WorldWideScience

Sample records for plant cells progress

  1. 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.

  2. Cell-size dependent progression of the cell cycle creates homeostasis and flexibility of plant cell size

    Science.gov (United States)

    R. Jones, Angharad; Forero-Vargas, Manuel; Withers, Simon P.; Smith, Richard S.; Traas, Jan; Dewitte, Walter; Murray, James A. H.

    2017-01-01

    Mean cell size at division is generally constant for specific conditions and cell types, but the mechanisms coupling cell growth and cell cycle control with cell size regulation are poorly understood in intact tissues. Here we show that the continuously dividing fields of cells within the shoot apical meristem of Arabidopsis show dynamic regulation of mean cell size dependent on developmental stage, genotype and environmental signals. We show cell size at division and cell cycle length is effectively predicted using a two-stage cell cycle model linking cell growth and two sequential cyclin dependent kinase (CDK) activities, and experimental results concur in showing that progression through both G1/S and G2/M is size dependent. This work shows that cell-autonomous co-ordination of cell growth and cell division previously observed in unicellular organisms also exists in intact plant tissues, and that cell size may be an emergent rather than directly determined property of cells. PMID:28447614

  3. Rhodococcus fascians infection accelerates progression of tobacco BY-2 cells into mitosis through rapid changes in plant gene expression.

    Science.gov (United States)

    Vandeputte, Olivier; Vereecke, Danny; Mol, Adeline; Lenjou, Marc; Van Bockstaele, Dirk; El Jaziri, Mondher; Baucher, Marie

    2007-01-01

    * To characterize plant cell cycle activation following Rhodococcus fascians infection, bacterial impact on cell cycle progression of tobacco BY-2 cells was investigated. * S-phase-synchronized BY-2 cells were cocultivated with R. fascians and cell cycle progression was monitored by measuring mitotic index, cell cycle gene expression and flow cytometry parameters. Cell cycle alteration was further investigated by cDNA-AFLP (amplified fragment length polymorphism). * It was shown that cell cycle progression of BY-2 cells was accelerated only upon infection with bacteria whose virulence gene expression was induced by a leafy gall extract. Thirty-eight BY-2 genes showed a differential expression within 6 h post-infection. Among these, seven were previously associated with specific plant cell cycle phases (in particular S and G2/M phases). Several genes also showed a differential expression during leafy gall formation. * R. fascians-infected BY-2 cells provide a simple model to identify plant genes related to leafy gall development. R. fascians can also be regarded as a useful biotic agent to alter cell cycle progression and, thereby, gain a better understanding of cell cycle regulation in plants.

  4. 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.

  5. 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.

  6. [Hydroxyproline: Rich glycoproteins of the plant and cell wall]. Annual technical progress report, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Varner, J.E.

    1993-06-01

    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.

  7. 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.

  8. Development of molten carbonate fuel cell power plant. Quarterly technical progress report, February 1-April 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J. R.

    1980-01-01

    Work has been initiated during this first quarter under all four program tasks and by all major participants as described. Task 1.0 activity (establish power plant reference design) concentrated upon definition of user requirements and establishment of power plant subsystem alternatives and characteristics. Task 2.0 work (stack and cell design development and verification) was initiated with a heavy emphasis upon test facilities preparation. A total of 27 laboratory cells were operated during this reporting period and a total of nine cells continued on test at the end of the quarter. Investigation of alternative anode and cathode materials proceeded; a dual-porosity anode was fabricated and tested. Over 10,000 endurance hours on a state-of-the-art cell carried-over from a previous program has been achieved and 1500 hours endurance has been obtained with sheet metal cells. Results presented for electrolyte structure development include comparative data for spray-dried and modified aqueous slurry process powders. Shake-down tests with a rotating disc electrode apparatus for fundamental measurements are described. Concept designs for both prototype and subscale stacks have been identified. Task 3.0 effort (development capability for full-scale stack tests) included preparation of an overall test plan to commercialization for molten carbonate fuel cells and of a functional specification for the tenth-scale stack test facility; drafts of both documents were completed for internal review. Cost-effective manufacturing assessment of available designs and processes was initiated. Task 4.0 work (develop capabilities for operation of stacks on coal-derived gas) included gathering of available contaminants concentration and effects information and preparation of initial projections of contaminant ranges and concentrations. Accomplishments to date and activities planned for the next quarter are described.

  9. 植物多糖干预细胞黏附研究进展%Research progresses of plant polysaccharides on cell adhesion

    Institute of Scientific and Technical Information of China (English)

    徐先祥; 刁勇; 许瑞安; 孙爱静

    2012-01-01

    黏附分子介导的细胞黏附是最基本的生命现象,也是炎症、免疫、感染、血栓形成、肿瘤转移、伤口愈合等生理病理过程的细胞学基础,干预黏附己成为疾病防治的重要策略.植物多糖特别是中草药中的多糖具有抗炎、抗肿瘤、抗感染、调节免疫、保护心血管等多样的药理作用,本文综述了植物多糖对疾病过程中细胞黏附的干预作用.%Cell adhesion mediated by cell adhesion molecules (CAMs) constitutes essential life phenomenon. In inflammation, immunity, infection, thrombosis, tumor metastasis and wound healing, cell adhesion comes into being the basic physiological and pathological process. Intervening with cell adhesion has been the important therapeutic and prophylactic strategies for diseases. Accumulated evidence has indicated that plant polysaccharides especially those exacted from Chinese traditional and herbal drugs displayed various pharmacological effects such as anti-inflammation, anti-cancer, anti-infection, immunomodulation, cardiovascular protective effects and so on. In this paper, the research progress of plant polysaccharides on cell adhesion is reviewed.

  10. Coupling cell proliferation and development in plants.

    Science.gov (United States)

    Gutierrez, Crisanto

    2005-06-01

    Plant genome projects have revealed that both the cell-cycle components and the overall cell-cycle architecture are highly evolutionarily conserved. In addition to the temporal and spatial regulation of cell-cycle progression in individual cells, multicellularity has imposed extra layers of complexity that impinge on the balance of cell proliferation and growth, differentiation and organogenesis. In contrast to animals, organogenesis in plants is a postembryonic and continuous process. Differentiated plant cells can revert to a pluripotent state, proliferate and transdifferentiate. This unique potential is strikingly illustrated by the ability of certain cells to produce a mass of undifferentiated cells or a fully totipotent embryo, which can regenerate mature plants. Conversely, plant cells are highly resistant to oncogenic transformation. This review discusses the role that cell-cycle regulators may have at the interface between cell division and differentiation, and in the context of the high plasticity of plant cells.

  11. Better Plants Progress Update Fall 2013

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-09-23

    This Progress Update summarizes the significant energy saving achievements and cumulative cost savings made by these industry leaders from 2010-2012. The update also shares the plans and priorities over the next year for the Better Plants Program to continue to advance energy efficiency in the industrial sector.

  12. 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.

  13. 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.

  14. Plant Stem Cells

    National Research Council Canada - National Science Library

    Greb, Thomas; Lohmann, Jan U

    2016-01-01

    .... While the promise of organ regeneration and the end of cancer have captured our imagination, it has gone almost unnoticed that plant stem cells represent the ultimate origin of much of the food we...

  15. Frailty of two cell cycle checkpoints which prevent entry into mitosis and progression through early mitotic stages in higher plant cells.

    Science.gov (United States)

    del Campo, A; Giménez-Martín, G; López-Sáez, J F; de la Torre, C

    1997-11-01

    Allium cepa L. root meristems were given two short caffeine treatments spaced by 15 hours, the time which roughly corresponds to the duration of one cell cycle. In this way two subsequent cytokineses were prevented, and multinucleate cells with their in complement distributed into two, three or four nuclei were formed. Though all nuclei started to replicate synchronously in these cells, some of them (fast nuclei) completed their replication earlier than others (slow nuclei). The present report shows that two successive checkpoints operate before prometaphase in these cells. The first one prevents the entry of the fast nuclei into prophase until the slow ones have completed their replication. The second checkpoint ensures the synchronous entry into prometaphase after all nuclei have reached and finished prophase. By treating the multinucleate cells with an inhibitor of DNA synthesis at that time when fast but not slow nuclei had finished their replication, it was observed that both checkpoint mechanisms became leaky with time. Under these conditions the fast nuclei entered prophase in the presence of nuclei which were prevented from finishing the replication of their DNA. Subsequently, even prometaphase was triggered after a prolonged prophase. Finally, as expected from the presence of mitotic stages in these cells, nuclei with incompletely replicated DNA endured premature chromosome condensation. The prematurely condensed chromosomes either remained in a prometaphase-like stage until reconstitution nuclei formed or they followed the progression of the fast nuclei into metaphase and anaphase leading to the appearance of acentric chromosomal segments which after reconstitution gave rise to aneuploid nuclei containing unstable and broken DNA.

  16. [Progress in dedifferentiated fat cells].

    Science.gov (United States)

    Cheng, Feifei; Yang, Zhi; Qian, Cheng

    2014-10-01

    When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to dedifferentiated fat (DFAT) cells. DFAT cells have many advantages compared with adipose-derived stem cells (ASCs) and bone marrow mesenchymal stem cells (BMSCs). For example, DFAT cells are homogeneous and could be obtained from donors regardless of their age. Furthermore, DFAT cells also have the same multi-lineage potentials and low immunogenicity as ASCs. As an excellent source of seed cells for tissue engineering and stem cell transplantation, DFAT cells have better prospects in the treatment of many clinical diseases, such as bone defects, neurological diseases, ischemic heart disease and kidney disease. It is necessary to make more intensive studies of DFAT cells. This article summarizes progresses in the immunological characteristics, differentiation ability and potential clinical applications of DFAT cells.

  17. Progress in polymer solar cell

    Institute of Scientific and Technical Information of China (English)

    LI LiGui; LU GuangHao; YANG XiaoNiu; ZHOU EnLe

    2007-01-01

    This review outlines current progresses in polymer solar cell. Compared to traditional silicon-based photovoltaic (PV) technology, the completely different principle of optoelectric response in the polymer cell results in a novel configuration of the device and more complicated photovoltaic generation process. The conception of bulk-heterojunction (BHJ) is introduced and its advantage in terms of morphology is addressed. The main aspects including the morphology of photoactive layer, which limit the efficiency and stability of polymer solar cell, are discussed in detail. The solutions to boosting up both the efficiency and stability (lifetime) of the polymer solar cell are highlighted at the end of this review.

  18. Gene-enzyme relationships in somatic cells and their organismal derivatives in higher plants. Progress report. [In vitro cultivation of Nicotiana tissues and enzymological studies of gene expression at the cell level

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    Progress over the first 9 months of the project has been substantial along several avenues. We have focussed on Nicotiana sylvestris for intensive study for the reasons specified. The individual characteristics of this organism dictate the need to adapt cell culture techniques to the particular requirements of this species. We have devoted considerable effort to optimization of our system through largely empirical experimentation. Methodological advances have been made to improve techniques for isolating enzyme substrates (mainly pretyrosine) that are not commercially available and for refining analytical techniques for the qualitative assay of the new enzyme activities of aromatic biosynthesis recently found by our group. Enzymological studies have been carried out in organismal plant material as a part of the ultimate goal of defining gene expression at the organismal level in relationship to expression at the cell culture level.

  19. Development of molten carbonate fuel cell power plant technology. Quarterly technical progress report No. 5, October 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The overall objective of this program is to develop and verify the design of a prototype molten carbonate fuel cell stack which meets the requirements of a 1990's-competitive coal-fired electrical utility central station or industrial cogeneratin power plants. During this quarter, activity continued in all four task areas: Task 1 - system studies to define the reference power plant design; Task 2 - cell and stack design, development and verification; Task 3 - preparation for fabrication and testing of the full-scale prototype stack; and Task 4 - development of the capability to operate stacks on coal-derived gas.

  20. Stem cell function during plant vascular development.

    Science.gov (United States)

    Miyashima, Shunsuke; Sebastian, Jose; Lee, Ji-Young; Helariutta, Yka

    2013-01-23

    The plant vascular system, composed of xylem and phloem, evolved to connect plant organs and transport various molecules between them. During the post-embryonic growth, these conductive tissues constitutively form from cells that are derived from a lateral meristem, commonly called procambium and cambium. Procambium/cambium contains pluripotent stem cells and provides a microenvironment that maintains the stem cell population. Because vascular plants continue to form new tissues and organs throughout their life cycle, the formation and maintenance of stem cells are crucial for plant growth and development. In this decade, there has been considerable progress in understanding the molecular control of the organization and maintenance of stem cells in vascular plants. Noticeable advance has been made in elucidating the role of transcription factors and major plant hormones in stem cell maintenance and vascular tissue differentiation. These studies suggest the shared regulatory mechanisms among various types of plant stem cell pools. In this review, we focus on two aspects of stem cell function in the vascular cambium, cell proliferation and cell differentiation.

  1. 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

  2. DIRECT FUEL/CELL/TURBINE POWER PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2004-05-01

    This report includes the progress in development of Direct FuelCell/Turbine{reg_sign} (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation 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, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed testing of the pre-alpha DFC/T hybrid power plant. This power plant was constructed by integration of a 250kW fuel cell stack and a microturbine. The tests of the cascaded fuel cell concept for achieving high fuel utilizations were completed. The tests demonstrated that the concept results in higher power plant efficiency. Also, the preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed.

  3. Progressive Plant Growing Has Business Blooming

    Science.gov (United States)

    2006-01-01

    In 1997, AgriHouse, Inc. (d.b.a. Aeroponics International), a leading agri-biology company, united with NASA and BioServe Space Technologies, a nonprofit, NASA-sponsored partnership research center, to design a soil-less plant-growth experiment to be performed in microgravity, aboard the Mir space station. This experiment aimed to gauge the effectiveness of a non-pesticide solution on the immune responses of bean plants. In essence, the research consortium was looking for a means of keeping plants free from infection, without having to rely on the use of pesticides. This research, combined with follow-on grants from NASA, has helped Berthoud, Colorado-based AgriHouse gain credibility in the commercial marketplace with related technology and gross the capital necessary to conduct further research in a new-age field known as bio-pharming.

  4. Research Progress in Glycine Betaine Improving Plant Salty Stressful Tolerance

    Institute of Scientific and Technical Information of China (English)

    ZHU Hong; WANG Wenjie; YAN Yongqing; ZU Yuangang

    2008-01-01

    Many plants accumulate compatible solutes in response to the imposition of environmental stresses. Glycine betaine, which is one of compatible solutes in cell of plants, has been shown to have surviving ability for plant from salt stress. Effect of glycine betaine on improving plant salt resistance was discussed in plants under salt stress. The accumulation of glycine betaine protects plants against the damaging effects of stress. Strategies of glycine betaine against the damaging effects of stress were analyzed to clarify the roles of glycine betaine in salt stress tolerance of plants.

  5. 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.

  6. [Progress in stem cells and regenerative medicine].

    Science.gov (United States)

    Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

    2015-06-01

    Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

  7. 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.

  8. 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.

  9. Research Progress of Plant Type Microbial Fuel Cell%植物型微生物燃料电池研究进展

    Institute of Scientific and Technical Information of China (English)

    许鹏; 许丹; 张义; 夏世斌; 吴振斌

    2014-01-01

    The combination of the microbial fuel cell with aquatic plants(PMFC)is a new low -carbon environmental pro-tection technology ,it is an important innovation in the field of water pollution control and has raised widespread concern in the world .This paper reviews the current research situation about PMFC ,summarizes the principles of different types of PMF ,analyzes the factors influencing the power production of the PMFC and finally prospects the future application ,as well as working directions of this system .%微生物燃料电池(MFC )与水生植物相耦合,构成植物型微生物燃料电池(PMFC )系统是一项全新的低碳环保产能技术,是水污染控制领域的一项重要技术创新,已在国内外引起广泛关注。对植物型MFC的研究现状进行了综述,总结了不同类型PMFC的工作原理并分析了影响其产电的因素,最后对该系统未来的应用及研究方向进行了展望。

  10. 植物类Caspase及其调控细胞程序性死亡的研究进展%Progress in Caspase-Like Proteases and Their Regulatory Roles in Programmed Cell Death in Plants

    Institute of Scientific and Technical Information of China (English)

    詹洁; 何虎翼; 李文; 何龙飞

    2012-01-01

    Programmed cell death (PCD) plays an important role in the development and adaptation of plants under different environmental stresses. Cysteine-aspartic acid proteases (caspase) are responsible for initiating, executing and signal transduction of animal PCD. The existence of caspase-like proteases has been also demonstrated experimentally in plants by the applications of artificial synthesized substrates and inhibitors of caspase. Caspase-like proteases can be divided into three classes including metacaspases, vacuolar processing enzymes (VPEs) and saspases. In the paper, the progresses of the types, structures, locations, functions of caspase-like proteases and their regulatory roles in plant PCD are reviewed. Subsequently, a regulatory pathway of caspase-like proteases in plant PCD is also suggested. It can support a new insight into further study of caspase-like proteases and their effects in plant PCD.%植物细胞程序性死亡(PCD)在植物生长发育和逆境适应中发挥重要作用.半胱氨酸蛋白酶(caspase)调控动物PCD的启动、执行及信号转导.通过人工合成底物、动物caspase抑制剂等方法已证实在植物中存在类caspase,可分为metacas-pases、VPEs (vacuolar processing enzymes)和saspases等.本文综述了植物类caspase的种类、结构、定位、功能及其调控PCD的研究进展,提出植物PCD中类caspase作用的调控途径,为深入研究植物PCD提供参考.

  11. Lactobacillus decelerates cervical epithelial cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Katarina Vielfort

    Full Text Available We investigated cell cycle progression in epithelial cervical ME-180 cells during colonization of three different Lactobacillus species utilizing live cell microscopy, bromodeoxyuridine incorporation assays, and flow cytometry. The colonization of these ME-180 cells by L. rhamnosus and L. reuteri, originating from human gastric epithelia and saliva, respectively, was shown to reduce cell cycle progression and to cause host cells to accumulate in the G1 phase of the cell cycle. The G1 phase accumulation in L. rhamnosus-colonized cells was accompanied by the up-regulation and nuclear accumulation of p21. By contrast, the vaginal isolate L. crispatus did not affect cell cycle progression. Furthermore, both the supernatants from the lactic acid-producing L. rhamnosus colonies and lactic acid added to cell culture media were able to reduce the proliferation of ME-180 cells. In this study, we reveal the diversity of the Lactobacillus species to affect host cell cycle progression and demonstrate that L. rhamnosus and L. reuteri exert anti-proliferative effects on human cervical carcinoma cells.

  12. Plant single-cell and single-cell-type metabolomics.

    Science.gov (United States)

    Misra, Biswapriya B; Assmann, Sarah M; Chen, Sixue

    2014-10-01

    In conjunction with genomics, transcriptomics, and proteomics, plant metabolomics is providing large data sets that are paving the way towards a comprehensive and holistic understanding of plant growth, development, defense, and productivity. However, dilution effects from organ- and tissue-based sampling of metabolomes have limited our understanding of the intricate regulation of metabolic pathways and networks at the cellular level. Recent advances in metabolomics methodologies, along with the post-genomic expansion of bioinformatics knowledge and functional genomics tools, have allowed the gathering of enriched information on individual cells and single cell types. Here we review progress, current status, opportunities, and challenges presented by single cell-based metabolomics research in plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. [Research progress on plant diversity conservation in sand dune areas].

    Science.gov (United States)

    Liu, Zhi-min; Ma, Jun-ling

    2008-01-01

    The landscape in sand dune areas is characterized by the alternate distribution of sand dune and interdune lowland, and the unique floras in these areas are some endemic or rare plant species. In recent years, the decrease in plant species richness and the disappearance of some endemic or rare plant species in these areas have been received special attention, which were listed in the Program of International Biodiversity Conservation, and studied in many countries and districts. In this paper, the research progress in these fields was summarized from the aspects of significance of plant diversity conservation, formation mechanisms of plant diversity, ways of plant diversity conservation, roles of plant diversity research in the development of ecological theories, and important issues in operating plant diversity conservation project. To conserve plant diversity in sand dune areas, attentions should be paid to the differences in conservation goals (to maintain high species richness or to conserve endemic or rare species) among different regions, and the balances between the stabilization of active sand and the conservation of endemic or rare species, and the maintenance of high species richness and the conservation of endemic or rare species. It needed also to consider the sand dune and the interdune lowland as a unified landscape unit to explore the impacts of disturbances and habitat fragment on plant diversity.

  14. A plant-specific cyclin-dependent kinase is involved in the control of G2/M progression in plants.

    Science.gov (United States)

    Porceddu, A; Stals, H; Reichheld, J P; Segers, G; De Veylder, L; Barroco, R P; Casteels, P; Van Montagu, M; Inzé, D; Mironov, V

    2001-09-28

    Cyclin-dependent kinases (CDKs) control the key transitions in the eukaryotic cell cycle. All the CDKs known to control G(2)/M progression in yeast and animals are distinguished by the characteristic PSTAIRE motif in their cyclin-binding domain and are closely related. Higher plants contain in addition a number of more divergent non-PSTAIRE CDKs with still obscure functions. We show that a plant-specific type of non-PSTAIRE CDKs is involved in the control of the G(2)/M progression. In synchronized tobacco BY-2 cells, the corresponding protein, accumulated in a cell cycle-regulated fashion, peaking at the G(2)/M transition. The associated histone H1 kinase activity reached a maximum in mitosis and required a yet unidentified subunit to be fully active. Down-regulation of the associated kinase activity in transgenic tobacco plants using a dominant-negative mutation delayed G(2)/M transition. These results provide the first evidence that non-PSTAIRE CDKs are involved in the control of the G(2)/M progression in plants.

  15. Hosting the plant cells in vitro: recent trends in bioreactors.

    Science.gov (United States)

    Georgiev, Milen I; Eibl, Regine; Zhong, Jian-Jiang

    2013-05-01

    Biotechnological production of high-value metabolites and therapeutic proteins by plant in vitro systems has been considered as an attractive alternative of classical technologies. Numerous proof-of-concept studies have illustrated the feasibility of scaling up plant in vitro system-based processes while keeping their biosynthetic potential. Moreover, several commercial processes have been established so far. Though the progress on the field is still limited, in the recent years several bioreactor configurations has been developed (e.g., so-called single-use bioreactors) and successfully adapted for growing plant cells in vitro. This review highlights recent progress and limitations in the bioreactors for plant cells and outlines future perspectives for wider industrialization of plant in vitro systems as "green cell factories" for sustainable production of value-added molecules.

  16. 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.

  17. Progressive transformation of immortalized esophageal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Ying Shen; Li-Yan Xu; Min-Hua Chen; Jian Shen; Wei-Jia Cai; Yi Zeng

    2002-01-01

    AIM: To investigate the progressive transformation of immortal cells of human fetal esophageal epithelium induced by human papillomavirus, and to examine biological criteria of sequential passage of cells, including cellular phenotype, proliferative rate, telomerase, chromosome and tumorigenicity.METHODS: The SHEE cell series consisted of immortalized embryonic esophageal epithelium which was in malignant transformation when cultivated over sixty passages without co-carcinogens. Cells of the 10th, 31st, 60th and 85th passages were present in progressive development after being transfected with HPV. Cells were cultivated in a culture flask and 24-hole cultural plates. Progressive changes of morphology, cell growth, contact-inhibition, and anchoragedependent growth characteristics were examined by phase contrast microscopy. The cell proliferation rate was assayed by flow cytometry. The modal number of chromosomes was analyzed. HPV18E6E7 was detected by Western blot methods and activities of telomerase were analyzed by TRAP.Tumorigenicity of cells was detected with soft agar plates cultivated and with tumor formation in SCID mice.RESULTS: In morphological examination the 10th passage cells were in good differentiation, the 60th and 85th passages cells were in relatively poor differentiation, and the 31st passage cells had two distinct differentiations. The characteristics of the 85th and 60th passage cells were weakened at contact-inhibition and anchorage-dependent growth. Karyotypes of four stages of cells belonged to hyperdiploid or hypotriploid, and bimodal distribution of chromosomes appeared in the 31st and 60th passage cells. All of these characteristics combined with a increasing trend. The activities of telomerase were expressed in the latter three passages. Four fourths of SCID mice in the 85th passage cells and one fourth of SCID mice in the 60th passage cells developed tumors, but the cells in the 10th and 31st passage displayed no tumor formation

  18. 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.

  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. Cell cycle progression score predicts metastatic progression of clear cell renal cell carcinoma after resection.

    Science.gov (United States)

    Askeland, Eric J; Chehval, Vincent A; Askeland, Ryan W; Fosso, Placede G; Sangale, Zaina; Xu, Nafei; Rajamani, Saradha; Stone, Steven; Brown, James A

    2015-01-01

    The outcome of surgically resected, apparently localized, clear cell renal carcinoma (ccRCC) is uncertain. To evaluate if cell cycle progression (CCP) gene expression can predict future metastasis. Pathologic T2a-T3b tumors at University of Iowa were reviewed. Patients with known or suspected metastasis, lymph node involvement or who received neoadjuvant or adjuvant radiation, chemotherapy or immunotherapy were excluded. Case and control cohorts were defined as those who did or did not develop metastatic disease within 5 years. Measured levels of 31 cell cycle genes and 15 control genes from the tumor were calculated as a CCP score. Additionally, gene expression data for a separate ccRCC cohort was downloaded from The Cancer Genome Atlas (TCGA). Univariate analysis of 26 cases and 38 controls revealed that the CCP score predicted progression to metastasis (OR 2.65, p = 0.0091). In multivariate logistic regression modeling, CCP expression remained a significant independent predictor for progression (p = 0.026). The CCP score was also significantly associated with distant metastasis in the TCGA renal cancer cohort in both univariate (p = 1.0 × 10-9) and multivariate (p = 5.6 × 10-3) analysis. The CCP score has prognostic value in predicting metastatic progression after resection of organ-confined ccRCC.

  1. 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.

  2. 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

  3. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.|info:eu-repo/dai/nl/07493662X

    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

  4. 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

  5. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Science.gov (United States)

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2016-10-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  6. Regio- and stereoselectivities in plant cell biotransformation

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, H. [Okayama Univ. of Science (Japan)

    1995-12-01

    The ability of plant cultured cells to convert foreign substrates into more useful substances is of considerable interest. Therefore I have studied biotransformation of foreign substrate by plant cell suspension cultures. In this presentation, I report regio- and stereoselectivities in biotransformation of steroids and indole alkaloids and taxol by plant (tobacco, periwinkle, moss, orchid) cell suspension cultures.

