in seed germination and the defence process against pathogens. The main scope of the project is to apply microfluidic cell culture for the measurement of electrochemically...... for online, real-time, parallel analysis of important parameters such as redox activity (NADPH:NADP ratio), H2O2 concentration, oxygen consumption, extracellular pH, cell viability and release of target enzymes (α-amylase and limit dextrinase). Probing the intracellular redox activity is of major importance...

  18. Binary co-generative plants with height temperature SOFC fuel cells

    International Nuclear Information System (INIS)

    In this paper, a field of binary co-generative plants with height temperature SOFC fuel cells is presented. Special attention of application of height temperature SOFC fuel cells and binary co-generative units has been given. These units made triple electricity and heat. Principle of combination of fuel cells with binary cycles has been presented. A model and computer programme for calculation of BKPFC, has been created. By using the program, all the important characteristic-results are calculated: power, efficiency, emission, dimension and economic analysis. On base of results, conclusions and recommendations has been given. (Author)

  19. Plant RNA processing: soybean pre-mRNA in a pea cell-free extract

    International Nuclear Information System (INIS)

    Using a pea cell-free extract they have demonstrated the splicing of an SP6 fusion transcript containing an intron derived from the soybean seed storage protein β-subunit gene. Intron 115 from the conglycinin gene was cloned into a SP6 vector and transcribed using standard recombinant DNA techniques. Incubation of radioactively labeled fusion transcripts in the cell-free system produced a number of products which were identified by primer extension and S1 nuclease analysis. All the products are linear RNA molecules. Lariat intermediates, similar to those found in the yeast and HeLa cell RNA processing systems, have not been detected. The linear RNA products detected in their plant in vitro processing system have various portions of the intron removed which suggests that alternative splice sites are used in processing of this plant intron due to activation of cryptic splice sites or creation of splice sites in the fusion construction. The kinetics of the reactions and parameters of the extract are similar to those determined for the HeLa cell system. Sucrose gradient analysis has demonstrated that the plant RNA products sedimented in a 30S particle, similar in size to that found for the spliceosome of the HeLa cell system

  20. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...... of the physical and biochemical conditions in plant cells. As model system, we use a H(2)O(2) signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits...... which diffusion-mediated signaling is possible. We show that purely diffusive transmission of intracellular information by H(2)O(2) over a distance of 1 μm (typical distance between organelles, which may function as relay stations) is possible at frequencies well above 1 Hz, which is the highest...

  1. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian Lyngby; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca2+ ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...... of the physical and biochemical conditions in plant cells. As model system, we use a H2O2 signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits...... diffusion-mediated signaling is possible. We show that purely diffusive transmission of intracellular information by H2O2 over a distance of 1 μm (typical distance between organelles, which may function as relay stations) is possible at frequencies well above 1 Hz, which is the highest frequency observed...

  2. 50 ku keratin-like protein and β-microtublin coexist in higher plant cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IF-like proteins have been obtained from suspension cells of Nicotiana tabacum by selective extraction. Western blot analysis shows that the major components of IF-like proteins are 6 keratin-like proteins of 64, 58, 55, 54, 50 and 45 ku. Specially the 50 ku protein also reacts with polyantibody against microtublin. Two-dimensional gel electrophoresis shows that the 50 ku protein is composed of two different proteins and their amino acid sequences have been determined. Part of the sequence of one protein is identical to that of -microtublin and the other protein's sequence has no significant homologue, which should be a new sequence-unknown protein. These results suggest that 50 ku keratin-like protein and -microtublin coexist in higher plant cells, and that may lead to the phenomenon of co-distribution of IF and microtuble in plant cells.

  3. 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.

  4. Dye-sensitized solar cells with natural dyes extracted from plant seeds

    Science.gov (United States)

    El-Ghamri, Hatem S.; El-Agez, Taher M.; Taya, Sofyan A.; Abdel-Latif, Monzir S.; Batniji, Amal Y.

    2014-12-01

    The application of natural dyes extracted from plant seeds in the fabrication of dye-sensitized solar cells (DSSCs) has been explored. Ten dyes were extracted from different plant seeds and used as sensitizers for DSSCs. The dyes were characterized using UV-Vis spectrophotometry. DSSCs were prepared using TiO2 and ZnO nanostructured mesoporous films. The highest conversion efficiency of 0.875 % was obtained with an allium cepa (onion) extract-sensitized TiO2 solar cell. The process of TiO2-film sintering was studied and it was found that the sintering procedure significantly affects the response of the cell. The short circuit current of the DSSC was found to be considerably enhanced when the TiO2 semiconducting layer was sintered gradually.

  5. Antagonistic control of oxidative stress-induced cell death in Arabidopsis by two related, plant-specific zinc finger proteins

    OpenAIRE

    Epple, Petra; Mack, Amanda A.; Morris, Veronica R. F.; Dangl, Jeffery L.

    2003-01-01

    The most familiar form of plant programmed cell death is the hypersensitive response (HR) associated with successful plant immune responses. HR is preceded by an oxidative burst and the generation of both reactive oxygen intermediates (ROI) and NO. The Arabidopsis LSD1 gene encodes a negative regulator of plant programmed cell death that meets several criteria for a regulator of processes relevant to ROI management during pathogen responses. Here we demonstrate that a highly conserved L...

  6. Turning a plant tissue into a living cell froth through isotropic growth.

    Science.gov (United States)

    Corson, Francis; Hamant, Olivier; Bohn, Steffen; Traas, Jan; Boudaoud, Arezki; Couder, Yves

    2009-05-26

    The forms resulting from growth processes are highly sensitive to the nature of the driving impetus, and to the local properties of the medium, in particular, its isotropy or anisotropy. In turn, these local properties can be organized by growth. Here, we consider a growing plant tissue, the shoot apical meristem of Arabidopsis thaliana. In plants, the resistance of the cell wall to the growing internal turgor pressure is the main factor shaping the cells and the tissues. It is well established that the physical properties of the walls depend on the oriented deposition of the cellulose microfibrils in the extracellular matrix or cell wall; this order is correlated to the highly oriented cortical array of microtubules attached to the inner side of the plasma membrane. We used oryzalin to depolymerize microtubules and analyzed its influence on the growing meristem. This had no short-term effect, but it had a profound impact on the cell anisotropy and the resulting tissue growth. The geometry of the cells became similar to that of bubbles in a soap froth. At a multicellular scale, this switch to a local isotropy induced growth into spherical structures. A theoretical model is presented in which a cellular structure grows through the plastic yielding of its walls under turgor pressure. The simulations reproduce the geometrical properties of a normal tissue if cell division is included. If not, a "cell froth" very similar to that observed experimentally is obtained. Our results suggest strong physical constraints on the mechanisms of growth regulation. PMID:19423667

  7. Rhynchophorus ferrugineus midgut cell line to evaluate insecticidal potency of different plant essential oils.

    Science.gov (United States)

    Rizwan-ul-Haq, Muhammad; Aljabr, Ahmed Mohammed

    2015-03-01

    Cell cultures can be a potent and strong tool to evaluate the insecticidal efficiency of natural products. Plant essential oils have long been used as the fragrance or curative products around the world which means that they are safer to be used in close proximity of humans and mammals. In this study, a midgut cell line, developed from Rhynchophorus ferrugineus (RPW-1), was used for screening essential oils from nine different plants. Assays revealed that higher cell mortality was observed at 500 ppm which reached to 86, 65, 60, 59, 56, 54, 54, 53, and 53%, whereas lowest cell mortality at 1 ppm remained at 41, 23, 20, 17, 16, 15, 14, 13, and 10%, for Azadirachta indica, Piper nigrum, Mentha spicata, Cammiphora myrrha, Elettaria cardamomum, Zingiber officinale, Curcuma longa, Schinus molle, and Rosmarinus officinalis, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay revealed the percentage of cell growth inhibition was highest at 500 ppm and remained at 48, 45, 42, 37, 34, 29, 24, 22, and 18% against A. indica, P. nigrum, M. spicata, C. myrrha, E. cardamomum, Z. officinale, C. longa, S. molle, and R. officinalis, respectively. Lowest LC50 value (7.98 ppm) was found for A. indica, whereas the highest LC50 (483.11 ppm) was against R. officinalis. Thus, in this study, essential oils of A. indica exhibited the highest levels of toxicity, whereas those from R. officinalis exhibited the lowest levels of toxicity toward RPW-1 cells. PMID:25381034

  8. Rhynchophorus ferrugineus midgut cell line to evaluate insecticidal potency of different plant essential oils.

    Science.gov (United States)

    Rizwan-ul-Haq, Muhammad; Aljabr, Ahmed Mohammed

    2015-03-01

    Cell cultures can be a potent and strong tool to evaluate the insecticidal efficiency of natural products. Plant essential oils have long been used as the fragrance or curative products around the world which means that they are safer to be used in close proximity of humans and mammals. In this study, a midgut cell line, developed from Rhynchophorus ferrugineus (RPW-1), was used for screening essential oils from nine different plants. Assays revealed that higher cell mortality was observed at 500 ppm which reached to 86, 65, 60, 59, 56, 54, 54, 53, and 53%, whereas lowest cell mortality at 1 ppm remained at 41, 23, 20, 17, 16, 15, 14, 13, and 10%, for Azadirachta indica, Piper nigrum, Mentha spicata, Cammiphora myrrha, Elettaria cardamomum, Zingiber officinale, Curcuma longa, Schinus molle, and Rosmarinus officinalis, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay revealed the percentage of cell growth inhibition was highest at 500 ppm and remained at 48, 45, 42, 37, 34, 29, 24, 22, and 18% against A. indica, P. nigrum, M. spicata, C. myrrha, E. cardamomum, Z. officinale, C. longa, S. molle, and R. officinalis, respectively. Lowest LC50 value (7.98 ppm) was found for A. indica, whereas the highest LC50 (483.11 ppm) was against R. officinalis. Thus, in this study, essential oils of A. indica exhibited the highest levels of toxicity, whereas those from R. officinalis exhibited the lowest levels of toxicity toward RPW-1 cells.

  9. Multiparametric analysis, sorting, and transcriptional profiling of plant protoplasts and nuclei according to cell type.

    Science.gov (United States)

    Galbraith, David W; Janda, Jaroslav; Lambert, Georgina M

    2011-01-01

    Flow cytometry has been employed for the analysis of higher plants for approximately the last 30 years. For the angiosperms, ∼500,000 species, itself a daunting number, parametric measurements enabled through the use of flow cytometers started with basic descriptors of the individual cells and their contents, and have both inspired the development of novel cytometric methods that subsequently have been applied to organisms within other kingdoms of life, and adopted cytometric methods devised for other species, particularly mammals. Higher plants offer unique challenges in terms of flow cytometric analysis, notably the facts that their organs and tissues are complex three-dimensional assemblies of different cell types, and that their individual cells are, in general, larger than those of mammals.This chapter provides an overview of the general types of parametric measurement that have been applied to plants, and provides detailed methods for selected examples based on the plant model Arabidopsis thaliana. These illustrate the use of flow cytometry for the analysis of protoplasts and nuclear DNA contents (genome size and the cell cycle). These are further integrated with measurements focusing on specific cell types, based on transgenic expression of Fluorescent Proteins (FPs), and on analysis of the spectrum of transcripts found within protoplasts and nuclei. These measurements were chosen in particular to illustrate, respectively, the issues encountered in the flow analysis and sorting of large biological cells, typified by protoplasts; how to handle flow analyses under conditions that require processing of large numbers of samples in which the individual samples contain only a very small minority of objects of interest; and how to deal with exceptionally small amounts of RNA within the sorted samples.

  10. Cytotoxicity screening of Bangladeshi medicinal plant extracts on pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Abbasi Atiya

    2010-09-01

    Full Text Available Abstract Background There has been a long standing interest in the identification of medicinal plants and derived natural products for developing cancer therapeutics. Our study focuses upon pancreatic cancer, due to its high mortality rate, that is attributed in part to the lack of an effective chemotherapeutic agent. Previous reports on the use of medicinal plant extracts either alone or alongside conventional anticancer agents in the treatment of this cancer have shown promising results. This work aims to investigate the therapeutic properties of a library of medicinal plants from Bangladesh. Methods 56 extracts of 44 unique medicinal plants were studied. The extracts were screened for cytotoxicity against the pancreatic adenocarcinoma cell line Panc-1, using a label-free biosensor assay. The top cytotoxic extracts identified in this screen were tested on two additional pancreatic cancer cell lines (Mia-Paca2 and Capan-1 and a fibroblast cell line (Hs68 using an MTT proliferation assay. Finally, one of the most promising extracts was studied using a caspase-3 colorimetric assay to identify induction of apoptosis. Results Crude extracts of Petunia punctata, Alternanthera sessilis, and Amoora chittagonga showed cytotoxicity to three cancer cell lines with IC50 values ranging between 20.3 - 31.4 μg/mL, 13.08 - 34.9 μg/mL, and 42.8 - 49.8 μg/mL, respectively. Furthermore, treatment of Panc-1 cells with Petunia punctata was shown to increase caspase-3 activity, indicating that the observed cytotoxicity was mediated via apoptosis. Only Amoora chittagonga showed low cytotoxicity to fibroblast cells with an IC50 value > 100 μg/mL. Conclusion Based upon the initial screening work reported here, further studies aimed at the identification of active components of these three extracts and the elucidation of their mechanisms as cancer therapeutics are warranted.

  11. Design of process cell equipment layout and its associated piping in typical nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Nuclear fuel reprocessing plant processes spent nuclear fuel discharged from the nuclear reactor to separate chemically the uranium and plutonium. Spent nuclear fuel emits radiation due to the presence of fission products, actinides and activation products. The major operation steps in reprocessing plant are dismantling of spent fuel subassemblies, chopping of fuel pins and dissolution in concentrated nitric acid. Subsequently, this solution containing uranium and plutonium, fission products and actinides is subjected to solvent extraction with tributyl phosphate in diluent as solvent for separating uranium and plutonium from fission products and other actinides. In the design of a fuel reprocessing plant, apart from problems associated with conventional chemical process industries such as corrosion, materials handling, industrial and fire safety and economy, specific considerations such as health hazards from radioactivity (radiological safety) and damage to material by radiation are considered. This necessitates the processing of spent fuel inside the shielded process cells (concrete and lead cells) with remote operation and maintenance philosophy to prevent the contamination as well as radiation exposure to the operators and prevention of criticality in process tanks and equipments. Reprocessing plant consists of number of shielded process cells depending on the processing capacity and type of spent fuel handled. Concrete cells and lead cells houses various type of storage tanks, equipments, liquid transfer devices, etc with interconnecting small bore pipe lines for liquid transfer and supply of services, which runs in multiple layers, forming a high density piping inside the cells. In addition to this, cells have remote handling systems and gadgets for remote operation and maintenance wherever required. This paper highlights the design of process cells, its equipment layout and piping in typical reprocessing plant; the suitable material of construction

  12. Salt-mediated changes in leaf mesophyll cells of Lycopersicon esculentum Mill. plants

    Directory of Open Access Journals (Sweden)

    Magdalena Gapinska

    2014-09-01

    Full Text Available Five-week-old tomato plants (Lycopersicon esculentum cv. Perkoz grown in pots containing garden soil in a growth chamber were submitted to 50 or 150 mM NaCl for 1 h, 2 and 5 days. Tomato leaf anatomy generally did not change after short time salinity, except 5-day-treatment with 150 mM NaCl, where changed cell shape (shrunk and deformed simultaneously with increased volume of intercellular spaces (IS were observed. Although leaf hydration (H depleted only 1 h after 150 mM NaCl treatment both salt concentrations generated two coexisting populations of salt-affected mesophyll cells: (i slightly-affected (Sl-A which showed incipient plasmolysis or slightly changed shapes, and (ii severely-affected (Sv-A which showed severe plasmolysis; serious deformation of cell shape or disorganization including cell degeneration. In Sl-A cells salinity changed location and shape of chloroplasts which were: more rounded, with oversized starch grains (SG (2d or more flat (5d. Salt-mediated changes were becoming more distinguished and pronounced with length of 150 mM NaCl treatment. The amount of salt-affected cells was changing during the experiment and depended on the salt concentration. In 50 mM-treated plants salt-affected cells appeared 1 h after treatment (~40% and raised up to 78% on 2nd day, however the population of Sl-A cells dominated. In 150 mM NaCl-treated plants the percentage of affected cells raised during the experiment from 75% to 99%. Firstly Sl-A cells dominated, but on the 5th day the majority was Sv-A. Salt-affected cells were distributed quite evenly in palisade or spongy mesophyll, except 2 d after treatment with 50 mM NaCl, when their number was higher in the palisade mesophyll. Sv-A cells in the spongy mesophyll were located mostly near the bundle while in the palisade mesophyll more irregularly. Different susceptibility of cells to salt stress might be the consequence of an unequal distribution of osmotic stress and subsequent ionic

  13. Effect of Thai medicinal plant extracts on cell aggregation of Escherichia coli O157: H7.

    Directory of Open Access Journals (Sweden)

    Limsuwan, S.

    2005-08-01

    Full Text Available Medicinal plants have been used for treating diarrhoea but the interference mechanisms are not clearly understood. One possible hypothesis is that of an effect on cell surface hydrophobicity of microbial cells. In this study, we examined cell aggregation affected by crude extracts of Thai medicinal plants on cell surface hydrophobicity of Escherichia coli strains by salt aggregation test. Correlation between minimal inhibitory concentration and cell aggregation was performed. Aqueous and ethanolic extracts of 8 medicinal plants including Acacia catechu, Holarrhena antidysenterica, Peltophorum pterocarpum, Piper sarmentosum, Psidium guajava, Punica granatum, Quercus infectoria, and Tamarindus indica were tested with E. coli O157: H7 and other E. coli strains isolated from human, porcine, and foods. Aqueous extracts of Peltophorum pterocarpum, Psidium guajava, and Punica granatum were highly effective against E. coli O157: H7 with the MIC values of 0.09 to 0.39, 0.19 to 0.78, and 0.09 to 1.56 mg/ml, respectively. Ethanolic extract of Quercus infectoria and Punica granatum demonstrated good MIC values of 0.09 to 0.78, and 0.19 to 0.78 mg/ml, respectively. It was established that aqueous extracts of Punica granatum and Piper sarmentosum at high concentration (25 mg/ml enhanced cell aggregation of almost all E. coli strains while aqueous and ethanolic extracts ofQuercus infectoria enhanced cell aggregation of some E. coli strains. Correlation between minimal inhibitory concentration and cell aggregation was not found in this study.

  14. 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.

  15. Enhancement of Electricity Production by Graphene Oxide in Soil Microbial Fuel Cells and Plant Microbial Fuel Cells

    OpenAIRE

    Goto, Yuko; Yoshida, Naoko; Umeyama, Yuto; Yamada, Takeshi; Tero, Ryugo; Hiraishi, Akira

    2015-01-01

    The effects of graphene oxide (GO) on electricity generation in soil microbial fuel cells (SMFCs) and plant microbial fuel cell (PMFCs) were investigated. GO at concentrations ranging from 0 to 1.9 g⋅kg−1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs) utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity g...

  16. Mitochondrial pleomorphy in plant cells is driven by contiguous ER dynamics

    Directory of Open Access Journals (Sweden)

    Erica-Ashley eJaipargas

    2015-09-01

    Full Text Available Mitochondria are pleomorphic, double membrane-bound organelles involved in cellular energetics in all eukaryotes. Mitochondria in animal and yeast cells are typically tubular-reticulate structures and several micro-meters long but in green plants they are predominantly observed as 0.2-1.5µm punctae. While fission and fusion, through the coordinated activity of several conserved proteins, shapes mitochondria, the endoplasmic reticulum (ER has recently been identified as an additional player in this process in yeast and mammalian cells. The mitochondria-ER relationship in plant cells remains largely uncharacterized. Here, through live-imaging of the entire range of mitochondria pleomorphy we uncover the underlying basis for the predominantly punctate mitochondrial form in plants. We demonstrate that mitochondrial morphology changes in response to light and cytosolic sugar levels in an ER mediated manner. Whereas large ER polygons and low dynamics under dark conditions favor mitochondrial fusion and elongation, small ER polygons result in increased fission and predominantly small mitochondria. Hypoxia also reduces ER dynamics and increases mitochondrial fusion to produce giant mitochondria. By observing elongated mitochondria in normal plants and fission-impaired Arabidopsis nmt1-2 and drp3a mutants we also establish that thin extensions called matrixules and a beads-on-a-string mitochondrial phenotype are direct consequences of mitochondria-ER interactions.