  7. 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…

  8. Folates in plants: research advances and progress in crop biofortification

    Science.gov (United States)

    Gorelova, Vera; Ambach, Lars; Rébeillé, Fabrice; Stove, Christophe; Van Der Straeten, Dominique

    2017-03-01

    Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by folates make them essential in all living organisms. Plants, being able to synthesize folates de novo, serve as an excellent dietary source of folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today’s knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of folates in plants only starts to emerge. In the current review we will discuss the

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

    Directory of Open Access Journals (Sweden)

    Cécile eALBENNE

    2013-05-01

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

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

    Science.gov (United States)

    Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth

    2013-01-01

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

  11. Reprogramming cancer cells: overview & current progress.

    Science.gov (United States)

    Lim, Kian Lam; Teoh, Hoon Koon; Choong, Pei Feng; Teh, Hui Xin; Cheong, Soon Keng; Kamarul, Tunku

    2016-07-01

    Cancer is a disease with genetic and epigenetic origins, and the possible effects of reprogramming cancer cells using the defined sets of transcription factors remain largely uninvestigated. In the handful of publications available so far, findings have shown that reprogramming cancer cells changed the characteristics of the cells to differ from the parental cancer cells. These findings indicated the possibility of utilizing reprogramming technology to create a disease model in the laboratory to be used in studying the molecular pathogenesis or for drug screening of a particular cancer model. Despite numerous methods employed in generating induced pluripotent stem cells (iPSCs) from cancer cells only a few studies have successfully reprogrammed malignant human cells. In this review we will provide an overview on i) methods to reprogram cancer cells, ii) characterization of the reprogrammed cancer cells, and iii) the differential effects of reprogramming on malignancy, epigenetics and response of the cancer cells to chemotherapeutic agents. Continued technical progress in cancer cell reprogramming technology will be instrumental for more refined in vitro disease models and ultimately for the development of directed and personalized therapy for cancer patients in the future.

  12. Current progress with primate embryonic stem cells.

    Science.gov (United States)

    Byrne, James A; Mitalipov, Shoukhrat M; Wolf, Don P

    2006-05-01

    Embryonic stem cells (ESCs) can proliferate indefinitely, maintain an undifferentiated pluripotent state and differentiate into any cell type. Differentiation of ESCs into various specific cell-types may be able to cure or alleviate the symptoms of various degenerative diseases. Unresolved issues regarding maintaining function, possible apoptosis and tumor formation in vivo mean a prudent approach should be taken towards advancing ESCs into human clinical trials. Rhesus macaques provide the ideal model organism for testing the feasibility, efficacy and safety of ESC based therapies and significant numbers of primate ESC lines are now available. In this review, we will summarize progress in evaluating the genetic and epigenetic integrity of primate ESCs, examine their current use in pre-clinical trials and discuss the potential of producing ESC-derived cell populations that are genetically identical (isogenic) to the host by somatic cell nuclear transfer.

  13. Progress and prospects in stem cell therapy

    Institute of Scientific and Technical Information of China (English)

    Xiu-ling XU; Fei YI; Hui-ze PAN; Shun-lei DUAN; Zhi-chao DING; Guo-hong YUAN; Jing QU

    2013-01-01

    In the past few years,progress being made in stem cell studies has incontestably led to the hope of developing cell replacement based therapy for diseases deficient in effective treatment by conventional ways.The induced pluripotent stem cells (iPSCs) are of great interest of cell therapy research because of their unrestricted self-renewal and differentiation potentials.Proof of principle studies have successfully demonstrated that iPSCs technology would substantially benefit clinical studies in various areas,including neurological disorders,hematologic diseases,cardiac diseases,liver diseases and etc.On top of this,latest advances of gene editing technologies have vigorously endorsed the possibility of obtaining disease-free autologous cells from patient specific iPSCs.Here in this review,we summarize current progress of stem cell therapy research with special enthusiasm in iPSCs studies.In addition,we compare current gene editing technologies and discuss their potential implications in clinic application in the future.

  14. Perovskite Solar Cells: Progress and Advancements

    Directory of Open Access Journals (Sweden)

    Naveen Kumar Elumalai

    2016-10-01

    Full Text Available Organic–inorganic hybrid perovskite solar cells (PSCs have emerged as a new class of optoelectronic semiconductors that revolutionized the photovoltaic research in the recent years. The perovskite solar cells present numerous advantages include unique electronic structure, bandgap tunability, superior charge transport properties, facile processing, and low cost. Perovskite solar cells have demonstrated unprecedented progress in efficiency and its architecture evolved over the period of the last 5–6 years, achieving a high power conversion efficiency of about 22% in 2016, serving as a promising candidate with the potential to replace the existing commercial PV technologies. This review discusses the progress of perovskite solar cells focusing on aspects such as superior electronic properties and unique features of halide perovskite materials compared to that of conventional light absorbing semiconductors. The review also presents a brief overview of device architectures, fabrication methods, and interface engineering of perovskite solar cells. The last part of the review elaborates on the major challenges such as hysteresis and stability issues in perovskite solar cells that serve as a bottleneck for successful commercialization of this promising PV technology.

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

    Science.gov (United States)

    Wang, Tuo; Phyo, Pyae; Hong, Mei

    2016-09-01

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

  16. Cell Polarity Proteins in Breast Cancer Progression.

    Science.gov (United States)

    Rejon, Carlis; Al-Masri, Maia; McCaffrey, Luke

    2016-10-01

    Breast cancer, one of the leading causes of cancer related death in women worldwide, is a heterogeneous disease with diverse subtypes that have different properties and prognoses. The developing mammary gland is a highly proliferative and invasive tissue, and some of the developmental programs may be aberrantly activated to promote breast cancer progression. In the breast, luminal epithelial cells exhibit apical-basal polarity, and the failure to maintain this organizational structure, due to disruption of polarity complexes, is implicated in promoting hyperplasia and tumors. Therefore, understanding the mechanisms underlying loss of polarity will contribute to our knowledge of the early stages leading to the pathogenesis of the disease. In this review, we will discuss recent findings that support the idea that loss of apical-basal cell polarity is a crucial step in the acquisition of the malignant phenotype. Oncogene induced loss of tissue organization shares a conserved cellular mechanism with developmental process, we will further describe the role of the individual polarity complexes, the Par, Crumbs, and Scribble, to couple cell division orientation and cell growth. We will examine symmetric or asymmetric cell divisions in mammary stem cell and their contribution to the development of breast cancer subtypes and cancer stem cells. Finally, we will highlight some of the recent advances in our understanding of the molecular mechanisms by which changes in epithelial polarity programs promote invasion and metastasis through single cell and collective cell modes. J. Cell. Biochem. 117: 2215-2223, 2016. © 2016 Wiley Periodicals, Inc.

  17. Plant caspase-like proteases in plant programmed cell death

    OpenAIRE

    Xu, Qixian; Zhang, Lingrui

    2009-01-01

    Programmed cell death (PCD) is a genetically-controlled disassembly of the cell. In animal systems, the central core execution switch for apoptotic PCD is the activation of caspases (Cysteine-containing Aspartate-specific proteases). Accumulating evidence in recent years suggests the existence of caspase-like activity in plants and its functional involvement in various types of plant PCD, although no functional homologs of animal caspases were identified in plant genome. In this mini-review, ...

  18. 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

  19. Future Scenarios for Plant Virus Pathogens as Climate Change Progresses.

    Science.gov (United States)

    Jones, R A C

    2016-01-01

    Knowledge of how climate change is likely to influence future virus disease epidemics in cultivated plants and natural vegetation is of great importance to both global food security and natural ecosystems. However, obtaining such knowledge is hampered by the complex effects of climate alterations on the behavior of diverse types of vectors and the ease by which previously unknown viruses can emerge. A review written in 2011 provided a comprehensive analysis of available data on the effects of climate change on virus disease epidemics worldwide. This review summarizes its findings and those of two earlier climate change reviews and focuses on describing research published on the subject since 2011. It describes the likely effects of the full range of direct and indirect climate change parameters on hosts, viruses and vectors, virus control prospects, and the many information gaps and deficiencies. Recently, there has been encouraging progress in understanding the likely effects of some climate change parameters, especially over the effects of elevated CO2, temperature, and rainfall-related parameters, upon a small number of important plant viruses and several key insect vectors, especially aphids. However, much more research needs to be done to prepare for an era of (i) increasingly severe virus epidemics and (ii) increasing difficulties in controlling them, so as to mitigate their detrimental effects on future global food security and plant biodiversity.

  20. Microfluidic platforms for plant cells studies.

    Science.gov (United States)

    Sanati Nezhad, A

    2014-09-07

    Conventional methods of plant cell analysis rely on growing plant cells in soil pots or agarose plates, followed by screening the plant phenotypes in traditional greenhouses and growth chambers. These methods are usually costly, need a large number of experiments, suffer from low spatial resolution and disorderly growth behavior of plant cells, with lack of ability to locally and accurately manipulate the plant cells. Microfluidic platforms take advantage of miniaturization for handling small volume of liquids and providing a closed environment, with the purpose of in vitro single cell analysis and characterizing cell response to external cues. These platforms have shown their ability for high-throughput cellular analysis with increased accuracy of experiments, reduced cost and experimental times, versatility in design, ability for large-scale and combinatorial screening, and integration with other miniaturized sensors. Despite extensive research on animal cells within microfluidic environments for high-throughput sorting, manipulation and phenotyping studies, the application of microfluidics for plant cells studies has not been accomplished yet. Novel devices such as RootChip, RootArray, TipChip, and PlantChip developed for plant cells analysis, with high spatial resolution on a micrometer scale mimicking the internal microenvironment of plant cells, offering preliminary results on the capability of microfluidics to conquer the constraints of conventional methods. These devices have been used to study different aspects of plant cell biology such as gene expression, cell biomechanics, cellular mechanism of growth, cell division, and cells fusion. This review emphasizes the advantages of current microfluidic systems for plant science studies, and discusses future prospects of microfluidic platforms for characterizing plant cells response to diverse external cues.

  1. Progress in Electrolyte-Free Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yuzheng eLu

    2016-05-01

    Full Text Available Solid Oxide Fuel Cell (SOFC represents a clean electrochemical energy conversion technology with characteristics of high conversion efficiency and low emissions. It is one of the most important new energy technologies in the future. However, the manufacture of SOFCs based on the structure of anode/electrolyte/cathode is complicated and time-consuming. Thus, the cost for the entire fabrication and technology is too high to be affordable and challenges still hinder commercialization. Recently, a novel type of Electrolyte -free fuel cell (EFFC with single component was invented which could be the potential candidate for the next generation of advanced fuel cells. This paper briefly introduces the EFFC, working principle, performance and advantages with updated research progress. A number of key R&D issues about EFFCs have been addressed and future opportunities and challenges are discussed.

  2. Stem cells - biological update and cell therapy progress.

    Science.gov (United States)

    Girlovanu, Mihai; Susman, Sergiu; Soritau, Olga; Rus-Ciuca, Dan; Melincovici, Carmen; Constantin, Anne-Marie; Mihu, Carmen Mihaela

    2015-01-01

    In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods to prevent teratoma formation or the ethical and religious issues regarding especially the embryonic stem cell research. The direct differentiation of stem cells into specialized cells: cardiac myocytes, neural cells, pancreatic islets cells, may represent an option in treating incurable diseases such as: neurodegenerative diseases, type I diabetes, hematologic or cardiac diseases. Nevertheless, stem cell-based therapies, based on stem cell transplantation, remain mainly at the experimental stages and their major limitation is the development of teratoma and cancer after transplantation. The induced pluripotent stem cells (hiPSCs) represent a prime candidate for future cell therapy research because of their significant self-renewal and differentiation potential and the lack of ethical issues. This article presents an overview of the biological advances in the study of stem cells and the current progress made in the field of regenerative medicine.

  3. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific

  4. Cell cycle activation by plant parasitic nematodes

    NARCIS (Netherlands)

    Goverse, A.; Almeida Engler, de J.; Verhees, J.; Krol, van der S.; Helder, J.; Gheysen, G.

    2000-01-01

    Sedentary nematodes are important pests of crop plants. They are biotrophic parasites that can induce the (re)differentiation of either differentiated or undifferentiated plant cells into specialized feeding cells. This (re)differentiation includes the reactivation of the cell cycle in specific plan

  5. Physiological functions of plant cell coverings.

    Science.gov (United States)

    Hoson, Takayuki

    2002-08-01

    The cell coverings of plants have two important functions in plant life. Plant cell coverings are deeply involved in the regulation of the life cycle of plants: each stage of the life cycle, such as germination, vegetative growth, reproductive growth, and senescence, is strongly influenced by the nature of the cell coverings. Also, the apoplast, which consists of the cell coverings, is the field where plant cells first encounter the outer environment, and so becomes the major site of plant responses to the environment. In the regulation of each stage of the life cycle and the response to each environmental signal, some specific constituents of the cell coverings, such as xyloglucans in dicotyledons and 1,3,1,4-beta-glucans in Gramineae, act as the key component. The physiological functions of plant cell coverings are sustained by the metabolic turnover of these components. The components of the cell coverings are supplied from the symplast, but then they are modified or degraded in the apoplast. Thus, the metabolism of the cell coverings is regulated through the cross-talk between the symplast and the apoplast. The understanding of physiological functions of plant cell coverings will be greatly advanced by the use of genomic approaches. At the same time, we need to introduce nanobiological techniques for clarifying the minute changes in the cell coverings that occur in a small part within each cell.

  6. Progress in Genome Editing Technology and Its Application in Plants

    Science.gov (United States)

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, protein-dependent DNA cleavage systems (i.e., zinc-finger nucleases, ZFN, and transcription activator-like effector nucleases, TALEN), RNA-dependent DNA cleavage systems (i.e., clustered regularly interspaced short palindromic repeats-CRISPR associated proteins, CRISPR-Cas9, CRISPR-Cpf1, and CRISPR-C2c1), and RNA-dependent RNA cleavage systems (i.e., RNA interference, RNAi, and CRISPR-C2c2). All these techniques can lead to double-stranded (DSB) or single-stranded breaks (SSB), and result in either random mutations via non-homologous end-joining (NHEJ) or targeted mutation via homologous recombination (HR). Thus, site-directed mutagenesis can be induced via targeted gene knock-out, knock-in, or replacement to modify specific characteristics including morphology-modification, resistance-enhancement, and physiological mechanism-improvement along with plant growth and development. In this paper, an non-comprehensive review on the development of different GETs as applied to plants is presented. PMID:28261237

  7. Progress in Genome Editing Technology and Its Application in Plants.

    Science.gov (United States)

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, protein-dependent DNA cleavage systems (i.e., zinc-finger nucleases, ZFN, and transcription activator-like effector nucleases, TALEN), RNA-dependent DNA cleavage systems (i.e., clustered regularly interspaced short palindromic repeats-CRISPR associated proteins, CRISPR-Cas9, CRISPR-Cpf1, and CRISPR-C2c1), and RNA-dependent RNA cleavage systems (i.e., RNA interference, RNAi, and CRISPR-C2c2). All these techniques can lead to double-stranded (DSB) or single-stranded breaks (SSB), and result in either random mutations via non-homologous end-joining (NHEJ) or targeted mutation via homologous recombination (HR). Thus, site-directed mutagenesis can be induced via targeted gene knock-out, knock-in, or replacement to modify specific characteristics including morphology-modification, resistance-enhancement, and physiological mechanism-improvement along with plant growth and development. In this paper, an non-comprehensive review on the development of different GETs as applied to plants is presented.

  8. K+ channels and cell cycle progression in tumor cells

    Directory of Open Access Journals (Sweden)

    HALIMA eOUADID-AHIDOUCH

    2013-08-01

    Full Text Available K+ ions play a major role in many cellular processes. The deregulation of K+ signaling is associated with a variety of diseases such as hypertension, atherosclerosis, or diabetes. K+ ions are important for setting the membrane potential, the driving force for Ca2+ influx, and regulate volume of growing cells. Moreover, it is increasingly recognized that K+ channels control cell proliferation through a novel signaling mechanisms triggered and modulated independently of ion fluxes. In cancer, aberrant expression, regulation and/or sublocalization of K+ channels can alter the downstream signals that converge on the cell cycle machinery. Various K+ channels are involved in cell cycle progression and are needed only at particular stages of the cell cycle. Consistent with this idea, the expression of Eag1 and HERG channels fluctuate along the cell cycle. Despite of acquired knowledge, our understanding of K+ channels functioning in cancer cells requires further studies. These include identifying the molecular mechanisms controling the cell cycle machinery. By understanding how K+ channels regulate cell cycle progression in cancer cells, we will gain insights into how cancer cells subvert the need for K+ signal and its downstream targets to proliferate.

  9. 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

  10. Cell-penetrating peptides: From mammalian to plant cells

    OpenAIRE

    Eudes, François; Chugh, Archana

    2008-01-01

    Internalization of cell-penetrating peptides, well described in mammalian cell system, has recently been reported in a range of plant cells by three independent groups. Despite fundamental differences between animal cell and plant cell composition, the CPP uptake pattern between the mammalian system and the plant system is very similar. Tat, Tat-2 pVEC and transportan internalisation is concentration dependent and non saturable, enhanced at low temperature (4°C), and receptor independent. The...

  11. An intrinsic microRNA timer regulates progressive decline in shoot regenerative capacity in plants.

    Science.gov (United States)

    Zhang, Tian-Qi; Lian, Heng; Tang, Hongbo; Dolezal, Karel; Zhou, Chuan-Miao; Yu, Sha; Chen, Juan-Hua; Chen, Qi; Liu, Hongtao; Ljung, Karin; Wang, Jia-Wei

    2015-02-01

    Plant cells are totipotent and competent to regenerate from differentiated organs. It has been shown that two phytohormones, auxin and cytokinin, play critical roles within this process. As in animals, the regenerative capacity declines with age in plants, but the molecular basis for this phenomenon remains elusive. Here, we demonstrate that an age-regulated microRNA, miR156, regulates shoot regenerative capacity. As a plant ages, the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors leads to the progressive decline in shoot regenerative capacity. In old plants, SPL reduces shoot regenerative capacity by attenuating the cytokinin response through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs, which encode the transcriptional activators in the cytokinin signaling pathway. Consistently, the increased amount of exogenous cytokinin complements the reduced shoot regenerative capacity in old plants. Therefore, the recruitment of age cues in response to cytokinin contributes to shoot regenerative competence. © 2015 American Society of Plant Biologists. All rights reserved.

  12. Polarity in plant asymmetric cell division: Division orientation and cell fate differentiation.

    Science.gov (United States)

    Shao, Wanchen; Dong, Juan

    2016-11-01

    Asymmetric cell division (ACD) is universally required for the development of multicellular organisms. Unlike animal cells, plant cells have a rigid cellulosic extracellular matrix, the cell wall, which provides physical support and forms communication routes. This fundamental difference leads to some unique mechanisms in plants for generating asymmetries during cell division. However, plants also utilize intrinsically polarized proteins to regulate asymmetric signaling and cell division, a strategy similar to the differentiation mechanism found in animals. Current progress suggests that common regulatory modes, i.e. protein spontaneous clustering and cytoskeleton reorganization, underlie protein polarization in both animal and plant cells. Despite these commonalities, it is important to note that intrinsic mechanisms in plants are heavily influenced by extrinsic cues. To control physical asymmetry in cell division, although our understanding is fragmentary thus far, plants might have evolved novel polarization strategies to orientate cell division plane. Recent studies also suggest that the phytohormone auxin, one of the most pivotal small molecules in plant development, regulates ACD in plants. Copyright © 2016. Published by Elsevier Inc.

  13. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  14. Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor

    Science.gov (United States)

    Parks, Kelsey

    2009-01-01

    Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

  15. Plant stem cells as innovation in cosmetics.

    Science.gov (United States)

    Moruś, Martyna; Baran, Monika; Rost-Roszkowska, Magdalena; Skotnicka-Graca, Urszula

    2014-01-01

    The stem cells thanks to their ability of unlimited division number or transformation into different cell types creating organs, are responsible for regeneration processes. Depending on the organism in which the stem cells exists, they divide to the plant or animal ones. The later group includes the stem cells existing in both embryo's and adult human's organs. It includes, among others, epidermal stem cells, located in the hair follicle relieves and also in its basal layers, and responsible for permanent regeneration of the epidermis. Temporary science looks for method suitable for stimulation of the epidermis stem cells, amongst the other by delivery of e.g., growth factors for proliferation that decrease with the age. One of the methods is the use of the plant cell culture technology, including a number of methods that should ensure growth of plant cells, issues or organs in the environment with the microorganism-free medium. It uses abilities of the different plant cells to dedifferentiation into stem cells and coming back to the pluripotent status. The extracts obtained this way from the plant stem cells are currently used for production of both common or professional care cosmetics. This work describes exactly impact of the plant stem cell extract, coming from one type of the common apple tree (Uttwiler Spätlauber) to human skin as one of the first plant sorts, which are used in cosmetology and esthetic dermatology.

  16. Gene Delivery into Plant Cells for Recombinant Protein Production

    Directory of Open Access Journals (Sweden)

    Qiang Chen

    2015-01-01

    Full Text Available Recombinant proteins are primarily produced from cultures of mammalian, insect, and bacteria cells. In recent years, the development of deconstructed virus-based vectors has allowed plants to become a viable platform for recombinant protein production, with advantages in versatility, speed, cost, scalability, and safety over the current production paradigms. In this paper, we review the recent progress in the methodology of agroinfiltration, a solution to overcome the challenge of transgene delivery into plant cells for large-scale manufacturing of recombinant proteins. General gene delivery methodologies in plants are first summarized, followed by extensive discussion on the application and scalability of each agroinfiltration method. New development of a spray-based agroinfiltration and its application on field-grown plants is highlighted. The discussion of agroinfiltration vectors focuses on their applications for producing complex and heteromultimeric proteins and is updated with the development of bridge vectors. Progress on agroinfiltration in Nicotiana and non-Nicotiana plant hosts is subsequently showcased in context of their applications for producing high-value human biologics and low-cost and high-volume industrial enzymes. These new advancements in agroinfiltration greatly enhance the robustness and scalability of transgene delivery in plants, facilitating the adoption of plant transient expression systems for manufacturing recombinant proteins with a broad range of applications.

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

    Science.gov (United States)

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

    2014-10-01

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

  18. [On plant stem cells and animal stem cells].

    Science.gov (United States)

    You, Yun; Jiang, Chao; Huang, Lu-Qi

    2014-01-01

    A comparison of plant and animal stem cells can highlight core aspects of stem-cell biology. In both kingdoms, stem cells are defined by their clonogenic properties and are maintained by intercellular signals. The signaling molecules are different in plants and animals stem cell niches, but the roles of argonaute and polycomb group proteins suggest that there are some molecular similarities.

  19. 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...

  20. Polarity establishment, morphogenesis, and cultured plant cells in space

    Science.gov (United States)

    Krikorian, Abraham D.

    1989-01-01

    Plant development entails an orderly progression of cellular events both in terms of time and geometry. There is only circumstantial evidence that, in the controlled environment of the higher plant embryo sac, gravity may play a role in embryo development. It is still not known whether or not normal embryo development and differentiation in higher plants can be expected to take place reliably and efficiently in the micro g space environment. It seems essential that more attention be given to studying aspects of reproductive biology in order to be confident that plants will survive seed to seed to seed in a space environment. Until the time arrives when successive generations of plants can be grown, the best that can be done is utilize the most appropriate systems and begin, piece meal, to accumulate information on important aspects of plant reproduction. Cultured plant cells can play an important role in these activities since they can be grown so as to be morphogenetically competent, and thus can simulate those embryogenic events more usually identified with fertilized eggs in the embryo sac of the ovule in the ovary. Also, they can be manipulated with relative ease. The extreme plasticity of such demonstrably totipotent cell systems provides a means to test environmental effects such as micro g on a potentially free-running entity. The successful manipulation and management of plant cells and propagules in space also has significance for exploitation of biotechnologies in space since such systems, perforce, are an important vehicle whereby many genetic engineering manipulations are achieved.

  1. Mir-33 regulates cell proliferation and cell cycle progression.

    Science.gov (United States)

    Cirera-Salinas, Daniel; Pauta, Montse; Allen, Ryan M; Salerno, Alessandro G; Ramírez, Cristina M; Chamorro-Jorganes, Aranzazu; Wanschel, Amarylis C; Lasuncion, Miguel A; Morales-Ruiz, Manuel; Suarez, Yajaira; Baldan, Ángel; Esplugues, Enric; Fernández-Hernando, Carlos

    2012-03-01

    Cholesterol metabolism is tightly regulated at the cellular level and is essential for cellular growth. microRNAs (miRNAs), a class of noncoding RNAs, have emerged as critical regulators of gene expression, acting predominantly at posttranscriptional level. Recent work from our group and others has shown that hsa-miR-33a and hsa-miR-33b, miRNAs located within intronic sequences of the Srebp genes, regulate cholesterol and fatty acid metabolism in concert with their host genes. Here, we show that hsa-miR-33 family members modulate the expression of genes involved in cell cycle regulation and cell proliferation. MiR-33 inhibits the expression of the cyclin-dependent kinase 6 (CDK6) and cyclin D1 (CCND1), thereby reducing cell proliferation and cell cycle progression. Overexpression of miR-33 induces a significant G 1 cell cycle arrest in Huh7 and A549 cell lines. Most importantly, inhibition of miR-33 expression using 2'fluoro/methoxyethyl-modified (2'F/MOE-modified) phosphorothioate backbone antisense oligonucleotides improves liver regeneration after partial hepatectomy (PH) in mice, suggesting an important role for miR-33 in regulating hepatocyte proliferation during liver regeneration. Altogether, these results suggest that Srebp/miR-33 locus may cooperate to regulate cell proliferation, cell cycle progression and may also be relevant to human liver regeneration.

  2. [Genetic regulation of plant shoot stem cells].

    Science.gov (United States)

    Al'bert, E V; Ezhova, T A

    2013-02-01

    This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.

  3. Catalysts of plant cell wall loosening

    OpenAIRE

    Cosgrove, Daniel J.

    2016-01-01

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

  4. 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...

  5. Plant cells: immobilization and oxygen transfer.

    NARCIS (Netherlands)

    Hulst, A.C.

    1987-01-01

    The study described in this thesis is part of the integrated project 'Biotechnological production of non-persistent bioinsecticides by means of plant cells invitro ' and was done in close cooperation with the research Institute Ital within the framework of NOVAPLANT. The plant cells us

  6. Cell fusion and nuclear fusion in plants.

    Science.gov (United States)

    Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

    2016-12-01

    Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall.

  7. Transport vesicle formation in plant cells.

    Science.gov (United States)

    Hwang, Inhwan; Robinson, David G

    2009-12-01

    In protein trafficking, transport vesicles bud from donor compartments and carry cargo proteins to target compartments with which they fuse. Thus, vesicle formation is an essential step in protein trafficking. As for mammals, plant cells contain the three major types of vesicles: COPI, COPII, and CCV and the major molecular players in vesicle-mediated protein transport are also present. However, plant cells generally contain more isoforms of the coat proteins, ARF GTPases and their regulatory proteins, as well as SNAREs. In addition, plants have established some unique subfamilies, which may reflect plant cell-specific conditions such as the absence of an ER-Golgi intermediate compartment and the combined activities of the TGN and early endosome. Thus, even though we are still at an early stage in understanding the physiological function of these proteins, it is already clear that vesicle-mediated protein transport in plant cells displays both similarities as well as differences in animal cells.

  8. 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

  9. [Research progress of genetic engineering on medicinal plants].

    Science.gov (United States)

    Teng, Zhong-qiu; Shen, Ye

    2015-02-01

    The application of genetic engineering technology in modern agriculture shows its outstanding role in dealing with food shortage. Traditional medicinal plant cultivation and collection have also faced with challenges, such as lack of resources, deterioration of environment, germplasm of recession and a series of problems. Genetic engineering can be used to improve the disease resistance, insect resistance, herbicides resistant ability of medicinal plant, also can improve the medicinal plant yield and increase the content of active substances in medicinal plants. Thus, the potent biotechnology can play an important role in protection and large area planting of medicinal plants. In the development of medicinal plant genetic engineering, the safety of transgenic medicinal plants should also be paid attention to. A set of scientific safety evaluation and judgment standard which is suitable for transgenic medicinal plants should be established based on the recognition of the particularity of medicinal plants.

  10. Enzymatic Modification of Plant Cell Wall Polysaccharides

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  11. Enzymatic Modification of Plant Cell Wall Polysaccharides

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  12. Prospects for advanced coal-fuelled fuel cell power plants

    Science.gov (United States)

    Jansen, D.; Vanderlaag, P. C.; Oudhuis, A. B. J.; Ribberink, J. S.

    1994-04-01

    As part of ECN's in-house R&D programs on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO2 emissions, and to find possible ways for CO2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fueled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fueled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency.

  13. Plant cell proliferation inside an inorganic host.

    Science.gov (United States)

    Perullini, Mercedes; Rivero, María Mercedes; Jobbágy, Matías; Mentaberry, Alejandro; Bilmes, Sara A

    2007-01-10

    In recent years, much attention has been paid to plant cell culture as a tool for the production of secondary metabolites and the expression of recombinant proteins. Plant cell immobilization offers many advantages for biotechnological processes. However, the most extended matrices employed, such as calcium-alginate, cannot fully protect entrapped cells. Sol-gel chemistry of silicates has emerged as an outstanding strategy to obtain biomaterials in which living cells are truly protected. This field of research is rapidly developing and a large number of bacteria and yeast-entrapping ceramics have already been designed for different applications. But even mild thermal and chemical conditions employed in sol-gel synthesis may result harmful to cells of higher organisms. Here we present a method for the immobilization of plant cells that allows cell growth at cavities created inside a silica matrix. Plant cell proliferation was monitored for a 6-month period, at the end of which plant calli of more than 1 mm in diameter were observed inside the inorganic host. The resulting hybrid device had good mechanical stability and proved to be an effective barrier against biological contamination, suggesting that it could be employed for long-term plant cell entrapment applications.

  14. Gene Delivery into Plant Cells for Recombinant Protein Production

    OpenAIRE

    Qiang Chen; Huafang Lai

    2015-01-01

    Recombinant proteins are primarily produced from cultures of mammalian, insect, and bacteria cells. In recent years, the development of deconstructed virus-based vectors has allowed plants to become a viable platform for recombinant protein production, with advantages in versatility, speed, cost, scalability, and safety over the current production paradigms. In this paper, we review the recent progress in the methodology of agroinfiltration, a solution to overcome the challenge of transgene d...

  15. Cloning higher plants from aseptically cultured tissues and cells

    Science.gov (United States)

    Krikorian, A. D.

    1982-01-01

    A review of aseptic culture methods for higher plants is presented, which focuses on the existing problems that limit or prevent the full realization of cloning plants from free cells. It is shown that substantial progress in clonal multiplication has been made with explanted stem tips or lateral buds which can be stimulated to produce numerous precocious axillary branches. These branches can then be separated or subdivided and induced to root in order to yield populations of genetically and phenotypically uniorm plantlets. Similarly, undifferentiated calluses can sometimes be induced to form shoots and/or roots adventitiously. Although the cell culture techniques required to produce somatic embryos are presently rudimentary, steady advances are being made in learning how to stimulate formation of somatic or adventive embryos from totipotent cells grown in suspension cultures. It is concluded that many problems exist in the producing and growing of totipotent or morphogenetically competent cell suspensions, but the potential benefits are great.

  16. [Mechanisms of potassium transport in plants and fungi]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Slayman, C.L.

    1993-07-01

    Progress is reported on three front namely survey of ion channels in Arabidopsis; chemical characterization of the tonoplast cation channel (YVC1) in Saccharomyces; and characterization of a fungal proton pump cloned into mammalian cells. Continued work with the yeast plasma-membrane K{sup +} channel (YPK1) led to clear demonstrations that gating of YPK1 depends upon the disequilibrium voltage for K{sup +}, rather than upon the absolute membrane voltage, and that all channels observable in the yeast plasmalemma are unchanged in primary pump mutants. Preliminary patch-clamp studies on the plasmalemma of Neurospora also identified two conspicuous cation channels in that membrane. A concerted effort to measure cytoplasmic pH in Saccharomyces and Neurospora by means of fluorescent pH indicators evinced two important findings that dyes taken up in (lipophilic) heavily esterified forms accumulate in vacuoles, not in the cytosol; and that the size and distribution of fungal vacuoles can be manipulated dramatically by altering carbon metabolism.

  17. 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.

  18. Chloroplast dysfunction causes multiple defects in cell cycle progression in the Arabidopsis crumpled leaf mutant.

    Science.gov (United States)

    Hudik, Elodie; Yoshioka, Yasushi; Domenichini, Séverine; Bourge, Mickaël; Soubigout-Taconnat, Ludivine; Mazubert, Christelle; Yi, Dalong; Bujaldon, Sandrine; Hayashi, Hiroyuki; De Veylder, Lieven; Bergounioux, Catherine; Benhamed, Moussa; Raynaud, Cécile

    2014-09-01

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants.

  19. Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant

    KAUST Repository

    Hudik, Elodie

    2014-07-18

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants.

  20. B cells and antibodies in progressive multiple sclerosis: Contribution to neurodegeneration and progression.

    Science.gov (United States)

    Fraussen, Judith; de Bock, Laura; Somers, Veerle

    2016-09-01

    Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by demyelination, axonal degeneration and gliosis. The progressive form of MS is an important research topic as not much is known about its underlying mechanisms and no therapy is available. Although progressive MS is traditionally considered to be driven by neurodegeneration, compartmentalized CNS inflammation is currently accepted as one of the driving processes behind neurodegeneration and progression. In this review, the involvement of B cells and antibodies in progressive MS is discussed. The identification of meningeal ectopic B cell follicles in secondary progressive MS (SPMS) patients and the successful use of B cell-depleting therapy in primary progressive MS (PPMS) patients have underlined the importance of B cells in progressive MS. Proof is also available for the role of antibodies in neurodegeneration and progression in MS. Here, oligoclonal immunoglobulin M (IgM) production and autoreactive antibodies are described, with a focus on antibodies directed against sperm-associated antigen 16 (SPAG16). Further research into the role of B cells and autoantibodies in MS progression can lead to novel prognostic and theranostic opportunities.

  1. Stochastic Cell Fate Progression in Embryonic Stem Cells

    Science.gov (United States)

    Zou, Ling-Nan; Doyle, Adele; Jang, Sumin; Ramanathan, Sharad

    2013-03-01

    Studies on the directed differentiation of embryonic stem (ES) cells suggest that some early developmental decisions may be stochastic in nature. To identify the sources of this stochasticity, we analyzed the heterogeneous expression of key transcription factors in single ES cells as they adopt distinct germ layer fates. We find that under sufficiently stringent signaling conditions, the choice of lineage is unambiguous. ES cells flow into differentiated fates via diverging paths, defined by sequences of transitional states that exhibit characteristic co-expression of multiple transcription factors. These transitional states have distinct responses to morphogenic stimuli; by sequential exposure to multiple signaling conditions, ES cells are steered towards specific fates. However, the rate at which cells travel down a developmental path is stochastic: cells exposed to the same signaling condition for the same amount of time can populate different states along the same path. The heterogeneity of cell states seen in our experiments therefore does not reflect the stochastic selection of germ layer fates, but the stochastic rate of progression along a chosen developmental path. Supported in part by the Jane Coffin Childs Fund

  2. Quantification of fluorescent reporters in plant cells.

    Science.gov (United States)

    Pound, Michael; French, Andrew P; Wells, Darren M

    2015-01-01

    Fluorescent reporters are powerful tools for plant research. Many studies require accurate determination of fluorescence intensity and localization. Here, we describe protocols for the quantification of fluorescence intensity in plant cells from confocal laser scanning microscope images using semiautomated software and image analysis techniques.

  3. 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.

  4. Plant cells in vitro under altered gravity.

    Science.gov (United States)

    Klymchuk, D O

    1998-07-01

    Establishing the role of gravity in plant requires information about how gravity regulates the metabolism of individual cells. Plant cells and tissues in vitro are valuable models for such purpose. Disrupted intercellular relations in such models have allowed to elucidate both the gravity role in non-specialised to gravity plant cells and the correlative relation role of an intact plant organism. The data obtained from non-numerous space and clinostat experiments with plant cells in vitro have demonstrated that their metabolism is sensitive to g-environment. The most experiments have shown a decrease in the biomass production and cell proliferation of spaceflight samples compared with ground controls, although there is study reporting of increased biomass production in an anise suspension culture and D. carota crown gall tissue culture. At the same time, results of experiments with single carrot cells and tomato callus culture demonstrated similarities in differentiation process in microgravity and in ground controls. Noted ultrastructural arrangement in cells, especially mitochondria and plastids, have been related to altered energy load and functions of organelles in microgravity, as well as changes in the lipid peroxidation and the content of malonic dyaldehyde in a haplopappus tissue culture under altered gravity supposed with modification of membrane structural-functional state. This article focuses on growth aspects of the cultured cells in microgravity and under clinostat conditions and considers those aspects that require further analysis.

  5. One fungus, one name promotes progressive plant pathology.

    Science.gov (United States)

    Wingfield, Michael J; De Beer, Z Wilhelm; Slippers, Bernard; Wingfield, Brenda D; Groenewald, Johannes Z; Lombard, Lorenzo; Crous, Pedro W

    2012-08-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms, for which the taxonomy and, in particular, a dual nomenclature system have frustrated and confused practitioners of plant pathology. The emergence of DNA sequencing has revealed cryptic taxa and revolutionized our understanding of relationships in the fungi. The impacts on plant pathology at every level are already immense and will continue to grow rapidly as new DNA sequencing technologies continue to emerge. DNA sequence comparisons, used to resolve a dual nomenclature problem for the first time only 19 years ago, have made it possible to approach a natural classification for the fungi and to abandon the confusing dual nomenclature system. The journey to a one fungus, one name taxonomic reality has been long and arduous, but its time has come. This will inevitably have a positive impact on plant pathology, plant pathologists and future students of this hugely important discipline on which the world depends for food security and plant health in general. This contemporary review highlights the problems of a dual nomenclature, especially its impact on plant pathogenic fungi, and charts the road to a one fungus, one name system that is rapidly drawing near. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

  6. Isolation of plant cell wall proteins

    OpenAIRE

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

    2007-01-01

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

  7. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; Beer, de Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2012-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  8. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; De Beer, Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2011-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  9. Host plant resistance to parasitic weeds; recent progress and bottlenecks.

    Science.gov (United States)

    Yoder, John I; Scholes, Julie D

    2010-08-01

    Parasitic witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) directly invade the roots of crop plants connecting to the vascular system and abstracting nutrients and water. As a consequence they cause devastating losses in crop yield. Genetic resistance to parasitic weeds is a highly desirable component of any control strategy. Resistance to parasitic plants can occur at different stages of the parasite lifecycle: before attachment to the host, during penetration of the root or after establishment of vascular connections. New studies are beginning to shed light on the molecular mechanisms and signaling pathways involved in plant-plant resistance. The first resistance gene to Striga, encoding a CC-NBS-LRR Resistance protein (R) has been identified and cloned suggesting that host plants resist attack from parasitic plants using similar surveillance mechanisms as those used against fungal and bacterial pathogens. It is becoming clear that the salicylic acid (SA) signaling pathway plays an important role in resistance to parasitic plants and genes encoding pathogenesis-related (PR) proteins are upregulated in a number of the resistant interactions. New strategies for engineering resistance to parasitic plants are also being explored, including the expression of parasite-specific toxins in host roots and RNAi to silence parasite genes crucial for development.

  10. Research progress on electrical signals in higher plants

    Institute of Scientific and Technical Information of China (English)

    Xiaofei Yan; Zhongyi Wang; Lan Huang; Cheng Wang; Ruifeng Hou; Zhilong Xu; Xiaojun Qiao

    2009-01-01

    This review introduces the characteristics of electrical signals in higher plants and their corresponding physiological significance,and describes in detail the impact of environmental factors (e.g.light and temperature) on the electrical potential of the plants.Also,we evaluate the measurement techniques used for electrical signals in plants,including intracellular measurement,extracellular measurement,measurement of the ion channel based on the patch-clamp technique and on the non-invasive microelectrode vibrating probe technique.We also give a brief review of the applications of these methods for investigating electrical signals in plants.The ionic mechanism of electrical activity in plants is then discussed in terms of environmental response in higher plants,and this is used to provide a theoretical basis for quantitative description of the electrical signals in plants.A model for interpretation of the electrical signal mechanisms in higher plants is discussed,but further experiments are required for the verification of this model.(C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences.Published by Elsevier Limited and Science in China Press.All rights reserved.

  11. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; Beer, de Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2012-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  12. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; De Beer, Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2011-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  13. [Mechanisms of inhibition of viral replication in plants]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    Progress is described concerning genetic mapping CMV movement genes for CMV coat protein in squash and ToMV gene in tomato. These gene products appear to be involved in resistance to squash and tomato mosaic viruses respectively.

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

    DEFF Research Database (Denmark)

    Liesche, Johannes; Schulz, Alexander

    2015-01-01

    cell wall interface. Transport through plasmodesmata, the cell wall channels that directly connect plant cells, is regulated not only by a fixed size exclusion limit, but also by physiological and pathological adaptation. The noninvasive approach described here offers the possibility of precisely......Movement of nutrients and signaling compounds from cell to cell is an essential process for plant growth and development. To understand processes such as carbon allocation, cell communication, and reaction to pathogen attack it is important to know a specific molecule’s capacity to pass a specific...

  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. Quantitative Aspects of Cyclosis in Plant Cells.

    Science.gov (United States)

    Howells, K. F.; Fell, D. A.

    1979-01-01

    Describes an exercise which is currently used in a course in cell physiology at Oxford Polytechnic in England. This exercise can give students some idea of the molecular events involved in bringing about movement of chloroplasts (and other organelles) in plant cells. (HM)

  17. Progress in portable direct methanol fuel cell

    Institute of Scientific and Technical Information of China (English)

    佘沛亮; 胡信国; 陈怀林

    2004-01-01

    The progresses in portable DMFC worldwide were reviewed, the current status of its components, catalysts, proton exchange membrane and flow field plate, the market development of portable electronic appliances, such as mobile phone, PDA and notebook were introduced.

  18. Research progress of Tunisian medicinal plants used for acute diabetes

    Institute of Scientific and Technical Information of China (English)

    Wissem Aidi Wannes; Brahim Marzouk

    2016-01-01

    The use of the medicinal plants in treating diabetes is frequent in Africa, especially in Tunisia, and it is ritually transmitted from generation to generation within cultures. Many of Tunisian medicinal plants have been experimentally validated. A comprehensive re-view was conducted to pile up information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the treatment of diabetes. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the treatment of diabetes and to draw attention of the health professionals and scientists working in the field of phar-macology and therapeutics to develop new drug formulations to cure different kinds of diabetes.

  19. Research progress of Tunisian medicinal plants used for acute diabetes

    Directory of Open Access Journals (Sweden)

    Wissem Aidi Wannes

    2016-09-01

    Full Text Available The use of the medicinal plants in treating diabetes is frequent in Africa, especially in Tunisia, and it is ritually transmitted from generation to generation within cultures. Many of Tunisian medicinal plants have been experimentally validated. A comprehensive review was conducted to pile up information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the treatment of diabetes. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the treatment of diabetes and to draw attention of the health professionals and scientists working in the field of pharmacology and therapeutics to develop new drug formulations to cure different kinds of diabetes.

  20. Progress in Research of Bacteria Fertilizer Strengthening Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).

  1. Studies on the control of cell wall extension. Yearly progress report, September 1, 1978-August 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, R. E.

    1979-01-01

    Research has been centered around the question as to how plant cell enlargement is controlled and regulated at the cellular level. Progress is reported on the following projects: proton permeability of plant cuticles; the control of osmoregulation in Avena coleoptiles; an analysis of the acid-extension curves. (ACR)

  2. 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.

  3. Measuring the Mechanical Properties of Plant Cell Walls

    Directory of Open Access Journals (Sweden)

    Hannes Vogler

    2015-03-01

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

  4. Bone marrow myeloid cells in regulation of multiple myeloma progression.

    Science.gov (United States)

    Herlihy, Sarah E; Lin, Cindy; Nefedova, Yulia

    2017-08-01

    Survival, growth, and response to chemotherapy of cancer cells depends strongly on the interaction of cancer cells with the tumor microenvironment. In multiple myeloma, a cancer of plasma cells that localizes preferentially in the bone marrow, the microenvironment is highly enriched with myeloid cells. The majority of myeloid cells are represented by mature and immature neutrophils. The contribution of the different myeloid cell populations to tumor progression and chemoresistance in multiple myeloma is discussed.

  5. 76 FR 78702 - Progress Energy Florida, Inc. (Combined License Application for Levy County Nuclear Power Plant...

    Science.gov (United States)

    2011-12-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Progress Energy Florida, Inc. (Combined License Application for Levy County Nuclear Power Plant...) and 2.321(b), the Atomic Safety and Licensing Board (Board) in the above-captioned Progress Energy...

  6. Ricin Trafficking in Plant and Mammalian Cells

    Directory of Open Access Journals (Sweden)

    Robert A. Spooner

    2011-06-01

    Full Text Available Ricin is a heterodimeric plant protein that is potently toxic to mammalian and many other eukaryotic cells. It is synthesized and stored in the endosperm cells of maturing Ricinus communis seeds (castor beans. The ricin family has two major members, both, lectins, collectively known as Ricinus communis agglutinin ll (ricin and Ricinus communis agglutinin l (RCA. These proteins are stored in vacuoles within the endosperm cells of mature Ricinus seeds and they are rapidly broken down by hydrolysis during the early stages of post-germinative growth. Both ricin and RCA traffic within the plant cell from their site of synthesis to the storage vacuoles, and when they intoxicate mammalian cells they traffic from outside the cell to their site of action. In this review we will consider both of these trafficking routes.

  7. Alteration of cell cycle progression by Sindbis virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ruirong; Saito, Kengo [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Isegawa, Naohisa [Laboratory Animal Center, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Shirasawa, Hiroshi, E-mail: sirasawa@faculty.chiba-u.jp [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan)

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G{sub 1} phase preferred to proliferate during S/G{sub 2} phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G{sub 1} phase than in cells infected during S/G{sub 2} phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases.

  8. 水生植物在微生物燃料电池中的应用研究进展%Progress on Application of Aquatic Plants in Microbial Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    何洁; 张晟; 滕加泉; 夏世斌

    2013-01-01

    Microbial fuel cell (MFC) can degrade pollutants and simultaneously convert chemical energy to electricity.As an interdisciplinary exploration in sewage treatment which recovers environment friendly energy, it provides new technology to effectively solve energy and environment problem.Aquatic plants in microbial fuel cell have been tested which show good sewage purification effect and biological producing electrical characteristics.Recently there are two categories for use of aquatic plant as MFC.One uses plant root zone as battery anode, to use root zone secretions to solve the problem of MFC fuel, and the other directly uses low water plants algae for building biocathode MFC, to use algae photosynthesis producing oxygen and build aerobic biocathode MFC, then restore CO2.Mechanism, regulation measure, operating conditions and technological parameters of aquatic plant in MFC were analyzed and reviewed, further study was also proposed.%微生物燃料电池在降解污染物的同时能将污染物中的化学能转化为电能.研究微生物燃料电池是对污水处理过程中回收环境友好能源的多学科交叉探索,可以为我国有效解决能源与环境问题提供新的技术途径.水生植物在微生物燃料电池研究中已得到了应用,显示出了良好的污水净化效果和生物产电特性.目前利用水生植物构建的微生物燃料电池,一类是将高等植物根区作为电池的阳极系统,目的是利用根区分泌物解决MFC的燃料问题;另一类是直接将低等水生植物藻类构建生物阴极型微生物燃料电池,其实质是利用藻类光合作用产氧构建好氧型生物阴极微生物燃料电池而还原CO2.文章对水生植物在微生物燃料中的作用机制、调控措施、运行条件、工艺参数等方面的研究现状进行了综合分析,也提出了需要深入研究的方向.

  9. 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.

  10. Review. Elimination of viruses in plants: twenty years of progress

    Directory of Open Access Journals (Sweden)

    A. Panattoni

    2013-02-01

    Full Text Available To shed light on trends about elimination of viruses from plants, a bibliographic research was conducted to identify thermotherapy, chemotherapy and tissue culture trials published from 1991 through 2010. Among woody plants, grapevine, apple and peach are the most frequent targets of sanitation protocols because their health status is strictly regulated. Even if thermotherapy represents the preferred method for the host, grapevine viruses can also be eliminated with chemotherapy and tissue culture; apple viruses respond to chemotherapy as well. Although a similar trend was reported among herbaceous plants, chemotherapy was the most frequently used technique in potato. With regard to virus, thermotherapy was successfully applied against viruses belonging to 13 families and an unassigned genus. Instead, chemotherapy and tissue culture techniques eradicated viruses belonging to fewer families (nine. An interpretation of thermotherapy effects considers the new metabolic “pathways” triggered by the natural antiviral response emitted by the infected plant, with particular reference to virus-induced gene silencing. With regard to chemotherapy, several groups of antiviral drugs belong to inosine monophosphate dehydrogenase inhibitors, S-adenosylhomocysteine hydrolase inhibitors, neuraminidase inhibitors. Tissue culture, usually adopted to regenerate plantlets in biotechnological breeding programs, represents the less used tool for eliminate viruses from plants.

  11. UV-Induced cell death in plants.

    Science.gov (United States)

    Nawkar, Ganesh M; Maibam, Punyakishore; Park, Jung Hoon; Sahi, Vaidurya Pratap; Lee, Sang Yeol; Kang, Chang Ho

    2013-01-14

    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).

  12. 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.

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

    DEFF Research Database (Denmark)

    Liesche, Johannes; Schulz, Alexander

    2015-01-01

    cell wall interface. Transport through plasmodesmata, the cell wall channels that directly connect plant cells, is regulated not only by a fixed size exclusion limit, but also by physiological and pathological adaptation. The noninvasive approach described here offers the possibility of precisely......Movement of nutrients and signaling compounds from cell to cell is an essential process for plant growth and development. To understand processes such as carbon allocation, cell communication, and reaction to pathogen attack it is important to know a specific molecule’s capacity to pass a specific...... determining the plasmodesmata-mediated cell wall permeability for small molecules in living cells. The method is based on photoactivation of the fluorescent tracer caged fluorescein. Non-fluorescent caged fluorescein is applied to a target tissue, where it is taken up passively into all cells. Imaged...

  14. 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…

  15. Interdisciplinary Research and Training Program in the Plant Sciences. Technical progress report, February 1, 1991--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Wolk, C.P.

    1992-07-01

    Research on plants continued. Topics include: Molecular basis of symbiotic plant-microbe interations; enzymatic mechanisms and regulation of plant cell wall biosynthesis; molecular mechanisms that regulate the expression of genes in plants; resistance of plants to environmental stress; studies on hormone biosynthesis and action; plant cell wall proteins; interaction of nuclear and organelle genomes; sensor transduction in plants; molecular mechanisms of trafficking in the plant cell; regulation of lipid metabolism; molecular bases of plant disease resistance mechanisms; biochemical and molecular aspects of plant pathogenesis; developmental biology of nitrogen-fixing cyanobacteria; environmental control of plant development and its relation to plant hormones.

  16. Single Entity Electrochemistry Progresses to Cell Counting.

    Science.gov (United States)

    Gooding, J Justin

    2016-10-10

    Red blood cells have been counted in an electrochemical collision experiment recently described by Compton and co-workers. As a cell collides with the electrode it lyses and a current is observed from the reduction of oxygen from within the cell.

  17. Progress in Genome Editing Technology and Its Application in Plants

    OpenAIRE

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, pr...

  18. Control of the actin cytoskeleton in plant cell growth

    NARCIS (Netherlands)

    Hussey, P.J.; Ketelaar, M.J.; Deeks, M.J.

    2006-01-01

    Plant cells grow through increases in volume and cell wall surface area. The mature morphology of a plant cell is a product of the differential rates of expansion between neighboring zones of the cell wall during this process. Filamentous actin arrays are associated with plant cell growth, and the a

  19. Recent advances in plant cell wall proteomics.

    Science.gov (United States)

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

    2008-02-01

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

  20. Cancer stem cell targeted therapy: progress amid controversies

    Science.gov (United States)

    Wang, Tao; Shigdar, Sarah; Gantier, Michael P.; Hou, Yingchun; Wang, Li; Li, Yong; Shamaileh, Hadi Al; Yin, Wang; Zhou, Shu-Feng; Zhao, Xinhan; Duan, Wei

    2015-01-01

    Although cancer stem cells have been well characterized in numerous malignancies, the fundamental characteristics of this group of cells, however, have been challenged by some recent observations: cancer stem cells may not necessary to be rare within tumors; cancer stem cells and non-cancer stem cells may undergo reversible phenotypic changes; and the cancer stem cells phenotype can vary substantially between patients. Here the current status and progresses of cancer stem cells theory is illustrated and via providing a panoramic view of cancer therapy, we addressed the recent controversies regarding the feasibility of cancer stem cells targeted anti-cancer therapy. PMID:26496035

  1. 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

  2. Progress with nonhuman primate embryonic stem cells.

    Science.gov (United States)

    Wolf, Don P; Kuo, Hung-Chih; Pau, K-Y Francis; Lester, Linda

    2004-12-01

    Embryonic stem cells hold potential in the fields of regenerative medicine, developmental biology, tissue regeneration, disease pathogenicity, and drug discovery. Embryonic stem (ES) cell lines are now available in primates, including man, rhesus, and cynomologous monkeys. Monkey ES cells serve as invaluable clinically relevant models for studies that can't be conducted in humans because of practical or ethical limitations, or in rodents because of differences in physiology and anatomy. Here, we review the current status of nonhuman primate research with ES cells, beginning with a description of their isolation, characterization, and availability. Substantial limitations still plague the use of primate ES cells, such as their required growth on feeder layers, poor cloning efficiency, and restricted availability. The ability to produce homogenous populations of both undifferentiated as well as differentiated phenotypes is an important challenge, and genetic approaches to achieving these objectives are discussed. Finally, safety, efficiency, and feasibility issues relating to the transplantation of ES-derived cells are considered.