  17. A versatile click-compatible monolignol probe to study lignin deposition in plant cell walls.

    Science.gov (United States)

    Pandey, Jyotsna L; Wang, Bo; Diehl, Brett G; Richard, Tom L; Chen, Gong; Anderson, Charles T

    2015-01-01

    Lignin plays important structural and functional roles in plants by forming a hydrophobic matrix in secondary cell walls that enhances mechanical strength and resists microbial decay. While the importance of the lignin matrix is well documented and the biosynthetic pathways for monolignols are known, the process by which lignin precursors or monolignols are transported and polymerized to form this matrix remains a subject of considerable debate. In this study, we have synthesized and tested an analog of coniferyl alcohol that has been modified to contain an ethynyl group at the C-3 position. This modification enables fluorescent tagging and imaging of this molecule after its incorporation into plant tissue by click chemistry-assisted covalent labeling with a fluorescent azide dye, and confers a distinct Raman signature that could be used for Raman imaging. We found that this monolignol analog is incorporated into in vitro-polymerized dehydrogenation polymer (DHP) lignin and into root epidermal cell walls of 4-day-old Arabidopsis seedlings. Incorporation of the analog in stem sections of 6-week-old Arabidopsis thaliana plants and labeling with an Alexa-594 azide dye revealed the precise locations of new lignin polymerization. Results from this study indicate that this molecule can provide high-resolution localization of lignification during plant cell wall maturation and lignin matrix assembly. PMID:25884205

  18. A versatile click-compatible monolignol probe to study lignin deposition in plant cell walls.

    Directory of Open Access Journals (Sweden)

    Jyotsna L Pandey

    Full Text Available Lignin plays important structural and functional roles in plants by forming a hydrophobic matrix in secondary cell walls that enhances mechanical strength and resists microbial decay. While the importance of the lignin matrix is well documented and the biosynthetic pathways for monolignols are known, the process by which lignin precursors or monolignols are transported and polymerized to form this matrix remains a subject of considerable debate. In this study, we have synthesized and tested an analog of coniferyl alcohol that has been modified to contain an ethynyl group at the C-3 position. This modification enables fluorescent tagging and imaging of this molecule after its incorporation into plant tissue by click chemistry-assisted covalent labeling with a fluorescent azide dye, and confers a distinct Raman signature that could be used for Raman imaging. We found that this monolignol analog is incorporated into in vitro-polymerized dehydrogenation polymer (DHP lignin and into root epidermal cell walls of 4-day-old Arabidopsis seedlings. Incorporation of the analog in stem sections of 6-week-old Arabidopsis thaliana plants and labeling with an Alexa-594 azide dye revealed the precise locations of new lignin polymerization. Results from this study indicate that this molecule can provide high-resolution localization of lignification during plant cell wall maturation and lignin matrix assembly.

  19. Destructuring plant biomass: Focus on fungal and extremophilic cell wall hydrolases

    Science.gov (United States)

    Guerriero, Gea; Hausman, Jean-Francois; Strauss, Joseph; Ertan, Haluk; Siddiqui, Khawar Sohail

    2016-01-01

    The use of plant biomass as feedstock for biomaterial and biofuel production is relevant in the current bio-based economy scenario of valorizing renewable resources. Fungi, which degrade complex and recalcitrant plant polymers, secrete different enzymes that hydrolyze plant cell wall polysaccharides. The present review discusses the current research trends on fungal, as well as extremophilic cell wall hydrolases that can withstand extreme physico-chemical conditions required in efficient industrial processes. Secretomes of fungi from the phyla Ascomycota, Basidiomycota, Zygomycota and Neocalli-mastigomycota are presented along with metabolic cues (nutrient sensing, coordination of carbon and nitrogen metabolism) affecting their composition. We conclude the review by suggesting further research avenues focused on the one hand on a comprehensive analysis of the physiology and epigenetics underlying cell wall degrading enzyme production in fungi and on the other hand on the analysis of proteins with unknown function and metagenomics of extremophilic consortia. The current advances in consolidated bioprocessing, altered secretory pathways and creation of designer plants are also examined. Furthermore, recent developments in enhancing the activity, stability and reusability of enzymes based on synergistic, proximity and entropic effects, fusion enzymes, structure-guided recombination between homologous enzymes and magnetic enzymes are considered with a view to improving saccharification. PMID:25804821

  20. Is gene activity in plant cells affected by UMTS-irradiation? A whole genome approach

    Directory of Open Access Journals (Sweden)

    Julia C Engelmann

    2008-10-01

    Full Text Available Julia C Engelmann3,* Rosalia Deeken1,* Tobias Müller3, Günter Nimtz2, M Rob G Roelfsema1, Rainer Hedrich11Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences; 2Institute of Physics II, University of Cologne, Cologne, Germany; 3Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany; *These authors contributed equally to this workAbstract: Mobile phone technology makes use of radio frequency (RF electromagnetic fields transmitted through a dense network of base stations in Europe. Possible harmful effects of RF fields on humans and animals are discussed, but their effect on plants has received little attention. In search for physiological processes of plant cells sensitive to RF fields, cell suspension cultures of Arabidopsis thaliana were exposed for 24 h to a RF field protocol representing typical microwave exposition in an urban environment. mRNA of exposed cultures and controls was used to hybridize Affymetrix-ATH1 whole genome microarrays. Differential expression analysis revealed significant changes in transcription of 10 genes, but they did not exceed a fold change of 2.5. Besides that 3 of them are dark-inducible, their functions do not point to any known responses of plants to environmental stimuli. The changes in transcription of these genes were compared with published microarray datasets and revealed a weak similarity of the microwave to light treatment experiments. Considering the large changes described in published experiments, it is questionable if the small alterations caused by a 24 h continuous microwave exposure would have any impact on the growth and reproduction of whole plants.Keywords: suspension cultured plant cells, radio frequency electromagnetic fields, microarrays, Arabidopsis thaliana

  1. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    Science.gov (United States)

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  2. Tubule-guided cell-to-cell movement of a plant virus requires class XI myosin motors.

    Directory of Open Access Journals (Sweden)

    Khalid Amari

    2011-10-01

    Full Text Available Cell-to-cell movement of plant viruses occurs via plasmodesmata (PD, organelles that evolved to facilitate intercellular communications. Viral movement proteins (MP modify PD to allow passage of the virus particles or nucleoproteins. This passage occurs via several distinct mechanisms one of which is MP-dependent formation of the tubules that traverse PD and provide a conduit for virion translocation. The MP of tubule-forming viruses including Grapevine fanleaf virus (GFLV recruit the plant PD receptors called Plasmodesmata Located Proteins (PDLP to mediate tubule assembly and virus movement. Here we show that PDLP1 is transported to PD through a specific route within the secretory pathway in a myosin-dependent manner. This transport relies primarily on the class XI myosins XI-K and XI-2. Inactivation of these myosins using dominant negative inhibition results in mislocalization of PDLP and MP and suppression of GFLV movement. We also found that the proper targeting of specific markers of the Golgi apparatus, the plasma membrane, PD, lipid raft subdomains within the plasma membrane, and the tonoplast was not affected by myosin XI-K inhibition. However, the normal tonoplast dynamics required myosin XI-K activity. These results reveal a new pathway of the myosin-dependent protein trafficking to PD that is hijacked by GFLV to promote tubule-guided transport of this virus between plant cells.

  3. Bioaerosols from a Food Waste Composting Plant Affect Human Airway Epithelial Cell Remodeling Genes

    Directory of Open Access Journals (Sweden)

    Ming-Wei Chang

    2013-12-01

    Full Text Available The composting procedure in food waste plants generates airborne bioaerosols that have the potential to damage human airway epithelial cells. Persistent inflammation and repair responses induce airway remodeling and damage to the respiratory system. This study elucidated the expression changes of airway remodeling genes in human lung mucoepidermoid NCI-H292 cells exposed to bioaerosols from a composting plant. Different types of microorganisms were detectable in the composting plant, using the agar culture method. Real-time polymerase chain reaction was used to quantify the level of Aspergillus fumigatus and the profile of remodeling genes. The real-time PCR results indicated that the amount of A. fumigatus in the composting hall was less than 102 conidia. The endotoxins in the field bioaerosols were determined using a limulus amebocyte lysate test. The endotoxin levels depended on the type of particulate matter (PM, with coarse particles (2.5–10 μm having higher endotoxin levels than did fine particles (0.5–2.5 μm. After exposure to the conditioned medium of field bioaerosol samples, NCI-H292 cells showed increased pro-inflammatory interleukin (IL-6 release and activated epidermal growth factor receptor (EGFR, transforming growth factor (TGF-β1 and cyclin-dependent kinase inhibitor 1 (p21WAF1/CIP1 gene expression, but not of matrix metallopeptidase (MMP-9. Airborne endotoxin levels were higher inside the composting hall than they were in other areas, and they were associated with PM. This suggested that airborne bioaerosols in the composting plant contained endotoxins and microorganisms besides A. fumigatus that cause the inflammatory cytokine secretion and augment the expression of remodeling genes in NCI-H292 cells. It is thus necessary to monitor potentially hazardous materials from bioaerosols in food composting plants, which could affect the health of workers.

  4. Boron Plays an Important Role in the Regulation of Plant Cell Growth

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Boron is an essential nutrition for higher plants.However, the primary function of boron remains a matter of discussion.Boron may function by forming complexes with compounds having cis-hydroxyl groups(diols), e.g., pectic materials in cell walls, glycoproteins or glycolipids in membranes and o-diphenols.The well-defined functions of boron are its involvement in maintaining cell wall structure and both the structural and the functional integrity of plasma membrane.Lack of boron causes an increase in the leakage of ions and compounds which reflects the impairment of plasma membrane.Boron is functionally important in forming a pectic network in cell wall which is responsible for the extensibility of cell wall and consequently regulates cell growth.

  5. Study of Plant Cell Wall Polymers Affected by Metal Accumulation Using Stimulated Raman Scattering Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shi-You [Harvard Univ., Cambridge, MA (United States)

    2015-03-02

    This project aims to employ newly-developed chemical imaging techniques to measure, in real-time, the concentration, dynamics and spatial distribution of plant cell wall polymers during biomass growth with inoculation of transgenic symbiotic fungi, and to explore a new pathway of delivering detoxified metal to plant apoplast using transgenic symbiotic fungi, which will enhance metal accumulation from soil, and potentially these metals may in turn be used as catalysts to improve the efficiency of biomass conversion to biofuels. The proposed new pathway of biomass production will: 1) benefit metal and radionuclide contaminant mobility in subsurface environments, and 2) potentially improve biomass production and process for bioenergy

  6. Aequorin-based measurements of intracellular Ca2+-signatures in plant cells

    Directory of Open Access Journals (Sweden)

    Mithöfer Axel

    2002-01-01

    Full Text Available Due to the involvement of calcium as a main second messenger in the plant signaling pathway, increasing interest has been focused on the calcium signatures supposed to be involved in the patterning of the specific response associated to a given stimulus. In order to follow these signatures we described here the practical approach to use the non-invasive method based on the aequorin technology. Besides reviewing the advantages and disadvantages of this method we report on results showing the usefulness of aequorin to study the calcium response to biotic (elicitors and abiotic stimuli (osmotic shocks in various compartments of plant cells such as cytosol and nucleus.

  7. 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.

  8. EVALUATION OF CELL CYCLE OF Aspergillus nidulans EXPOSED TO THE EXTRACT OF Copaifera officinalis L PLANT

    Directory of Open Access Journals (Sweden)

    Simone Jurema Ruggeri Chiuchetta, Uériton Dias de Oliveira e Josy Fraccaro de Marins

    2006-12-01

    Full Text Available The oil extracted from the Copaifera officinalis L plant has been used in popular medicine to the treatment of several diseases, like cancer. In eukaryotic cells, the process of cellular proliferation follows a standard cycle, named cellular cycle. The transformation of a normal cell in a malignant one requires several steps, in which genes that control normal cellular division or cellular death are modified. Aspergillus nidulans fungus is an excellent system for the study of the cellular differentiation. Its asexual cycle results in the formation of conidia, which are disposed like chains, constituting a structure named conidiophore. This structure consists in an aerial hifae, multinucleate vesicle and uninucleate cells. Current research evaluated the capacity of the C. officinalis L plant extract in promoting alterations in the cellular cycle of A. nidulans diploid strains, by observing macroscopic and microscopic alterations in cellular growth of this fungus. Results shown that no macroscopic alterations were observed in cellular growth of strains exposed to the extract, however, microscopic alterations of conidiophore have been observed in the different extract concentrations analyzed. In this way, the study of the action of C. officinalis L plant extract becomes important considering the fact that this substance is capable to promote alterations in cellular cycle of eukaryotic cells.

  9. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    Science.gov (United States)

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity. PMID:16169172

  10. Acetylesterase-Mediated Deacetylation of Pectin Impairs Cell Elongation, Pollen Germination, and Plant Reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gou J. Y.; Liu C.; Miller, L. M.; Hou, G.; Yu, X.-H.; Chen, X.-Y.

    2012-01-01

    Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility.

  11. The toxicity of extracts of plant parts of Moringa stenopetala in HEPG2 cells in vitro.

    Science.gov (United States)

    Mekonnen, Negussu; Houghton, Peter; Timbrell, John

    2005-10-01

    The cytotoxicity of extracts from a widely used species of plant, Moringa stenopetala, was assessed in HEPG2 cells, by measuring the leakage of lactate dehydrogenase (LDH) and cell viability. The functional integrity of extract-exposed cells was determined by measuring intracellular levels of ATP and glutathione (GSH). The ethanol extracts of leaves and seeds increased significantly (p leaf and seed extracts. At a concentration of 500 microg/mL, the water extract of leaves increased (p leaf extract decreased GSH levels at a concentration of 500 microg/mL (p Moringa stenopetala show that they contain toxic substances that are extractable with organic solvents or are formed during the process of extraction with these solvents. The significant depletion of ATP and GSH only occurred at concentrations of extract that caused leakage of LDH. Further investigation with this plant in order to identify the constituents extracted and their individual toxic effects both in vivo and in vitro is warranted. This study also illustrates the utility of cell culture for screening plant extracts for potential toxicity.

  12. An economic and technical assessment of the use of plant cell cultures for natural product synthesis on an industrial scale.

    Science.gov (United States)

    Fowler, M W; Cresswell, R C; Stafford, A M

    1990-01-01

    Plant cell cultures may be used as an alternative source of established natural products, as a source of novel 'lead' compounds or as a source of enzymes for modification of precursors. Only a few plant cell processes are operating commercially and their performance characteristics are industrial secrets. The economic aspects of natural product synthesis in plant cell cultures are presented on the basis of data derived from work on a pilot plant with bioreactors of 5-80 litres in which cells are grown in batch liquid culture. Cost analysis shows that the labour costs of operating plant cell culture processes are much higher than those for microbial processes, which reflects the longer process times of plant systems. These can be reduced by increasing the cell growth rate, the biomass yield and/or the product yield. Higher yields can be obtained by optimizing media conditions, but there are no standard guidelines for this. Each system has to be developed individually. Reducing the number of production runs a year, usually by increasing the number of days for which each batch of cells is synthesizing product, can markedly decrease costs. Economic assessment of the viability of production in plant cell cultures must consider not only production costs but also the expected market price of the product and the volume of sales.

  13. The female gametophyte: an emerging model for cell type-specific systems biology in plant development

    Directory of Open Access Journals (Sweden)

    Marc William Schmid

    2015-11-01

    Full Text Available Systems biology, a holistic approach describing a system emerging from the interactions of its molecular components, critically depends on accurate qualitative determination and quantitative measurements of these components. Development and improvement of large-scale profiling methods (omics now facilitates comprehensive measurements of many relevant molecules. For multicellular organisms, such as animals, fungi, algae, and plants, the complexity of the system is augmented by the presence of specialized cell types and organs, and a complex interplay within and between them. Cell type-specific analyses are therefore crucial for the understanding of developmental processes and environmental responses. This review first gives an overview of current methods used for large-scale profiling of specific cell types exemplified by recent advances in plant biology. The focus then lies on suitable model systems to study plant development and cell type specification. We introduce the female gametophyte of flowering plants as an ideal model to study fundamental developmental processes. Moreover, the female reproductive lineage is of importance for the emergence of evolutionary novelties such as an unequal parental contribution to the tissue nurturing the embryo or the clonal production of seeds by asexual reproduction (apomixis. Understanding these processes is not only interesting from a developmental or evolutionary perspective, but bears great potential for further crop improvement and the simplification of breeding efforts. We finally highlight novel methods, which are already available or which will likely soon facilitate large-scale profiling of the specific cell types of the female gametophyte in both model and non-model species. We conclude that it may take only few years until an evolutionary systems biology approach toward female gametogenesis may decipher some of its biologically most interesting and economically most valuable processes.

  14. Multivariable Robust Control of a Simulated Hybrid Solid Oxide Fuel Cell Gas Turbine Plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsai A, Banta L, Tucker D

    2010-08-01

    This work presents a systematic approach to the multivariable robust control of a hybrid fuel cell gas turbine plant. The hybrid configuration under investigation built by the National Energy Technology Laboratory comprises a physical simulation of a 300kW fuel cell coupled to a 120kW auxiliary power unit single spool gas turbine. The public facility provides for the testing and simulation of different fuel cell models that in turn help identify the key difficulties encountered in the transient operation of such systems. An empirical model of the built facility comprising a simulated fuel cell cathode volume and balance of plant components is derived via frequency response data. Through the modulation of various airflow bypass valves within the hybrid configuration, Bode plots are used to derive key input/output interactions in transfer function format. A multivariate system is then built from individual transfer functions, creating a matrix that serves as the nominal plant in an H{sub {infinity}} robust control algorithm. The controller’s main objective is to track and maintain hybrid operational constraints in the fuel cell’s cathode airflow, and the turbo machinery states of temperature and speed, under transient disturbances. This algorithm is then tested on a Simulink/MatLab platform for various perturbations of load and fuel cell heat effluence. As a complementary tool to the aforementioned empirical plant, a nonlinear analytical model faithful to the existing process and instrumentation arrangement is evaluated and designed in the Simulink environment. This parallel task intends to serve as a building block to scalable hybrid configurations that might require a more detailed nonlinear representation for a wide variety of controller schemes and hardware implementations.

  15. Biochemistry, proteomics and phosphoproteomics of plant mitochondria from non-photosynthetic cells

    Directory of Open Access Journals (Sweden)

    Jesper Foged Havelund

    2013-03-01

    Full Text Available Mitochondria fulfill some basic roles in all plant cells. They supply the cell with energy in the form of ATP and reducing equivalents (NAD(PH and they provide the cell with intermediates for a range of biosynthetic pathways. In addition to this, mitochondria contribute to a number of specialized functions depending on the tissue and cell type, as well as environmental conditions. We will here review the biochemistry and proteomics of mitochondria from non-green cells and organs, which differ from those of photosynthetic organs in a number of respects. We will briefly cover purification of mitochondria and general biochemical properties such as oxidative phosphorylation. We will then mention a few adaptive properties in response to water stress, seed maturation and germination and the ability to function under hypoxic conditions. The discussion will mainly focus on Arabidopsis cell cultures, etiolated germinating rice seedlings and potato tubers as model plants. It will cover the general proteome as well as the posttranslational modification protein phosphorylation. To date 64 phosphorylated mitochondrial proteins with a total of 103 phosphorylation sites have been identified.

  16. Golgi-mediated synthesis and secretion of matrix polysaccharides of the primary cell wall of higher plants.

    OpenAIRE

    Azeddine eDriouich; marie-laure efollet-gueye; sophie eBernard; sumaira ekousar; Laurence eChevalier; Maité eVicré; Olivier eLerouxel

    2012-01-01

    The Golgi apparatus of eukaryotic cells is known for its central role in the processing, sorting and transport of proteins to intra- and extracellular compartments. In plants, it has the additional task of assembling and exporting the non-cellulosic polysaccharides of the cell wall matrix including pectin and hemicelluloses, which are important for plant development and protection. In this review, we focus on the biosynthesis of complex polysaccharides of the primary cell wall. We present and...

  17. Golgi-Mediated Synthesis and Secretion of Matrix Polysaccharides of the Primary Cell Wall of Higher Plants

    OpenAIRE

    Driouich, Azeddine; Follet-Gueye, Marie-Laure; Bernard, Sophie; Kousar, Sumaira,; Chevalier, Laurence; Vicré-Gibouin, Maïté; Lerouxel, Olivier

    2012-01-01

    The Golgi apparatus of eukaryotic cells is known for its central role in the processing, sorting, and transport of proteins to intra- and extra-cellular compartments. In plants, it has the additional task of assembling and exporting the non-cellulosic polysaccharides of the cell wall matrix including pectin and hemicelluloses, which are important for plant development and protection. In this review, we focus on the biosynthesis of complex polysaccharides of the primary cell wall of eudicotyle...

  18. Continuous Flow Separation of Hydrophobin Fusion Proteins from Plant Cell Culture Extract.

    Science.gov (United States)

    Reuter, Lauri J; Conley, Andrew J; Joensuu, Jussi J

    2016-01-01

    Fusion to fungal hydrophobins has proven to be a useful tool to enhance accumulation and recovery of recombinant proteins in plants. Aqueous two-phase separation (ATPS) is an attractive system to capture hydrophobin fusion proteins from plant extracts. The process can simultaneously purify and concentrate target protein with minimal background. ATPS avoids the use of chromatographic column steps, can be carried out in a short time frame, and is amenable to industrial-scale protein purification. A drawback of performing ATPS in large volumes is the lengthy time required for phase separation; however, this can be avoided by incorporating continuous systems, which are often preferred by the processing industry. This method chapter illustrates the capture of GFP-HFBI hydrophobin fusion protein from BY-2 plant cell suspension extract using a semi-continuous ATPS method. PMID:26614291

  19. Resilience of roof-top Plant-Microbial Fuel Cells during Dutch winter

    International Nuclear Information System (INIS)

    The Plant-Microbial Fuel Cell (P-MFC) is in theory a technology that could produce sustainable electricity continuously. We operated two designs of the P-MFC under natural roof-top conditions in the Netherlands for 221 days, including winter, to test its resilience. Current and power densities are not stable under outdoor conditions. Highest obtained power density was 88 mW m−2, which is lower than was achieved under lab-conditions (440 mW m−2). Cathode potential was in our case dependent on solar radiation, due to algae growth, making the power output dependent on a diurnal cycle. The anode potential of the P-MFC is influenced by temperature, leading to a decrease in electricity production during low temperature periods and no electricity production during frost periods. Due to freezing of the roots, plants did not survive winter and therefore did not regrow in spring. In order to make a sustainable, stable and weather independent electricity production system of the P-MFC attention should be paid to improving cathode stability and cold insulation of anode and cathode. Only when power output of the Plant-Microbial Fuel Cell can be increased under outdoor conditions and plant-vitality can be sustained over winter, it can be a promising sustainable electricity technology for the future. -- Highlights: ► Plant-Microbial Fuel Cells (P-MFCs) produce sustainable electricity under outdoor conditions. ► During frost periods no electricity is produced in P-MFCs. ► Cathodes limit performance of P-MFCs under outdoor conditions. ► Spartina anglica in P-MFCs does not survive on a roof-top during Dutch winter. ► The P-MFC needs optimization of power output to be a promising sustainable electricity technology

  20. Human ortholog of a plant salicylic acid receptor found in SK-N-SH cell line.

    Science.gov (United States)

    Skubatz, Hanna; Howald, William N

    2013-12-01

    Our previous studies have described the purification and characterization of a novel plant NAD(P)-reductase like protein (RL) from the thermogenic appendix of the Sauromatum guttatum inflorescence. RL is mainly located in cytoplasm of thermogenic plants and it can act like a bistable switch. It adopts a compact conformation during heat-production and a more expanded conformation when heat is not generated. Addition of salicylic acid, a natural thermogenic inducer, at picomolar concentration to a solution of purified RL induced a discontinuous volume phase transition in which the volume of RL in the oligomeric form expanded and shrunk repeatedly every 4-5 min. In the present study using ESI-MS analysis we have demonstrated the existence of RL in the human SK-N-SH cell line and in mouse brain tissue. The molecular mass of human RL is in the same range as of its plant counterpart, 34,140 ± 34 Da. The charge state distribution of the human RL is identical to its plant counterpart from the Sauromatum appendix during heat-production. Human RL was present in the compact state when it was purified from the SK-N-SH cell line When these cells were treated with salicylic acid (10 μM) a shift to a much more compact conformation was observed. It seems that the potential of RL to respond to salicylic acid was conserved. These results may reveal the existence of a thermoregulation system that is evolutionarily conserved and is operating by conformational changes. This discovery may also represent an opportunity for a better understanding of some of the diverse functions of salicylic acid and aspirin in plants and humans.

  1. Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Laughter, Mark D [ORNL; Whitaker, J Michael [ORNL; Howell, John [University of Glasgow

    2010-01-01

    Uranium enrichment service providers are expanding existing enrichment plants and constructing new facilities to meet demands resulting from the shutdown of gaseous diffusion plants, the completion of the U.S.-Russia highly enriched uranium downblending program, and the projected global renaissance in nuclear power. The International Atomic Energy Agency (IAEA) conducts verification inspections at safeguarded facilities to provide assurance that signatory States comply with their treaty obligations to use nuclear materials only for peaceful purposes. Continuous, unattended monitoring of load cells in UF{sub 6} feed/withdrawal stations can provide safeguards-relevant process information to make existing safeguards approaches more efficient and effective and enable novel safeguards concepts such as information-driven inspections. The IAEA has indicated that process load cell monitoring will play a central role in future safeguards approaches for large-scale gas centrifuge enrichment plants. This presentation will discuss previous work and future plans related to continuous load cell monitoring, including: (1) algorithms for automated analysis of load cell data, including filtering methods to determine significant weights and eliminate irrelevant impulses; (2) development of metrics for declaration verification and off-normal operation detection ('cylinder counting,' near-real-time mass balancing, F/P/T ratios, etc.); (3) requirements to specify what potentially sensitive data is safeguards relevant, at what point the IAEA gains on-site custody of the data, and what portion of that data can be transmitted off-site; (4) authentication, secure on-site storage, and secure transmission of load cell data; (5) data processing and remote monitoring schemes to control access to sensitive and proprietary information; (6) integration of process load cell data in a layered safeguards approach with cross-check verification; (7) process mock-ups constructed to provide

  2. Phospholipase d activation correlates with microtubule reorganization in living plant cells.

    Science.gov (United States)

    Dhonukshe, Pankaj; Laxalt, Ana M; Goedhart, Joachim; Gadella, Theodorus W J; Munnik, Teun

    2003-11-01

    A phospholipase D (PLD) was shown recently to decorate microtubules in plant cells. Therefore, we used tobacco BY-2 cells expressing the microtubule reporter GFP-MAP4 to test whether PLD activation affects the organization of plant microtubules. Within 30 min of adding n-butanol, a potent activator of PLD, cortical microtubules were released from the plasma membrane and partially depolymerized, as visualized with four-dimensional confocal imaging. The isomers sec- and tert-butanol, which did not activate PLD, did not affect microtubule organization. The effect of treatment on PLD activation was monitored by the in vivo formation of phosphatidylbutanol, a specific reporter of PLD activity. Tobacco cells also were treated with mastoparan, xylanase, NaCl, and hypoosmotic stress as reported activators of PLD. We confirmed the reports and found that all treatments induced microtubule reorganization and PLD activation within the same time frame. PLD still was activated in microtubule-stabilized (taxol) and microtubule-depolymerized (oryzalin) situations, suggesting that PLD activation triggers microtubular reorganization and not vice versa. Exogenously applied water-soluble synthetic phosphatidic acid did not affect the microtubular cytoskeleton. Cell cycle studies revealed that n-butanol influenced not just interphase cortical microtubules but also those in the preprophase band and phragmoplast, but not those in the spindle structure. Cell growth and division were inhibited in the presence of n-butanol, whereas sec- and tert-butanol had no such effects. Using these novel insights, we propose a model for the mechanism by which PLD activation triggers microtubule reorganization in plant cells.

  3. Expanding xylose metabolism in yeast for plant cell wall conversion to biofuels.

    Science.gov (United States)

    Li, Xin; Yu, Vivian Yaci; Lin, Yuping; Chomvong, Kulika; Estrela, Raíssa; Park, Annsea; Liang, Julie M; Znameroski, Elizabeth A; Feehan, Joanna; Kim, Soo Rin; Jin, Yong-Su; Glass, N Louise; Cate, Jamie H D

    2015-01-01

    Sustainable biofuel production from renewable biomass will require the efficient and complete use of all abundant sugars in the plant cell wall. Using the cellulolytic fungus Neurospora crassa as a model, we identified a xylodextrin transport and consumption pathway required for its growth on hemicellulose. Reconstitution of this xylodextrin utilization pathway in Saccharomyces cerevisiae revealed that fungal xylose reductases act as xylodextrin reductases, producing xylosyl-xylitol oligomers as metabolic intermediates. These xylosyl-xylitol intermediates are generated by diverse fungi and bacteria, indicating that xylodextrin reduction is widespread in nature. Xylodextrins and xylosyl-xylitol oligomers are then hydrolyzed by two hydrolases to generate intracellular xylose and xylitol. Xylodextrin consumption using a xylodextrin transporter, xylodextrin reductases and tandem intracellular hydrolases in cofermentations with sucrose and glucose greatly expands the capacity of yeast to use plant cell wall-derived sugars and has the potential to increase the efficiency of both first-generation and next-generation biofuel production. PMID:25647728

  4. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Zor, Kinga; Heiskanen, Arto;

    This project focuses on developing and applying a tissue culture system with electrochemical and optical detection techniques for tissue culture of barley aleurone layer to increase understanding of the underlying mechanisms of programmed cell death (PCD) in plants. The major advantage of electro......This project focuses on developing and applying a tissue culture system with electrochemical and optical detection techniques for tissue culture of barley aleurone layer to increase understanding of the underlying mechanisms of programmed cell death (PCD) in plants. The major advantage...... of electrochemical detection systems is that they can be miniaturized, multiplexed and automated without losing their performance[1,2]. Combining tissue culture with electrochemical and optical detection allows implementation of a wide range of assays for online, real-time, parallel analysis of important parameters...

  5. Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

    Directory of Open Access Journals (Sweden)

    Sang-Kyu Jung

    2012-01-01

    Full Text Available A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE, which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies.

  6. Plant regeneration from cell suspension-derived protoplasts of Saintpaulia ionantha Wendl.

    Science.gov (United States)

    Hoshino, Y; Nakano, M; Mii, M

    1995-03-01

    Friable calli were induced on leaf segments of Saintpaulia ionantha Wendl. on B5 medium containing 1 mg l(-1) 2,4-D and 2 g l(-1) casein hydrolysate. Cell suspension cultures were readily established from these friable calli and protoplasts could be isolated from the cells with yields of 1-3×10(7)/g f. wt.. By culturing in 0.1 % gellan gum-solidified B5 medium supplemented with 1 mg l(-1) 2,4-D and 0.1 M each of sucrose and mannitol at a density of 1×10(5)/ml, the protoplasts divided within 6 days and formed macro-colonies after 2 months of culture. Shoot regeneration from protoplast-derived calli was obtained by sequential treatment of the calli with plant growth regulators: initially with 1 mg l(-1) each of NAA and BA for 2 months followed by 0.01 mg l(-1) NAA and 5 mg l(-1) BA for 4 months. Regenerated plants were established after rooting of the shoots on half-strength MS medium, and successfully transferred to the greenhouse. The regenerated plants grew into flowering stage and showed the same phenotype as the parent plant. PMID:24185329

  7. Gall-forming root-knot nematodes hijack key plant cellular functions to induce multinucleate and hypertrophied feeding cells.

    Science.gov (United States)

    Favery, Bruno; Quentin, Michaël; Jaubert-Possamai, Stéphanie; Abad, Pierre

    2016-01-01

    Among plant-parasitic nematodes, the root-knot nematodes (RKNs) of the Meloidogyne spp. are the most economically important genus. RKN are root parasitic worms able to infect nearly all crop species and have a wide geographic distribution. During infection, RKNs establish and maintain an intimate relationship with the host plant. This includes the creation of a specialized nutritional structure composed of multinucleate and hypertrophied giant cells, which result from the redifferentiation of vascular root cells. Giant cells constitute the sole source of nutrients for the nematode and are essential for growth and reproduction. Hyperplasia of surrounding root cells leads to the formation of the gall or root-knot, an easily recognized symptom of plant infection by RKNs. Secreted effectors produced in nematode salivary glands and injected into plant cells through a specialized feeding structure called the stylet play a critical role in the formation of giant cells. Here, we describe the complex interactions between RKNs and their host plants. We highlight progress in understanding host plant responses, focusing on how RKNs manipulate key plant processes and functions, including cell cycle, defence, hormones, cellular scaffold, metabolism and transport.

  8. 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.

  9. Osmotin, a plant antifungal protein, subverts signal transduction to enhance fungal cell susceptibility.

    Science.gov (United States)

    Yun, D J; Ibeas, J I; Lee, H; Coca, M A; Narasimhan, M L; Uesono, Y; Hasegawa, P M; Pardo, J M; Bressan, R A

    1998-05-01

    The plant pathogenesis-related protein osmotin is an antifungal cytotoxic agent that causes rapid cell death in the yeast S. cerevisiae. We show here that osmotin uses a signal transduction pathway to weaken defensive cell wall barriers and increase its cytotoxic efficacy. The pathway activated by osmotin includes the regulatory elements of the mating pheromone response STE4, STE18, STE20, STE5, STE11, STE7, FUS3, KSS1, and STE12. Neither the pheromone receptor nor its associated G protein alpha subunit GPA1 are required for osmotin action. However, mutation of SST2, a negative regulator of G alpha proteins, resulted in supersensitivity to osmotin. Phosphorylation of STE7 was rapidly stimulated by osmotin preceding any changes in cell vitality or morphology. These results demonstrate that osmotin subverts target cell signal transduction as part of its mechanism of action. PMID:9660964

  10. Unraveling the response of plant cells to cytotoxic saponins: Role of metallothionein and nitric oxide

    OpenAIRE

    Balestrazzi, Alma; Macovei, Anca; Tava, Aldo; Avato, Pinarosa; Raimondi, Elena; Daniela CARBONERA

    2011-01-01

    A wide range of pharmacological properties are ascribed to natural saponins, in addition to their biological activities against herbivores, plant soil-borne pathogens and pests. As for animal cells, the cytotoxicity and the chemopreventive role of saponins are mediated by a complex network of signal transduction pathways which include reactive oxygen species (ROS) and nitric oxide (NO). The involvement of other relevant components of the saponin-related signaling routes, such as the Tumor Nec...

  11. Recognition and degradation of plant cell wall polysaccharides by two human gut symbionts.

    OpenAIRE

    Martens, Eric C.; Lowe, Elisabeth C.; Herbert Chiang; Nicholas A Pudlo; Meng Wu; McNulty, Nathan P.; D Wade Abbott; Bernard Henrissat; Gilbert, Harry J.; Bolam, David N.; Jeffrey I Gordon

    2011-01-01

    Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for cat...

  12. Recent advances towards development and commercialization of plant cell culture processes for synthesis of biomolecules

    OpenAIRE

    Wilson, Sarah A.; Roberts, Susan C.

    2011-01-01

    Plant cell culture systems were initially explored for use in commercial synthesis of several high value secondary metabolites, allowing for sustainable production that was not limited by the low yields associated with natural harvest or the high cost associated with complex chemical synthesis. Although there have been some commercial successes, most notably paclitaxel production from Taxus sp., process limitations exist with regards to low product yields and inherent production variability. ...

  13. Chloride regulates leaf cell size and water relations in tobacco plants

    OpenAIRE

    Franco-Navarro, Juan D.; Brumós Fuentes, Javier; Rosales Villegas, Miguel Á.; Cubero Font, Paloma; Talón Cubillo, Manuel; Colmenero Flores, José M.

    2015-01-01

    Chloride (Cl–) is a micronutrient that accumulates to macronutrient levels since it is normally available in nature and actively taken up by higher plants. Besides a role as an unspecific cell osmoticum, no clear biological roles have been explicitly associated with Cl– when accumulated to macronutrient concentrations. To address this question, the glycophyte tobacco (Nicotiana tabacum L. var. Habana) has been treated with a basal nutrient solution supplemented with one of three salt combinat...

  14. Recent advances on the posttranslational modifications of EXTs and their roles in plant cell walls

    DEFF Research Database (Denmark)

    Velasquez, Melina; Salter, Juan Salgado; Dorosz, Javier Gloazzo;

    2012-01-01

    The genetic set up and the enzymes that define the O-glycosylation sites and transfer the activated sugars to cell wall glycoprotein Extensins (EXTs) have remained unknown for a long time. We are now beginning to see the emerging components of the molecular machinery that assembles these complex O......-glycoproteins on the plant cell wall. Genes conferring the posttranslational modifications, i.e., proline hydroxylation and subsequent O-glycosylation, of the EXTs have been recently identified. In this review we summarize the enzymes that define the O-glycosylation sites on the O-glycoproteins, i.e., the prolyl 4...

  15. Uptake of Uranium and Other Elements of Concern by Plants Growing on Uranium Mill Tailings Disposal Cells

    Science.gov (United States)

    Joseph, C. N.; Waugh, W.; Glenn, E.

    2015-12-01

    The U.S. Department of Energy (DOE) is responsible for long-term stewardship of disposal cells for uranium mill tailings throughout the United States. Rock-armored disposal cell covers create favorable habitat for deep-rooted plants by reducing soil evaporation, increasing soil water storage, and trapping windblown dust, thereby providing water and nutrients for plant germination and establishment. DOE is studying the tradeoffs of potential detrimental and beneficial effects of plants growing on disposal cell covers to develop a rational and consistent vegetation management policy. Plant roots often extend vertically through disposal cell covers into underlying tailings, therefore, uptake of tailings contaminants and dissemination through animals foraging on stems and leaves is a possible exposure pathway. The literature shows that plant uptake of contaminants in uranium mill tailings occurs, but levels can vary widely depending on plant species, tailings and soil chemistry, and cover soil hydrology. Our empirical field study measured concentrations of uranium, radium, thorium, molybdenum, selenium, manganese, lead, and arsenic in above ground tissues harvested from plants growing on disposal cells near Native American communities in western states that represent a range of climates, cover designs, cover soil types, and vegetation types. For risk screening, contaminant levels in above ground tissues harvested from plants on disposal cells were compared to Maximum Tolerance Levels (MTLs) set for livestock by the National Research Council, and to tissue levels in the same plant species growing in reference areas near disposal cells. Although tailings were covered with uncontaminated soils, for 14 of 46 comparisons, levels of uranium and other contaminants were higher in plants growing on disposal cells compared to reference area plants, indicating possible mobilization of these elements from the tailing into plant tissues. However, with one exception, all plant

  16. 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.