  3. Current Progress with Primate Embryonic Stem Cells

    OpenAIRE

    Byrne, James A.; Mitalipov, Shoukhrat M.; Wolf, Don P

    2006-01-01

    Embryonic stem cells (ESCs) can proliferate indefinitely, maintain an undifferentiated pluripotent state and differentiate into any cell type. Differentiation of ESCs into various specific cell-types may be able to cure or alleviate the symptoms of various degenerative diseases. Unresolved issues regarding maintaining function, possible apoptosis and tumor formation in vivo mean a prudent approach should be taken towards advancing ESCs into human clinical trials. Rhesus macaques provide the i...

  4. Recent progress in histochemistry and cell biology.

    Science.gov (United States)

    Hübner, Stefan; Efthymiadis, Athina

    2012-04-01

    Studies published in Histochemistry and Cell Biology in the year 2011 represent once more a manifest of established and newly sophisticated techniques being exploited to put tissue- and cell type-specific molecules into a functional context. The review is therefore the Histochemistry and Cell Biology's yearly intention to provide interested readers appropriate summaries of investigations touching the areas of tissue biology, developmental biology, the biology of the immune system, stem cell research, the biology of subcellular compartments, in order to put the message of such studies into natural scientific-/human- and also pathological-relevant correlations.

  5. Mechanical control of mitotic progression in single animal cells.

    Science.gov (United States)

    Cattin, Cedric J; Düggelin, Marcel; Martinez-Martin, David; Gerber, Christoph; Müller, Daniel J; Stewart, Martin P

    2015-09-08

    Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback-controlled confinement of single cells while characterizing their progression through mitosis. We identify three force regimes according to the cell response: small forces (∼5 nN) that accelerate mitotic progression, intermediate forces where cells resist confinement (50-100 nN), and yield forces (>100 nN) where a significant decline in cell height impinges on microtubule spindle function, thereby inhibiting mitotic progression. Yield forces are coincident with a nonlinear drop in cell height potentiated by persistent blebbing and loss of cortical F-actin homogeneity. Our results suggest that a buildup of actomyosin-dependent cortical tension and intracellular pressure precedes mechanical failure, or herniation, of the cell cortex at the yield force. Thus, we reveal how the mechanical properties of mitotic cells and their response to external forces are linked to mitotic progression under conditions of mechanical confinement.

  6. 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

  7. Plant cells : immobilization and oxygen transfer

    NARCIS (Netherlands)

    Hulst, A.C.

    1987-01-01

    The study described in this thesis is part of the integrated project 'Biotechnological production of non-persistent bioinsecticides by means of plant cells invitro ' and was done in close cooperation with the research Institute Ital within the framework

  8. 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,...

  9. 50 years of medicinal plant research - every progress in methodology is a progress in science.

    Science.gov (United States)

    Phillipson, J David

    2003-06-01

    Many scientific methods of analysis have been developed for the investigation of the constituents and biological activities of medicinal plants during the 50 years since the inaugural meeting of the Gesellschaft für Arzneipflanzenforschung (GA). The chromatographic (e. g., TLC, GLC, HPLC), spectroscopic (e. g., UV, IR, 1H- and 13C-NMR, MS), and biological (e. g., anticancer, anti-inflammatory, immunostimulant, antiprotozoal, CNS) techniques utilized for medicinal plant research are briefly reviewed. The contribution that advances in scientific methodology have made to our understanding of the actions of some herbal medicines (e. g., Echinacea, Ginkgo, St John's wort, Cannabis), as well as to ethnopharmacology and biotechnology, are briefly summarized. Plants have provided many medicinal drugs in the past and remain as a potential source of novel therapeutic agents. Despite all of the powerful analytical techniques available, the majority of plant species has not been investigated chemically or biologically in any great detail and even well known medicinal plants require further clinical study.

  10. Myoepithelial cell differentiation markers in ductal carcinoma in situ progression.

    Science.gov (United States)

    Russell, Tanya D; Jindal, Sonali; Agunbiade, Samiat; Gao, Dexiang; Troxell, Megan; Borges, Virginia F; Schedin, Pepper

    2015-11-01

    We describe a preclinical model that investigates progression of early-stage ductal carcinoma in situ (DCIS) and report that compromised myoepithelial cell differentiation occurs before transition to invasive disease. Human breast cancer MCF10DCIS.com cells were delivered into the mouse mammary teat by intraductal injection in the absence of surgical manipulations and accompanying wound-healing confounders. DCIS-like lesions developed throughout the mammary ducts with full representation of human DCIS histologic patterns. Tumor cells were incorporated into the normal mammary epithelium, developed ductal intraepithelial neoplasia and DCIS, and progressed to invasive carcinoma, suggesting the model provides a rigorous approach to study early stages of breast cancer progression. Mammary glands were evaluated for myoepithelium integrity with immunohistochemical assays. Progressive loss of the myoepithelial cell differentiation markers p63, calponin, and α-smooth muscle actin was observed in the mouse myoepithelium surrounding DCIS-involved ducts. p63 loss was an early indicator, calponin loss intermediate, and α-smooth muscle actin a later indicator of compromised myoepithelium. Loss of myoepithelial calponin was specifically associated with gain of the basal marker p63 in adjacent tumor cells. In single time point biopsies obtained from 16 women diagnosed with pure DCIS, a similar loss in myoepithelial cell markers was observed. These results suggest that further research is warranted into the role of myoepithelial cell p63 and calponin expression on DCIS progression to invasive disease.

  11. 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

  12. 2015 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-12-23

    The 2015 Annual Progress Report summarizes fiscal year 2015 activities and accomplishments by projects funded by the DOE Hydrogen and Fuel Cells Program. It covers the program areas of hydrogen production; hydrogen delivery; hydrogen storage; fuel cells; manufacturing R&D; technology validation; safety, codes and standards; systems analysis; and market transformation.

  13. 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.

  14. Review of Recent Progress in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Fan-Tai Kong

    2007-08-01

    Full Text Available We introduced the structure and the principle of dye-sensitized solar cell (DSC. The latest results about the critical technology and the industrialization research on dye-sensitized solar cells were reviewed. The development of key components, including nanoporous semiconductor films, dye sensitizers, redox electrolyte, counter electrode, and conducting substrate in dye-sensitized solar cells was reviewed in detail. The developing progress and prospect of dye-sensitized solar cells from small cells in the laboratory to industrialization large-scale production were reviewed. At last, the future development of DSC was prospective for the tendency of dye-sensitized solar cells.

  15. Progress in glial cell studies in some laboratories in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Glial cells in the central nervous system(CNS) consist of a heterogeneous population of cell types,each characterized by distinct morphological features,physiological properties,and specific markers.In contrast to the previous view that glial cells were passive elements in the brain,accumulating evidence suggests that glial cells are active participants in various brain functions and brain disorders.This review summarizes recent progress of glial cell studies from several groups in China,ranging from studies about the mechanisms of neuron-glia crosstalking to investigations on the roles of glial cells in various CNS disorders.

  16. Instrumentation and process control for fossil demonstration plants. Quarterly technical progress report, January--March 1977

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L.G.; O' Fallon, N.M.

    1977-09-01

    Progress during the quarter of January through March 1977 on ANL 189a 49622R2, Instrumentation and Process Control for Fossil Demonstration Plants (FDP) is reported. Work has been performed on updating the study of the state-of-the-art of instrumentation for Fossil Demonstration Plants (FDP), on development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. Progress in these areas is described.

  17. Research Progress and Perspectives of Nitrogen Fixing Bacterium, Gluconacetobacter diazotrophicus, in Monocot Plants

    Directory of Open Access Journals (Sweden)

    N. Eskin

    2014-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a nitrogen fixing bacterium originally found in monocotyledon sugarcane plants in which the bacterium actively fixes atmosphere nitrogen and provides significant amounts of nitrogen to plants. This bacterium mainly colonizes intercellular spaces within the roots and stems of plants and does not require the formation of the complex root organ like nodule. The bacterium is less plant/crop specific and indeed G. diazotrophicus has been found in a number of unrelated plant species. Importantly, as the bacterium was of monocot plant origin, there exists a possibility that the nitrogen fixation feature of the bacterium may be used in many other monocot crops. This paper reviews and updates the research progress of G. diazotrophicus for the past 25 years but focuses on the recent research development.

  18. Genetic improvement of biofuel plants: recent progress and patents.

    Science.gov (United States)

    Johnson, T Sudhakar; Badri, Jyothi; Sastry, R Kalpana; Shrivastava, Anshul; Kishor, P B Kavi; Sujatha, M

    2013-04-01

    Due to depleting reserves of fossil fuels, political uncertainties, increase in demand of energy needs and growing concerns of environmental effects, bioenergy as an alternative source of energy needs had taken centre stage globally. In this report, we review the progress made in lignocellulose, cellulose and fermentation based biofuels in addition to tree borne oil seeds. Algae as a source of feedstock for the biofuel has also been reviewed. Recent efforts in genome sequencing of biofuel crops and molecular breeding approaches have increased our understanding towards crop improvement of major feedstocks. Besides, patenting trends in bioenergy sector were assessed by patent landscape analysis. The results showed an increasing trend in published patents during the last decade which is maximum during 2011. A conceptual framework of "transgenesis in biofuels to industrial application" was developed based on the patent analytics viz., International Patent Classification (IPC) analysis and Theme Maps. A detailed claim analysis based on the conceptual framework assessed the patenting trends that provided an exhaustive dimension of the technology. The study emphasizes the current thrust in bioenergy sector by various public and private institutions to expedite the process of biofuel production.

  19. [Progress in research and application of gene engineering on medicinal plants].

    Science.gov (United States)

    Wang, Min; Huang, Lu-qi; Li, Meng-meng

    2008-06-01

    China is the country possessing the largest amount of trade and consumption of medicinal plants in the world. Research and application of gene engineering on medicinal plants are the one of the most promising ways to increase the productivity and quality of medicinal plants, reduce the resource stress, and enhance the competitive power and sustainable development ability of the medicinal plants industry. In spite of the great progress in research and application of plant gene engineering worldwide, the research of gene transformation has mostly been conducted on some model plants, and the application of transgenic plant has been limited to a few staple and important crop species. For medicinal plants, recently the researches of gene transformation has emerged, however, compared with other crop and economic plants, it is still a very limited amount. On the basis of a general introduction of application of transgenic plants, this paper focuses on the present situation of the research and application of gene engineering on medicinal plants, to put forward the problems in this field, and give a prospect for its development.

  20. Redox regulation in plant programmed cell death.

    Science.gov (United States)

    De Pinto, M C; Locato, V; De Gara, L

    2012-02-01

    Programmed cell death (PCD) is a genetically controlled process described both in eukaryotic and prokaryotic organisms. Even if it is clear that PCD occurs in plants, in response to various developmental and environmental stimuli, the signalling pathways involved in the triggering of this cell suicide remain to be characterized. In this review, the main similarities and differences in the players involved in plant and animal PCD are outlined. Particular attention is paid to the role of reactive oxygen species (ROS) as key inducers of PCD in plants. The involvement of different kinds of ROS, different sites of ROS production, as well as their interaction with other molecules, is crucial in activating PCD in response to specific stimuli. Moreover, the importance is stressed on the balance between ROS production and scavenging, in various cell compartments, for the activation of specific steps in the signalling pathways triggering this cell suicide process. The review focuses on the complexity of the interplay between ROS and antioxidant molecules and enzymes in determining the most suitable redox environment required for the occurrence of different forms of PCD. © 2011 Blackwell Publishing Ltd.

  1. Current progress and prospects of induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Induced pluripotent stem(iPS) cells are derived from somatic cells by ectopic expression of few transcription factors.Like embryonic stem(ES) cells,iPS cells are able to self-renew indefinitely and to differentiate into all types of cells in the body.iPS cells hold great promise for regenerative medicine,because iPS cells circumvent not only immunological rejection but also ethical issues.Since the first report on the derivation of iPS cells in 2006,many laboratories all over the world started research on iPS cells and have made significant progress.This paper reviews recent progress in iPS cell research,including the methods to generate iPS cells,the molecular mechanism of reprogramming in the formation of iPS cells,and the potential applications of iPS cells in cell replacement therapy.Current problems that need to be addressed and the prospects for iPS research are also discussed.

  2. Characterization of Plant Functions Using Cultured Plant Cells, and Biotechnological Applications

    National Research Council Canada - National Science Library

    SATO, Fumihiko

    2013-01-01

    .... On the other hand, the use of plant cell cultures for the more basic characterization of plant functions is rather limited due to the difficulties associated with functional differentiation in cell cultures...

  3. 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.

  4. 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.

  5. Control of triacylglycerol biosynthesis in plants. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-31

    Seeds of most species of the Umbelliferae (Apiaciae), Araliaceae, and Garryaceae families are characterized by their high content of the unusual C{sub 18} monounsaturated fatty acid petroselinic acid (18:l{Delta}{sup 6cis}). Prior to a recent report of this lab, little was known of the biosynthetic origin of the cis{Delta}{sup 6} double bond of petroselinic acid. Such knowledge may be of both biochemical and biotechnological significance. Because petroselinic acid is potentially the product of a novel desaturase, information regarding its synthesis may contribute to an understanding of fatty acid desaturation mechanisms in plants. Through chemical cleavage at its double bond, petroselinic acid can be used as a precursor of lauric acid (12:0), a component of detergents and surfactants, and adipic acid (6:0 dicarboxylic), the monomeric component of nylon 6,6. Therefore, the development of an agronomic source of an oil rich in petroselinic acid is of biotechnological interest. As such, studies of petroselinic acid biosynthesis may provide basic information required for any attempt to genetically engineer the production and accumulation of this fatty acid in an existing oilseed.

  6. Research progress of genome editing and derivative technologies in plants.

    Science.gov (United States)

    Qiwei, Shan; Caixia, Gao

    2015-10-01

    Genome editing technologies using engineered nucleases have been widely used in many model organisms. Genome editing with sequence-specific nuclease (SSN) creates DNA double-strand breaks (DSBs) in the genomic target sites that are primarily repaired by the non-homologous end joining (NHEJ) or homologous recombination (HR) pathways, which can be employed to achieve targeted genome modifications such as gene mutations, insertions, replacements or chromosome rearrangements. There are three major SSNs─zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN) and clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) system. In contrast to ZFN and TALEN, which require substantial protein engineering to each DNA target, the CRISPR/Cas9 system requires only a change in the guide RNA. For this reason, the CRISPR/Cas9 system is a simple, inexpensive and versatile tool for genome engineering. Furthermore, a modified version of the CRISPR/Cas9 system has been developed to recruit heterologous domains that can regulate endogenous gene expression, such as activation, depression and epigenetic regulation. In this review, we summarize the development and applications of genome editing technologies for basic research and biotechnology, as well as highlight challenges and future directions, with particular emphasis on plants.

  7. 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.

  8. Isolation of plant cell wall proteins.

    Science.gov (United States)

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

    2008-01-01

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

  9. Novel roles of plant RETINOBLASTOMA-RELATED (RBR) protein in cell proliferation and asymmetric cell division.

    Science.gov (United States)

    Desvoyes, Bénédicte; de Mendoza, Alex; Ruiz-Trillo, Iñaki; Gutierrez, Crisanto

    2014-06-01

    The retinoblastoma (Rb) protein was identified as a human tumour suppressor protein that controls various stages of cell proliferation through the interaction with members of the E2F family of transcription factors. It was originally thought to be specific to animals but plants contain homologues of Rb, called RETINOBLASTOMA-RELATED (RBR). In fact, the Rb-E2F module seems to be a very early acquisition of eukaryotes. The activity of RBR depends on phosphorylation of certain amino acid residues, which in most cases are well conserved between plant and animal proteins. In addition to its role in cell-cycle progression, RBR has been shown to participate in various cellular processes such as endoreplication, transcriptional regulation, chromatin remodelling, cell growth, stem cell biology, and differentiation. Here, we discuss the most recent advances to define the role of RBR in cell proliferation and asymmetric cell division. These and other reports clearly support the idea that RBR is used as a landing platform of a plethora of cellular proteins and complexes to control various aspects of cell physiology and plant development.

  10. Current progress and prospects of induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    CHEN LingYi; Liu Lin

    2009-01-01

    Induced pluripotent stem (iPS) cells are derived from somatic cells by ectopic expression of few transcription factors. Like embryonic stem (ES) cells, iPS cells are able to self-renew indefinitely and to differentiate into all types of cells in the body. iPS cells hold great promise for regenerative medicine,because iPS ceils circumvent not only immunological rejection but also ethical issues. Since the first report on the derivation of iPS cells in 2006, many laboratories all over the world started research on iPS cells and have made significant progress. This paper reviews recent progress in iPS cell research,Including the methods to generate iPS cells, the molecular mechanism of reprogramming in the formation of iPS ceils, and the potential applications of iPS cells in cell replacement therapy. Current problems that need to be addressed and the prospects for iPS research are also discussed.

  11. Chemistry research and development. Progress report, December 1978-May 1979. [Component, pilot plant, instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Miner, F. J.

    1980-06-30

    Progress and activities are reported on component development, pilot plant development, and instrumentation and statistical systems. Specific items studied include processing of pond sludge, transport of radioactive materials and wastes, corrosion, decontamination and cleaning, fluidized-bed incineration, Pu contamination of soils, chemical analysis, radiometric analysis, security. (DLC)

  12. Clearing of invasive alien plants in South Africa: a preliminary assessment of costs and progress

    CSIR Research Space (South Africa)

    Marais, R

    2004-01-01

    Full Text Available This paper provides estimates of the costs of clearing important species of invasive alien plants, as well as of progress made with clearing, based on data from a recently developed GIS-based project information system. Before the deployment...

  13. Research progress on isolation and cloning of functional genes in tea plants

    Institute of Scientific and Technical Information of China (English)

    MA Chunlei; CHEN Liang

    2007-01-01

    Tea,which has many sanitarian functions,is one of the most popular non-alcoholic soft and healthy beverages in the world.In many countries,as well as in China,tea (Camellia sinensis) is an important cash crop.It has great value as a source of secondary metabolic products.Molecular biology of tea plants has been one of the most active and kinetic research fields of tea science for the last decade.Isolation and cloning of important functional genes of tea plants have a critical significance on elucidating the molecular mechanism of high quality,yield and resistance,as well as genetic manipulating via biotechnological approaches for tea plants.In this paper,we introduced the research progress on the isolation and cloning of functional genes in tea plants.In addition,the brief prospect on the research of functional genes of tea plants in the near future is also given out.

  14. Inhibition of cell-cycle progression in human colorectal carcinoma Lovo cells by andrographolide.

    Science.gov (United States)

    Shi, Ming-Der; Lin, Hui-Hsuan; Lee, Yi-Che; Chao, Jian-Kang; Lin, Rong-An; Chen, Jing-Hsien

    2008-08-11

    In recent years, attention has been focused on the anti-cancer properties of pure components, an important role in the prevention of disease. Andrographolide (Andro), the major constituent of Andrographis paniculata (Burm. F.) Nees plant, is implicated towards its pharmacological activity. To investigate the mechanism basis for the anti-tumor properties of Andro, Andro was used to examine its effect on cell-cycle progression in human colorectal carcinoma Lovo cells. The data from cell growth experiment showed that Andro exhibited the anti-proliferation effect on Lovo cells in a time- and dose-dependent manner. This event was accompanied the arrest of the cells at the G1-S phase by Andro at the tested concentrations of 0-30 microM. Cellular uptake of Andro and Andro was confirmed by capillary electrophoresis analysis and the intracellular accumulation of Andro (0.61+/-0.07 microM/mg protein) was observed when treatment of Lovo cells with Andro for 12h. In addition, an accumulation of the cells in G1 phase (15% increase for 10 microM of Andro) was observed as well as by the association with a marked decrease in the protein expression of Cyclin A, Cyclin D1, Cdk2 and Cdk4. Andro also inducted the content of Cdk inhibitor p21 and p16, and the phosphorylation of p53. Further immunoprecipitation studies found that, in response to the treatment, the formation of Cyclin D1/Cdk4 and Cyclin A/Cdk2 complexes had declined, preventing the phosphorylation of Rb and the subsequent dissociation of Rb/E2F complex. These results suggested Andro can inhibit Lovo cell growth by G1-S phase arrest, and was exerted by inducing the expression of p53, p21 and p16 that, in turn, repressed the activity of Cyclin D1/Cdk4 and/or Cyclin A/Cdk2, as well as Rb phosphorylation.

  15. Cross-talk of nitric oxide and reactive oxygen species in plant programed cell death

    Directory of Open Access Journals (Sweden)

    Yiqin eWang

    2013-08-01

    Full Text Available In plants, programed cell death (PCD is an important mechanism to regulate multiple aspects of growth and development, as well as to remove damaged or infected cells during responses to environmental stresses and pathogen attacks. Under biotic and abiotic stresses, plant cells exhibit a rapid synthesis of nitric oxide (NO and a parallel accumulation of reactive oxygen species (ROS. Frequently, these responses trigger a PCD process leading to an intrinsic execution of plant cells. The accumulating evidence suggests that both NO and ROS play key roles in PCD. These redox active small molecules can trigger cell death either independently or synergistically. Here we summarize the recent progress on the cross-talk of NO and ROS signals in the hypersensitive response (HR, leaf senescence and other kinds of plant PCD caused by diverse cues.

  16. Plant Cell Adaptive Responses to Microgravity

    Science.gov (United States)

    Kordyum, Elizabeth; Kozeko, Liudmyla; Talalaev, Alexandr

    Microgravity is an abnormal environmental condition that plays no role in the functioning of biosphere. Nevertheless, the chronic effect of microgravity in space flight as an unfamiliar factor does not prevent the development of adaptive reactions at the cellular level. In real microgravity in space flight under the more or less optimal conditions for plant growing, namely temperature, humidity, CO2, light intensity and directivity in the hardware angiosperm plants perform an “reproductive imperative”, i.e. they flower, fruit and yield viable seeds. It is known that cells of a multicellular organism not only take part on reactions of the organism but also carry out processes that maintain their integrity. In light of these principles, the problem of the identification of biochemical, physiological and structural patterns that can have adaptive significance at the cellular and subcellular level in real and simulated microgravity is considered. Cytological studies of plants developing in real and simulated microgravity made it possible to establish that the processes of mitosis, cytokinesis, and tissue differentiation of vegetative and generative organs are largely normal. At the same time, under microgravity, essential reconstruction in the structural and functional organization of cell organelles and cytoskeleton, as well as changes in cell metabolism and homeostasis have been described. In addition, new interesting data concerning the influence of altered gravity on lipid peroxidation intensity, the level of reactive oxygen species, and antioxidant system activity, just like on the level of gene expression and synthesis of low-molecular and high-molecular heat shock proteins were recently obtained. So, altered gravity caused time-dependent increasing of the HSP70 and HSP90 levels in cells, that may indicate temporary strengthening of their functional loads that is necessary for re-establish a new cellular homeostasis. Relative qPCR results showed that

  17. Progress and challenges in using stable isotopes to trace plant carbon and water relations across scales

    Directory of Open Access Journals (Sweden)

    C. Werner

    2012-08-01

    Full Text Available Stable isotope analysis is a powerful tool for assessing plant carbon and water relations and their impact on biogeochemical processes at different scales. Our process-based understanding of stable isotope signals, as well as technological developments, has progressed significantly, opening new frontiers in ecological and interdisciplinary research. This has promoted the broad utilisation of carbon, oxygen and hydrogen isotope applications to gain insight into plant carbon and water cycling and their interaction with the atmosphere and pedosphere. Here, we highlight specific areas of recent progress and new research challenges in plant carbon and water relations, using selected examples covering scales from the leaf to the regional scale. Further, we discuss strengths and limitations of recent technological developments and approaches and highlight new opportunities arising from unprecedented temporal and spatial resolution of stable isotope measurements.

  18. The potential of single-cell profiling in plants.

    Science.gov (United States)

    Efroni, Idan; Birnbaum, Kenneth D

    2016-04-05

    Single-cell transcriptomics has been employed in a growing number of animal studies, but the technique has yet to be widely used in plants. Nonetheless, early studies indicate that single-cell RNA-seq protocols developed for animal cells produce informative datasets in plants. We argue that single-cell transcriptomics has the potential to provide a new perspective on plant problems, such as the nature of the stem cells or initials, the plasticity of plant cells, and the extent of localized cellular responses to environmental inputs. Single-cell experimental outputs require different analytical approaches compared with pooled cell profiles and new tools tailored to single-cell assays are being developed. Here, we highlight promising new single-cell profiling approaches, their limitations as applied to plants, and their potential to address fundamental questions in plant biology.

  19. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Alam Hunain

    2012-01-01

    Full Text Available Abstract Background Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC. Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. Methods To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131 using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Results Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041, increased lymph node metastasis (P = 0.001, less differentiation (P = 0.005, increased recurrence (P = 0.038 and shorter survival (P = 0.004 of the patients. Conclusion In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and

  20. Whole-Mount DAPI Staining and Measurement of DNA Content in Plant Cells.

    Science.gov (United States)

    Schnittger, Arp; Hülskamp, Martin

    2007-01-01

    INTRODUCTIONDuring development, many plant cells undergo endoreduplication, whereby ploidy increases to a multiple of the normal 2C content. For example, trichome development is accompanied by an increase in ploidy to 32C, indicating that trichome cells undergo four rounds of endoreduplication. In the protocol described here, DNA levels, and hence developmental progress in the corresponding cells, are measured by staining the DNA with a fluorescent marker and then quantifying the fluorescence of individual nuclei.

  1. Chemical Synthesis of Oligosaccharides related to the Cell Walls of Plants and Algae

    DEFF Research Database (Denmark)

    Kinnaert, Christine; Daugaard, Mathilde; Nami, Faranak

    2017-01-01

    Plant cell walls are composed of an intricate network of polysaccharides and proteins that varies during the developmental stages of the cell. This makes it very challenging to address the functions of individual wall components in cells, especially for highly complex glycans. Fortunately, struct......, and arabinogalactans, as well as glycans unique to algae. Representative synthetic routes within each class are discussed in detail and the progress in carbohydrate chemistry over recent decades is highlighted....

  2. Mesenchymal stem cells: key players in cancer progression.

    Science.gov (United States)

    Ridge, Sarah M; Sullivan, Francis J; Glynn, Sharon A

    2017-02-01

    Tumour progression is dependent on the interaction between tumour cells and cells of the surrounding microenvironment. The tumour is a dynamic milieu consisting of various cell types such as endothelial cells, fibroblasts, cells of the immune system and mesenchymal stem cells (MSCs). MSCs are multipotent stromal cells that are known to reside in various areas such as the bone marrow, fat and dental pulp. MSCs have been found to migrate towards inflammatory sites and studies have shown that they also migrate towards and incorporate into the tumour. The key question is how they interact there. MSCs may interact with tumour cells through paracrine signalling. On the other hand, MSCs have the capacity to differentiate to various cell types such as osteocytes, chondrocytes and adipocytes and it is possible that MSCs differentiate at the site of the tumour. More recently it has been shown that cross-talk between tumour cells and MSCs has been shown to increase metastatic potential and promote epithelial-to-mesenchymal transition. This review will focus on the role of MSCs in tumour development at various stages of progression from growth of the primary tumour to the establishment of distant metastasis.

  3. Research progress on the red cell diseases in China

    Institute of Scientific and Technical Information of China (English)

    YUE Lan-zhu; SHAO Zong-hong

    2012-01-01

    In recent years,there have been lots of progresses in the studies on red cell diseases in China,especially bone marrow failure diseases including immune-related pancytopenia,aplastic anemia,myelodysplastic syndrome,and paroxymal nocturnal hemoglobinuria.Numerous laboratory experiments as well as clinical researches have been carried out by Chinese hematologists,which brought about much clearer pathogenesis,more rational diagnosis methods and more effective therapies for red cell diseases.

  4. 2013 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-12-01

    The 2013 Annual Progress Report summarizes fiscal year 2013 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; market transformation; and systems analysis.

  5. 2011 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    Satyapal, Sunita [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2011-11-01

    The 2011 Annual Progress Report summarizes fiscal year 2011 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; education; market transformation; and systems analysis.

  6. 2014 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-11-01

    The 2014 Annual Progress Report summarizes fiscal year 2014 activities and accomplishments by projects funded by the DOE Hydrogen Program. It covers the program areas of hydrogen production and delivery; hydrogen storage; fuel cells; manufacturing; technology validation; safety, codes and standards; market transformation; and systems analysis.

  7. Chloroplast Dysfunction Causes Multiple Defects in Cell Cycle Progression in the Arabidopsis crumpled leaf Mutant1[C][W

    Science.gov (United States)

    Hudik, Elodie; Yoshioka, Yasushi; Domenichini, Séverine; Bourge, Mickaël; Soubigout-Taconnat, Ludivine; Mazubert, Christelle; Yi, Dalong; Bujaldon, Sandrine; Hayashi, Hiroyuki; De Veylder, Lieven; Bergounioux, Catherine; Benhamed, Moussa; Raynaud, Cécile

    2014-01-01

    The majority of research on cell cycle regulation is focused on the nuclear events that govern the replication and segregation of the genome between the two daughter cells. However, eukaryotic cells contain several compartmentalized organelles with specialized functions, and coordination among these organelles is required for proper cell cycle progression, as evidenced by the isolation of several mutants in which both organelle function and overall plant development were affected. To investigate how chloroplast dysfunction affects the cell cycle, we analyzed the crumpled leaf (crl) mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for a chloroplastic protein and displays particularly severe developmental defects. In the crl mutant, we reveal that cell cycle regulation is altered drastically and that meristematic cells prematurely enter differentiation, leading to reduced plant stature and early endoreduplication in the leaves. This response is due to the repression of several key cell cycle regulators as well as constitutive activation of stress-response genes, among them the cell cycle inhibitor SIAMESE-RELATED5. One unique feature of the crl mutant is that it produces aplastidic cells in several organs, including the root tip. By investigating the consequence of the absence of plastids on cell cycle progression, we showed that nuclear DNA replication occurs in aplastidic cells in the root tip, which opens future research prospects regarding the dialogue between plastids and the nucleus during cell cycle regulation in higher plants. PMID:25037213

  8. Mechanistic insights into aging, cell cycle progression, and stress response

    Directory of Open Access Journals (Sweden)

    Troy Anthony Alan Harkness

    2012-06-01

    Full Text Available The longevity of an organism depends on the health of its cells. Throughout life cells are exposed to numerous intrinsic and extrinsic stresses, such as free radicals, generated through mitochondrial electron transport, and ultraviolet irradiation. The cell has evolved numerous mechanisms to scavenge free radicals and repair damage induced by these insults. One mechanism employed by the yeast Saccharomyces cerevisiae to combat stress utilizes the Anaphase Promoting Complex (APC, an essential multi-subunit ubiquitin-protein ligase structurally and functionally conserved from yeast to humans that controls progression through mitosis and G1. We have observed that yeast cells expressing compromised APC subunits are sensitive to multiple stresses and have shorter replicative and chronological lifespans. In a pathway that runs parallel to that regulated by the APC, members of the Forkhead box (Fox transcription factor family also regulate stress responses. The yeast Fox orthologues Fkh1 and Fkh2 appear to drive the transcription of stress response factors and slow early G1 progression, while the APC seems to regulate chromatin structure, chromosome segregation, and resetting of the transcriptome in early G1. In contrast, under non-stress conditions, the Fkhs play a complex role in cell cycle progression, partially through activation of the APC. Direct and indirect interactions between the APC and the yeast Fkhs appear to be pivotal for lifespan determination. Here we explore the potential for these interactions to be evolutionarily conserved as a mechanism to balance cell cycle regulation with stress responses.

  9. Cell cycle progression in response to oxygen levels.

    Science.gov (United States)

    Ortmann, Brian; Druker, Jimena; Rocha, Sonia

    2014-09-01

    Hypoxia' or decreases in oxygen availability' results in the activation of a number of different responses at both the whole organism and the cellular level. These responses include drastic changes in gene expression, which allow the organism (or cell) to cope efficiently with the stresses associated with the hypoxic insult. A major breakthrough in the understanding of the cellular response to hypoxia was the discovery of a hypoxia sensitive family of transcription factors known as the hypoxia inducible factors (HIFs). The hypoxia response mounted by the HIFs promotes cell survival and energy conservation. As such, this response has to deal with important cellular process such as cell division. In this review, the integration of oxygen sensing with the cell cycle will be discussed. HIFs, as well as other components of the hypoxia pathway, can influence cell cycle progression. The role of HIF and the cell molecular oxygen sensors in the control of the cell cycle will be reviewed.

  10. Natural killer cells in hepatitis C: Current progress.

    Science.gov (United States)

    Yoon, Joo Chun; Yang, Chang Mo; Song, Youkyong; Lee, Jae Myun

    2016-01-28

    Patients infected with the hepatitis C virus (HCV) are characterized by a high incidence of chronic infection, which results in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The functional impairment of HCV-specific T cells is associated with the evolution of an acute infection to chronic hepatitis. While T cells are the important effector cells in adaptive immunity, natural killer (NK) cells are the critical effector cells in innate immunity to virus infections. The findings of recent studies on NK cells in hepatitis C suggest that NK cell responses are indeed important in each phase of HCV infection. In the early phase, NK cells are involved in protective immunity to HCV. The immune evasion strategies used by HCV may target NK cells and might contribute to the progression to chronic hepatitis C. NK cells may control HCV replication and modulate hepatic fibrosis in the chronic phase. Further investigations are, however, needed, because a considerable number of studies observed functional impairment of NK cells in chronic HCV infection. Interestingly, the enhanced NK cell responses during interferon-α-based therapy of chronic hepatitis C indicate successful treatment. In spite of the advances in research on NK cells in hepatitis C, establishment of more physiological HCV infection model systems is needed to settle unsolved controversies over the role and functional status of NK cells in HCV infection.

  11. 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.

  12. 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

  13. 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

  14. The potential of single-cell profiling in plants

    OpenAIRE

    Efroni, Idan; Birnbaum, Kenneth D

    2016-01-01

    Single-cell transcriptomics has been employed in a growing number of animal studies, but the technique has yet to be widely used in plants. Nonetheless, early studies indicate that single-cell RNA-seq protocols developed for animal cells produce informative datasets in plants. We argue that single-cell transcriptomics has the potential to provide a new perspective on plant problems, such as the nature of the stem cells or initials, the plasticity of plant cells, and the extent of localized ce...

  15. Research progress on the use of plant allelopathy in agriculture and the physiological and ecological mechanisms of allelopathy

    Directory of Open Access Journals (Sweden)

    Fang eCheng

    2015-11-01

    Full Text Available Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment or negative effects (e.g., autotoxicity, soil sickness, or biological invasion. To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory / inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1 Description of management practices related to allelopathy and allelochemicals in agriculture. (2 Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3 Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4 Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on

  16. Research Progress on the use of Plant Allelopathy in Agriculture and the Physiological and Ecological Mechanisms of Allelopathy.

    Science.gov (United States)

    Cheng, Fang; Cheng, Zhihui

    2015-01-01

    Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment) or negative effects (e.g., autotoxicity, soil sickness, or biological invasion). To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory/inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides, and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1) Description of management practices related to allelopathy and allelochemicals in agriculture. (2) Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3) Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4) Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on plant

  17. Spermatogonial stem cells from domestic animals: progress and prospects.

    Science.gov (United States)

    Zheng, Yi; Zhang, Yaqing; Qu, Rongfeng; He, Ying; Tian, Xiue; Zeng, Wenxian

    2014-03-01

    Spermatogenesis, an elaborate and male-specific process in adult testes by which a number of spermatozoa are produced constantly for male fertility, relies on spermatogonial stem cells (SSCs). As a sub-population of undifferentiated spermatogonia, SSCs are capable of both self-renewal (to maintain sufficient quantities) and differentiation into mature spermatozoa. SSCs are able to convert to pluripotent stem cells during in vitro culture, thus they could function as substitutes for human embryonic stem cells without ethical issues. In addition, this process does not require exogenous transcription factors necessary to produce induced-pluripotent stem cells from somatic cells. Moreover, combining genetic engineering with germ cell transplantation would greatly facilitate the generation of transgenic animals. Since germ cell transplantation into infertile recipient testes was first established in 1994, in vivo and in vitro study and manipulation of SSCs in rodent testes have been progressing at a staggering rate. By contrast, their counterparts in domestic animals, despite the failure to reach a comparable level, still burgeoned and showed striking advances. This review outlines the recent progressions of characterization, isolation, in vitro propagation, and transplantation of spermatogonia/SSCs from domestic animals, thereby shedding light on future exploration of these cells with high value, as well as contributing to the development of reproductive technology for large animals.

  18. [Progress in early pancreas development and reprogramming of terminally differentiated cells into β cells].

    Science.gov (United States)

    Mingjun, Cao; Huansheng, Dong; Qingjie, Pan; Hongjun, Wang; Xiao, Dong

    2014-06-01

    Type 1 diabetes mellitus (T1DM) is an autoimmune disease in which the immune system attacks insulin-secreting β cells, thus leading to an absolute deficiency of insulin. Patients must rely on exogenous insulin, which cannot effectively prevent diabetes complications. Generation of insulin-secreting cells by reprogramming of pluripotent stem cells or somatic cells is a potential approach for the treatment of T1DM. These cells can be used for cell therapy and drug screening, and may eventually provide a cure for the disease. Significant progress has been made in generating insulin-secreting cells through the expression of β cell specific transcription factors in stem cells or somatic cells. In this review, we summarize recent research progress in early pancreas development, β cell specific transcription factors and reprogramming of terminally differentiated cells into β cells.

  19. Recent Progress of Somatic Cell Nuclear Transfer in Pigs

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoming; Dou Zhongying

    2005-01-01

    Research in the field of somatic cell nuclear transfer (SCNT) and transgenic cloning in pigs has become a global hotspot, because porcine organs probably can be the first source of donor organs for human xenotransplantation. In recent years, though great progress has been made in porcine SCNT, the efficiency of nuclear transfer remains very low (<1% ). Thus, it is necessary to improve the procedure of nuclear transfer and to investigate some basic problems further. Recent progress and the related problems of SCNT in pigs are reviewed and analyzed so as to offer some beneficial illumination to researchers.

  20. Mesenchymal stem cells in diabetes treatment: progress and perspectives

    Directory of Open Access Journals (Sweden)

    Yu CHENG

    2016-08-01

    Full Text Available Diabetes is a chronic metabolic disorder caused by relative or absolute insulin deficient or reduced sensitivity of target cells to insulin. Mesenchymal stem cells (MSCs are adult stem cells with multiple differentiation potential, self-renewable and immunoregulatory properties. Accumulating evidences from clinic or animal experiments recent years showed that MSCs infusion could ameliorate hyperglycemia in diabetes. The research progress of MSCs in diabetes treatment is summarized and a corresponding perspective is herewith proposed in present paper. DOI: 10.11855/j.issn.0577-7402.2016.07.16

  1. Xanthohumol inhibits cell cycle progression and proliferation of larynx cancer cells in vitro.

    Science.gov (United States)

    Sławińska-Brych, Adrianna; Król, Sylwia Katarzyna; Dmoszyńska-Graniczka, Magdalena; Zdzisińska, Barbara; Stepulak, Andrzej; Gagoś, Mariusz

    2015-10-05

    Xanthohumol (XN), a prenylflavonoid derived from the hop plant (Humulus lupulus L.) has been found to exhibit a broad spectrum of biological properties, including anti-cancer activity. In this study, the mechanisms involved in anti-cancer activity of XN in human RK33 and RK45 larynx cancer cell lines were investigated. The effect of XN on the viability of larynx cancer and normal cells (human skin fibroblasts HSF and rat oligodendroglia-derived cells, OLN-93) was compared. Additionally, the influence of XN on proliferation, cell cycle progression, induction of apoptosis in larynx cancer cells, as well as the molecular mechanisms underlying in these processes were analyzed. XN promoted the reduction of cell viability in cancer cells, but showed low cytotoxicity to normal cells. The decrease in cell viability in the cancer cells was coupled with induction of apoptosis via two pathways. The mechanisms involved in these effects of XN were associated with cell growth inhibition by induction of cell cycle arrest in the G1 phase, increased p53 and p21/WAF1 expression levels, downregulation of cyclin D1 and Bcl-2, and activation of caspases-9, -8, and -3. Moreover, this compound inhibited phosphorylation of ERK1/2, suggesting a key role of the ERKs pathway in the XN-mediated growth suppressing effects against the studied cells. These results indicate that XN could be used as a potential agent for the treatment of patients with larynx cancer.

  2. Involvement of NANOG upregulation in malignant progression of human cells.

    Science.gov (United States)

    Li, Yang; Higashiyama, Shinji; Shimakage, Misuzu; Kawahara, Kunimitsu; Yutsudo, Masuo; Watari, Akihiro

    2013-03-01

    Previously, we isolated cell lines that display various degrees of transformed phenotypes from a single-cell population of human diploid fibroblasts (RB) containing a large deletion (13q14-22) in one copy of chromosome 13. They included a cell line transfected with SV40 early genes (RBSV), an immortalized cell line (RBI), an anchorage-independent cell line (RBS), and a tumorigenic cell line (RBT). Here, we analyzed gene expression profiles in these cell lines and showed that expression of some fibroblast-specified or mesenchyme-specified genes were downregulated, and those of stem cell-specified genes, including NANOG, were upregulated during malignant progression. When NANOG expression was knocked down with a short hairpin NANOG expression vector (shNANOG vector) in the RBS and RBT cells, the anchorage independency and tumorigenicity were repressed. We next examined various cancer cell lines for NANOG expression and showed that some cancer cell lines expressed a high level of normal and/or variant NANOG proteins. Overexpression of NANOG mRNA in lung adenocarcinoma was also shown by in situ hybridization. All these data indicate the involvement of NANOG in tumorigenesis.

  3. Evolution and diversity of green plant cell walls.

    Science.gov (United States)

    Popper, Zoë A

    2008-06-01

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

  4. 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.

  5. Progress in gene transfer by germ cells in mammals

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Use of germ cells as vectors for transgenesis in mammals has been well developed and offers exciting prospects for experimental and applied biology, agricultural and medical sciences.Such approach is referred to as either male germ cell mediated gene transfer (MGCMGT)or female germ cell mediated gene transfer(FGCMGT)technique.Sperm-mediated gene transfer (SMGT),including its alternative method,testis-mediated gene transfer(TMGT),becomes an established and reliable method for transgenesis.They have been extensively used for producing transgenic animals.The newly developed approach of FGCMGT,ovary-mediated gene transfer(OMGT) is also a novel and useful tool for efficient transgenesis.This review highlights an overview of the recent progress in germ cell mediated gene transfer techniques,methods developed and mechanisms of nucleic acid uptake by germ cells.

  6. Progress on the emitter wrap-through silicon solar cell

    Science.gov (United States)

    Gee, J. M.; Buck, M. E.; Schubert, W. K.; Basore, P. A.

    The Emitter Wrap-Through (EWT) solar cell is a back-contacted solar cell with a carrier-collection junction (emitter) on the front surface. Elimination of grids from the front surface allows for higher performance by eliminating grid-obscuration losses and reducing series resistance, while keeping an emitter on the front surface maintains high collection efficiency in solar-grade materials with modest diffusion lengths. The EWT cell uses laser-drilled vias to wrap the emitter diffusion on the front surface to interdigitated contacts on the back surface. We report on progress towards demonstration of two concepts for the EWT cell. The first EWT concept uses a fabrication sequence based on heavily diffused grooves and plated metallizations, and the second EWT concept uses a single furnace step and screen-printed metallizations. We also report on demonstration of double-sided carrier collection in the EWT cell.

  7. Detection of Changes in the Medicago sativa Retinoblastoma-Related Protein (MsRBR1) Phosphorylation During Cell Cycle Progression in Synchronized Cell Suspension Culture.

    Science.gov (United States)

    Ayaydin, Ferhan; Kotogány, Edit; Ábrahám, Edit; Horváth, Gábor V

    2017-01-01

    Deepening our knowledge on the regulation of the plant cell division cycle depends on techniques that allow for the enrichment of cell populations in defined cell cycle phases. Synchronization of cell division can be achieved using different plant tissues; however, well-established cell suspension cultures provide large amount of biological sample for further analyses. Here, we describe the methodology of the establishment, propagation, and analysis of a Medicago sativa suspension culture that can be used for efficient synchronization of the cell division. A novel 5-ethynyl-2'-deoxyuridine (EdU)-based method is used for the estimation of cell fraction that enters DNA synthesis phase of the cell cycle and we also demonstrate the changes in the phosphorylation level of Medicago sativa retinoblastoma-related protein (MsRBR1) during cell cycle progression.

  8. Stem cells: progressions and applications in clinical medicine

    Directory of Open Access Journals (Sweden)

    Ali Hosseini Bereshneh

    2016-05-01

    of them in transferring gene into different cells. Today, this method have had considerable progress in the treatment of many disease. In this review study, some aspect of stem cells like types and characteristic, origin, derivation techniques, storage conditions and differentiation to target tissues, current clinical usage and their therapeutic capabilities will be discussed.

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

    Science.gov (United States)

    Nühse, Thomas S

    2012-01-01

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

  10. Plant cortical microtubule dynamics and cell division plane orientation

    NARCIS (Netherlands)

    Chakrabortty, Bandan

    2017-01-01

    This thesis work aimed at a better understanding of the molecular basis of oriented cell division in plant cell. As, the efficiency of plant morphogenesis depends on oriented cell division, this work should contribute  towards a fundamental understanding of the  molecular basis of

  11. 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

  12. Ultrastructure of autophagy in plant cells: a review.

    Science.gov (United States)

    van Doorn, Wouter G; Papini, Alessio

    2013-12-01

    Just as with yeasts and animal cells, plant cells show several types of autophagy. Microautophagy is the uptake of cellular constituents by the vacuolar membrane. Although microautophagy seems frequent in plants it is not yet fully proven to occur. Macroautophagy occurs farther away from the vacuole. In plants it is performed by autolysosomes, which are considerably different from the autophagosomes found in yeasts and animal cells, as in plants these organelles contain hydrolases from the onset of their formation. Another type of autophagy in plant cells (called mega-autophagy or mega-autolysis) is the massive degradation of the cell at the end of one type of programmed cell death (PCD). Furthermore, evidence has been found for autophagy during degradation of specific proteins, and during the internal degeneration of chloroplasts. This paper gives a brief overview of the present knowledge on the ultrastructure of autophagic processes in plants.

  13. Coordinating cell polarity and cell cycle progression: what can we learn from flies and worms?

    Science.gov (United States)

    Noatynska, Anna; Tavernier, Nicolas; Gotta, Monica; Pintard, Lionel

    2013-08-07

    Spatio-temporal coordination of events during cell division is crucial for animal development. In recent years, emerging data have strengthened the notion that tight coupling of cell cycle progression and cell polarity in dividing cells is crucial for asymmetric cell division and ultimately for metazoan development. Although it is acknowledged that such coupling exists, the molecular mechanisms linking the cell cycle and cell polarity machineries are still under investigation. Key cell cycle regulators control cell polarity, and thus influence cell fate determination and/or differentiation, whereas some factors involved in cell polarity regulate cell cycle timing and proliferation potential. The scope of this review is to discuss the data linking cell polarity and cell cycle progression, and the importance of such coupling for asymmetric cell division. Because studies in model organisms such as Caenorhabditis elegans and Drosophila melanogaster have started to reveal the molecular mechanisms of this coordination, we will concentrate on these two systems. We review examples of molecular mechanisms suggesting a coupling between cell polarity and cell cycle progression.

  14. Progress Towards an Interdisciplinary Science of Plant Phenology: Building Predictions Across Space, Time and Species Diversity

    Science.gov (United States)

    Wolkovich, Elizabeth M.; Cook, Benjamin I.; Davies, T. Jonathan

    2013-01-01

    Climate change has brought renewed interest in the study of plant phenology - the timing of life history events. Data on shifting phenologies with warming have accumulated rapidly, yet research has been comparatively slow to explain the diversity of phenological responses observed across latitudes, growing seasons and species. Here, we outline recent efforts to synthesize perspectives on plant phenology across the fields of ecology, climate science and evolution. We highlight three major axes that vary among these disciplines: relative focus on abiotic versus biotic drivers of phenology, on plastic versus genetic drivers of intraspecific variation, and on cross-species versus autecological approaches. Recent interdisciplinary efforts, building on data covering diverse species and climate space, have found a greater role of temperature in controlling phenology at higher latitudes and for early-flowering species in temperate systems. These efforts have also made progress in understanding the tremendous diversity of responses across species by incorporating evolutionary relatedness, and linking phenological flexibility to invasions and plant performance. Future research with a focus on data collection in areas outside the temperate mid-latitudes and across species' ranges, alongside better integration of how risk and investment shape plant phenology, offers promise for further progress.

  15. Improving human reliability through better nuclear power plant system design. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Golay, M.W.

    1995-01-10

    The project on {open_quotes}Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performance{close_quotes} has been undertaken in order to address the important problem of human error in advanced nuclear power plant designs. Most of the creativity in formulating such concepts has focused upon improving the mechanical reliability of safety related plant systems. However, the lack of a mature theory has retarded similar progress in reducing the likely frequencies of human errors. The main design mechanism used to address this class of concerns has been to reduce or eliminate the human role in plant operations and accident response. The plan of work being pursued in this project is to perform a set of experiments involving human subject who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants. In the tests the systems are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds. Ultimately this computer is also to be used in compiling the results of the project. The work of this project is focused upon nuclear power plant applications. However, the persuasiveness of human errors in using all sorts of electromechanical machines gives it a much greater potential importance. Because of this we are attempting to pursue our work in a fashion permitting broad generalizations.

  16. Advances in plant cell type-specific genome-wide studies of gene expression

    Institute of Scientific and Technical Information of China (English)

    Ying WANG; Yuling JIAO

    2011-01-01

    Cell is the functional unit of life.To study the complex interactions of systems of biological molecules,it is crucial to dissect these molecules at the cell level.In recent years,major progresses have been made by plant biologists to profile gene expression in specific cell types at the genome-wide level.Approaches based on the isolation of cells,polysomes or nuclei have been developed and successfully used for studying the cell types from distinct organs of several plant species.These cell-level data sets revealed previously unrecognized cellular properties,such as cell-specific gene expression modules and hormone response centers,and should serve as essential resources for functional genomic analyses.Newly developed technologies are more affordable to many laboratories and should help to provide new insights at the cellular resolution in the near future.

  17. 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.

  18. Research Progress of Photoanodes for Quantum Dot Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    LI Zhi-min

    2017-08-01

    Full Text Available This paper presents the development status and tendency of quantum dot sensitized solar cells. Photoanode research progress and its related technologies are analyzed in detail from the three ways of semiconductor thin films, quantum dot co-sensitization and quantum dot doping, deriving from the approach that the conversion efficiency can be improved by photoanode modification for quantum dot sensitized solar cells. According to the key factors which restrict the cell efficiency, the promising future development of quantum dot sensitized solar cells is proposed,for example,optimizing further the compositions and structures of semiconductor thin films for the photoanodes, exploring new quantum dots with broadband absorption and developing high efficient techniques of interface modification.

  19. Progress in spondylarthritis. Immunopathogenesis of spondyloarthritis: which cells drive disease?

    Science.gov (United States)

    Melis, Lode; Elewaut, Dirk

    2009-01-01

    Spondyloarthritides, or SpA, form a cluster of chronic inflammatory diseases with the axial skeleton as the most typical disease localisation, although extra-articular manifestations such as intestinal inflammation may frequently occur during the course of the disease. This review summarises recent progress in our understanding of the immunopathogenesis of SpA with special emphasis on the cellular constituents considered to be responsible for the initiation and/or perpetuation of inflammation. There are several arguments favouring a role for haematopoietic cells in the pathophysiology of spondyloarthritis, including HLA-B27-associated dendritic cell disturbances, HLA-B27 misfolding properties and T helper 17 cells. In addition, recent studies have pointed toward a pivotal role for stromal cells. A major challenge, however, remains to determine how recently identified genetic associations such as interleukin-23 receptor polymorphisms may influence cellular targets in spondyloarthritis.

  20. Plant and animal stem cells: similar yet different.

    Science.gov (United States)

    Heidstra, Renze; Sabatini, Sabrina

    2014-05-01

    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 new tissues. Plant stem cell niches are located within the meristems, which are organized structures that are responsible for most post-embryonic development. The continuous organ production that is characteristic of plant growth requires a robust regulatory network to keep the balance between pluripotent stem cells and differentiating progeny. Components of this network have now been elucidated and provide a unique opportunity for comparing strategies that were developed in the animal and plant kingdoms, which underlie the logic of stem cell behaviour.