  17. Ion bombardment induced formation of micro-craters in plant cell envelopes

    International Nuclear Information System (INIS)

    Ion beam bombardment of biological material has been recently applied for gene transfer in both plant and bacterial cells. A consistent physical mechanism for this significant result has not yet been developed. A fundamental question about the mechanism is the possible formation of pathways due to ion bombardment that are responsible for the gene transfer. We have carried out investigations of the effects of low-energy bombardment by both gaseous and metallic ion species of onion skin cells on their surface microstructure. Our experimental results reveal evidence demonstrating that the formation of micro-crater-like structures on the plant cell envelope surface is a general phenomenon consequent to ion bombardment, no matter what ion species, under certain ion beam conditions. The micro-craters are about 0.1-1 μm in size (diameter) and a few tens of nanometers in depth. The micro-crater formation process seems to be unrelated to the chemical composition of and rapid water evaporation from the cell envelope, but is associated with the special microstructure of the cell wall

  18. AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca(2+) increase.

    Science.gov (United States)

    Francia, Doriana; Chiltz, Annick; Lo Schiavo, Fiorella; Pugin, Alain; Bonfante, Paola; Cardinale, Francesca

    2011-09-01

    The molecular dialogue occurring prior to direct contact between the fungal and plant partners of arbuscular-mycorrhizal (AM) symbioses begins with the release of fungal elicitors, so far only partially identified chemically, which can activate specific signaling pathways in the host plant. We show here that the activation of MAPK is also induced by exudates of germinating spores of Gigaspora margarita in cultured cells of the non-leguminous species tobacco (Nicotiana tabacum), as well as in those of the model legume Lotus japonicus. MAPK activity peaked about 15 min after the exposure of the host cells to the fungal exudates (FE). FE were also responsible for a rapid and transient increase in free cytosolic Ca(2+) in Nicotiana plumbaginifolia and tobacco cells, and pre-treatment with a Ca(2+)-channel blocker (La(3+)) showed that in these cells, MAPK activation was dependent on the cytosolic Ca(2+) increase. A partial dependence of MAPK activity on the common Sym pathway could be demonstrated for a cell line of L. japonicus defective for LjSym4 and hence unable to establish an AM symbiosis. Our results show that MAPK activation is triggered by an FE-induced cytosolic Ca(2+) transient, and that a Sym genetic determinant acts to modulate the intensity and duration of this activity.

  19. Ectopic KNOX Expression Affects Plant Development by Altering Tissue Cell Polarity and Identity[OPEN

    Science.gov (United States)

    Rebocho, Alexandra B.

    2016-01-01

    Plant development involves two polarity types: tissue cell (asymmetries within cells are coordinated across tissues) and regional (identities vary spatially across tissues) polarity. Both appear altered in the barley (Hordeum vulgare) Hooded mutant, in which ectopic expression of the KNOTTED1-like Homeobox (KNOX) gene, BKn3, causes inverted polarity of differentiated hairs and ectopic flowers, in addition to wing-shaped outgrowths. These lemma-specific effects allow the spatiotemporal analysis of events following ectopic BKn3 expression, determining the relationship between KNOXs, polarity, and shape. We show that tissue cell polarity, based on localization of the auxin transporter SISTER OF PINFORMED1 (SoPIN1), dynamically reorients as ectopic BKn3 expression increases. Concurrently, ectopic expression of the auxin importer LIKE AUX1 and boundary gene NO APICAL MERISTEM is activated. The polarity of hairs reflects SoPIN1 patterns, suggesting that tissue cell polarity underpins oriented cell differentiation. Wing cell files reveal an anisotropic growth pattern, and computational modeling shows how polarity guiding growth can account for this pattern and wing emergence. The inverted ectopic flower orientation does not correlate with SoPIN1, suggesting that this form of regional polarity is not controlled by tissue cell polarity. Overall, the results suggest that KNOXs trigger different morphogenetic effects through interplay between tissue cell polarity, identity, and growth. PMID:27553356

  20. Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus

    Science.gov (United States)

    Li-Byarlay, Hongmei; Pittendrigh, Barry R.; Murdock, Larry L.

    2016-01-01

    Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant–insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology. PMID:27594789

  1. Cladosporium fulvum Avr4 protects fungal cell walls against hydrolysis by plant chitinases accumulating during infection.

    Science.gov (United States)

    van den Burg, Harrold A; Harrison, Stuart J; Joosten, Matthieu H A J; Vervoort, Jacques; de Wit, Pierre J G M

    2006-12-01

    Resistance against the leaf mold fungus Cladosporium fulvum is mediated by the tomato Cf proteins which belong to the class of receptor-like proteins and indirectly recognize extracellular avirulence proteins (Avrs) of the fungus. Apart from triggering disease resistance, Avrs are believed to play a role in pathogenicity or virulence of C. fulvum. Here, we report on the avirulence protein Avr4, which is a chitin-binding lectin containing an invertebrate chitin-binding domain (CBM14). This domain is found in many eukaryotes, but has not yet been described in fungal or plant genomes. We found that interaction of Avr4 with chitin is specific, because it does not interact with other cell wall polysaccharides. Avr4 binds to chitin oligomers with a minimal length of three N-acetyl glucosamine residues. In vitro, Avr4 protects chitin against hydrolysis by plant chitinases. Avr4 also binds to chitin in cell walls of the fungi Trichoderma viride and Fusarium solani f. sp. phaseoli and protects these fungi against normally deleterious concentrations of plant chitinases. In situ fluorescence studies showed that Avr4 also binds to cell walls of C. fulvum during infection of tomato, where it most likely protects the fungus against tomato chitinases, suggesting that Avr4 is a counter-defensive virulence factor.

  2. Role of a Transcriptional Regulator in Programmed Cell Death and Plant Development

    Energy Technology Data Exchange (ETDEWEB)

    Julie M. Stone

    2008-09-13

    The long-term goal of this research is to understand the role(s) and molecular mechanisms of programmed cell death (PCD) in the controlling plant growth, development and responses to biotic and abiotic stress. We developed a genetic selection scheme to identify A. thaliana FB1-resistant (fbr) mutants as a way to find genes involved in PCD (Stone et al., 2000; Stone et al., 2005; Khan and Stone, 2008). The disrupted gene in fbr6 (AtSPL14) responsible for the FB1-insensitivity and plant architecture phenotypes encodes a plant-specific SBP DNA-binding domain transcriptional regulator (Stone et al., 2005; Liang et al., 2008). This research plan is designed to fill gaps in the knowledge about the role of SPL14 in plant growth and development. The work is being guided by three objectives aimed at determining the pathways in which SPL14 functions to modulate PCD and/or plant development: (1) determine how SPL14 functions in plant development, (2) identify target genes that are directly regulated by SPL14, and (3) identify SPL14 modifications and interacting proteins. We made significant progress during the funding period. Briefly, some major accomplishments are highlighted below: (1) To identify potential AtSPL14 target genes, we identified a consensus DNA binding site for the AtSPL14 SBP DNA-binding domain using systematic evolution of ligands by exponential selection (SELEX) and site-directed mutagenesis (Liang et al., 2008). This consensus binding site was used to analyze Affymetrix microarray gene expression data obtained from wild-type and fbr6 mutant plants to find possible AtSPL14-regulated genes. These candidate AtSPL14-regulated genes are providing new information on the molecular mechanisms linking plant PCD and plant development through modulation of the 26S proteasome. (2) Transgenic plants expressing epitope-tagged versions of AtSPL14 are being used to confirm the AtSPL14 targets (by ChIP-PCR) and further dissect the molecular interactions (Nazarenus, Liang

  3. Lutein, a Natural Carotenoid, Induces α-1,3-Glucan Accumulation on the Cell Wall Surface of Fungal Plant Pathogens.

    Science.gov (United States)

    Otaka, Junnosuke; Seo, Shigemi; Nishimura, Marie

    2016-01-01

    α-1,3-Glucan, a component of the fungal cell wall, is a refractory polysaccharide for most plants. Previously, we showed that various fungal plant pathogens masked their cell wall surfaces with α-1,3-glucan to evade plant immunity. This surface accumulation of α-1,3-glucan was infection specific, suggesting that plant factors might induce its production in fungi. Through immunofluorescence observations of fungal cell walls, we found that carrot (Daucus carota) extract induced the accumulation of α-1,3-glucan on germlings in Colletotrichum fioriniae, a polyphagous fungal pathogen that causes anthracnose disease in various dicot plants. Bioassay-guided fractionation of carrot leaf extract successfully identified two active substances that caused α-1,3-glucan accumulation in this fungus: lutein, a carotenoid widely distributed in plants, and stigmasterol, a plant-specific membrane component. Lutein, which had a greater effect on C. fioriniae, also induced α-1,3-glucan accumulation in other Colletotrichum species and in the phylogenetically distant rice pathogen Cochliobolus miyabeanus, but not in the rice pathogen Magnaporthe oryzae belonging to the same phylogenetic subclass as Colletotrichum. Our results suggested that fungal plant pathogens reorganize their cell wall components in response to specific plant-derived compounds, which these pathogens may encounter during infection. PMID:27483218

  4. Degradation behaviour of phosphinothricin in nontransgenic and transgenic maize- and rape cells as well as in whole plants. Final report

    International Nuclear Information System (INIS)

    Up to now only very few publications are available about the metabolism of phosphinothricin (D/L-PPT, trade names: BASTA trademark, LIBERTY trademark) in plants. In most of these reports degradation studies with cell cultures using very low herbicide concentrations are described. There are no publications about the degradation in transgenic intact plants under outdoor conditions yet. In order to clarify the question, whether the degradation in transgenic crops may differ from that in nontransgenic plants and if there exist differences between D- and L-PPT, the degradation of 14C-D/L-, -L- and -D-PPT in transgenic and nontransgenic cell cultures as well as in intact, transgenic rape and maize plants was studied under outdoor conditions. D-PPT was not metabolised to a reasonable extent both in cell cultures and whole plants, all metabolites were formed from L-PPT. At harvest the amounts of total residues in maize plants ranged from 9 to 16% of the applied herbicide dosage and in rape plants from 35 to 47%. In nontransgenic plant cells L-PPT was exclusively metabolised to different methylphosphinico fatty acids. The main metabolite both in transgenic cells and whole plants with a content of 60 to 90% of total residues in rape and maize was N-acetyl-L-PPT, which seems to be stable in transgenic plants. In addition very low amounts of the same methylphosphinico fatty acids as in nontransgenic cells were detected in transgenic plants. More than 95% of the total residues were extractable by water, the formation of nonpolar and nonextractable residues was below 4%. At harvest the highest amounts of the residues were found in the treated leaves (4-15%), the lowest in the kernals (0,07-0,6%). According to these results total residues of PPT will not exceed the official tolerances in transgenic rape and maize if application follows good agricultural practice. (orig.)

  5. Terrific Trichomes (and Other Specialised Cells) in African Violets: How to Get a Lot from One Plant in the Classroom

    Science.gov (United States)

    Cottrell, Vicki M.

    2013-01-01

    African violet (genus "Saintpaulia") was identified as a particularly suitable genus for the study of specialised plant cells in the classroom using microscopes. The techniques described here involve simple preparation without staining. The cells and structures that can be investigated include: trichomes (hairs); stomata; guard cells and…

  6. An assessment of plant biointrusion at the Uranium Mill Tailings Remedial Action Project rock-covered disposal cells

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    This study is one of a number of special studies that have been conducted regarding various aspects of the Uranium Mill Tailings Remedial Action (UMTRA) Project. This special study was proposed following routine surveillance and maintenance surveys and observations reported in a special study of vegetative covers (DOE, 1988), in which plants were observed growing up through the rock erosion layer at recently completed disposal cells. Some of the plants observed were deep-rooted woody species, and questions concerning root intrusion into disposal cells and the need to control plant growth were raised. The special study discussed in this report was designed to address some of the ramifications of plant growth on disposal cells that have rock covers. The NRC has chosen rock covers over vegetative covers in the arid western United States because licenses cannot substantiate that the vegetative covers will be significantly greater than 30 percent and preferably 70 percent,'' which is the amount of vegetation required to reduce flow to a point of stability.'' The potential impacts of vegetation growing in rock covers are not addressed by the NRC (1990). The objectives, then, of this study were to determine the species of plants growing on two rock-covered disposal cells, study the rooting pattern of plants on these cells, and identify possible impacts of plant root penetration on these and other UMTRA Project rock-covered cells.

  7. An assessment of plant biointrusion at the Uranium Mill Tailings Remedial Action Project rock-covered disposal cells

    International Nuclear Information System (INIS)

    This study is one of a number of special studies that have been conducted regarding various aspects of the Uranium Mill Tailings Remedial Action (UMTRA) Project. This special study was proposed following routine surveillance and maintenance surveys and observations reported in a special study of vegetative covers (DOE, 1988), in which plants were observed growing up through the rock erosion layer at recently completed disposal cells. Some of the plants observed were deep-rooted woody species, and questions concerning root intrusion into disposal cells and the need to control plant growth were raised. The special study discussed in this report was designed to address some of the ramifications of plant growth on disposal cells that have rock covers. The NRC has chosen rock covers over vegetative covers in the arid western United States because licenses cannot substantiate that the vegetative covers ''will be significantly greater than 30 percent and preferably 70 percent,'' which is the amount of ''vegetation required to reduce flow to a point of stability.'' The potential impacts of vegetation growing in rock covers are not addressed by the NRC (1990). The objectives, then, of this study were to determine the species of plants growing on two rock-covered disposal cells, study the rooting pattern of plants on these cells, and identify possible impacts of plant root penetration on these and other UMTRA Project rock-covered cells

  8. 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.

  9. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development.

    Directory of Open Access Journals (Sweden)

    Valera V Peremyslov

    Full Text Available Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI, cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6-1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development.

  10. Recognition and degradation of plant cell wall polysaccharides by two human gut symbionts.

    Directory of Open Access Journals (Sweden)

    Eric C Martens

    2011-12-01

    Full Text Available Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for catabolism of many complex carbohydrates. However, the role of these systems in degrading the chemically diverse repertoire of plant cell wall glycans remains unknown. Here we show that two closely related human gut Bacteroides, B. thetaiotaomicron and B. ovatus, are capable of utilizing nearly all of the major plant and host glycans, including rhamnogalacturonan II, a highly complex polymer thought to be recalcitrant to microbial degradation. Transcriptional profiling and gene inactivation experiments revealed the identity and specificity of the polysaccharide utilization loci (PULs that encode individual Sus-like systems that target various plant polysaccharides. Comparative genomic analysis indicated that B. ovatus possesses several unique PULs that enable degradation of hemicellulosic polysaccharides, a phenotype absent from B. thetaiotaomicron. In contrast, the B. thetaiotaomicron genome has been shaped by increased numbers of PULs involved in metabolism of host mucin O-glycans, a phenotype that is undetectable in B. ovatus. Binding studies of the purified sensor domains of PUL-associated hybrid two-component systems in conjunction with transcriptional analyses demonstrate that complex oligosaccharides provide the regulatory cues that induce PUL activation and that each PUL is highly specific for a defined cell wall polymer. These results provide a view of how these species have diverged into different carbohydrate niches by evolving genes that target

  11. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development

    Science.gov (United States)

    Peremyslov, Valera V.; Cole, Rex A.; Fowler, John E.; Dolja, Valerian V.

    2015-01-01

    Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6–1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development. PMID:26426395

  12. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

  13. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth. PMID:25907061

  14. Possible dual regulatory circuits involving AtS6K1 in the regulation of plant cell cycle and growth.

    Science.gov (United States)

    Shin, Yun-jeong; Kim, Sunghan; Du, Hui; Choi, Soonyoung; Verma, Desh Pal S; Cheon, Choong-Ill

    2012-05-01

    The role of Arabidopsis S6 Kinase 1 (AtS6K1), a downstream target of TOR kinase, in controlling plant growth and ribosome biogenesis was characterized after generating transgenic plants expressing AtS6K1 under auxin-inducible promoter. Down regulation of selected cell cycle regulatory genes upon auxin treatment was observed in the transgenic plants, confirming the negative regulatory role of AtS6K1 in the plant cell cycle progression reported earlier. Callus tissues established from these transgenic plants grew to larger cell masses with more number of enlarged cells than untransformed control, demonstrating functional implication of AtS6K1 in the control of plant cell size. The observed negative correlation between the expression of AtS6K1 and the cell cycle regulatory genes, however, was completely reversed in protoplasts generated from the transgenic plants expressing AtS6K1, suggesting a possible existence of dual regulatory mechanism of the plant cell cycle regulation mediated by AtS6K1. An alternative method of kinase assay, termed "substrate-mediated kinase pull down", was employed to examine the additional phosphorylation on other domains of AtS6K1 and verified the phosphorylation of both amino- and carboxy-terminal domains, which is a novel finding regarding the phosphorylation target sites on plant S6Ks by upstream regulatory kinases. In addition, this kinase assay under the stress conditions revealed the salt- and sugar-dependencies of AtS6K1 phosphorylations.

  15. Measuring the osmotic water permeability coefficient (Pf) of spherical cells: isolated plant protoplasts as an example.

    Science.gov (United States)

    Shatil-Cohen, Arava; Sibony, Hadas; Draye, Xavier; Chaumont, François; Moran, Nava; Moshelion, Menachem

    2014-10-08

    Studying AQP regulation mechanisms is crucial for the understanding of water relations at both the cellular and the whole plant levels. Presented here is a simple and very efficient method for the determination of the osmotic water permeability coefficient (P(f)) in plant protoplasts, applicable in principle also to other spherical cells such as frog oocytes. The first step of the assay is the isolation of protoplasts from the plant tissue of interest by enzymatic digestion into a chamber with an appropriate isotonic solution. The second step consists of an osmotic challenge assay: protoplasts immobilized on the bottom of the chamber are submitted to a constant perfusion starting with an isotonic solution and followed by a hypotonic solution. The cell swelling is video recorded. In the third step, the images are processed offline to yield volume changes, and the time course of the volume changes is correlated with the time course of the change in osmolarity of the chamber perfusion medium, using a curve fitting procedure written in Matlab (the 'PfFit'), to yield P(f).

  16. Plant and microorganisms support media for electricity generation in biological fuel cells with living hydrophytes.

    Science.gov (United States)

    Salinas-Juárez, María Guadalupe; Roquero, Pedro; Durán-Domínguez-de-Bazúa, María Del Carmen

    2016-12-01

    Plant support media may impact power output in a biological fuel cell with living plants, due to the physical and biochemical processes that take place in it. A material for support medium should provide the suitable conditions for the robust microbial growth and its metabolic activity, degrading organic matter and other substances; and, transferring electrons to the anode. To consider the implementation of this type of bio-electrochemical systems in constructed wetlands, this study analyzes the electrochemical behavior of biological fuel cells with the vegetal species Phragmites australis, by using two different support media: graphite granules and a volcanic slag, commonly known as tezontle (stone as light as hair, from the Aztec or Nahuatl language). Derived from the results, both, graphite and tezontle have the potential to be used as support medium for plants and microorganisms supporting a maximum power of 26.78mW/m(2) in graphite reactors. These reactors worked under mixed control: with ohmic and kinetic resistances of the same order of magnitude. Tezontle reactors operated under kinetic control with a high activation resistance supplying 9.73mW/m(2). These performances could be improved with stronger bacterial populations in the reactor, to ensure the rapid depletion of substrate.

  17. Rapid and simple isolation of vascular, epidermal and mesophyll cells from plant leaf tissue.

    Science.gov (United States)

    Endo, Motomu; Shimizu, Hanako; Araki, Takashi

    2016-08-01

    To understand physiological phenomena at the tissue level, elucidation of tissue-specific molecular functions in vivo is required. As an example of the current state of affairs, many genes in plants have been reported to have discordant levels of expression between bulk tissues and the specific tissues in which the respective gene product is principally functional. The principal challenge in deciphering such tissue-specific functions lies in separating tissues with high spatiotemporal resolution to evaluate accurate gene expression profiles. Here, we provide a simple and rapid tissue isolation protocol to isolate all three major leaf tissues (mesophyll, vasculature and epidermis) from Arabidopsis within 30 min with high purity. On the basis of the different cell-to-cell connectivities of tissues, the mesophyll isolation is achieved by making protoplasts, and the vasculature and epidermis isolation is achieved through sonication and enzymatic digestion of leaves. We have successfully tested the protocol on several other plant species, including crop plants such as soybean, tomato and wheat. Furthermore, isolated tissues can be used not only for tissue-specific transcriptome assays but also potentially for tissue-specific proteome and methylome assays. PMID:27388555

  18. Expression of a begomoviral DNAβ gene in transgenic Nicotiana plants induced abnormal cell division

    Institute of Scientific and Technical Information of China (English)

    CUI Xiao-feng; LI Yun-qin; HU Dong-wei; ZHOU Xue-ping

    2005-01-01

    An increasing number of monopartite begomoviruses are being identified that a satellite molecule (DNAβ) is required to induce typical symptoms in host plants. DNAβ encodes a single gene (termed βC1) encoded in the complementary-sense. We have produced transgenic Nicotiana benthamiana and N. tabacum plants expressing theβC1 gene of a DNAβ associated with Tomato yellow leaf curl China virus (TYLCCNV), under the control of the Cauliflower mosaic virus 35S promoter. Transgenic plants expressing βC1 showed severe developmental abnormalities in both species. Microscopic analysis of sections of both transgenic and non-transgenic N. tabacum leaves showed abnormal outgrowths of transgenic N. tabacum to be due to disorganized cell division (hyperplasia) of spongy and palisade parenchyma. Immuno-gold labeling of sections with a polyclonal antibody against the βC1 protein showed that the βC1 protein accumulated in the nuclei of cells. The possible biological function of the βC1 protein was discussed.