  1. Programmed cell death in the plant immune system.

    Science.gov (United States)

    Coll, N S; Epple, P; Dangl, J L

    2011-08-01

    Cell death has a central role in innate immune responses in both plants and animals. Besides sharing striking convergences and similarities in the overall evolutionary organization of their innate immune systems, both plants and animals can respond to infection and pathogen recognition with programmed cell death. The fact that plant and animal pathogens have evolved strategies to subvert specific cell death modalities emphasizes the essential role of cell death during immune responses. The hypersensitive response (HR) cell death in plants displays morphological features, molecular architectures and mechanisms reminiscent of different inflammatory cell death types in animals (pyroptosis and necroptosis). In this review, we describe the molecular pathways leading to cell death during innate immune responses. Additionally, we present recently discovered caspase and caspase-like networks regulating cell death that have revealed fascinating analogies between cell death control across both kingdoms.

  2. New plant-growth medium for increased power output of the Plant-Microbial Fuel Cell

    NARCIS (Netherlands)

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

    2012-01-01

    In a Plant-Microbial Fuel Cell anode-conditions must be created that are favorable for plant growth and electricity production. One of the major aspects in this is the composition of the plant-growth medium. Hoagland medium has been used until now, with added phosphate buffer to reduce potential

  3. Progress in the Multijunction Solar Cell Mantech Program

    Science.gov (United States)

    Keener, David N.; Marvin, Dean; Brinker, David J.; Curtis, Henry B.

    2004-01-01

    In September, 1995, the joint Wright Laboratory/Phillips Laboratory/NASA Lewis Multijunction Solar Cell Manufacturing Technology (ManTech) Program began to improve multijunction cell performance and scale them up to production size and quantity to support Air Force and commercial satellite programs. The first milestone of the program has been reached and the purpose of this paper is to present the results of the program so far. The objectives of the Multijunction Solar Cell ManTech Program are to increase the GaInP2/GaAs/Ge lot average cell efficiency to 24-26%, increase the cell size to > or equal to 16 sq cm while maintaining high efficiency, and limit the per cell costs to cells. Advanced manufacturing technology and process control techniques such as in-situ process monitoring and real time process feedback are being used to optimize multijunction solar cell growth processes to achieve these goals. This paper will discuss progress made in Phase I of the program and give an overview of Phase II but will focus on side-by-side testing results collected by Phillips Laboratory and NASA Lewis on Phase I deliverable cells from both vendors. Cell performance, pre- and post radiation, and temperature coefficient results on initial production multijunction solar cells will be presented and discussed. The data shows that this technology meets the objectives of the program, and that, in the interim before a new solar simulation standard becomes widely available, the measurement techniques being used by the major space solar cell manufacturers are providing adequate testing results for solar array design.

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

    Science.gov (United States)

    Wilson, Sarah A; Roberts, Susan C

    2012-04-01

    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. A variety of strategies are being developed to overcome these limitations including elicitation, in situ product removal and metabolic engineering with single genes and transcription factors. Recently, the plant cell culture production platform has been extended to pharmaceutically active heterologous proteins. Plant systems are beneficial because they are able to produce complex proteins that are properly glycosylated, folded and assembled without the risk of contamination by toxins that are associated with mammalian or microbial production systems. Additionally, plant cell culture isolates transgenic material from the environment, allows for more controllable conditions over field-grown crops and promotes secretion of proteins to the medium, reducing downstream purification costs. Despite these benefits, the increase in cost of heterologous protein synthesis in plant cell culture as opposed to field-grown crops is significant and therefore processes must be optimized with regard to maximizing secretion and enhancing protein stability in the cell culture media. This review discusses recent advancements in plant cell culture processing technology, focusing on progress towards overcoming the problems associated with commercialization of these production systems and highlighting recent commercial successes.

  5. Research progress of plant population genomics based on high-throughput sequencing.

    Science.gov (United States)

    Yunsheng, Wang

    2016-08-01

    Population genomics, a new paradigm for population genetics, combine the concepts and techniques of genomics with the theoretical system of population genetics and improve our understanding of microevolution through identification of site-specific effect and genome-wide effects using genome-wide polymorphic sites genotypeing. With the appearance and improvement of the next generation high-throughput sequencing technology, the numbers of plant species with complete genome sequences increased rapidly and large scale resequencing has also been carried out in recent years. Parallel sequencing has also been done in some plant species without complete genome sequences. These studies have greatly promoted the development of population genomics and deepened our understanding of the genetic diversity, level of linking disequilibium, selection effect, demographical history and molecular mechanism of complex traits of relevant plant population at a genomic level. In this review, I briely introduced the concept and research methods of population genomics and summarized the research progress of plant population genomics based on high-throughput sequencing. I also discussed the prospect as well as existing problems of plant population genomics in order to provide references for related studies.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ye eXia

    2014-10-01

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

  8. 荧光蛋白在植物活细胞液泡成像中的应用研究进展%Recent Progress in Living Cell Imaging of Plant Vacuole Using Fluorescent-protein Transgenic Lines and Three-dimensional Imaging

    Institute of Scientific and Technical Information of China (English)

    叶庆亮; 曹建华

    2011-01-01

    高等植物细胞中,液泡在各种细胞信号转导事件和形态建成中起着重要的作用.这一细胞内部结构在分裂和分化期间其功能和形状不断地变化着.为分析这些连续的变化,绿色荧光蛋白(green fluorescent protein,GFP)及其他荧光蛋白活体标记技术普遍用来跟踪特异蛋白的定位及变动.为使液泡可视成像,有几种途径可用来选择适当的荧光蛋白融合伴侣,如液泡膜内在蛋白和构造蛋白相关蛋白等就非常适合应用于液泡成像.此外,三维重建法在定位细胞内广为分布的细胞器时也不可或缺.同时,等值面表面模化过程对液泡膜成像也非常有用.本文综述液泡的结构、种类和功能,并概括各种融合的绿色荧光蛋白在植物活细胞液泡成像中的应用及其三维成像技术的研究进展.%In high plant cells, vacuoles play important roles in a variety of cellular events, including cell division,morphogenesis, and signal transduction.These intracellular structures undergo dynamic changes in their shapes and functions during cell division and differentiation, and to analyze these sequential structural changes, the vital labeling technique, using the green-fluorescent protein or other fluorescent proteins, has commonly been used to follow the localization and translocation of specific proteins.To visualize vacuoles, the tonoplast-intrinsic proteins and syntaxin-related proteins are available for selecting the appropriate fluorescent-protein fusion partner for vacuolar imaging.In addition, three-dimensional reconstruction methods are indispensable for localizing the widely distributed organelles within the cell.The maximum intensity projection method is suitable for cytoskeletal structures, while contour-based surface modeling possesses many advantages for vacuolar membranes.In this article, we summarize the plant vacuoles and the recent progress in living cell imaging of the plant vacuoles using various fusions

  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. Epigenetic memory and cell fate reprogramming in plants.

    Science.gov (United States)

    Birnbaum, Kenneth D; Roudier, François

    2017-02-01

    Plants have a high intrinsic capacity to regenerate from adult tissues, with the ability to reprogram adult cell fates. In contrast, epigenetic mechanisms have the potential to stabilize cell identity and maintain tissue organization. The question is whether epigenetic memory creates a barrier to reprogramming that needs to be erased or circumvented in plant regeneration. Early evidence suggests that, while chromatin dynamics impact gene expression in the meristem, a lasting constraint on cell fate is not established until late stages of plant cell differentiation. It is not yet clear whether the plasticity of plant cells arises from the ability of cells to erase identity memory or to deploy cells that may exhibit cellular specialization but still lack an epigenetic restriction on cell fate alteration.

  11. 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)

  12. Plant cell wall-degrading enzymes and their secretion in plant-pathogenic fungi.

    Science.gov (United States)

    Kubicek, Christian P; Starr, Trevor L; Glass, N Louise

    2014-01-01

    Approximately a tenth of all described fungal species can cause diseases in plants. A common feature of this process is the necessity to pass through the plant cell wall, an important barrier against pathogen attack. To this end, fungi possess a diverse array of secreted enzymes to depolymerize the main structural polysaccharide components of the plant cell wall, i.e., cellulose, hemicellulose, and pectin. Recent advances in genomic and systems-level studies have begun to unravel this diversity and have pinpointed cell wall-degrading enzyme (CWDE) families that are specifically present or enhanced in plant-pathogenic fungi. In this review, we discuss differences between the CWDE arsenal of plant-pathogenic and non-plant-pathogenic fungi, highlight the importance of individual enzyme families for pathogenesis, illustrate the secretory pathway that transports CWDEs out of the fungal cell, and report the transcriptional regulation of expression of CWDE genes in both saprophytic and phytopathogenic fungi.

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Glenn, Donald R.

    rated at 500 kW, are on-site and will be installed to the BOP upon completion of the BOP pretests now in the final stages. Full operation and commencement of the formal demonstration is to begin late this year. Now five years old, the Fuel Cell Commercialization Group (FCCG) has grown to include over 30 buyers. The Group's Committees have been actively working with FCE personnel to hone the plant's performance, configuration and cost/benefit trade-offs to assure a market-responsive unit results from the collaboration. A standard contract has been developed for use with the FCCG buyers to streamline the purchase agreement negotiations for the early units. These are essential steps to support a market entry for the 2.8 MW power plant in 1999. The paper details the program's progress and provides additional information on the current demonstration and stack test efforts, with comparisons to earlier test data. Recent accomplishments and planned efforts to affect market entry of the first production units is reviewed as well.

  16. Liver cancer stem cell markers: Progression and therapeutic implications

    Science.gov (United States)

    Sun, Jing-Hui; Luo, Qing; Liu, Ling-Ling; Song, Guan-Bin

    2016-01-01

    Cancer stem cells (CSCs) are a small subpopulation in cancer, have been proposed to be cancer-initiating cells, and have been shown to be responsible for chemotherapy resistance and cancer recurrence. The identification of CSC subpopulations inside a tumor presents a new understanding of cancer development because it implies that tumors can only be eradicated by targeting CSCs. Although advances in liver cancer detection and treatment have increased the possibility of curing the disease at early stages, unfortunately, most patients will relapse and succumb to their disease. Strategies aimed at efficiently targeting liver CSCs are becoming important for monitoring the progress of liver cancer therapy and for evaluating new therapeutic approaches. Herein, we provide a critical discussion of biological markers described in the literature regarding liver cancer stem cells and the potential of these markers to serve as therapeutic targets. PMID:27053846

  17. Photovoltaic cells and photodetectors made with semiconductor polymers: recent progress

    Science.gov (United States)

    Yu, Gang; Srdanov, Gordana; Wang, Hailiang; Cao, Yong; Heeger, Alan J.

    2000-05-01

    In this presentation, we discuss recent progress on polymer photovoltaic cells and polymer photodetectors. By improving the fill-factor of polymer photovoltaic cells, the energy conversion efficiency was improved significantly to over 4 percent. Such high efficiency polymer photovoltaic cells are promising for many applications including e-papers, e-books and smart-windows. Polymer photodetectors with similar device configuration show high photosensitivity, low dark current, large dynamic range, linear intensity dependence, low noise level and fast response time. These parameters are comparable to or even better than their inorganic counterparts. The advantages of low manufacturing cost, large detection area, and easy hybridization and integration with other electronic or optical components make them promising for a variety of applications including chemical/biomedical analysis, full-color digital image sensing and high energy radiation detection.

  18. Polarity in plant asymmetric cell division: Division orientation and cell fate differentiation

    OpenAIRE

    Shao, Wanchen; Dong, Juan

    2016-01-01

    Asymmetric cell division (ACD) is universally required for the development of multicellular organisms. Unlike animal cells, plant cells have a rigid cellulosic extracellular matrix, the cell wall, which provides physical support and forms communication routes. This fundamental difference leads to some unique mechanisms in plants for generating asymmetries during cell division. However, plants also utilize intrinsically polarized proteins to regulate asymmetric signaling and cell division, a s...

  19. Haspin has Multiple Functions in the Plant Cell Division Regulatory Network.

    Science.gov (United States)

    Kozgunova, Elena; Suzuki, Takamasa; Ito, Masaki; Higashiyama, Tetsuya; Kurihara, Daisuke

    2016-04-01

    Progression of cell division is controlled by various mitotic kinases. In animal cells, phosphorylation of histone H3 at Thr3 by the kinase Haspin (haploid germ cell-specific nuclear protein kinase) promotes centromeric Aurora B localization to regulate chromosome segregation. However, less is known about the function of Haspin in regulatory networks in plant cells. Here, we show that inhibition of Haspin with 5-iodotubercidin (5-ITu) in Bright Yellow-2 (BY-2) cells delayed chromosome alignment. Haspin inhibition also prevented the centromeric localization of Aurora3 kinase (AUR3) and disrupted its function. This suggested that Haspin plays a role in the specific positioning of AUR3 on chromosomes in plant cells, a function conserved in animals. The results also indicated that Haspin and AUR3 are involved in the same pathway, which regulates chromosome alignment during prometaphase/metaphase. Remarkably, Haspin inhibition by 5-ITu also led to a severe cytokinesis defect, resulting in binuclear cells with a partially formed cell plate. The 5-ITu treatment did not affect microtubules, AUR1/2 or the NACK-PQR pathway; however, it did alter the distribution of actin filaments on the cell plate. Together, these results suggested that Haspin has several functions in regulating cell division in plant cells: in the localization of AUR3 on centromeres and in regulating late cell plate expansion during cytokinesis.

  20. 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

  1. 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

  2. Genome modifications in plant cells by custom-made restriction enzymes.

    Science.gov (United States)

    Tzfira, Tzvi; Weinthal, Dan; Marton, Ira; Zeevi, Vardit; Zuker, Amir; Vainstein, Alexander

    2012-05-01

    Genome editing, i.e. the ability to mutagenize, insert, delete and replace sequences, in living cells is a powerful and highly desirable method that could potentially revolutionize plant basic research and applied biotechnology. Indeed, various research groups from academia and industry are in a race to devise methods and develop tools that will enable not only site-specific mutagenesis but also controlled foreign DNA integration and replacement of native and transgene sequences by foreign DNA, in living plant cells. In recent years, much of the progress seen in gene targeting in plant cells has been attributed to the development of zinc finger nucleases and other novel restriction enzymes for use as molecular DNA scissors. The induction of double-strand breaks at specific genomic locations by zinc finger nucleases and other novel restriction enzymes results in a wide variety of genetic changes, which range from gene addition to the replacement, deletion and site-specific mutagenesis of endogenous and heterologous genes in living plant cells. In this review, we discuss the principles and tools for restriction enzyme-mediated gene targeting in plant cells, as well as their current and prospective use for gene targeting in model and crop plants.

  3. 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.

  4. Progressive intracranial fusiform aneurysms and T-cell immunodeficiency.

    Science.gov (United States)

    Piantino, Juan A; Goldenberg, Fernando D; Pytel, Peter; Wagner-Weiner, Linda; Ansari, Sameer A

    2013-02-01

    In the pediatric population, intracranial fusiform aneurysms have been associated with human immunodeficiency virus/acquired immunodeficiency syndrome and rarely with opportunistic infections related to other immunodeficiencies. The HIV virus and other infectious organisms have been implicated in the pathophysiology of these aneurysms. We present a child with T-cell immunodeficiency but no evidence of human immunodeficiency virus or opportunistic intracranial infections that developed progressive bilateral fusiform intracranial aneurysms. Our findings suggest a role of immunodeficiency or inflammation in the formation of some intracranial aneurysms.

  5. 2015 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    Popovich, Neil

    2015-12-01

    In the past year, the DOE Hydrogen Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

  6. 2012 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    2012-12-01

    In the past year, the DOE Hydrogen Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

  7. 2016 Annual Progress Report: DOE Hydrogen and Fuel Cells Program

    Energy Technology Data Exchange (ETDEWEB)

    Satyapal, Sunita [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-02-01

    In the past year, the DOE Hydrogen Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

  8. Progress of air-breathing cathode in microbial fuel cells

    Science.gov (United States)

    Wang, Zejie; Mahadevan, Gurumurthy Dummi; Wu, Yicheng; Zhao, Feng

    2017-07-01

    Microbial fuel cell (MFC) is an emerging technology to produce green energy and vanquish the effects of environmental contaminants. Cathodic reactions are vital for high electrical power density generated from MFCs. Recently tremendous attentions were paid towards developing high performance air-breathing cathodes. A typical air-breathing cathode comprises of electrode substrate, catalyst layer, and air-diffusion layer. Prior researches demonstrated that each component influenced the performance of air-breathing cathode MFCs. This review summarized the progress in development of the individual component and elaborated main factors to the performance of air-breathing cathode.

  9. Medicinally important secondary metabolites in recombinant microorganisms or plants: progress in alkaloid biosynthesis.

    Science.gov (United States)

    Schäfer, Holger; Wink, Michael

    2009-12-01

    Plants produce a high diversity of natural products or secondary metabolites which are important for the communication of plants with other organisms. A prominent function is the protection against herbivores and/or microbial pathogens. Some natural products are also involved in defence against abiotic stress, e.g. UV-B exposure. Many of the secondary metabolites have interesting biological properties and quite a number are of medicinal importance. Because the production of the valuable natural products, such as the anticancer drugs paclitaxel, vinblastine or camptothecin in plants is a costly process, biotechnological alternatives to produce these alkaloids more economically become increasingly important. This review provides an overview of the state of art to produce alkaloids in recombinant microorganisms, such as bacteria or yeast. Some progress has been made in metabolic engineering usually employing a single recombinant alkaloid gene. More importantly, for benzylisoquinoline, monoterpene indole and diterpene alkaloids (taxanes) as well as some terpenoids and phenolics the proof of concept for production of complex alkaloids in recombinant Escherichia coli and yeast has already been achieved. In a long-term perspective, it will probably be possible to generate gene cassettes for complete pathways, which could then be used for production of valuable natural products in bioreactors or for metabolic engineering of crop plants. This will improve their resistance against herbivores and/or microbial pathogens.

  10. Animal and plant stem cells concepts, propagation and engineering

    CERN Document Server

    Pavlović, Mirjana

    2017-01-01

    This book provides a multifaceted look into the world of stem cells and explains the similarities and differences between plant and human stem cells. It explores the intersection between animals and plants and explains their cooperative role in bioengineering studies. The book treats both theoretical and practical aspects of stem cell research. It covers the advantages and limitations of many common applications related to stem cells: their sources, categories, engineering of these cells, reprogramming of their functions, and their role as novel cellular therapeutic approach. Written by experts in the field, the book focuses on aspects of stem cells ranging from expansion-propagation to metabolic reprogramming. It introduces the emergence of cancer stem cells and different modalities in targeted cancer stem cell therapies. It is a valuable source of fresh information for academics and researchers, examining molecular mechanisms of animal and plant stem cell regulation and their usage for therapeutic applicati...

  11. [Effect of inhibitors serine/threonine protein kinases and protein phosphatases on mitosis progression of synchronized tobacco by-2 cells].

    Science.gov (United States)

    Sheremet, Ia A; Emets, A I; Azmi, A; Vissenberg, K; Verbelen, J-P; Blium, Ia B

    2012-01-01

    In order to investigate the role of various serine/ threonine protein kinases and protein phosphatases in the regulation of mitosis progression in plant cells the influence of cyclin-dependent (olomoucine) and Ca2+ -calmodulin-dependent (W7) protein kinases inhibitors, as well as protein kinase C inhibitors (H7 and staurosporine) and protein phosphatases inhibitor (okadaic acid) on mitosis progression in synchronized tobacco BY-2 cells has been studied. It was found that BY-2 culture treatment with inhibitors of cyclin dependent protein kinases and protein kinase C causes prophase delay, reduces the mitotic index and displaces of mitotic peak as compare with control cells. Inhibition of Ca2+ -calmodulin dependent protein kinases enhances the cell entry into prophase and delays their exit from mitosis. Meanwhile inhibition of serine/threonine protein phosphatases insignificantly enhances of synchronized BY-2 cells entering into all phases of mitosis.

  12. Production of recombinant proteins in suspension-cultured plant cells.

    Science.gov (United States)

    Plasson, Carole; Michel, Rémy; Lienard, David; Saint-Jore-Dupas, Claude; Sourrouille, Christophe; de March, Ghislaine Grenier; Gomord, Véronique

    2009-01-01

    Plants have emerged in the past decade as a suitable alternative to the current production systems for recombinant pharmaceutical proteins and, today their potential for low-cost production of high quality, much safer and biologically active mammalian proteins is largely documented. Among various plant expression systems being explored, genetically modified suspension-cultured plant cells offer a promising system for production of biopharmaceuticals. Indeed, when compared to other plant-based production platforms that have been explored, suspension-cultured plant cells have the advantage of being totally devoid of problems associated with the vagaries of weather, pest, soil and gene flow in the environment. Because of short growth cycles, the timescale needed for the production of recombinant proteins in plant cell culture can be counted in days or weeks after transformation compared to months needed for the production in transgenic plants. Moreover, recovery and purification of recombinant proteins from plant biomass is an expensive and technically challenging business that may amount to 80-94% of the final product cost. One additional advantage of plant cell culture is that the recombinant protein fused with a signal sequence can be expressed and secreted into the culture medium, and therefore recovered and purified in the absence of large quantities of contaminating proteins. Consequently, the downstream processing of proteins extracted from plant cell culture medium is less expensive, which may/does balance the higher costs of fermentation. When needed for clinical use, recombinant proteins are easily produced in suspension-cultured plant cells under certified, controllable and sterile conditions that offer improved safety and provide advantages for good manufacturing practices and regulatory compliance. In this chapter, we present basic protocols for rapid generation of transgenic suspension-cultured cells of Nicotiana tabacum, Oriza sativa and Arabidopis

  13. 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

  14. 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.

  15. 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

  16. The influence of reactive oxygen species on cell cycle progression in mammalian cells.

    Science.gov (United States)

    Verbon, Eline Hendrike; Post, Jan Andries; Boonstra, Johannes

    2012-12-10

    Cell cycle regulation is performed by cyclins and cyclin dependent kinases (CDKs). Recently, it has become clear that reactive oxygen species (ROS) influence the presence and activity of these enzymes and thereby control cell cycle progression. In this review, we first describe the discovery of enzymes specialized in ROS production: the NADPH oxidase (NOX) complexes. This discovery led to the recognition of ROS as essential players in many cellular processes, including cell cycle progression. ROS influence cell cycle progression in a context-dependent manner via phosphorylation and ubiquitination of CDKs and cell cycle regulatory molecules. We show that ROS often regulate ubiquitination via intermediate phosphorylation and that phosphorylation is thus the major regulatory mechanism influenced by ROS. In addition, ROS have recently been shown to be able to activate growth factor receptors. We will illustrate the diverse roles of ROS as mediators in cell cycle regulation by incorporating phosphorylation, ubiquitination and receptor activation in a model of cell cycle regulation involving EGF-receptor activation. We conclude that ROS can no longer be ignored when studying cell cycle progression. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. B-1 cells and concomitant immunity in Ehrlich tumour progression.

    Science.gov (United States)

    Azevedo, M C; Palos, M C; Osugui, L; Laurindo, M F; Masutani, D; Nonogaki, S; Bachi, A L L; Melo, F H M; Mariano, M

    2014-05-01

    Concomitant immunity is a phenomenon in which a tumour-bearing host is resistant to the growth of an implanted secondary tumour. Metastases are considered to be secondary tumours that develop spontaneously during primary tumour growth, suggesting the involvement of concomitant immunity in controlling the rise of metastases. It has been demonstrated that B-1 cells, a subset of B-lymphocytes found predominantly in pleural and peritoneal cavities, not only increase the metastatic development of murine melanoma B16F10, but also are capable of differentiating into mononuclear phagocytes, modulating inflammatory responses in wound healing, in oral tolerance and in Paracoccidiose brasiliensis infections. Here, we studied B-1 cells' participation in concomitant immunity during Ehrlich tumour progression. Our results show that B-1 cells obtained from BALB/c mice previously injected with Ehrlich tumour in the footpad were able to protect BALB/c and BALB/Xid mice against Ehrlich tumour challenge. In addition, it was demonstrated that BALB/Xid show faster tumour growth and have lost concomitant immunity, and that this state can be partially restored by reconstituting these animals with B-1 cells. However, further researches are required to establish the mechanism involving B-1 cells in Ehrlich tumour growth. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Progress in nanostructured photoanodes for dye-sensitized solar cells

    Science.gov (United States)

    Liu, Xueyang; Fang, Jian; Liu, Yong; Lin, Tong

    2016-09-01

    Solar cells represent a principal energy technology to convert light into electricity. Commercial solar cells are at present predominately produced by single- or multi-crystalline silicon wafers. The main drawback to silicon-based solar cells, however, is high material and manufacturing costs. Dye-sensitized solar cells (DSSCs) have attracted much attention during recent years because of the low production cost and other advantages. The photoanode (working electrode) plays a key role in determining the performance of DSSCs. In particular, nanostructured photoanodes with a large surface area, high electron transfer efficiency, and low electron recombination facilitate to prepare DSSCs with high energy conversion efficiency. In this review article, we summarize recent progress in the development of novel photoanodes for DSSCs. Effect of semiconductor material (e.g. TiO2, ZnO, SnO2, N2O5, and nano carbon), preparation, morphology and structure (e.g. nanoparticles, nanorods, nanofibers, nanotubes, fiber/particle composites, and hierarchical structure) on photovoltaic performance of DSSCs is described. The possibility of replacing silicon-based solar cells with DSSCs is discussed.

  19. Recent progress and challenges of organometal halide perovskite solar cells

    Science.gov (United States)

    Yang, Liyan; Barrows, Alexander T.; Lidzey, David G.; Wang, Tao

    2016-02-01

    We review recent progress in the development of organometal halide perovskite solar cells. We discuss different compounds used to construct perovskite photoactive layers, as well as the optoelectronic properties of this system. The factors that affect the morphology of the perovskite active layer are explored, e.g. material composition, film deposition methods, casting solvent and various post-treatments. Different strategies are reviewed that have recently emerged to prepare high performing perovskite films, creating polycrystalline films having either large or small grain size. Devices that are constructed using meso-superstructured and planar architectures are summarized and the impact of the fabrication process on operational efficiency is discussed. Finally, important research challenges (hysteresis, thermal and moisture instability, mechanical flexibility, as well as the development of lead-free materials) in the development of perovskite solar cells are outlined and their potential solutions are discussed.

  20. 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.

  1. Recent Progress on Systems and Synthetic Biology Approaches to Engineer Fungi As Microbial Cell Factories.

    Science.gov (United States)

    Amores, Gerardo Ruiz; Guazzaroni, María-Eugenia; Arruda, Letícia Magalhães; Silva-Rocha, Rafael

    2016-04-01

    Filamentous fungi are remarkable organisms naturally specialized in deconstructing plant biomass and this feature has a tremendous potential for biofuel production from renewable sources. The past decades have been marked by a remarkable progress in the genetic engineering of fungi to generate industry-compatible strains needed for some biotech applications. In this sense, progress in this field has been marked by the utilization of high-throughput techniques to gain deep understanding of the molecular machinery controlling the physiology of these organisms, starting thus the Systems Biology era of fungi. Additionally, genetic engineering has been extensively applied to modify wellcharacterized promoters in order to construct new expression systems with enhanced performance under the conditions of interest. In this review, we discuss some aspects related to significant progress in the understating and engineering of fungi for biotechnological applications, with special focus on the construction of synthetic promoters and circuits in organisms relevant for industry. Different engineering approaches are shown, and their potential and limitations for the construction of complex synthetic circuits in these organisms are examined. Finally, we discuss the impact of engineered promoter architecture in the single-cell behavior of the system, an often-neglected relationship with a tremendous impact in the final performance of the process of interest. We expect to provide here some new directions to drive future research directed to the construction of high-performance, engineered fungal strains working as microbial cell factories.

  2. Dynamic Fluctuation of Circulating Tumor Cells during Cancer Progression

    Directory of Open Access Journals (Sweden)

    Mazen A. Juratli

    2014-01-01

    Full Text Available Circulating tumor cells (CTCs are a promising diagnostic and prognostic biomarker for metastatic tumors. We demonstrate that CTCs’ diagnostic value might be increased through real-time monitoring of CTC dynamics. Using preclinical animal models of breast cancer and melanoma and in vivo flow cytometry with photoacoustic and fluorescence detection schematics, we show that CTC count does not always correlate with the primary tumor size. Individual analysis elucidated many cases where the highest level of CTCs was detected before the primary tumor starts progressing. This phenomenon could be attributed to aggressive tumors developing from cancer stem cells. Furthermore, real-time continuous monitoring of CTCs reveals that they occur at highly variable rates in a detection point over a period of time (e.g., a range of 0–54 CTCs per 5 min. These same fluctuations in CTC numbers were observed in vivo in epithelial and non-epithelial metastatic tumors, in different stages of tumor progression, and in different vessels. These temporal CTC fluctuations can explain false negative results of a one-time snapshot test in humans. Indeed, we observed wide variations in the number of CTCs in subsequent blood samples taken from the same metastatic melanoma patient, with some samples being CTC-free. If these phenomena are confirmed in our ongoing in vivo clinical trials, this could support a personalized strategy of CTC monitoring for cancer patients.

  3. Dynamic Fluctuation of Circulating Tumor Cells during Cancer Progression

    Energy Technology Data Exchange (ETDEWEB)

    Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A. [Phillips Classic Laser and Nanomedicine Laboratories, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Melerzanov, Alexander V. [Moscow Institute of Physics and Technology (MIPT), Moscow Region, 141700 (Russian Federation); Zharov, Vladimir P. [Phillips Classic Laser and Nanomedicine Laboratories, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Arkansas Nanomedicine Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Moscow Institute of Physics and Technology (MIPT), Moscow Region, 141700 (Russian Federation); Galanzha, Ekaterina I., E-mail: egalanzha@uams.edu [Phillips Classic Laser and Nanomedicine Laboratories, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States)

    2014-01-15

    Circulating tumor cells (CTCs) are a promising diagnostic and prognostic biomarker for metastatic tumors. We demonstrate that CTCs’ diagnostic value might be increased through real-time monitoring of CTC dynamics. Using preclinical animal models of breast cancer and melanoma and in vivo flow cytometry with photoacoustic and fluorescence detection schematics, we show that CTC count does not always correlate with the primary tumor size. Individual analysis elucidated many cases where the highest level of CTCs was detected before the primary tumor starts progressing. This phenomenon could be attributed to aggressive tumors developing from cancer stem cells. Furthermore, real-time continuous monitoring of CTCs reveals that they occur at highly variable rates in a detection point over a period of time (e.g., a range of 0–54 CTCs per 5 min). These same fluctuations in CTC numbers were observed in vivo in epithelial and non-epithelial metastatic tumors, in different stages of tumor progression, and in different vessels. These temporal CTC fluctuations can explain false negative results of a one-time snapshot test in humans. Indeed, we observed wide variations in the number of CTCs in subsequent blood samples taken from the same metastatic melanoma patient, with some samples being CTC-free. If these phenomena are confirmed in our ongoing in vivo clinical trials, this could support a personalized strategy of CTC monitoring for cancer patients.

  4. An epigenetic view of plant cells cultured in vitro: somaclonal variation and beyond.

    Science.gov (United States)

    Miguel, Célia; Marum, Liliana

    2011-07-01

    Epigenetic mechanisms are highly dynamic events that modulate gene expression. As more accurate and powerful tools for epigenetic analysis become available for application in a broader range of plant species, analysis of the epigenetic landscape of plant cell cultures may turn out to be crucial for understanding variant phenotypes. In vitro plant cell and tissue culture methodologies are important for many ongoing plant propagation and breeding programmes as well as for cutting-edge research in several plant model species. Although it has long been known that in vitro conditions induce variation at several levels, most studies using such conditions rely on the assumption that in vitro cultured plant cells/tissues mostly conform genotypically and phenotypically. However, when large-scale clonal propagation is the aim, there has been a concern in confirming true-to-typeness using molecular markers for evaluating stability. While in most reports genetic variation has been found to occur at relatively modest frequencies, variation in DNA methylation patterns seems to be much more frequent and in some cases it has been directly implicated in phenotypic variation. Recent advances in the field of epigenetics have uncovered highly dynamic mechanisms of chromatin remodelling occurring during cell dedifferentiation and differentiation processes on which in vitro adventitious plant regeneration systems are based. Here, an overview of recent findings related to developmental switches occurring during in vitro culture is presented. Additionally, an update on the detection of epigenetic variation in plant cell cultures will be provided and discussed in the light of recent progress in the plant epigenetics field.

  5. Do mitochondria play a role in remodelling lace plant leaves during programmed cell death?

    Directory of Open Access Journals (Sweden)

    Lane Stephanie

    2011-06-01

    Full Text Available Abstract Background Programmed cell death (PCD is the regulated death of cells within an organism. The lace plant (Aponogeton madagascariensis produces perforations in its leaves through PCD. The leaves of the plant consist of a latticework of longitudinal and transverse veins enclosing areoles. PCD occurs in the cells at the center of these areoles and progresses outwards, stopping approximately five cells from the vasculature. The role of mitochondria during PCD has been recognized in animals; however, it has been less studied during PCD in plants. Results The following paper elucidates the role of mitochondrial dynamics during developmentally regulated PCD in vivo in A. madagascariensis. A single areole within a window stage leaf (PCD is occurring was divided into three areas based on the progression of PCD; cells that will not undergo PCD (NPCD, cells in early stages of PCD (EPCD, and cells in late stages of PCD (LPCD. Window stage leaves were stained with the mitochondrial dye MitoTracker Red CMXRos and examined. Mitochondrial dynamics were delineated into four categories (M1-M4 based on characteristics including distribution, motility, and membrane potential (ΔΨm. A TUNEL assay showed fragmented nDNA in a gradient over these mitochondrial stages. Chloroplasts and transvacuolar strands were also examined using live cell imaging. The possible importance of mitochondrial permeability transition pore (PTP formation during PCD was indirectly examined via in vivo cyclosporine A (CsA treatment. This treatment resulted in lace plant leaves with a significantly lower number of perforations compared to controls, and that displayed mitochondrial dynamics similar to that of non-PCD cells. Conclusions Results depicted mitochondrial dynamics in vivo as PCD progresses within the lace plant, and highlight the correlation of this organelle with other organelles during developmental PCD. To the best of our knowledge, this is the first report of

  6. ADAM12 produced by tumor cells rather than stromal cells accelerates breast tumor progression

    DEFF Research Database (Denmark)

    Frohlich, Camilla; Nehammer, Camilla; Albrechtsen, Reidar

    2011-01-01

    Expression of ADAM12 is low in most normal tissues, but is markedly increased in numerous human cancers, including breast carcinomas. We have previously shown that overexpression of ADAM12 accelerates tumor progression in a mouse model of breast cancer (PyMT). In the present study, we found...... that ADAM12 deficiency reduces breast tumor progression in the PyMT model. However, the catalytic activity of ADAM12 appears to be dispensable for its tumor-promoting effect. Interestingly, we demonstrate that ADAM12 endogenously expressed in tumor-associated stroma in the PyMT model does not influence...... tumor progression, but that ADAM12 expression by tumor cells is necessary for tumor progression in these mice. This finding is consistent with our observation that in human breast carcinoma ADAM12 is almost exclusively located in tumor cells and only rarely seen in the tumor-associated stroma. We...

  7. 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.

  8. Fuel Cell Power Plants Renewable and Waste Fuels

    Science.gov (United States)

    2011-01-13

    Fuel Cell Power Plants Renewable and Waste Fuels DOE-DOD Workshop Washington, DC. January 13, 2011 reliable, efficient, ultra-clean Report...2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Fuel Cell Power Plants Renewable and Waste Fuels 5a. CONTRACT...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES presented at the DOE-DOD Waste-to-Energy using Fuel Cells Workshop held

  9. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

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

  10. Programmed Cell Death Progresses Differentially in Epidermal and Mesophyll Cells of Lily Petals.

    Directory of Open Access Journals (Sweden)

    Hiroko Mochizuki-Kawai

    Full Text Available In the petals of some species of flowers, programmed cell death (PCD begins earlier in mesophyll cells than in epidermal cells. However, PCD progression in each cell type has not been characterized in detail. We separately constructed a time course of biochemical signs and expression patterns of PCD-associated genes in epidermal and mesophyll cells in Lilium cv. Yelloween petals. Before visible signs of senescence could be observed, we found signs of PCD, including DNA degradation and decreased protein content in mesophyll cells only. In these cells, the total proteinase activity increased on the day after anthesis. Within 3 days after anthesis, the protein content decreased by 61.8%, and 22.8% of mesophyll cells was lost. A second peak of proteinase activity was observed on day 6, and the number of mesophyll cells decreased again from days 4 to 7. These biochemical and morphological results suggest that PCD progressed in steps during flower life in the mesophyll cells. PCD began in epidermal cells on day 5, in temporal synchrony with the time course of visible senescence. In the mesophyll cells, the KDEL-tailed cysteine proteinase (LoCYP and S1/P1 nuclease (LoNUC genes were upregulated before petal wilting, earlier than in epidermal cells. In contrast, relative to that in the mesophyll cells, the expression of the SAG12 cysteine proteinase homolog (LoSAG12 drastically increased in epidermal cells in the final stage of senescence. These results suggest that multiple PCD-associated genes differentially contribute to the time lag of PCD progression between epidermal and mesophyll cells of lily petals.

  11. Human Cpr (Cell Cycle Progression Restoration) Genes Impart a Far(-) Phenotype on Yeast Cells

    OpenAIRE

    Edwards, M. C.; Liegeois, N.; Horecka, J.; DePinho, R A; Sprague-Jr., G. F.; Tyers, M; Elledge, S J

    1997-01-01

    Regulated cell cycle progression depends on the proper integration of growth control pathways with the basic cell cycle machinery. While many of the central molecules such as cyclins, CDKs, and CKIs are known, and many of the kinases and phosphatases that modify the CDKs have been identified, little is known about the additional layers of regulation that impinge upon these molecules. To identify new regulators of cell proliferation, we have selected for human and yeast cDNAs that when overexp...

  12. 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. 

  13. Environment, safety and Health Progress Assessment of the Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report documents the result of the US Department of Energy`s (DOE) Environment, Safety and Health (ES&H) Progress Assessment of the DOE Rocky Flats Plant (RFP) in Golden, Colorado. The assessment, which was conducted during the period of May 17 through May 28, 1993, included a selective review of the ES&H management systems and programs of the responsible DOE Headquarters Program Offices (Defense Programs (DP) and Environmental Restoration and Waste Management (EM)), the DOE Rocky Flats Office (RFO), and the site contractor, EG&G Rocky Flats, Inc. (EG&G). Despite the near constant state of flux under which RFP has been required to operate, the Progress Assessment Team has concluded that significant progress has been made in correcting the deficiencies identified in the 1989 Assessment and in responding responsibly to regulations, and DOE directives and guidance that have been issued since that time. The Team concluded that the improvements have been concentrated in the activities associated with plutonium facilities and in regulatory driven programs. Much remains to be done with respect to implementing on a sitewide basis those management systems that anchor an organization`s pursuit of continuous ES&H improvement. Furthermore the Team concluded that the pace of improvement has been constrained by a combination of factors that have limited the site`s ability to manage change in the pursuit of sitewide ES&H excellence.

  14. Apoptotic-like programmed cell death in plants.

    Science.gov (United States)

    Reape, Theresa J; McCabe, Paul F

    2008-01-01

    Programmed cell death (PCD) is now accepted as a fundamental cellular process in plants. It is involved in defence, development and response to stress, and our understanding of these processes would be greatly improved through a greater knowledge of the regulation of plant PCD. However, there may be several types of PCD that operate in plants, and PCD research findings can be confusing if they are not assigned to a specific type of PCD. The various cell-death mechanisms need therefore to be carefully described and defined. This review describes one of these plant cell death processes, namely the apoptotic-like PCD (AL-PCD). We begin by examining the hallmark 'apoptotic-like' features (protoplast condensation, DNA degradation) of the cell's destruction that are characteristic of AL-PCD, and include examples of AL-PCD during the plant life cycle. The review explores the possible cellular 'executioners' (caspase-like molecules; mitochondria; de novo protein synthesis) that are responsible for the hallmark features of the cellular destruction. Finally, senescence is used as a case study to show that a rigorous definition of cell-death processes in plant cells can help to resolve arguments that occur in the scientific literature regarding the timing and control of plant cell death.

  15. Mechanisms of developmentally controlled cell death in plants.

    Science.gov (United States)

    Van Durme, Matthias; Nowack, Moritz K

    2016-02-01

    During plant development various forms of programmed cell death (PCD) are implemented by a number of cell types as inherent part of their differentiation programmes. Differentiation-induced developmental PCD is gradually prepared in concert with the other cell differentiation processes. As precocious or delayed PCD can have detrimental consequences for plant development, the actual execution of PCD has to be tightly controlled. Once triggered, PCD is irrevocably and rapidly executed accompanied by the breakdown of cellular compartments. In most developmental PCD forms, cell death is followed by cell corpse clearance. Devoid of phagocytic mechanisms, dying plant cells have to prepare their own demise in a cell-autonomous fashion before their deaths, ensuring the completion of cell clearance post mortem. Depending on the cell type, cell clearance can be complete or rather selective, and persistent corpses of particular cells accomplish vital functions in the plant body. The present review attempts to give an update on the molecular mechanisms that coordinate differentiation-induced PCD as vital part of plant development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Progress and challenges of engineering a biophysical carbon dioxide-concentrating mechanism into higher plants.

    Science.gov (United States)

    Rae, Benjamin D; Long, Benedict M; Förster, Britta; Nguyen, Nghiem D; Velanis, Christos N; Atkinson, Nicky; Hee, Wei Yih; Mukherjee, Bratati; Price, G Dean; McCormick, Alistair J

    2017-04-24

    Growth and productivity in important crop plants is limited by the inefficiencies of the C3 photosynthetic pathway. Introducing CO2-concentrating mechanisms (CCMs) into C3 plants could overcome these limitations and lead to increased yields. Many unicellular microautotrophs, such as cyanobacteria and green algae, possess highly efficient biophysical CCMs that increase CO2 concentrations around the primary carboxylase enzyme, Rubisco, to enhance CO2 assimilation rates. Algal and cyanobacterial CCMs utilize distinct molecular components, but share several functional commonalities. Here we outline the recent progress and current challenges of engineering biophysical CCMs into C3 plants. We review the predicted requirements for a functional biophysical CCM based on current knowledge of cyanobacterial and algal CCMs, the molecular engineering tools and research pipelines required to translate our theoretical knowledge into practice, and the current challenges to achieving these goals. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. [Progress in predicting animal feed intake of plant secondary compounds by spectral analysis].

    Science.gov (United States)

    Wang, Yuan-Su; Hong, Fu-Zeng; Wang, Kun

    2007-09-01

    Study on feed intake of phytophagic animals is a key issue in promoting animal productivity and conservation of wild life. However, how to accurately predict the feed intake of grazing animal and wild life is a long remaining problem. Under the mechanism of co-evolution, plant produces secondary compounds such as phenolics, terpenoids and nitrogen-containing compounds to avoid or reduce animal herbivorous damage as a defensive strategy, while animal attained detoxification capacity of biotransforming and mineralizing the compounds by microbial activities and reactions such as hydrolysis and reduction. The attributes of feedstuff and the amount of a particular feed consumed by the animal affect directly the urinary excretion of secondary metabolites. Plant secondary compounds and their metabolites can be efficiently extracted, separated and structure-identified by spectroscopic analytic method. Then the feed intake of the animal can be accurately measured or predicted by the inference model of concentration-ratio that is based on the regression of correlating the secondary metabolites to the precursors in plant. Aromatic compounds, an universal occurrence in vascular plants, play an important role in predicting feed intake of ruminants. Progresses have been made all-around about the new method. Intensive studies have found that different species and developing stage of plant have varying kinds and levels of secondary compounds, and the age, gender and type of animal have different capacity of metabolizing the compounds. Increasing concentrations of the compounds in the diet led to a dose-dependent decrease in food intake best described as an exponential decay. Animals that had not previously been exposed to the compounds ate significantly more when first offered food containing the compound than on subsequent days. Advanced spectroscopic analytic method has been developed and widely applied in extraction (e. g. microwave assisted extraction and ultrasonic extraction

  19. An introduction to plant cell culture: the future ahead.

    Science.gov (United States)

    Loyola-Vargas, Víctor M; Ochoa-Alejo, Neftalí

    2012-01-01

    Plant cell, tissue, and organ culture (PTC) techniques were developed and established as an experimental necessity for solving important fundamental questions in plant biology, but they currently represent very useful biotechnological tools for a series of important applications such as commercial micropropagation of different plant species, generation of disease-free plant materials, production of haploid and doublehaploid plants, induction of epigenetic or genetic variation for the isolation of variant plants, obtention of novel hybrid plants through the rescue of hybrid embryos or somatic cell fusion from intra- or intergeneric sources, conservation of valuable plant germplasm, and is the keystone for genetic engineering of plants to produce disease and pest resistant varieties, to engineer metabolic pathways with the aim of producing specific secondary metabolites or as an alternative for biopharming. Some other miscellaneous applications involve the utilization of in vitro cultures to test toxic compounds and the possibilities of removing them (bioremediation), interaction of root cultures with nematodes or mycorrhiza, or the use of shoot cultures to maintain plant viruses. With the increased worldwide demand for biofuels, it seems that PTC will certainly be fundamental for engineering different plants species in order to increase the diversity of biofuel options, lower the price marketing, and enhance the production efficiency. Several aspects and applications of PTC such as those mentioned above are the focus of this edition.

  20. 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.

  1. Role of proline in cell wall synthesis and plant development and its implications in plant ontogeny

    Directory of Open Access Journals (Sweden)

    POLAVARAPU BILHAN KAVI KISHOR

    2015-07-01

    Full Text Available Proline is a proteogenic amino acid and accumulates both under stress and non-stress conditions as a beneficial solute in plants. Recent discoveries point out that proline plays an important role in plant growth and differentiation across life cycle. It is a key determinant of many cell wall proteins that plays important roles in plant development. The role of extensins (EXTs, arabinogalactan proteins (AGPs and hydroxyproline- and proline-rich proteins (H/PRPs as important components of cell wall proteins that play pivotal roles in cell wall signal transduction cascades, plant development and stress tolerance is discussed in this review. Molecular insights are also provided here into the plausible roles of proline transporters modulating key events in plant development. In addition, the roles of proline during seed developmental transitions including storage protein synthesis are discussed.

  2. Effect of Lithium on Cell Cycle Progression of Pig Airway Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    陈文书; 吴人亮; 王曦; 李媛; 郝天玲

    2004-01-01

    To investigate the effect of lithium on cell cycle progression of airway epithelial cells,primary pig tracheobronchial epithelial cells were incubated with lithium chloride (LiCl) at different concentrations (0, 5 mmol/L, and 10 mmol/L) and time (12 h, 16 h and 24 h). After the treatment, cells were counted, cell cycle profile was measured by BrdU labeling and flow cytometry, and expression of cyclin D1 and cyclin B1 were detected by Western blotting. The results showed that after 24h of 10mmol/L but not 5mmol/L LiCl treatment, proliferation of cells was slowed down as manifested by delayed confluence and cell number accumulation (P<0.05). Lithium did not change the percentage of cells in S phase (P>0.05), but 24 h incubation with 10 mmol/L LiCl induced a G2/M cell cycle arrest. Furthermore, 10mmol/L LiCl elevated cyclin D1 expression after 12h treatment, while expression of cyclin B1 increased more significantly after 24h incubation. These data demonstrate that lithium inhibits proliferation of pig airway epithelial cells by inhibiting cell cycle progression, and suggest that lithium-sensitive molecule(s) such as glycogen synthase kinase 3 may have a role in the regulation of growth of airway epithelial cells.

  3. Impairment of cell cycle progression by aflatoxin B1 in human cell lines.

    Science.gov (United States)

    Ricordy, R; Gensabella, G; Cacci, E; Augusti-Tocco, G

    2002-05-01

    Aflatoxin B1 is a mycotoxin produced by Aspergillus flavus and Aspergillus parasiticum, which may be present as a food contaminant. It is known to cause acute toxic effects and act as a carcinogenic agent. The carcinogenic action has been related to its ability to form unstable adducts with DNA, which represent possible mutagenic sites. On the other hand, the primary cellular target responsible for its toxic action has not yet been clearly identified. Previous data suggested a possible correlation between cell proliferation and responsiveness to aflatoxin toxicity. These observations led us to investigate the effect of the toxin on cell cycle progression of three human cell lines (HepG2, SK-N-MC and SK-N-SH derived from liver and nervous tissue tumours); they were shown to display different responses to toxin exposure and have different growth kinetics. We performed analysis of the cell cycle, DNA synthesis and expression of p21 and p53 in the presence and absence of the toxin in all cell lines exposed. The results of cell cycle cytofluorometric analysis show significant alterations of cell cycle progression as a result of toxin treatment. In all cell lines exposure to a 24 h toxin treatment causes a dose-dependent accumulation in S phase, however, the ability to recover from impairment to traverse S phase varies in the cell lines under study. SK-N-MC cells appear more prone to resume DNA synthesis when the toxin is removed, while the other two cell lines maintain a significant inhibition of DNA synthesis, as indicated by cytofluorimetry and [(3)H]dTR incorporation. The level of p53 and p21 expression in the three cell lines was examined by western blot analysis and significant differences were detected. The ready resumption of DNA synthesis displayed by SK-N-MC cells could possibly be related to the absence of p53 control of cell cycle progression.

  4. 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.

  5. Formation and maintenance of the Golgi apparatus in plant cells.

    Science.gov (United States)

    Ito, Yoko; Uemura, Tomohiro; Nakano, Akihiko

    2014-01-01

    The Golgi apparatus plays essential roles in intracellular trafficking, protein and lipid modification, and polysaccharide synthesis in eukaryotic cells. It is well known for its unique stacked structure, which is conserved among most eukaryotes. However, the mechanisms of biogenesis and maintenance of the structure, which are deeply related to ER-Golgi and intra-Golgi transport systems, have long been mysterious. Now having extremely powerful microscopic technologies developed for live-cell imaging, the plant Golgi apparatus provides an ideal system to resolve the question. The plant Golgi apparatus has unique features that are not conserved in other kingdoms, which will also give new insights into the Golgi functions in plant life. In this review, we will summarize the features of the plant Golgi apparatus and transport mechanisms around it, with a focus on recent advances in Golgi biogenesis by live imaging of plants cells.

  6. Alkaline polymer electrolyte fuel cells: Principle, challenges, and recent progress

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polymer electrolyte membrane fuel cells (PEMFC) have been recognized as a significant power source in future energy systems based on hydrogen. The current PEMFC technology features the employment of acidic polymer electrolytes which, albeit superior to electrolyte solutions, have intrinsically limited the catalysts to noble metals, fundamentally preventing PEMFC from widespread deployment. An effective solution to this problem is to develop fuel cells based on alkaline polymer electrolytes (APEFC), which not only enable the use of non-precious metal catalysts but also avoid the carbonate-precipitate issue which has been troubling the conventional alkaline fuel cells (AFC). This feature article introduces the principle of APEFC, the challenges, and our research progress, and focuses on strategies for developing key materials, including high-performance alkaline polyelectrolytes and stable non-precious metal catalysts. For alkaline polymer electrolytes, high ionic conductivity and satisfactory mechanical property are difficult to be balanced, therefore polymer cross-linking is an ultimate strategy. For non-precious metal catalysts, it is urgent to improve the catalytic activity and stability. New materials, such as transition-metal complexes, nitrogen-doped carbon nanotubes, and metal carbides, would become applicable in APEFC.

  7. Copper entry into human cells: progress and unanswered questions.

    Science.gov (United States)

    Maryon, Edward B; Molloy, Shannon A; Zimnicka, Adriana M; Kaplan, Jack H

    2007-06-01

    In this brief review we summarize what is known about the role of hCTR1 in mediating the entry of copper into human cells. There is a body of information that clearly identifies this protein as being a major source (though not the only source) of copper entry into human cells, and thus a crucial element of copper homeostasis. However, much remains that is poorly understood and key aspects of the physiological roles of hCTR1 and its regulation are only superficially appreciated. The particular characteristics of a transport process that in vivo involves the binding, transmembrane transport and release of a substrate that is not present in a free form in the intracellular or extracellular compartments poses particular challenges that are not encountered in the transport of more familiar physiologically important metal cations. Thus much of what we have learned about the more commonly encountered transported ions provides an inadequate model for studies of copper homeostasis. In this article we review progress made and identify the major questions that need to be resolved before an adequate description is attained of how copper entry into human cells is mediated and regulated by hCTR1.