  19. Dynamic response of prevacuolar compartments to brefeldin a in plant cells.

    Science.gov (United States)

    Tse, Yu Chung; Lo, Sze Wan; Hillmer, Stefan; Dupree, Paul; Jiang, Liwen

    2006-12-01

    Little is known about the dynamics and molecular components of plant prevacuolar compartments (PVCs) in the secretory pathway. Using transgenic tobacco (Nicotiana tabacum) Bright-Yellow-2 (BY-2) cells expressing membrane-anchored yellow fluorescent protein (YFP) reporters marking Golgi or PVCs, we have recently demonstrated that PVCs are mobile multivesicular bodies defined by vacuolar sorting receptor proteins. Here, we demonstrate that Golgi and PVCs have different sensitivity in response to brefeldin A (BFA) treatment in living tobacco BY-2 cells. BFA at low concentrations (5-10 microg mL(-1)) induced YFP-marked Golgi stacks to form both endoplasmic reticulum-Golgi hybrid structures and BFA-induced aggregates, but had little effect on YFP-marked PVCs in transgenic BY-2 cells at both confocal and immunogold electron microscopy levels. However, BFA at high concentrations (50-100 microg mL(-1)) caused both YFP-marked Golgi stacks and PVCs to form aggregates in a dose- and time-dependent manner. Normal Golgi or PVC signals can be recovered upon removal of BFA from the culture media. Confocal immunofluorescence and immunogold electron microscopy studies with specific organelle markers further demonstrate that the PVC aggregates are distinct, but physically associated, with Golgi aggregates in BFA-treated cells and that PVCs might lose their internal vesicle structures at high BFA concentration. In addition, vacuolar sorting receptor-marked PVCs in root-tip cells of tobacco, pea (Pisum sativum), mung bean (Vigna radiata), and Arabidopsis (Arabidopsis thaliana) upon BFA treatment are also induced to form similar aggregates. Thus, we have demonstrated that the effects of BFA are not limited to endoplasmic reticulum and Golgi, but extend to PVC in the endomembrane system, which might provide a quick tool for distinguishing Golgi from PVC for its identification and characterization, as well as a possible new tool in studying PVC-mediated protein traffic in plant cells

  20. Stringent control of cytoplasmic Ca2+ in guard cells of intact plants compared to their counterparts in epidermal strips or guard cell protoplasts.

    Science.gov (United States)

    Levchenko, V; Guinot, D R; Klein, M; Roelfsema, M R G; Hedrich, R; Dietrich, P

    2008-01-01

    Cytoplasmic calcium elevations, transients, and oscillations are thought to encode information that triggers a variety of physiological responses in plant cells. Yet Ca(2+) signals induced by a single stimulus vary, depending on the physiological state of the cell and experimental conditions. We compared Ca(2+) homeostasis and stimulus-induced Ca(2+) signals in guard cells of intact plants, epidermal strips, and isolated protoplasts. Single-cell ratiometric imaging with the Ca(2+)-sensitive dye Fura 2 was applied in combination with electrophysiological recordings. Guard cell protoplasts were loaded with Fura 2 via a patch pipette, revealing a cytoplasmic free Ca(2+) concentration of around 80 nM at -47 mV. Upon hyperpolarization of the plasma membrane to -107 mV, the Ca(2+) concentration increased to levels exceeding 400 nM. Intact guard cells were able to maintain much lower cytoplasmic free Ca(2+) concentrations at hyperpolarized potentials, the average concentration at -100 mV was 183 and 90 nM in epidermal strips and intact plants, respectively. Further hyperpolarization of the plasma membrane to -160 mV induced a sustained rise of the guard cell cytoplasmic Ca(2+) concentration, which slowly returned to the prestimulus level in intact plants but not in epidermal strips. Our results show that cytoplasmic Ca(2+) concentrations are stringently controlled in guard cells of intact plants but become increasingly more sensitive to changes in the plasma membrane potential in epidermal strips and isolated protoplasts.

  1. Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study

    OpenAIRE

    Anastasiia I. Evkaikina; Marina A. Romanova; Olga V. Voitsekhovskaja

    2014-01-01

    Plasmodesmata (PD) serve for the exchange of information in form of miRNA, proteins, and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis) PD, which can connect any adjacent cells, ...

  2. Cytotoxicity of Elaoephorbia drupifera and other Cameroonian medicinal plants against drug sensitive and multidrug resistant cancer cells

    OpenAIRE

    Kuete, Victor; Voukeng, Igor K; Tsobou, Roger; Mbaveng, Armelle T; Wiench, Benjamin; Beng, Veronique P; Efferth, Thomas

    2013-01-01

    Background Multidrug resistance (MDR) is a major hurdle for cancer treatment worldwide and accounts for chemotherapy failure in over 90% of patients with metastatic cancer. Evidence of the cytotoxicity of Cameroonian plants against cancer cell lines including MDR phenotypes is been intensively and progressively provided. The present work was therefore designed to evaluate the cytotoxicity of the methanol extracts of twenty-two Cameroonian medicinal plants against sensitive and MDR cancer cell...

  3. MYB3Rs, plant homologs of Myb oncoproteins, control cell cycle-regulated transcription and form DREAM-like complexes.

    Science.gov (United States)

    Kobayashi, Kosuke; Suzuki, Toshiya; Iwata, Eriko; Magyar, Zoltán; Bögre, László; Ito, Masaki

    2015-01-01

    Plant MYB3R transcription factors, homologous to Myb oncoproteins, regulate the genes expressed at G2 and M phases in the cell cycle. Recent studies showed that MYB3Rs constitute multiprotein complexes that may correspond to animal complexes known as DREAM or dREAM. Discovery of the putative homologous complex in plants uncovered their significant varieties in structure, function, dynamics, and heterogeneity, providing insight into conserved and diversified aspects of cell cycle-regulated gene transcription.

  4. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions.

    Science.gov (United States)

    Houston, Kelly; Tucker, Matthew R; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  5. The Plant Cell Wall: A Complex and Dynamic Structure As Revealed by the Responses of Genes under Stress Conditions

    Science.gov (United States)

    Houston, Kelly; Tucker, Matthew R.; Chowdhury, Jamil; Shirley, Neil; Little, Alan

    2016-01-01

    The plant cell wall has a diversity of functions. It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens. The cell wall must also retain some flexibility, such that when subjected to developmental, biotic, or abiotic stimuli it can be rapidly remodeled in response. Genes encoding enzymes capable of synthesizing or hydrolyzing components of the plant cell wall show differential expression when subjected to different stresses, suggesting they may facilitate stress tolerance through changes in cell wall composition. In this review we summarize recent genetic and transcriptomic data from the literature supporting a role for specific cell wall-related genes in stress responses, in both dicot and monocot systems. These studies highlight that the molecular signatures of cell wall modification are often complex and dynamic, with multiple genes appearing to respond to a given stimulus. Despite this, comparisons between publically available datasets indicate that in many instances cell wall-related genes respond similarly to different pathogens and abiotic stresses, even across the monocot-dicot boundary. We propose that the emerging picture of cell wall remodeling during stress is one that utilizes a common toolkit of cell wall-related genes, multiple modifications to cell wall structure, and a defined set of stress-responsive transcription factors that regulate them. PMID:27559336

  6. Pectic substances from soybean cell walls distinguish themselves from other plant cell wall pectins

    NARCIS (Netherlands)

    Huisman, M.M.H.; Schols, H.A.; Voragen, A.G.J.

    2003-01-01

    The uncommon structural features of soybean cell wall pectic substances explain their resistance to degradation by enzymes generally used to degrade this kind of polymers, and indicates that a search for new enzymes is required to enable enzymatic modification of these polysaccharides

  7. Expression of the major mugwort pollen allergen Art v 1 in tobacco plants and cell cultures: problems and perspectives for allergen production in plants.

    Science.gov (United States)

    Siegert, Marc; Pertl-Obermeyer, Heidi; Gadermaier, Gabriele; Ferreira, Fatima; Obermeyer, Gerhard

    2012-03-01

    An economic and cheap production of large amounts of recombinant allergenic proteins might become a prerequisite for the common use of microarray-based diagnostic allergy assays which allow a component-specific diagnosis. A molecular pharming strategy was applied to express the major allergen of Artemisia vulgaris pollen, Art v 1, in tobacco plants and tobacco cell cultures. The original Art v 1 with its endogenous signal peptide which directs Art v 1 to the secretory pathway, was expressed in transiently transformed tobacco leaves but was lost in stable transformed tobacco plants during the alternation of generations. Using a light-regulated promoter and "hiding" the recombinant Art v 1 in the ER succeeded in expression of Art v 1 over three generations of tobacco plants and in cell cultures generated from stable transformed plants. However, the amounts of the recombinant allergen were sufficient for analysis but not high enough to allow an economic production. Although molecular pharming has been shown to work well for the production of non-plant therapeutic proteins, it might be less efficient for closely related plant proteins. PMID:22159963

  8. Expression of the major mugwort pollen allergen Art v 1 in tobacco plants and cell cultures: problems and perspectives for allergen production in plants.

    Science.gov (United States)

    Siegert, Marc; Pertl-Obermeyer, Heidi; Gadermaier, Gabriele; Ferreira, Fatima; Obermeyer, Gerhard

    2012-03-01

    An economic and cheap production of large amounts of recombinant allergenic proteins might become a prerequisite for the common use of microarray-based diagnostic allergy assays which allow a component-specific diagnosis. A molecular pharming strategy was applied to express the major allergen of Artemisia vulgaris pollen, Art v 1, in tobacco plants and tobacco cell cultures. The original Art v 1 with its endogenous signal peptide which directs Art v 1 to the secretory pathway, was expressed in transiently transformed tobacco leaves but was lost in stable transformed tobacco plants during the alternation of generations. Using a light-regulated promoter and "hiding" the recombinant Art v 1 in the ER succeeded in expression of Art v 1 over three generations of tobacco plants and in cell cultures generated from stable transformed plants. However, the amounts of the recombinant allergen were sufficient for analysis but not high enough to allow an economic production. Although molecular pharming has been shown to work well for the production of non-plant therapeutic proteins, it might be less efficient for closely related plant proteins.

  9. Target or barrier? The cell wall of early- and later- diverging plants vs cadmium toxicity: differences in the response mechanisms

    Directory of Open Access Journals (Sweden)

    Luigi eParrotta

    2015-03-01

    Full Text Available Increasing industrialization and urbanization result in emission of pollutants in the environment including toxic heavy metals, as cadmium and lead. Among the different heavy metals contaminating the environment, cadmium raises great concern, as it is ecotoxic and as such can heavily impact ecosystems. The cell wall is the first structure of plant cells to come in contact with heavy metals. Its composition, characterized by proteins, polysaccharides and in some instances lignin and other phenolic compounds, confers the ability to bind non-covalently and/or covalently heavy metals via functional groups. A strong body of evidence in the literature has shown the role of the cell wall in heavy metal response: it sequesters heavy metals, but at the same time its synthesis and composition can be severely affected. The present review analyzes the dual property of plant cell walls, i.e. barrier and target of heavy metals, by taking Cd toxicity as example. Following a summary of the known physiological and biochemical responses of plants to Cd, the review compares the wall-related mechanisms in early- and later-diverging land plants, by considering the diversity in cell wall composition. By doing so, common as well as unique response mechanisms to metal/cadmium toxicity are identified among plant phyla and discussed. After discussing the role of hyperaccumulators’ cell walls as a particular case, the review concludes by considering important aspects for plant engineering.

  10. Pep1, a secreted effector protein of Ustilago maydis, is required for successful invasion of plant cells.

    Directory of Open Access Journals (Sweden)

    Gunther Doehlemann

    2009-02-01

    Full Text Available The basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1, that is essential for penetration. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, Deltapep1 mutants arrest during penetration of the epidermal cell and elicit a strong plant defense response. Using Affymetrix maize arrays, we identified 116 plant genes which are differentially regulated in Deltapep1 compared to wild type infections. Most of these genes are related to plant defense. By in vivo immunolocalization, live-cell imaging and plasmolysis approaches, we detected Pep1 in the apoplastic space as well as its accumulation at sites of cell-to-cell passages. Site-directed mutagenesis identified two of the four cysteine residues in Pep1 as essential for function, suggesting that the formation of disulfide bridges is crucial for proper protein folding. The barley covered smut fungus Ustilago hordei contains an ortholog of pep1 which is needed for penetration of barley and which is able to complement the U. maydis Deltapep1 mutant. Based on these results, we conclude that Pep1 has a conserved function essential for establishing compatibility that is not restricted to the U. maydis / maize interaction.

  11. Solid oxide fuel cell power plant having a bootstrap start-up system

    Energy Technology Data Exchange (ETDEWEB)

    Lines, Michael T

    2016-10-04

    The bootstrap start-up system (42) achieves an efficient start-up of the power plant (10) that minimizes formation of soot within a reformed hydrogen rich fuel. A burner (48) receives un-reformed fuel directly from the fuel supply (30) and combusts the fuel to heat cathode air which then heats an electrolyte (24) within the fuel cell (12). A dilute hydrogen forming gas (68) cycles through a sealed heat-cycling loop (66) to transfer heat and generated steam from an anode side (32) of the electrolyte (24) through fuel processing system (36) components (38, 40) and back to an anode flow field (26) until fuel processing system components (38, 40) achieve predetermined optimal temperatures and steam content. Then, the heat-cycling loop (66) is unsealed and the un-reformed fuel is admitted into the fuel processing system (36) and anode flow (26) field to commence ordinary operation of the power plant (10).

  12. Extracellular peptidase hunting for improvement of protein production in plant cells and roots

    Directory of Open Access Journals (Sweden)

    Jérôme eLallemand

    2015-02-01

    Full Text Available Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion, in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA and human serum immunoglobulins G (hIgGs. Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing.

  13. Identification and localization of transformed cells in agrobacterium tumefaciens-induced plant tumors

    Science.gov (United States)

    Rezmer; Schlichting; Wachter; Ullrich

    1999-10-01

    Agrobacterium tumefaciens-induced tumors of dicotyledonous plants consist of well-defined vascular bundle-like structures originating from transformed cells. The current view that 25% of the tumor cells are transformed has been re-investigated by using beta-glucuronidase (gus)-gene-containing wild-type bacteria (A281 p35S gus-int). Regularly growing stem and leaf tumors showed irregular GUS-staining patterns in the different plant species, Ricinus communis L., Cucurbita maxima L., Vicia faba L. and Kalanchoe daigremontiana Hamet et Perrier. Variable staining and inconsistency between staining and tumor growth suggested an inhibition of gus expression. By polymerase chain reaction (PCR) and reverse transcriptase-PCR analyses it became evident that gus is also integrated into the DNA of unstainable tumor parts but not expressed. These results and area calculations of tissues unable to contain the bacterial transferred-DNA with gus provide strong evidence that in A. tumefaciens-induced tumors most cells, or even all, are transformed, i.e. ca. 100%. PMID:10550620

  14. Biotransformation of alpha- and 6beta-santonin by fungus and plant cell cultures.

    Science.gov (United States)

    Yang, L; Dai, J; Sakai, J-I; Ando, M

    2006-06-01

    One fungus, Abisidia coerulea IFO 4011, and suspended cell cultures of one plant, Asparagus officinalis, were employed to bioconvert alpha- and 6beta-santonin. Incubation of alpha-santonin with the cell cultures of the fungus afforded two products, 11beta-hydroxy-alpha-santonin (1, in 76.5% yield) and 8alpha-hydroxy-alpha-santonin (2, in 2.0% yield). And from 6beta-santonin, four major products (3, 4, 5 and 6) and four minor products (7, 8, 9 and 10) were obtained, including 8alpha-hydroxylated products in trace yields. Very interestingly, a skeletal rearrangement occurred and a guaiane product (13) formed in a very low yield when alpha-santonin incubating with A.officinalis cell cultures, while not in the case of 6beta-santonin as substrate. Among the obtained 15 products, 2, 7, 8, 9, 10 and 12 are new compounds. The fact of 8alpha hydroxylation of santonin enables the formation of 8,12-eudesmanolide instead of 6,12-eudesmanolide and some useful modification at C-8 position. In addition, these reactions would provide evidence for the biogenesis between different types of eudesmane and/or guaiane compounds in the plants in nature. PMID:16864442

  15. 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).

  16. Model system for plant cell biology: GFP imaging in living onion epidermal cells

    Science.gov (United States)

    Scott, A.; Wyatt, S.; Tsou, P. L.; Robertson, D.; Allen, N. S.

    1999-01-01

    The ability to visualize organelle localization and dynamics is very useful in studying cellular physiological events. Until recently, this has been accomplished using a variety of staining methods. However, staining can give inaccurate information due to nonspecific staining, diffusion of the stain or through toxic effects. The ability to target green fluorescent protein (GFP) to various organelles allows for specific labeling of organelles in vivo. The disadvantages of GFP thus far have been the time and money involved in developing stable transformants or maintaining cell cultures for transient expression. In this paper, we present a rapid transient expression system using onion epidermal peels. We have localized GFP to various cellular compartments (including the cell wall) to illustrate the utility of this method and to visualize dynamics of these compartments. The onion epidermis has large, living, transparent cells in a monolayer, making them ideal for visualizing GFP. This method is easy and inexpensive, and it allows for testing of new GFP fusion proteins in a living tissue to determine deleterious effects and the ability to express before stable transformants are attempted.

  17. How endogenous plant cell-wall degradation mechanisms can help achieve higher efficiency in saccharification of biomass.

    Science.gov (United States)

    Tavares, Eveline Q P; De Souza, Amanda P; Buckeridge, Marcos S

    2015-07-01

    Cell-wall recalcitrance to hydrolysis still represents one of the major bottlenecks for second-generation bioethanol production. This occurs despite the development of pre-treatments, the prospect of new enzymes, and the production of transgenic plants with less-recalcitrant cell walls. Recalcitrance, which is the intrinsic resistance to breakdown imposed by polymer assembly, is the result of inherent limitations in its three domains. These consist of: (i) porosity, associated with a pectin matrix impairing trafficking through the wall; (ii) the glycomic code, which refers to the fine-structural emergent complexity of cell-wall polymers that are unique to cells, tissues, and species; and (iii) cellulose crystallinity, which refers to the organization in micro- and/or macrofibrils. One way to circumvent recalcitrance could be by following cell-wall hydrolysis strategies underlying plant endogenous mechanisms that are optimized to precisely modify cell walls in planta. Thus, the cell-wall degradation that occurs during fruit ripening, abscission, storage cell-wall mobilization, and aerenchyma formation are reviewed in order to highlight how plants deal with recalcitrance and which are the routes to couple prospective enzymes and cocktail designs with cell-wall features. The manipulation of key enzyme levels in planta can help achieving biologically pre-treated walls (i.e. less recalcitrant) before plants are harvested for bioethanol production. This may be helpful in decreasing the costs associated with producing bioethanol from biomass. PMID:25922489

  18. Thermo-economic analysis of a solid oxide fuel cell and steam injected gas turbine plant integrated with woodchips gasification

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2014-01-01

    This paper presents a thermo-economic analysis of an integrated biogas-fueled solid oxide fuel cell (SOFC) system for electric power generation. Basic plant layout consists of a gasification plant (GP), an SOFC and a retrofitted steam-injected gas turbine (STIG). Different system configurations...... and simulations are presented and investigated. A parallel analysis for simpler power plants, combining GP, SOFC, and hybrid gas turbine (GT) is carried out to obtain a reference point for thermodynamic results. Thermodynamic analysis shows energetic and exergetic efficiencies for optimized plant above 53% and 43...

  19. A rapid and robust assay for detection of S-phase cell cycle progression in plant cells and tissues by using ethynyl deoxyuridine

    Directory of Open Access Journals (Sweden)

    Horváth Gábor V

    2010-01-01

    Full Text Available Abstract Background Progress in plant cell cycle research is highly dependent on reliable methods for detection of cells replicating DNA. Frequency of S-phase cells (cells in DNA synthesis phase is a basic parameter in studies on the control of cell division cycle and the developmental events of plant cells. Here we extend the microscopy and flow cytometry applications of the recently developed EdU (5-ethynyl-2'-deoxyuridine-based S-phase assay to various plant species and tissues. We demonstrate that the presented protocols insure the improved preservation of cell and tissue structure and allow significant reduction in assay duration. In comparison with the frequently used detection of bromodeoxyuridine (BrdU and tritiated-thymidine incorporation, this new methodology offers several advantages as we discuss here. Results Applications of EdU-based S-phase assay in microscopy and flow cytometry are presented by using cultured cells of alfalfa, Arabidopsis, grape, maize, rice and tobacco. We present the advantages of EdU assay as compared to BrdU-based replication assay and demonstrate that EdU assay -which does not require plant cell wall digestion or DNA denaturation steps, offers reduced assay duration and better preservation of cellular, nuclear and chromosomal morphologies. We have also shown that fast and efficient EdU assay can also be an efficient tool for dual parameter flow cytometry analysis and for quantitative assessment of replication in thick root samples of rice. Conclusions In plant cell cycle studies, EdU-based S-phase detection offers a superior alternative to the existing S-phase assays. EdU method is reliable, versatile, fast, simple and non-radioactive and it can be readily applied to many different plant systems.

  20. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens

    DEFF Research Database (Denmark)

    Moller, Isabel Eva; de Fine Licht, Henrik Hjarvard; Harholt, Jesper;

    2011-01-01

    The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus......, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste...

  1. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    Science.gov (United States)

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-01

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  2. Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant

    OpenAIRE

    Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

    2014-01-01

    This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The prop...

  3. Displacement of organelles in plant gravireceptor cells by vibrational forces and ultrasound.

    Science.gov (United States)

    Kuznetsov, O.; Nechitailo, G.; Kuznetsov, A.

    Plant gravity perception can be studied by displacing statoliths inside receptor cells by forces other than gravity. Due to mechanical heterogeneity of statocytes various ponderomotive forces can be used for this purpose. In a plant subjected to non- symmetric vibrations statoliths experience inertial force proportional to the difference between their density and that of cytoplasm and to the instantaneous acceleration of the cell. This force causes cyclic motion of statoliths relative to cytoplasm and, depending on the profile of oscillations, can result in a net displacement of them (due to complex rheology of the cell interior), similar to sedimentation. This can be described as "vibrational" ponderomotive force acting on the statoliths. Vertically growing Arabidopsis seedlings, subjected to horizontal, sawtooth shaped oscillations (250 Hz, 1.5 mm amplitude), showed 17+/-2o root curvature toward and shoot curvature of 11+/-3o against the stronger acceleration. When the polarity of the oscillations was reversed, the direction of curvature of shoots and roots was also reversed. Control experiments with starchless mutants (TC7) produced no net curvature, which indicates that dense starch-filled amyloplasts are needed for the effect. These control experiments also eliminate touch-induced reactions or other side-effects as the cause of the curvature. Linum roots curved 25+/-7o . Ceratodon protonemata subjected to the same oscillations have shown displacement of plastids and curvature consistent with the pattern observed during graviresponse: positively gravitropic wwr mutant curved in the direction of the plastid displacement, WT curved in the opposite direction. Acoustic ponderomotive forces, originating from transfer of a sonic beam momentum to the medium due to sound scattering and attenuation in a mechanically heterogeneous system, also can displace statoliths. Vertical flax seedlings curved away from the ultrasonic source (800 kHz, 0.1 W/cm2 ) presumably as a

  4. Cytoplasmic streaming in plant cells emerges naturally by microfilament self-organization.

    Science.gov (United States)

    Woodhouse, Francis G; Goldstein, Raymond E

    2013-08-27

    Many cells exhibit large-scale active circulation of their entire fluid contents, a process termed cytoplasmic streaming. This phenomenon is particularly prevalent in plant cells, often presenting strikingly regimented flow patterns. The driving mechanism in such cells is known: myosin-coated organelles entrain cytoplasm as they process along actin filament bundles fixed at the periphery. Still unknown, however, is the developmental process that constructs the well-ordered actin configurations required for coherent cell-scale flow. Previous experimental works on streaming regeneration in cells of Characean algae, whose longitudinal flow is perhaps the most regimented of all, hint at an autonomous process of microfilament self-organization driving the formation of streaming patterns during morphogenesis. Working from first principles, we propose a robust model of streaming emergence that combines motor dynamics with both microscopic and macroscopic hydrodynamics to explain how several independent processes, each ineffectual on its own, can reinforce to ultimately develop the patterns of streaming observed in the Characeae and other streaming species.

  5. Plastid osmotic stress influences cell differentiation at the plant shoot apex.

    Science.gov (United States)

    Wilson, Margaret E; Mixdorf, Matthew; Berg, R Howard; Haswell, Elizabeth S

    2016-09-15

    The balance between proliferation and differentiation in the plant shoot apical meristem is controlled by regulatory loops involving the phytohormone cytokinin and stem cell identity genes. Concurrently, cellular differentiation in the developing shoot is coordinated with the environmental and developmental status of plastids within those cells. Here, we employ an Arabidopsis thaliana mutant exhibiting constitutive plastid osmotic stress to investigate the molecular and genetic pathways connecting plastid osmotic stress with cell differentiation at the shoot apex. msl2 msl3 mutants exhibit dramatically enlarged and deformed plastids in the shoot apical meristem, and develop a mass of callus tissue at the shoot apex. Callus production in this mutant requires the cytokinin receptor AHK2 and is characterized by increased cytokinin levels, downregulation of cytokinin signaling inhibitors ARR7 and ARR15, and induction of the stem cell identity gene WUSCHEL Furthermore, plastid stress-induced apical callus production requires elevated plastidic reactive oxygen species, ABA biosynthesis, the retrograde signaling protein GUN1, and ABI4. These results are consistent with a model wherein the cytokinin/WUS pathway and retrograde signaling control cell differentiation at the shoot apex. PMID:27510974

  6. Three-Dimensional, Live-Cell Imaging of Chromatin Dynamics in Plant Nuclei Using Chromatin Tagging Systems.

    Science.gov (United States)

    Hirakawa, Takeshi; Matsunaga, Sachihiro

    2016-01-01

    In plants, chromatin dynamics spatiotemporally change in response to various environmental stimuli. However, little is known about chromatin dynamics in the nuclei of plants. Here, we introduce a three-dimensional, live-cell imaging method that can monitor chromatin dynamics in nuclei via a chromatin tagging system that can visualize specific genomic loci in living plant cells. The chromatin tagging system is based on a bacterial operator/repressor system in which the repressor is fused to fluorescent proteins. A recent refinement of promoters for the system solved the problem of gene silencing and abnormal pairing frequencies between operators. Using this system, we can detect the spatiotemporal dynamics of two homologous loci as two fluorescent signals within a nucleus and monitor the distance between homologous loci. These live-cell imaging methods will provide new insights into genome organization, development processes, and subnuclear responses to environmental stimuli in plants. PMID:27557696

  7. The Utilization of Plant Facilities on the International Space Station—The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions

    Directory of Open Access Journals (Sweden)

    Ann-Iren Kittang Jost

    2015-01-01

    Full Text Available In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8–14 days on single cells (plant protoplasts. Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station.

  8. The Utilization of Plant Facilities on the International Space Station-The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions.

    Science.gov (United States)

    Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning

    2015-01-20

    In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g) conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8-14 days) on single cells (plant protoplasts). Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station.

  9. Fuel cell power plants for decentralised CHP applications; Brennstoffzellen-Kraftwerke fuer dezentrale KWK-Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Ohmer, Martin; Mattner, Katja [FuelCell Energy Solutions GmbH, Dresden (Germany)

    2015-06-01

    Fuel cells are the most efficient technology to convert chemical energy into electricity and heat and thus they could have a major impact on reducing fuel consumption, CO{sub 2} and other emissions (NO{sub x}, SO{sub x} and particulate matter). Fired with natural or biogas and operated with an efficiency of up to 49 % a significant reduction of fuel costs can be achieved in decentralised applications. Combined heat and power (CHP) configurations add value for a wide range of industrial applications. The exhaust heat of approximately 400 C can be utilised for heating purposes and the production of steam. Besides, it can be also fed directly to adsorption cooling systems. With more than 110 fuel cell power plants operating worldwide, this technology is a serious alternative to conventional gas turbines or gas engines.

  10. Overexpression of the carbohydrate binding module of strawberry expansin2 in Arabidopsis thaliana modifies plant growth and cell wall metabolism.

    Science.gov (United States)

    Nardi, Cristina F; Villarreal, Natalia M; Rossi, Franco R; Martínez, Santiago; Martínez, Gustavo A; Civello, Pedro M

    2015-05-01

    Several cell wall enzymes are carbohydrate active enzymes that contain a putative Carbohydrate Binding Module (CBM) in their structures. The main function of these non-catalitic modules is to facilitate the interaction between the enzyme and its substrate. Expansins are non-hydrolytic proteins present in the cell wall, and their structure includes a CBM in the C-terminal that bind to cell wall polymers such as cellulose, hemicelluloses and pectins. We studied the ability of the Expansin2 CBM (CBMFaEXP2) from strawberry (Fragaria x ananassa, Duch) to modify the cell wall of Arabidopsis thaliana. Plants overexpressing CBMFaEXP2 were characterized phenotypically and biochemically. Transgenic plants were taller than wild type, possibly owing to a faster growth of the main stem. Cell walls of CBMFaEXP2-expressing plants were thicker and contained higher amount of pectins. Lower activity of a set of enzymes involved in cell wall degradation (PG, β-Gal, β-Xyl) was found, and the expression of the corresponding genes (AtPG, Atβ-Gal, Atβ-Xyl5) was reduced also. In addition, a decrease in the expression of two A. thaliana Expansin genes (AtEXP5 and AtEXP8) was observed. Transgenic plants were more resistant to Botrytis cinerea infection than wild type, possibly as a consequence of higher cell wall integrity. Our results support the hypothesis that the overexpression of a putative CBM is able to modify plant cell wall structure leading to modulation of wall loosening and plant growth. These findings might offer a tool to controlling physiological processes where cell wall disassembly is relevant, such as fruit softening. PMID:25837738

  11. Resistance to cereal rusts at the plant cell wall - what can we learn from other host-pathogen systems?

    NARCIS (Netherlands)

    Collins, N.C.; Niks, R.E.; Schulze-Lefert, P.

    2007-01-01

    The ability of plant cells to resist invasion by pathogenic fungi at the cell periphery (pre-invasion resistance) differs from other types of resistance that are generally triggered after parasite entry and during differentiation of specialised intracellular feeding structures. Genetic sources of pr

  12. Structural studies of complex carbohydrates of plant cell walls. Progress report, June 15, 1992--June 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, A.G.

    1994-10-01

    This report contains the abstracts of fourteen papers published, in press, or in preparation reporting on research activities to investigate the structure, as well as the function of cell walls in plants. This document also contains research on methods to determine the structure of complex carbohydrates of the cell walls.

  13. Recent advances in phytoplasma research: from genetic diversity and genome evolution to pathogenic redirection of plant stem cell fate

    Science.gov (United States)

    Parasitizing phloem sieve cells and being transmitted by insects, phytoplasmas are a unique group of cell wall-less bacteria responsible for numerous plant diseases worldwide. Due to difficulties in establishing axenic culture of phytoplasmas, phenotypic characters suitable for conventional microbia...

  14. Cell wall compositional changes during incubation of plant roots measured by mid-infrared diffuse reflectance spectroscopy and fiber analysis

    Science.gov (United States)

    Plant roots, particularly the constituents of root cell walls (hemicellulose, cellulose and lignin), are important contributors to soil organic matter. Little is known about the cell wall composition of many important crop species or compositional changes as roots decay. The objectives of this stu...

  15. Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes

    NARCIS (Netherlands)

    Lee, K.M.; Driever, S.M.; Heuvelink, E.; Rüger, S.; Zimmermann, U.; Gelder, de A.; Marcelis, L.F.M.

    2012-01-01

    Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. Leaf patch clamp pressure changes, a measure for relative changes in cell turgor, were monitored at three different hei

  16. Differential effect of plant lectins on mast cells of different origins

    Directory of Open Access Journals (Sweden)

    F.C. Lopes

    2005-06-01

    Full Text Available Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A, lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA, and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A and on Rowett nude rat (animal free of immunoglobulins peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA. No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars. Additionally, the lectins

  17. Electron tomography of cryo-immobilized plant tissue: a novel approach to studying 3D macromolecular architecture of mature plant cell walls in situ.

    Directory of Open Access Journals (Sweden)

    Purbasha Sarkar

    Full Text Available Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼ 2 nm, and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF, cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we

  18. Comparative secretome analysis suggests low plant cell wall degrading capacity in Frankia symbionts

    Directory of Open Access Journals (Sweden)

    Normand Philippe

    2008-01-01

    genomes, suggesting that plant cell wall polysaccharide degradation may not be crucial to root infection, or that this degradation varies among strains. We hypothesize that the relative lack of secreted polysaccharide-degrading enzymes in Frankia reflects a strategy used by these bacteria to avoid eliciting host defense responses. The esterases, lipases, and proteases found in the core Frankia secretome might facilitate hyphal penetration through the cell wall, release carbon sources, or modify chemical signals. The core secretome also includes extracellular solute-binding proteins and Frankia-specific hypothetical proteins that may enable the actinorhizal symbiosis.

  19. Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Timmers, Ruud A.; Strik, David P.B.T.B.; Hamelers, Bert; Buisman, Cees [Wageningen Univ. (Netherlands). Sub-dept. of Environmental Technology; Rothballer, Michael; Hartmann, Anton [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Neuherberg (Germany). Dept. Microbe-Plant Interactions; Engel, Marion; Schulz, Stephan; Schloter, Michael [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Neuherberg (Germany). Dept. Terrestrial Ecogenetics

    2012-04-15

    The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into the competition for electron donor in a PMFC. This paper characterises the anode-rhizosphere bacterial community of a Glyceria maxima (reed mannagrass) PMFC. Electrochemically active bacteria (EAB) were located on the root surfaces, but they were more abundant colonising the graphite granular electrode. Anaerobic cellulolytic bacteria dominated the area where most of the EAB were found, indicating that the current was probably generated via the hydrolysis of cellulose. Due to the presence of oxygen and nitrate, short-chain fatty acid-utilising denitrifiers were the major competitors for the electron donor. Acetate-utilising methanogens played a minor role in the competition for electron donor, probably due to the availability of graphite granules as electron acceptors. (orig.)

  20. An Agrobacterium VirE2 channel for transferred-DNA transport into plant cells.

    Science.gov (United States)

    Dumas, F; Duckely, M; Pelczar, P; Van Gelder, P; Hohn, B

    2001-01-16

    Transferred DNA (T-DNA) transfer from Agrobacterium tumefaciens into eukaryotic cells is the only known example of interkingdom DNA transfer. T-DNA is a single-stranded segment of Agrobacterium's tumor-inducing plasmid that enters the plant cell as a complex with the bacterial virulence proteins VirD2 and VirE2. The VirE2 protein is highly induced on contact of A. tumefaciens with a plant host and has been reported to act in late steps of transfer. One of its previously demonstrated functions is binding to the single-stranded (ss) T-DNA and protecting it from degradation. Recent experiments suggest other functions of the protein. A combination of planar lipid bilayer experiments, vesicle swelling assays, and DNA transport experiments demonstrated that VirE2 can insert itself into artificial membranes and form channels. These channels are voltage gated, anion selective, and single-stranded DNA-specific and can facilitate the efficient transport of single-stranded DNA through membranes. These experiments demonstrate a VirE2 function as a transmembrane DNA transporter, which could have applications in gene delivery systems. PMID:11149937

  1. Intermediate-sized natural gas fueled carbonate fuel cell power plants

    Science.gov (United States)

    Sudhoff, Frederick A.; Fleming, Donald K.

    1994-04-01

    This executive summary of the report describes the accomplishments of the joint US Department of Energy's (DOE) Morgantown Energy Technology Center (METC) and M-C POWER Corporation's Cooperative Research and Development Agreement (CRADA) No. 93-013. This study addresses the intermediate power plant size between 2 megawatt (MW) and 200 MW. A 25 MW natural-gas, fueled-carbonate fuel cell power plant was chosen for this purpose. In keeping with recent designs, the fuel cell will operate under approximately three atmospheres of pressure. An expander/alternator is utilized to expand exhaust gas to atmospheric conditions and generate additional power. A steam-bottoming cycle is not included in this study because it is not believed to be cost effective for this system size. This study also addresses the simplicity and accuracy of a spreadsheet-based simulation with that of a full Advanced System for Process Engineering (ASPEN) simulation. The personal computer can fully utilize the simple spreadsheet model simulation. This model can be made available to all users and is particularly advantageous to the small business user.

  2. Deciphering the roles of acyl-CoA-binding proteins in plant cells.

    Science.gov (United States)

    Lung, Shiu-Cheung; Chye, Mee-Len

    2016-09-01

    Lipid trafficking is vital for metabolite exchange and signal communications between organelles and endomembranes. Acyl-CoA-binding proteins (ACBPs) are involved in the intracellular transport, protection, and pool formation of acyl-CoA esters, which are important intermediates and regulators in lipid metabolism and cellular signaling. In this review, we highlight recent advances in our understanding of plant ACBP families from a cellular and developmental perspective. Plant ACBPs have been extensively studied in Arabidopsis thaliana (a dicot) and to a lesser extent in Oryza sativa (a monocot). Thus far, they have been detected in the plasma membrane, vesicles, endoplasmic reticulum, Golgi apparatus, apoplast, cytosol, nuclear periphery, and peroxisomes. In combination with biochemical and molecular genetic tools, the widespread subcellular distribution of respective ACBP members has been explicitly linked to their functions in lipid metabolism during development and in response to stresses. At the cellular level, strong expression of specific ACBP homologs in specialized cells, such as embryos, stem epidermis, guard cells, male gametophytes, and phloem sap, is of relevance to their corresponding distinct roles in organ development and stress responses. Other interesting patterns in their subcellular localization and spatial expression that prompt new directions in future investigations are discussed. PMID:26340904

  3. The Cryoprotectant Effect of Polysaccharides from Plants and Microalgae on Human White Blood Cells.

    Science.gov (United States)

    Khudyakov, Andrey Nikolayevich; Polezhaeva, Tatyana Vitalyevna; Zaitseva, Oksana Olegovna; Gűnter, Elena Aleksandrovna; Solomina, Olga Nurzadinovna; Popeyko, Oksana Viktorovna; Shubakov, Anatolyi Aleksandrovich; Vetoshkin, Konstantin Aleksandrovich

    2015-08-01

    The use of carbohydrates as cryoprotectants is increasing. In this study the effects of incorporating polysaccharides extracted from plants and microalgae originating in northern Russia, into cryoprotectant solutions used to preserve human white blood cells were investigated. Cells in the presence of the polysaccharides were cooled to either -40°C or -80°C, using a two-step cooling process. The morphological and functional indicators of the cryopreserved leukocytes were assessed by light microscopy. When combined with glycerol, the pectin-polysaccharides Lemnan from common duckweed (Lemna minor L.) and Comaruman from marsh cinquefoil (Comarum palustre L), were capable of lowering the freezing point of the cryoprotectant solution and helped to preserve the integrity of the human white blood cell membranes at temperatures below zero. In addition, the increase in phagocytic activity of neutrophils was confirmed. In the context of the contemporary search for effective cell cryoprotectants, the results of this research demonstrate that the cryopreservation of biospecimens in a polysaccharide environment is a promising trend in applied medicine, which can be considered an alternative to traditional cryogenic nitrogen techniques. PMID:26186407

  4. Cooperative antiproliferative and differentiation-enhancing activity of medicinal plant extracts in acute myeloid leukemia cells.

    Science.gov (United States)

    Zhamanbayeva, Gulzhan T; Aralbayeva, Araylim N; Murzakhmetova, Maira K; Tuleukhanov, Sultan T; Danilenko, Michael

    2016-08-01

    Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy with poor prognosis and limited treatment options. Sea buckthorn (Hippophae rhamnoides) berries, dog rose (Rosa canina) rosehips, and garden sage (Salvia officinalis) and oregano (Origanum vulgare) aerial parts are widely used in traditional medicine and exhibit antitumor effects in preclinical models. However, these plants remain scarcely tested for antileukemic activity. Here, we show that their water-ethanol leaf extracts reduced the growth and viability of AML cells and, at non-cytotoxic doses, potentiated cell differentiation induced by a low concentration of 1α,25-dihydroxyvitamin D3, the hormonal form of vitamin D, in a cell type-dependent manner. The latter effect was accompanied by upregulation of the vitamin D receptor protein components and its transcriptional activity. Furthermore, at minimally effective doses the extracts cooperated with one another to produce marked cytostatic effects associated with a partial S-phase arrest and a modest induction of apoptosis. In contrast, these combinations only slightly affected the growth and viability of proliferating normal human peripheral blood mononuclear cells. In addition, the extracts strongly inhibited microsomal lipid peroxidation and protected normal erythrocytes against hypoosmotic shock. Our results suggest that further exploration of the enhanced antileukemic effects of the combinations tested here may lead to the development of alternative therapeutic and preventive approaches against AML. PMID:27470342

  5. Modulation of P-glycoprotein function and multidrug resistance in cancer cells by Thai plant extracts.

    Science.gov (United States)

    Takano, M; Kakizoe, S; Kawami, M; Nagai, J; Patanasethnont, D; Sripanidkulchai, B; Yumoto, R

    2014-11-01

    The effects of ethanol extracts from Thai plants belonging to the families of Annonaceae, Rutaceae, and Zingiberaceae on P-glycoprotein (P-gp) function and multidrug resistance were examined in paclitaxel-resistant HepG2 (PR-HepG2) cells. All the extracts tested, significantly increased the accumulation of [3H]paclitaxel, a P-gp substrate, in the cells. Among nine extracts, Z01 and Z02, extracts from Curcuma comosa and Kaempferia marginata (Zingiberaceae family), respectively, potently increased the accumulation. In addition, Z01 and Z02 increased the accumulation of other P-gp substrates, rhodamine 123 and doxorubicin, in PR-HepG2 cells in a concentration-dependent manner. Increased accumulation of rhodamine 123 and doxorubicin by Z01 and Z02 was also confirmed by confocal laser scanning microscopy. The effect of Z01 and Z02 pretreatment on the expression of MDR1 mRNA was also examined. The expression of MDR1 mRNA was not affected by the treatment of PR-HepG2 cells with these extracts for 48 hours. Cytotoxicity of paclitaxel was examined by XTT and protein assays in the absence and presence of Z02. Z02 potentiated the cytotoxicity of paclitaxel in PR-HepG2 cells. These results suggest that Curcuma comosa and Kaempferia marginata belonging to Zingiberaceae are useful sources to search for new P-gp modulator(s) that can be used to overcome multidrug resistance of cancer cells.

  6. Modulation of P-glycoprotein function and multidrug resistance in cancer cells by Thai plant extracts.

    Science.gov (United States)

    Takano, M; Kakizoe, S; Kawami, M; Nagai, J; Patanasethnont, D; Sripanidkulchai, B; Yumoto, R

    2014-11-01

    The effects of ethanol extracts from Thai plants belonging to the families of Annonaceae, Rutaceae, and Zingiberaceae on P-glycoprotein (P-gp) function and multidrug resistance were examined in paclitaxel-resistant HepG2 (PR-HepG2) cells. All the extracts tested, significantly increased the accumulation of [3H]paclitaxel, a P-gp substrate, in the cells. Among nine extracts, Z01 and Z02, extracts from Curcuma comosa and Kaempferia marginata (Zingiberaceae family), respectively, potently increased the accumulation. In addition, Z01 and Z02 increased the accumulation of other P-gp substrates, rhodamine 123 and doxorubicin, in PR-HepG2 cells in a concentration-dependent manner. Increased accumulation of rhodamine 123 and doxorubicin by Z01 and Z02 was also confirmed by confocal laser scanning microscopy. The effect of Z01 and Z02 pretreatment on the expression of MDR1 mRNA was also examined. The expression of MDR1 mRNA was not affected by the treatment of PR-HepG2 cells with these extracts for 48 hours. Cytotoxicity of paclitaxel was examined by XTT and protein assays in the absence and presence of Z02. Z02 potentiated the cytotoxicity of paclitaxel in PR-HepG2 cells. These results suggest that Curcuma comosa and Kaempferia marginata belonging to Zingiberaceae are useful sources to search for new P-gp modulator(s) that can be used to overcome multidrug resistance of cancer cells. PMID:25985578

  7. A 160-kilodalton epithelial cell surface glycoprotein recognized by plant lectins that inhibit the adherence of Actinomyces naeslundii.

    OpenAIRE

    Brennan, M J; Cisar, J O; Sandberg, A L

    1986-01-01

    The adherence of Actinomyces naeslundii to human epithelial (KB) cells is mediated by the interaction of a fimbrial lectin on this oral bacterium with epithelial cell receptors exposed by sialidase. The D-galactose- and N-acetyl-D-galactosamine-reactive plant lectins from peanut and from Bauhinia purpurea inhibit this interaction. This report describes the partial purification and characterization of a 160-kilodalton (kDa) cell surface glycoprotein which is the principal receptor for these le...

  8. Two parametric cell cycle analyses of plant cell suspension cultures with fragile, isolated nuclei to investigate heterogeneity in growth of batch cultivations.

    Science.gov (United States)

    Haas, Christiane; Hegner, Richard; Helbig, Karsten; Bartels, Kristin; Bley, Thomas; Weber, Jost

    2016-06-01

    Plant cell suspensions are frequently considered to be heterogeneous with respect to growth in terms of progression of the cells through the cell cycle and biomass accumulation. Thus, segregated data of fractions in different cycle phases during cultivation is needed to develop robust production processes. Bromodeoxyuridine (BrdU) incorporation and BrdU-antibodies or 5-ethynyl-2'-deoxyuridine (EdU) click-it chemistry are frequently used to acquire such information. However, their use requires centrifugation steps that cannot be readily applied to sensitive cells, particularly if nuclei have to be extracted from the protective cellular milieu and envelopes for DNA analysis. Therefore, we have established a BrdU-Hoechst stain quenching protocol for analyzing nuclei directly isolated from delicate plant cell suspension cultures. After adding BrdU to test Harpagophytum procumbens cell suspension cultures the cell cycle distribution could be adequately resolved using its incorporation for the following 72 h (after which BrdU slowed biomass accumulation). Despite this limitation, the protocol allows resolution of the cell cycle distribution of cultures that cannot be analyzed using commonly applied methods due to the cells' fragility. The presented protocol enabled analysis of cycling heterogeneities in H. procumbens batch cultivations, and thus should facilitate process control of secondary metabolite production from fragile plant in vitro cultures. Biotechnol. Bioeng. 2016;113: 1244-1250. © 2015 Wiley Periodicals, Inc. PMID:26614913

  9. System approaches to study root hairs as a single cell plant model: current status and future perspectives

    Directory of Open Access Journals (Sweden)

    Md Shakhawat eHossain

    2015-05-01

    Full Text Available Our current understanding of plant functional genomics derives primarily from measurements of gene, protein and/or metabolite levels averaged over the whole plant or multicellular tissues. These approaches risk diluting the response of specific cells that might respond strongly to the treatment but whose signal is diluted by the larger proportion of non-responding cells. For example, if a gene is expressed at a low level, does this mean that it is indeed lowly expressed or is it highly expressed, but only in a few cells? In order to avoid these issues, we adopted the soybean root hair cell, derived from a single, differentiated root epidermal cell, as a single-cell model for functional genomics. Root hair cells are intrinsically interesting since they are major conduits for root water and nutrient uptake and are also the preferred site of infection by nitrogen-fixing rhizobium bacteria. Although a variety of other approaches have been used to study single plant cells or single cell types, the root hair system is perhaps unique in allowing application of the full repertoire of functional genomic and biochemical approaches. In this mini review, we summarize our published work and place this within the broader context of root biology, with a significant focus on understanding the initial events in the soybean-rhizobium interaction.

  10. Plants control the properties and actuation of their organs through the orientation of cellulose fibrils in their cell walls.

    Science.gov (United States)

    Burgert, Ingo; Fratzl, Peter

    2009-07-01

    Plants use the orientation of cellulose microfibrils to create cell walls with anisotropic properties related to specific functions. This enables organisms to control the shape and size of cells during growth, to adjust the mechanical performance of tissues, and to perform bending movements of organs. We review the key function of cellulose orientation in defining structural-functional relationships in cell walls from a biomechanics perspective, and illustrate this by examples mainly from our own work. First, primary cell-wall expansion largely depends on the organization of cellulose microfibrils in newly deposited tissue and model calculations allow an estimate of how their passive re-orientation may influence the growth of cells. Moreover, mechanical properties of secondary cell walls depend to a large extent on the orientation of cellulose fibrils and we discuss strategies whereby plants utilize this interrelationship for adaptation. Lastly, we address the question of how plants regulate complex organ movements by designing appropriate supramolecular architectures at the level of the cell wall. Several examples, from trees to grasses, show that the cellulose architecture in the cell wall may be used to direct the swelling or shrinking of cell walls and thereby generate internal growth stress or movement of organs.

  11. To Stretch the Boundary of Secondary Metabolite Production in Plant Cell-Based Bioprocessing: Anthocyanin as a Case Study

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2004-01-01

    Full Text Available Plant cells and tissue cultures hold great promise for controlled production of a myriad of useful secondary metabolites on demand. The current yield and productivity cannot fulfill the commercial goal of a plant cell-based bioprocess for the production of most secondary metabolites. In order to stretch the boundary, recent advances, new directions and opportunities in plant cell-based bioprocessing, have been critically examined for the 10 years from 1992 to 2002. A review of the literature indicated that most of the R&D work was devoted predominantly to studies at an empirical level. A rational approach to molecular plant cell bioprocessing based on the fundamental understanding of metabolic pathways and their regulations is urgently required to stimulate further advances; however, the strategies and technical framework are still being developed. It is the aim of this review to take a step forward in framing workable strategies and technologies for molecular plant cell-based bioprocessing. Using anthocyanin biosynthesis as a case study, an integrated postgenomic approach has been proposed. This combines the functional analysis of metabolic pathways for biosynthesis of a particular metabolite from profiling of gene expression and protein expression to metabolic profiling. A global correlation not only can thus be established at the three molecular levels, but also places emphasis on the interactions between primary metabolism and secondary metabolism; between competing and/or complimentary pathways; and between biosynthetic and post-biosynthetic events.

  12. Large-scale co-expression approach to dissect secondary cell wall formation across plant species

    Directory of Open Access Journals (Sweden)

    Colin eRuprecht

    2011-07-01

    Full Text Available Plant cell walls are complex composites largely consisting of carbohydrate-based polymers, and are generally divided into primary and secondary walls based on content and characteristics. Cellulose microfibrils constitute a major component of both primary and secondary cell walls and are synthesized at the plasma membrane by cellulose synthase (CESA complexes. Several studies in Arabidopsis have demonstrated the power of co-expression analyses to identify new genes associated with secondary wall cellulose biosynthesis. However, across-species comparative co-expression analyses remain largely unexplored. Here, we compared co-expressed gene vicinity networks of primary and secondary wall CESAs in Arabidopsis, barley, rice, poplar, soybean, Medicago and wheat, and identified gene families that are consistently co-regulated with cellulose biosynthesis. In addition to the expected polysaccharide acting enzymes, we also found many gene families associated with cytoskeleton, signaling, transcriptional regulation, oxidation and protein degradation. Based on these analyses, we selected and biochemically analyzed T-DNA insertion lines corresponding to approximately twenty genes from gene families that re-occur in the co-expressed gene vicinity networks of secondary wall CESAs across the seven species. We developed a statistical pipeline using principal component analysis (PCA and optimal clustering based on silhouette width to analyze sugar profiles. One of the mutants, corresponding to a pinoresinol reductase gene, displayed disturbed xylem morphology and held lower levels of lignin molecules. We propose that this type of large-scale co-expression approach, coupled with statistical analysis of the cell wall contents, will be useful to facilitate rapid knowledge transfer across plant species.

  13. Quantification of Förster resonance energy transfer by monitoring sensitized emission in living plant cells

    Directory of Open Access Journals (Sweden)

    Sara Mareike Müller

    2013-10-01

    Full Text Available Förster resonance energy transfer (FRET describes excitation energy exchange between two adjacent molecules typically in distances ranging from 2 to 10 nm. The process depends on dipole-dipole coupling of the molecules and its probability of occurrence cannot be proven directly. Mostly, fluorescence is employed for quantification as it represents a concurring process of relaxation of the excited singulet state S1 so that the probability of fluorescence decreases as the probability of FRET increases. This reflects closer proximity of the molecules or an orientation of donor and acceptor transition dipoles that facilitates FRET. Monitoring sensitized emission by 3-Filter-FRET allows for fast image acquisition and is suitable for quantifying FRET in dynamic systems such as living cells. In recent years, several calibration protocols were established to overcome previous difficulties in measuring FRET-efficiencies. Thus, we can now obtain by 3-filter FRET FRET-efficiencies that are comparable to results from sophisticated fluorescence lifetime measurements. With the discovery of fluorescent proteins and their improvement towards spectral variants and usability in plant cells, the tool box for in vivo FRET-analyses in plant cells was provided and FRET became applicable for the in vivo detection of protein-protein interactions and for monitoring conformational dynamics. The latter opened the door towards a multitude of FRET-sensors such as the widely applied Ca2+-sensor Cameleon. Recently, FRET-couples of two fluorescent proteins were supplemented by additional fluorescent proteins towards FRET-cascades in order to monitor more complex arrangements. Novel FRET-couples involving switchable fluorescent proteins promise increase the utility of FRET through combination with photoactivation-based super-resolution microscopy.

  14. Quantification of Förster resonance energy transfer by monitoring sensitized emission in living plant cells.

    Science.gov (United States)

    Müller, Sara M; Galliardt, Helena; Schneider, Jessica; Barisas, B George; Seidel, Thorsten

    2013-01-01

    Förster resonance energy transfer (FRET) describes excitation energy exchange between two adjacent molecules typically in distances ranging from 2 to 10 nm. The process depends on dipole-dipole coupling of the molecules and its probability of occurrence cannot be proven directly. Mostly, fluorescence is employed for quantification as it represents a concurring process of relaxation of the excited singlet state S1 so that the probability of fluorescence decreases as the probability of FRET increases. This reflects closer proximity of the molecules or an orientation of donor and acceptor transition dipoles that facilitates FRET. Monitoring sensitized emission by 3-Filter-FRET allows for fast image acquisition and is suitable for quantifying FRET in dynamic systems such as living cells. In recent years, several calibration protocols were established to overcome to previous difficulties in measuring FRET-efficiencies. Thus, we can now obtain by 3-filter FRET FRET-efficiencies that are comparable to results from sophisticated fluorescence lifetime measurements. With the discovery of fluorescent proteins and their improvement toward spectral variants and usability in plant cells, the tool box for in vivo FRET-analyses in plant cells was provided and FRET became applicable for the in vivo detection of protein-protein interactions and for monitoring conformational dynamics. The latter opened the door toward a multitude of FRET-sensors such as the widely applied Ca(2+)-sensor Cameleon. Recently, FRET-couples of two fluorescent proteins were supplemented by additional fluorescent proteins toward FRET-cascades in order to monitor more complex arrangements. Novel FRET-couples involving switchable fluorescent proteins promise to increase the utility of FRET through combination with photoactivation-based super-resolution microscopy. PMID:24194740

  15. A parasitic nematode releases cytokinin that controls cell division and orchestrates feeding site formation in host plants

    Science.gov (United States)

    Siddique, Shahid; Radakovic, Zoran S.; De La Torre, Carola M.; Chronis, Demosthenis; Novák, Ondřej; Ramireddy, Eswarayya; Holbein, Julia; Matera, Christiane; Hütten, Marion; Gutbrod, Philipp; Anjam, Muhammad Shahzad; Rozanska, Elzbieta; Habash, Samer; Elashry, Abdelnaser; Sobczak, Miroslaw; Kakimoto, Tatsuo; Strnad, Miroslav; Schmülling, Thomas; Mitchum, Melissa G.; Grundler, Florian M. W.

    2015-01-01

    Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction. PMID:26417108

  16. Enhancement of electricity production by graphene oxide in soil microbial fuel cells and plant microbial fuel cells

    Directory of Open Access Journals (Sweden)

    Yuko eGoto

    2015-04-01

    Full Text Available The effects of graphene oxide (GO on electricity generation in soil microbial fuel cells (SMFCs and plant microbial fuel cell (PMFCs were investigated. GO at concentrations ranging from 0 to 1.9 g•kg-1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g•kg-1 of GO was 40 ± 19 mW•m-2, which was significantly higher than the value of 6.6 ± 8.9 mW•m-2 generated from GO-free SMFCs (p -2 of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs.

  17. Valine-Resistance, a Potential Marker in Plant Cell Genetics. I. Distinction between Two Types of Valine-Resistant Tobacco Mutants Isolated from Protoplast-Derived Cells

    OpenAIRE

    Bourgin, J. P.; Goujaud, J.; Missonier, C.; Pethe, C.

    1985-01-01

    In previous experiments, seven lines of valine-resistant plants were regenerated from protoplast-derived haploid tobacco mesophyll cells which had been UV mutagenized and submitted to selection by toxic concentrations of valine. In this study we described the transmission of valine-resistance to progeny and a preliminary phenotypical and biochemical characterization of the resistant plants.—Two types were thus distinguished among the seven mutant lines. Valine-resistance of the mutants of the...

  18. Impact of plant extracts tested in attention-deficit/hyperactivity disorder treatment on cell survival and energy metabolism in human neuroblastoma SH-SY5Y cells

    OpenAIRE

    Schmidt, Andreas Johannes; Krieg, Jürgen-Christian; Hemmeter, Ulrich Michael; Kircher, Tilo; Schulz, Eberhard; Clement, Hans-Willi; Heiser, Philip

    2010-01-01

    Abstract Plant extracts like Hypericum perforatum and Pycnogenol? have been tested as alternatives to the classical ADHD drugs. It has been possible to describe neuroprotective effects of such plant extracts. A reduction of ADHD symptoms could be shown in clinical studies after the application of Pycnogenol?, which is a pine bark extract. The impacts of the standardized herbal extracts Hypericum perforatum, Pycnogenol? and Enzogenol? up to a concentration of 5.000 ng/ml on cell sur...

  19. Protective Effects of Some Medicinal Plants from Lamiaceae Family Against Beta-Amyloid Induced Toxicity in PC12 Cell

    OpenAIRE

    S. Saeidnia; M Soodi; P Balali

    2012-01-01

    Background: Excessive accumulation of beta-amyliod peptide (Aβ), the major component of senile plaques in Alzheimer's disease (AD), causes neuronal cell death through induction of oxidative stress. Therefore, antioxidants may be of use in the treatment of AD. The medicinal plants from the Lamiaceae family have been widely used in Iranian traditional medicine. These plants contain compounds with antioxidant activity and some species in this family have been reported to have neuroprotective pro...

  20. Antiproliferative activity and phenotypic modification induced by selected Peruvian medicinal plants on human hepatocellular carcinoma Hep3B cells

    OpenAIRE

    Carraz, Maëlle; Lavergne, C.; Jullian, Valérie; Wright, M.; Gairin, J. E.; de la Cruz, M. G.; Bourdy, Geneviève

    2015-01-01

    Ethnopharmacological relevance: The high incidence of human hepatocellular carcinoma (HCC) in Peru and the wide use of medicinal plants in this country led us to study the activity against HCC cells in vitro of somes species used locally against liver and digestive disorders. Materials and methods: Ethnopharmacological survey: Medicinal plant species with a strong convergence of use for liver and digestive diseases were collected fresh in the wild or on markets, in two places of Peru: Chiclay...

  1. [Elaboration of the in vitro model system to study the interaction of phytopathogenic mollicutes with plant cells].

    Science.gov (United States)

    Korobkova, K S; Onyshchenko, A M; Panchenko, L P; Mamchur, O Ie; Dmytruk, O O; Red'ko, V I

    2009-01-01

    The model system based on the sugar beet calluses infected by mycoplasms (mollicutes) was elaborated, and changes in the callus cells morphology under the effect of these microorganisms were also studied. The calluses of sugar beet 3K51 cultivated on the Gamborg medium were infected by phytopathogenic mollicute Acholaplasma laidlawii var. granulum str.118. Under the effect of mollicute infection one could observe changes in the cell morphology of sugar beet calluses: the plant cells were transformed from round to lengthened, the intensity of polyploids forming was increased, their grouping and their total destruction were observed. Data of electron microscopy confirm the presence of the mollicute in the sugar beet calluses: acholeplasma cells were localized between and within undifferentiated plant cells. PMID:19938618

  2. The charophycean green algae as model systems to study plant cell walls and other evolutionary adaptations that gave rise to land plants

    DEFF Research Database (Denmark)

    Sørensen, Iben; Rose, Jocelyn K.C.; Doyle, Jeff J.;

    2012-01-01

    for terrestrial colonization. The nature and molecular bases of such traits are still being determined, but one critical adaptation is thought to have been the evolution of a complex cell wall. Very little is known about the identity, origins and diversity of the biosynthetic machinery producing the major suites...... of structural polymers (i. e., cell wall polysaccharides and associated molecules) that must have been in place for land colonization. However, it has been suggested that the success of the earliest land plants was partly based on the frequency of gene duplication, and possibly whole genome sduplications...

  3. Using Fluorescent Protein Fusions to Study Protein Subcellular Localization and Dynamics in Plant Cells.

    Science.gov (United States)

    Cui, Yong; Gao, Caiji; Zhao, Qiong; Jiang, Liwen

    2016-01-01

    Studies of protein subcellular localization and dynamics are helpful in understanding the cellular functions of proteins in an organism. In the past decade, the use of green fluorescent protein (GFP) as a fusion tag has dramatically extended our knowledge in this field. Transient expression and stable transformation of GFP-tagged proteins have been wildly used to study protein localization in vivo in different systems. Although GFP-based tags provide a fast and convenient way to characterize protein properties in living cells, several reports have demonstrated that GFP fusions might not accurately reflect the localization of the native protein as GFP tags may alter the protein properties. To facilitate proper usage of GFP tags in plant cell biology study, we describe detailed protocols to identify possible inhibitory effects of fluorescent tags on protein subcellular localization and to determine if a fluorescently tagged protein is localized to the correct subcellular compartment. Using Arabidopsis Endomembrane protein 12 (EMP12) as an example, we first show the possible inhibitory effect of GFP tags on proper protein localization and then describe the immunofluorescence labeling method to verify the correct localization of GFP fusion proteins. Next, a method is presented using the ImageJ program with the Pearson-Spearman correlation (PSC) colocalization plug-in for statistical quantification of colocalization ratios of two fluorophores. Finally we provide a detailed method for protein dynamics studies using spinning disk confocal microscopy in Arabidopsis cells. PMID:27515077

  4. Post-transcriptional Gene Silencing Induced by Short Interfering RNAs in Cultured Transgenic Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Wei Tang; Vanessa Samuels; Nicki Whitley; Nicole Bloom; Tinya DeLaGarza; Ronald J. Newton

    2004-01-01

    Short interfering RNA (siRNA) is widely used for studying post-transcriptional gene silencing and holds great promise as a tool for both identifying function of novel genes and validating drug targets. Two siRNA fragments (siRNA-a and -b),which were designed against different specific areas of coding region of the same target green fluorescent protein (GFP) gene, were used to silence GFP expression in cultured gfp transgenic cells of rice (Oryza sativa L.; OS), cotton (Gossypium hirsutum L.; GH), Fraser fir [Abies fraseri (Pursh) Poir; AF], and Virginia pine (Pinus virginiana Mill.; PV). Differential gene silencing was observed in the bombarded transgenic cells between two siRNAs, and these results were consistent with the inactivation of GFP confirmed by laser scanning microscopy, Northern blot,and siRNA analysis in tested transgenic cell cultures. These data suggest that siRNA-mediated gene inactivation can be the siRNA specific in different plant species. These results indicate that siRNA is a highly specific tool for targeted gene knockdown and for establishing siRNA-mediated gene silencing, which could be a reliable approach for large-scale screening of gene function and drug target validation.

  5. Comparison of single cell culture derived Solanum tuberosum L. plants and a model for their application in breeding programs.

    Science.gov (United States)

    Wenzel, G; Schieder, O; Przewozny, T; Sopory, S K; Melchers, G

    1979-03-01

    The techniques of microspore and protoplast regeneration starting from dihaploid Solanum tuberosum plants has been improved to such an extent that the production of more than 2000 microspore derived A1 plant lines and of several hundred protoplast derived plantlets has become possible. Further, from the dihaploid Solanum species S. phureja the regeneration of microspores to plants, and from the species S. infundibuliforme, S. sparsipilum and S. tarijense the regeneration of protoplasts to calluses, has been achieved. The plants descending from the two single cell culture systems are compared with reference to phenotypic markers and economic qualities. Some principles characteristic for either microspore or protoplast derived plants are examined and their significance is discussed. The results are compiled into an extended analytical synthetic breeding scheme based on a stepwise reduction of the autotetraploid to the monohaploid level and a subsequent controlled combination to a new synthetic completely heterozygous tetraploid potato.

  6. Effect of(12)C (+5) ion beam irradiation on cell viability and plant regeneration in callus, protoplasts and cell suspensions ofLavateva thuringiaca.

    Science.gov (United States)

    Vazquez-Tello, A; Uozumi, T; Hidaka, M; Kobayashi, Y; Watanabe, H

    1996-11-01

    The biological effects of irradiation with(12)C(+5) ion beam on plant cells have been analyzed. Protoplasts and cell suspensions ofLavatera thuringiaca, and a somatic hybrid callus (Hibiscus rosa-sinensis +Lavatera thuringiaca), were irradiated with doses from 0.05 to 50 Gy, and the effects on cell growth, cell division, cell viability and embryogenesis rates were analyzed. Irradiation with(12)C(+5) ion beam at relatively very low doses (5.0 Gy) significantly inhibited cell division, yet the survival rate and regeneration capability of the cells through somatic embryogenesis were conserved in more than 70 and 50 %, respectively. These results indicate that cell division is the most sensitive parameter to irradiation, accounting for the inhibition of colony formation and callus growth. The potential use of the(12)C(+5) ion beam in asymmetric protoplast fusion experiments is discussed. PMID:24178652

  7. Protective Effects of Some Medicinal Plants from Lamiaceae Family Against Beta-Amyloid Induced Toxicity in PC12 Cell

    Directory of Open Access Journals (Sweden)

    S Saeidnia

    2012-10-01

    Full Text Available Background: Excessive accumulation of beta-amyliod peptide (Aβ, the major component of senile plaques in Alzheimer's disease (AD, causes neuronal cell death through induction of oxidative stress. Therefore, antioxidants may be of use in the treatment of AD. The medicinal plants from the Lamiaceae family have been widely used in Iranian traditional medicine. These plants contain compounds with antioxidant activity and some species in this family have been reported to have neuroprotective properties. In the present study, methanolic extract of seven plants from salvia and satureja species were evaluated for their protective effects against beta-amyloid induced neurotoxicity.Methods: Aerial parts of the plants were extracted with ethyl acetate and methanol, respectively, by percolation at room temperature and subsequently, methanolic extracts of the plants were prepared. PC12 cells were incubated with different concentrations of the extracts in culture medium 1h prior to incubation with Aβ. Cell toxicity was assessed 24h after addition of Aβ by MTT assay.Results: Satureja bachtiarica, Salvia officinalis and Salvia macrosiphon methanolic extracts exhibited high protective effects against Aβ induced toxicity (P<0.001. Protective effects of Satureja bachtiarica and Salvia officinalis were dose-dependent.Conclusion: The main constituents of these extracts are polyphenolic and flavonoid compounds such as rosmarinic acid, naringenin, apigenin and luteolin which have antioxidant properties and may have a role in neuroprotection. Based on neuroprotective effect of these plants against Aβ induced toxicity, we recommend greater attention to their use in the treatment of Alzheimer disease.

  8. Plant lectin, ATF1011, on the tumor cell surface augments tumor-specific immunity through activation of T cells specific for the lectin.

    Science.gov (United States)

    Yoshimoto, R; Kondoh, N; Isawa, M; Hamuro, J

    1987-01-01

    The possibility that a plant lectin as a carrier protein would specifically activate T cells, resulting in the augmentation of antitumor immunity was investigated. ATF1011, a nonmitogenic lectin for T cells purified from Aloe arborescens Mill, bound equally to normal and tumor cells. ATF1011 binding on the MM102 tumor cell surfaces augmented anti-trinitrophenyl (TNP) antibody production of murine splenocytes when the mice were primarily immunized with TNP-conjugated MM102 tumor cells. The alloreactive cytotoxic T cell response was also augmented by allostimulator cells binding ATF1011 on the cell surfaces. These augmented responses may be assumed to be mediated by the activation of helper T cells recognizing ATF1011 as a carrier protein. Killer T cells were induced against ATF1011 antigen in the H-2 restricted manner using syngeneic stimulator cells bearing ATF1011 on the cell surfaces. When this lectin was administered intralesionally into the tumors, induction of cytotoxic effector cells was demonstrated. These results suggest that intralesionally administered ATF1011 binds to the tumor cell membrane and activates T cells specific for this carrier lectin in situ, which results in the augmented induction of systemic antitumor immunity. PMID:3496156

  9. Performance Comparison on Repowering of a Steam Power Plant with Gas Turbines and Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Masoud Rokni

    2016-05-01

    Full Text Available Repowering is a process for transforming an old power plant for greater capacity and/or higher efficiency. As a consequence, the repowered plant is characterized by higher power output and less specific CO2 emissions. Usually, repowering is performed by adding one or more gas turbines into an existing steam cycle which was built decades ago. Thus, traditional repowering results in combined cycles (CC. High temperature fuel cells (such as solid oxide fuel cell (SOFC could also be used as a topping cycle, achieving even higher global plant efficiency and even lower specific CO2 emissions. Decreasing the operating temperature in a SOFC allows the use of less complex materials and construction methods, consequently reducing plant and the electricity costs. A lower working temperature makes it also suitable for topping an existing steam cycle, instead of gas turbines. This is also the target of this study, repowering of an existing power plant with SOFC as well as gas turbines. Different repowering strategies are studied here, repowering with one gas turbine with and without supplementary firing, repowering with two gas turbines with and without supplementary firing and finally repowering using SOFC. Plant performances and CO2 emissions are compared for the suggested repowered plants.

  10. POTENTIAL USE OF MICROBIAL ELECTROLYSIS CELLS (MECs IN DOMESTIC WASTEWATER TREATMENT PLANTS FOR ENERGY RECOVERY

    Directory of Open Access Journals (Sweden)

    Adrian eEscapa

    2014-06-01

    Full Text Available Globally, large amounts of electrical energy are spent every year for domestic wastewater (dWW treatment. In the future, energy prices are expected to rise as the demand for energy resources increases and fossil fuel reserves become depleted. By using appropriate technologies, the potential chemical energy contained in the organic compounds present in dWWs might help to improve the energy and economic balance of dWW treatment plants. Bioelectrochemical Systems (BESs in general and microbial electrolysis cells (MECs in particular represent an emerging technology capable of harvesting part of this energy. This study offers an overview of the potential of using MEC technology in dWW treatment plants (dWWTPs to reduce the energy bill. It begins with a brief account of the basics of BESs, followed by an examination of how MECs can be integrated in dWW treatment plants (dWWTPs, identifying scaling-up bottlenecks and estimating potential energy savings. A simplified analysis showed that the use of MEC technology may help to reduce up to ~20% the energy consumption in a conventional dWWTP. The study concludes with a discussion of the future perspectives of MEC technology for dWW treatment. The growing rates of municipal water and wastewater treatment markets in Europe offer excellent business prospects and it is expected that the first generation of MECs could be ready within 1-4 years. However, before MEC technology may achieve practical implementation in dWWTPs, it needs not only to overcome important techno-economic challenges, but also to compete with other energy-producing technologies.

  11. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2016-09-27

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  12. 1997 Gordon Research Conference on Plant Cell Walls. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Staehelin, A.

    1999-08-25

    The Gordon Research Conference (GRC) on Plant Cell Walls was held at Tilton School, Tilton, New Hampshire, July 18-22, 1997. The conference was well attended with 106 participants. The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both US and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. In addition to these formal interactions, free time was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.

  13. Systems Level Engineering of Plant Cell Wall Biosynthesis to Improve Biofuel Feedstock Quality

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Samuel

    2013-09-27

    Our new regulatory model of cell wall biosynthesis proposes original network architecture with several newly incorporated components. The mapped set of protein-DNA interactions will serve as a foundation for 1) understanding the regulation of a complex and integral plant component and 2) the manipulation of crop species for biofuel and biotechnology purposes. This study revealed interesting and novel aspects of grass growth and development and further enforce the importance of a grass model system. By functionally characterizing a suite of genes, we have begun to improve the sparse model for transcription regulation of biomass accumulation in grasses. In the process, we have advanced methodology and brachy molecular genetic tools that will serve as valuable community resource.

  14. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Science.gov (United States)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2015-07-14

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  15. Design and development of major balance of plant components in solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

    2013-07-01

    The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

  16. Plant Cell Imaging Based on Nanodiamonds with Excitation-Dependent Fluorescence

    Science.gov (United States)

    Su, Li-Xia; Lou, Qing; Jiao, Zhen; Shan, Chong-Xin

    2016-09-01

    Despite extensive work on fluorescence behavior stemming from color centers of diamond, reports on the excitation-dependent fluorescence of nanodiamonds (NDs) with a large-scale redshift from 400 to 620 nm under different excitation wavelengths are so far much fewer, especially in biological applications. The fluorescence can be attributed to the combined effects of the fraction of sp2-hybridized carbon atoms among the surface of the fine diamond nanoparticles and the defect energy trapping states on the surface of the diamond. The excitation-dependent fluorescent NDs have been applied in plant cell imaging for the first time. The results reported in this paper may provide a promising route to multiple-color bioimaging using NDs.

  17. Screening of Venezuelan medicinal plant extracts for cytostatic and cytotoxic activity against tumor cell lines.

    Science.gov (United States)

    Taylor, Peter; Arsenak, Miriam; Abad, María Jesús; Fernández, Angel; Milano, Balentina; Gonto, Reina; Ruiz, Marie-Christine; Fraile, Silvia; Taylor, Sofía; Estrada, Omar; Michelangeli, Fabian

    2013-04-01

    There are estimated to be more than 20,000 species of plants in Venezuela, of which more than 1500 are used for medicinal purposes by indigenous and local communities. Only a relatively small proportion of these have been evaluated in terms of their potential as antitumor agents. In this study, we screened 308 extracts from 102 species for cytostatic and cytotoxic activity against a panel of six tumor cell lines using a 24-h sulphorhodamine B assay. Extracts from Clavija lancifolia, Hamelia patens, Piper san-vicentense, Physalis cordata, Jacaranda copaia, Heliotropium indicum, and Annona squamosa were the most cytotoxic, whereas other extracts from Calotropis gigantea, Hyptis dilatata, Chromolaena odorata, Siparuna guianensis, Jacaranda obtusifolia, Tapirira guianensis, Xylopia aromatica, Protium heptaphyllum, and Piper arboreum showed the greatest cytostatic activity. These results confirm previous reports on the cytotoxic activities of the above-mentioned plants as well as prompting further studies on others such as C. lancifolia and H. dilatata that have not been so extensively studied. PMID:22648665

  18. Study of CO2 recovery in a carbonate fuel cell tri-generation plant

    Science.gov (United States)

    Rinaldi, Giorgio; McLarty, Dustin; Brouwer, Jack; Lanzini, Andrea; Santarelli, Massimo

    2015-06-01

    The possibility of separating and recovering CO2 in a biogas plant that co-produces electricity, hydrogen, and heat is investigated. Exploiting the ability of a molten carbonate fuel cell (MCFC) to concentrate CO2 in the anode exhaust stream reduces the energy consumption and complexity of CO2 separation techniques that would otherwise be required to remove dilute CO2 from combustion exhaust streams. Three potential CO2 concentrating configurations are numerically simulated to evaluate potential CO2 recovery rates: 1) anode oxidation and partial CO2 recirculation, 2) integration with exhaust from an internal combustion engine, and 3) series connection of molten carbonate cathodes initially fed with internal combustion engine (ICE) exhaust. Physical models have been calibrated with data acquired from an operating MCFC tri-generating plant. Results illustrate a high compatibility between hydrogen co-production and CO2 recovery with series connection of molten carbonate systems offering the best results for efficient CO2 recovery. In this case the carbon capture ratio (CCR) exceeds 73% for two systems in series and 90% for 3 MCFC in series. This remarkably high carbon recovery is possible with 1.4 MWe delivered by the ICE system and 0.9 MWe and about 350 kg day-1 of H2 delivered by the three MCFC.

  19. The dynamics of plant cell-wall polysaccharide decomposition in leaf-cutting ant fungus gardens.

    Directory of Open Access Journals (Sweden)

    Isabel E Moller

    Full Text Available The degradation of live plant biomass in fungus gardens of leaf-cutting ants is poorly characterised but fundamental for understanding the mutual advantages and efficiency of this obligate nutritional symbiosis. Controversies about the extent to which the garden-symbiont Leucocoprinus gongylophorus degrades cellulose have hampered our understanding of the selection forces that induced large scale herbivory and of the ensuing ecological footprint of these ants. Here we use a recently established technique, based on polysaccharide microarrays probed with antibodies and carbohydrate binding modules, to map the occurrence of cell wall polymers in consecutive sections of the fungus garden of the leaf-cutting ant Acromyrmex echinatior. We show that pectin, xyloglucan and some xylan epitopes are degraded, whereas more highly substituted xylan and cellulose epitopes remain as residuals in the waste material that the ants remove from their fungus garden. These results demonstrate that biomass entering leaf-cutting ant fungus gardens is only partially utilized and explain why disproportionally large amounts of plant material are needed to sustain colony growth. They also explain why substantial communities of microbial and invertebrate symbionts have evolved associations with the dump material from leaf-cutting ant nests, to exploit decomposition niches that the ant garden-fungus does not utilize. Our approach thus provides detailed insight into the nutritional benefits and shortcomings associated with fungus-farming in ants.

  20. Screening of Venezuelan medicinal plant extracts for cytostatic and cytotoxic activity against tumor cell lines.

    Science.gov (United States)

    Taylor, Peter; Arsenak, Miriam; Abad, María Jesús; Fernández, Angel; Milano, Balentina; Gonto, Reina; Ruiz, Marie-Christine; Fraile, Silvia; Taylor, Sofía; Estrada, Omar; Michelangeli, Fabian

    2013-04-01

    There are estimated to be more than 20,000 species of plants in Venezuela, of which more than 1500 are used for medicinal purposes by indigenous and local communities. Only a relatively small proportion of these have been evaluated in terms of their potential as antitumor agents. In this study, we screened 308 extracts from 102 species for cytostatic and cytotoxic activity against a panel of six tumor cell lines using a 24-h sulphorhodamine B assay. Extracts from Clavija lancifolia, Hamelia patens, Piper san-vicentense, Physalis cordata, Jacaranda copaia, Heliotropium indicum, and Annona squamosa were the most cytotoxic, whereas other extracts from Calotropis gigantea, Hyptis dilatata, Chromolaena odorata, Siparuna guianensis, Jacaranda obtusifolia, Tapirira guianensis, Xylopia aromatica, Protium heptaphyllum, and Piper arboreum showed the greatest cytostatic activity. These results confirm previous reports on the cytotoxic activities of the above-mentioned plants as well as prompting further studies on others such as C. lancifolia and H. dilatata that have not been so extensively studied.