  8. Research Progress in Plant Metacaspase%植物Metacaspase研究进展

    Institute of Scientific and Technical Information of China (English)

    马聪; 孔维文

    2012-01-01

    The hypersensitive reaction is an important process in plant disease resistance. Similar to apoptosis in animals, it is programmed cell death (PCD) process in plants. Caspases (cysteine-dependent aspartate-specific proteases) play a central role in animal apoptotic pathways. No orthologous proteins of caspases have been found in plants, but a group of proteins with similar structures, termed metacaspases, have been found. In plants, some PCD processes depend on metacaspases, and others do not. We discuss researches into the structure and function of metacaspases. The biological functions of metacaspases and their roles in PCD pathways in plants remain to be explored.%过敏性坏死反应是植物的一种重要的抗病机制,类似于动物细胞凋亡,它是一种程序性细胞死亡(programmed cell death,PCD)过程.目前,已经确定半胱天冬蛋白酶(caspase)在动物PCD过程中起核心作用.在植物中,尚未发现其直系同源蛋白,但是有一类与其结构相似的蛋白酶,称为metacaspase.在植物不同的PCD过程中,有的依赖于metacaspase,而有的则不依赖于该类蛋白酶.目前对metacaspase的结构和功能已有了初步的研究,对其深入的研究则进展缓慢,其具体的生物学功能和在PCD信号路径中的定位有待进一步探索.

  9. Cytokinesis in plant and animal cells: endosomes 'shut the door'.

    Science.gov (United States)

    Baluska, Frantisek; Menzel, Diedrik; Barlow, Peter W

    2006-06-01

    For many years, cytokinesis in eukaryotic cells was considered to be a process that took a variety of forms. This is rather surprising in the face of an apparently conservative mitosis. Animal cytokinesis was described as a process based on an actomyosin-based contractile ring, assembling, and acting at the cell periphery. In contrast, cytokinesis of plant cells was viewed as the centrifugal generation of a new cell wall by fusion of Golgi apparatus-derived vesicles. However, recent advances in animal and plant cell biology have revealed that many features formerly considered as plant-specific are, in fact, valid also for cytokinetic animal cells. For example, vesicular trafficking has turned out to be important not only for plant but also for animal cytokinesis. Moreover, the terminal phase of animal cytokinesis based on midbody microtubule activity resembles plant cytokinesis in that interdigitating microtubules play a decisive role in the recruitment of cytokinetic vesicles and directing them towards the cytokinetic spaces which need to be plugged by fusing endosomes. Presently, we are approaching another turning point which brings cytokinesis in plant and animal cells even closer. As an unexpected twist, new studies reveal that both plant and animal cytokinesis is driven not so much by Golgi-derived vesicles but rather by homotypically and heterotypically fusing endosomes. These are generated from cytokinetic cortical sites defined by preprophase microtubules and contractile actomyosin ring, which induce local endocytosis of both the plasma membrane and cell wall material. Finally, plant and animal cytokinesis meet together at the physical separation of daughter cells despite obvious differences in their preparatory events.

  10. Semiconductor solar cells: Recent progress in terrestrial applications

    Science.gov (United States)

    Avrutin, V.; Izyumskaya, N.; Morkoç, H.

    2011-04-01

    this article, we discuss the progress, outstanding problems, and environmental issues associated with bulk Si, thin-film, and high-efficiency multi-junction solar cells.

  11. A comparison between nuclear dismantling during plant and animal programmed cell death.

    Science.gov (United States)

    Domínguez, Fernando; Cejudo, Francisco Javier

    2012-12-01

    Programmed cell death (PCD) is a process of organized destruction of cells, essential for the development and maintenance of cellular homeostasis of multicellular organisms. Cells undergoing PCD begin a degenerative process in response to internal or external signals, whereby the nucleus becomes one of the targets. The process of nuclear dismantling includes events affecting the nuclear envelope, such as formation of lobes at the nuclear surface, selective proteolysis of nucleoporins and nuclear pore complex clustering. In addition, chromatin condensation increases in coordination with DNA fragmentation. These processes have been largely studied in animals, but remain poorly understood in plants. The overall process of cell death has different morphological and biochemical features in plants and animals. However, recent advances suggest that nuclear dismantling in plant cells progresses with morphological and biochemical characteristics similar to those in apoptotic animal cells. In this review, we summarize nuclear dismantling in plant PCD, focusing on the similarities and differences with their animal counterparts. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  12. New fuel cell plants and power sources for submarines

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, B.; Sokolov, V. [CDB ME ' ' Rubin' ' (Russian Federation)

    2000-07-01

    The existing storage batteries for submarines have been analyzed, the quality of their design has been estimated and a power plant with electrochemical generators (fuel cells) has been suggested as an electric energy source. The history and the status of power plant design in Russia have been reflected. (authors)

  13. 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...

  14. The Nucleolonema of Plant and Animal Cells: A Comparison

    OpenAIRE

    Deltour, Roger; Motte, Patrick

    1990-01-01

    Depending on the author and the animal or plant origin of the material under study, the term "nucleolonema" is used in different contexts and thus indicates nucleolar ultrastructures that are different. In this paper, we attempt to clarify this state of affairs and to propose a definition for the plant cell nucleolonema. Peer reviewed

  15. Specification of Epidermal Cell Fate in Plant Shoots

    Directory of Open Access Journals (Sweden)

    Shinobu eTakada

    2014-02-01

    Full Text Available Land plants have evolved a single layer of epidermal cells, which are characterized by mostly anticlinal cell division patterns, formation of a waterproof coat called cuticle, and unique cell types such as stomatal guard cells and trichomes. The shoot epidermis plays important roles not only to protect plants from dehydration and pathogens but also to ensure their proper organogenesis and growth control. Extensive molecular genetic studies in Arabidopsis and maize have identified a number of genes that are required for epidermal cell differentiation. However, the mechanism that specifies shoot epidermal cell fate during plant organogenesis remains largely unknown. Particularly, little is known regarding positional information that should restrict epidermal cell fate to the outermost cell layer of the developing organs. Recent studies suggested that certain members of the HD-ZIP class IV homeobox genes are possible master regulators of shoot epidermal cell fate. Here, we summarize the roles of the regulatory genes that are involved in epidermal cell fate specification and discuss the possible mechanisms that limit the expression and/or activity of the master transcriptional regulators to the outermost cell layer in plant shoots.

  16. Progress Towards the Tomato Fruit Cell Wall Proteome

    Directory of Open Access Journals (Sweden)

    Eliel eRuiz May

    2013-05-01

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

  17. Systemic Inflammation in Progressive Multiple Sclerosis Involves Follicular T-Helper, Th17- and Activated B-Cells and Correlates with Progression

    DEFF Research Database (Denmark)

    Romme Christensen, Jeppe; Börnsen, Lars; Ratzer, Rikke

    2013-01-01

    Pathology studies of progressive multiple sclerosis (MS) indicate a major role of inflammation including Th17-cells and meningeal inflammation with ectopic lymphoid follicles, B-cells and plasma cells, the latter indicating a possible role of the newly identified subset of follicular T-helper (TFH......) cells. Although previous studies reported increased systemic inflammation in progressive MS it remains unclear whether systemic inflammation contributes to disease progression and intrathecal inflammation. This study aimed to investigate systemic inflammation in progressive MS and its relationship...... a pathogenic role of systemic inflammation in progressive MS. These observations may have implications for the treatment of progressive MS....

  18. Recent Progress Using High-throughput Sequencing Technologies in Plant Molecular Breeding

    Institute of Scientific and Technical Information of China (English)

    Qiang Gao; Guidong Yue; Wenqi Li; Junyi Wang; Jiaohui Xu; Ye Yin

    2012-01-01

    High-throughput sequencing is a revolutionary technological innovation in DNA sequencing.This technology has an ultra-low cost per base of sequencing and an overwhelmingly high data output.High-throughput sequencing has brought novel research methods and solutions to the research fields of genomics and post-genomics.Furthermore,this technology is leading to a new molecular breeding revolution that has landmark significance for scientific research and enables us to launch multi-level,multifaceted,and multi-extent studies in the fields of crop genetics,genomics,and crop breeding.In this paper,we review progress in the application of high-throughput sequencing technologies to plant molecular breeding studies.

  19. Instrumentation and process control for fossil demonstration plants. Annual technical progress report, October 1976--September 1977

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L. G.; O' Fallon, N. M.

    1977-10-01

    Progress on Instrumentation and Process Control for Fossil Demonstration Plants (FDP) is reported. Work has been performed on updating the study of the state-of-the-art of instrumentation for FDP, development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. A Solids/Gas Flow Test Facility (S/GFTF) under construction for instrument development, testing, evaluation, and calibration is described. The development work for several mass-flow and other on-line instruments is described: acoustic flowmeter, capacitive density flowmeter, neutron activation flowmeter, gamma ray correlation flowmeter, optical flowmeter, composition analysis system, and capacitive liquid interface level meter.

  20. Interaction of tumor cells with the immune system: implications for dendritic cell therapy and cancer progression.

    Science.gov (United States)

    Imhof, Marianne; Karas, Irene; Gomez, Ivan; Eger, Andreas; Imhof, Martin

    2013-01-01

    There is a continuous demand for preclinical modeling of the interaction of dendritic cells with the immune system and cancer cells. Recent progress in gene expression profiling with nucleic acid microarrays, in silico modeling and in vivo cell and animal approaches for non-clinical proof of safety and efficacy of these immunotherapies is summarized. Immunoinformatic approaches look promising to unfold this potential, although still unstable and difficult to interpret. Animal models have progressed a great deal in recent years, finally narrowing the gap from bench to bedside. However, translation to the clinic should be done with precaution. The most significant results concerning clinical benefit might come from detailed immunologic investigations made during well designed clinical trials of dendritic-cell-based therapies, which in general prove safe.

  1. Asymmetric cell divisions: a view from plant development.

    Science.gov (United States)

    Abrash, Emily B; Bergmann, Dominique C

    2009-06-01

    All complex multicellular organisms must solve the problem of generating diverse and appropriately patterned cell types. Asymmetric division, in which a single mother cell gives rise to daughters with distinct identities, is instrumental in the generation of cellular diversity and higher-level patterns. In animal systems, there exists considerable evidence for conserved mechanisms of polarization and asymmetric division. Here, we consider asymmetric cell divisions in plants, highlighting the unique aspects of plant cell biology and organismal development that constrain the process, but also emphasizing conceptual and mechanistic similarities with animal asymmetric divisions.

  2. 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.

  3. Heat stress induces ferroptosis-like cell death in plants

    Science.gov (United States)

    D’Ippólito, Sebastián; Colman, Silvana Lorena; Soto, Débora; Bartoli, Carlos Guillermo; Fiol, Diego Fernando

    2017-01-01

    In plants, regulated cell death (RCD) plays critical roles during development and is essential for plant-specific responses to abiotic and biotic stresses. Ferroptosis is an iron-dependent, oxidative, nonapoptotic form of cell death recently described in animal cells. In animal cells, this process can be triggered by depletion of glutathione (GSH) and accumulation of lipid reactive oxygen species (ROS). We investigated whether a similar process could be relevant to cell death in plants. Remarkably, heat shock (HS)–induced RCD, but not reproductive or vascular development, was found to involve a ferroptosis-like cell death process. In root cells, HS triggered an iron-dependent cell death pathway that was characterized by depletion of GSH and ascorbic acid and accumulation of cytosolic and lipid ROS. These results suggest a physiological role for this lethal pathway in response to heat stress in Arabidopsis thaliana. The similarity of ferroptosis in animal cells and ferroptosis-like death in plants suggests that oxidative, iron-dependent cell death programs may be evolutionarily ancient. PMID:28100685

  4. Function of trehalose and glycogen in cell cycle progression and cell viability in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Silljé, H H; Paalman, J W; ter Schure, E G; Olsthoorn, S Q; Verkleij, A J; Boonstra, Johannes; Verrips, C T

    1999-01-01

    Trehalose and glycogen accumulate in Saccharomyces cerevisiae when growth conditions deteriorate. It has been suggested that aside from functioning as storage factors and stress protectants, these carbohydrates may be required for cell cycle progression at low growth rates under carbon limitation. B

  5. Function of trehalose and glycogen in cell cycle progression and cell viability in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Silljé, H H; Paalman, J W; ter Schure, E G; Olsthoorn, S Q; Verkleij, A J; Boonstra, Johannes; Verrips, C T

    Trehalose and glycogen accumulate in Saccharomyces cerevisiae when growth conditions deteriorate. It has been suggested that aside from functioning as storage factors and stress protectants, these carbohydrates may be required for cell cycle progression at low growth rates under carbon limitation.

  6. Mechanical impulses can control metaphase progression in a mammalian cell.

    Science.gov (United States)

    Itabashi, Takeshi; Terada, Yasuhiko; Kuwana, Kenta; Kan, Tetsuo; Shimoyama, Isao; Ishiwata, Shin'ichi

    2012-05-08

    Chromosome segregation machinery is controlled by mechanochemical regulation. Tension in a mitotic spindle, which is balanced by molecular motors and polymerization-depolymerization dynamics of microtubules, is thought to be essential for determining the timing of chromosome segregation after the establishment of the kinetochore-microtubule attachments. It is not known, however, whether and how applied mechanical forces modulate the tension balance and chemically affect the molecular processes involved in chromosome segregation. Here we found that a mechanical impulse externally applied to mitotic HeLa cells alters the balance of forces within the mitotic spindle. We identified two distinct mitotic responses to the applied mechanical force that either facilitate or delay anaphase onset, depending on the direction of force and the extent of cell compression. An external mechanical impulse that physically increases tension within the mitotic spindle accelerates anaphase onset, and this is attributed to the facilitation of physical cleavage of sister chromatid cohesion. On the other hand, a decrease in tension activates the spindle assembly checkpoint, which impedes the degradation of mitotic proteins and delays the timing of chromosome segregation. Thus, the external mechanical force acts as a crucial regulator for metaphase progression, modulating the internal force balance and thereby triggering specific mechanochemical cellular reactions.

  7. Research progress of triphenylamine dye sensitizers of solar cells

    Directory of Open Access Journals (Sweden)

    Yifeng YU

    2015-04-01

    Full Text Available Dye-sensitized solar cells (DSSC attracted widespread attention for its low cost, being easy to manufacture, large-scale production and environmentally friendly features. Sensitizer is a core component of the DSSC which plays a role in collecting sunlight and injecting excited state electron into the conduction band of the semiconductor, which is crucial to the photo-electric conversion efficiency. Organic dyes have a number of advantages such as easy synthesizing and tuning of photo-physical and electrochemical properties through molecular design. Triphenylamine is a strong electron donating group, and its non-planar spatial structure makes the degree of the dye molecules aggregation to be decreased. These properties are conducive to improve the absorption properties of the dye and the electron transport efficiency. In recent years, triphenylamine or substituted triphenylamine as electron donor of organic sensitizers becomes the research focus for improving the photoelectric conversion efficiency of solar cells. In this paper, the progress of triphenylamine photosensitive dyes is described.

  8. Centrality of host cell death in plant-microbe interactions.

    Science.gov (United States)

    Dickman, Martin B; Fluhr, Robert

    2013-01-01

    Programmed cell death (PCD) is essential for proper growth, development, and cellular homeostasis in all eukaryotes. The regulation of PCD is of central importance in plant-microbe interactions; notably, PCD and features associated with PCD are observed in many host resistance responses. Conversely, pathogen induction of inappropriate cell death in the host results in a susceptible phenotype and disease. Thus, the party in control of PCD has a distinct advantage in these battles. PCD processes appear to be of ancient origin, as indicated by the fact that many features of cell death strategy are conserved between animals and plants; however, some of the details of death execution differ. Mammalian core PCD genes, such as caspases, are not present in plant genomes. Similarly, pro- and antiapoptotic mammalian regulatory elements are absent in plants, but, remarkably, when expressed in plants, successfully impact plant PCD. Thus, subtle structural similarities independent of sequence homology appear to sustain operational equivalence. The vacuole is emerging as a key organelle in the modulation of plant PCD. Under different signals for cell death, the vacuole either fuses with the plasmalemma membrane or disintegrates. Moreover, the vacuole appears to play a key role in autophagy; evidence suggests a prosurvival function for autophagy, but other studies propose a prodeath phenotype. Here, we describe and discuss what we know and what we do not know about various PCD pathways and how the host integrates signals to activate salicylic acid and reactive oxygen pathways that orchestrate cell death. We suggest that it is not cell death as such but rather the processes leading to cell death that contribute to the outcome of a given plant-pathogen interaction.

  9. From plants to animals; the role of plant cell death in ruminant herbivores.

    Science.gov (United States)

    Kingston-Smith, Alison H; Davies, Teri E; Edwards, Joan E; Theodorou, Michael K

    2008-01-01

    Plant cell death occurring as a result of adverse environmental conditions is known to limit crop production. It is less well recognized that plant cell death processes can also contribute to the poor environmental footprint of ruminant livestock production. Although the forage cells ingested by grazing ruminant herbivores will ultimately die, the lack of oxygen, elevated temperature, and challenge by microflora experienced in the rumen induce regulated plant stress responses resulting in DNA fragmentation and autolytic protein breakdown during the cell death process. Excessive ruminal proteolysis contributes to the inefficient conversion of plant to microbial and animal protein which results in up to 70% of the ingested nitrogen being returned to the land as the nitrogenous pollutants ammonia and urea. This constitutes a significant challenge for sustainable livestock production. As it is estimated that 25% of cultivated land worldwide is assigned to livestock production, it is clear that understanding the fundamental biology underlying cell death in ingested forage will have a highly significant role in minimizing the impact of human activities. This review examines our current understanding of plant metabolism in the rumen and explores opportunities for exploitation of plant genetics to advance sustainable land use.

  10. The Untapped Potential Of Plant Thin Cell Layers

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime

    2015-12-01

    Full Text Available Thin cell layers (TCLs, which contain a small number of cells or tissues, are explants excised from different organs (stems, leaves, roots, inflorescences, flowers, cotyledons, hypocotyls/epicotyls, and embryos. After almost 45 years of research, this culture system has been used for several monocotyledonous and dicotyledonous plants of commercial importance, and for model plants. The limited amount of cells in a TCL is of paramount importance because marker molecules/genes of differentiation can be easily localized in situ in the target/responsive cells. Thus, the use of TCLs has allowed, and continues to allow, for the expansion of knowledge in plant research in a practical and applied manner into the fields of tissue culture and micropropagation, cell and organ genetics, molecular biology, biochemistry, and development. Starting from a brief historical background, the actual and potential uses of the TCL system are briefly reviewed.

  11. Impaired germ cell development due to compromised cell cycle progression in Skp2-deficient mice

    Directory of Open Access Journals (Sweden)

    Nakayama Keiko

    2006-04-01

    Full Text Available Abstract Background The gonads are responsible for the production of germ cells through both mitosis and meiosis. Skp2 is the receptor subunit of an SCF-type ubiquitin ligase and is a major regulator of the progression of cells into S phase of the cell cycle, which it promotes by mediating the ubiquitin-dependent degradation of p27, an inhibitor of cell proliferation. However, the role of the Skp2-p27 pathway in germ cell development remains elusive. Results We now show that disruption of Skp2 in mice results in a marked impairment in the fertility of males, with the phenotypes resembling Sertoli cell-only syndrome in men. Testes of Skp2-/- mice manifested pronounced germ cell hypoplasia accompanied by massive apoptosis in spermatogenic cells. Flow cytometry revealed an increased prevalence of polyploidy in spermatozoa, suggesting that the aneuploidy of these cells is responsible for the induction of apoptosis. Disruption of the p27 gene of Skp2-/- mice restored germ cell development, indicating that the testicular hypoplasia of Skp2-/- animals is attributable to the antiproliferative effect of p27 accumulation. Conclusion Our results thus suggest that compromised cell cycle progression caused by the accumulation of p27 results in aneuploidy and the induction of apoptosis in gonadal cells of Skp2-/- mice. The consequent reduction in the number of mature gametes accounts for the decreased fertility of these animals. These findings reinforce the importance of the Skp2-p27 pathway in cell cycle regulation and in germ cell development.

  12. Plant cell culture strategies for the production of natural products.

    Science.gov (United States)

    Ochoa-Villarreal, Marisol; Howat, Susan; Hong, SunMi; Jang, Mi Ok; Jin, Young-Woo; Lee, Eun-Kyong; Loake, Gary J

    2016-03-01

    Plants have evolved a vast chemical cornucopia to support their sessile lifestyles. Man has exploited this natural resource since Neolithic times and currently plant-derived chemicals are exploited for a myriad of applications. However, plant sources of most high-value natural products (NPs) are not domesticated and therefore their production cannot be undertaken on an agricultural scale. Further, these plant species are often slow growing, their populations limiting, the concentration of the target molecule highly variable and routinely present at extremely low concentrations. Plant cell and organ culture constitutes a sustainable, controllable and environmentally friendly tool for the industrial production of plant NPs. Further, advances in cell line selection, biotransformation, product secretion, cell permeabilisation, extraction and scale-up, among others, are driving increases in plant NP yields. However, there remain significant obstacles to the commercial synthesis of high-value chemicals from these sources. The relatively recent isolation, culturing and characterisation of cambial meristematic cells (CMCs), provides an emerging platform to circumvent many of these potential difficulties. [BMB Reports 2016; 49(3): 149-158].

  13. 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.

  14. Programmed cell death in C. elegans, mammals and plants.

    Science.gov (United States)

    Lord, Christina E N; Gunawardena, Arunika H L A N

    2012-08-01

    Programmed cell death (PCD) is the regulated removal of cells within an organism and plays a fundamental role in growth and development in nearly all eukaryotes. In animals, the model organism Caenorhabditis elegans (C. elegans) has aided in elucidating many of the pathways involved in the cell death process. Various analogous PCD processes can also be found within mammalian PCD systems, including vertebrate limb development. Plants and animals also appear to share hallmarks of PCD, both on the cellular and molecular level. Cellular events visualized during plant PCD resemble those seen in animals including: nuclear condensation, DNA fragmentation, cytoplasmic condensation, and plasma membrane shrinkage. Recently the molecular mechanisms involved in plant PCD have begun to be elucidated. Although few regulatory proteins have been identified as conserved across all eukaryotes, molecular features such as the participation of caspase-like proteases, Bcl-2-like family members and mitochondrial proteins appear to be conserved between plant and animal systems. Transgenic expression of mammalian and C. elegans pro- and anti-apoptotic genes in plants has been observed to dramatically influence the regulatory pathways of plant PCD. Although these genes often show little to no sequence similarity they can frequently act as functional substitutes for one another, thus suggesting that action may be more important than sequence resemblance. Here we present a summary of these findings, focusing on the similarities, between mammals, C. elegans, and plants. An emphasis will be placed on the mitochondria and its role in the cell death pathway within each organism. Through the comparison of these systems on both a cellular and molecular level we can begin to better understand PCD in plant systems, and perhaps shed light on the pathways, which are controlling the process. This manuscript adds to the field of PCD in plant systems by profiling apoptotic factors, to scale on a protein

  15. Progress on Plant-Level Components for Nuclear Fuel Recycling: Commonality

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2011-08-15

    Progress made in developing a common mathematical modeling framework for plant-level components of a simulation toolkit for nuclear fuel recycling is summarized. This ongoing work is performed under the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program which has an element focusing on safeguards and separations (SafeSeps). One goal of this element is to develop a modeling and simulation toolkit for used nuclear fuel recycling. The primary function of the SafeSeps simulation toolkit is to enable the time-dependent coupling of separation modules and safeguards tools (either native or third-party supplied) that simulate and/or monitor the individual separation processes in a separations plant. The toolkit integration environment will offer an interface for the modules to register in the toolkit domain based on the commonality of diverse unit operations. This report discusses the source of this commonality from a combined mathematical modeling and software design perspectives, and it defines the initial basic concepts needed for development of application modules and their integrated form, that is, an application software. A unifying mathematical theory of chemical thermomechanical network transport for physicochemical systems is proposed and outlined as the basis for developing advanced modules. A program for developing this theory from the underlying first-principles continuum thermomechanics will be needed in future developments; accomplishment of this task will enable the development of a modern modeling approach for plant-level models. Rigorous, advanced modeling approaches at the plant-level can only proceed from the development of reduced (or low-order) models based on a solid continuum field theory foundation. Such development will pave the way for future programmatic activities on software verification, simulation validation, and model uncertainty quantification on a scientific basis; currently, no satisfactory foundation exists for

  16. Chromosomes and plant cell division in space

    Science.gov (United States)

    Krikorian, A. D.

    1988-01-01

    The objectives were: examination of chromosomal aberrations; development of an experimental system; and engineering design units (EDUs) evaluation. Evaluation criteria are presented. Procedures were developed for shuttle-based investigations which result in the procurement of plant root tips for subsequent cytological examination.

  17. 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.

  18. Trichomes as models for studying plant cell differentiation.

    Science.gov (United States)

    Yang, Changxian; Ye, Zhibiao

    2013-06-01

    Trichomes, originating from epidermal cells, are present on nearly all terrestrial plants. They exist in diverse forms, are readily accessible, and serve as an excellent model system for analyzing the molecular mechanisms in plant cell differentiation, including cell fate choices, cell cycle control, and cell morphogenesis. In Arabidopsis, two regulatory models have been identified that function in parallel in trichome formation; the activator-inhibitor model and the activator-depletion model. Cotton fiber, a similar unicellular structure, is controlled by some functional homologues of Arabidopsis trichome-patterning genes. Multicellular trichomes, as in tobacco and tomato, may form through a distinct pathway from unicellular trichomes. Recent research has shown that cell cycle control participates in trichome formation. In this review, we summarize the molecular mechanisms involved in the formation of unicellular and multicellular trichomes, and discuss the integration of the cell cycle in its initiation and morphogenesis.

  19. Structure and function of endosomes in plant cells.

    Science.gov (United States)

    Contento, Anthony L; Bassham, Diane C

    2012-08-01

    Endosomes are a heterogeneous collection of organelles that function in the sorting and delivery of internalized material from the cell surface and the transport of materials from the Golgi to the lysosome or vacuole. Plant endosomes have some unique features, with an organization distinct from that of yeast or animal cells. Two clearly defined endosomal compartments have been studied in plant cells, the trans-Golgi network (equivalent to the early endosome) and the multivesicular body (equivalent to the late endosome), with additional endosome types (recycling endosome, late prevacuolar compartment) also a possibility. A model has been proposed in which the trans-Golgi network matures into a multivesicular body, which then fuses with the vacuole to release its cargo. In addition to basic trafficking functions, endosomes in plant cells are known to function in maintenance of cell polarity by polar localization of hormone transporters and in signaling pathways after internalization of ligand-bound receptors. These signaling functions are exemplified by the BRI1 brassinosteroid hormone receptor and by receptors for pathogen elicitors that activate defense responses. After endocytosis of these receptors from the plasma membrane, endosomes act as a signaling platform, thus playing an essential role in plant growth, development and defense responses. Here we describe the key features of plant endosomes and their differences from those of other organisms and discuss the role of these organelles in cell polarity and signaling pathways.

  20. 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.

  1. Plant organelle proteomics: collaborating for optimal cell function.

    Science.gov (United States)

    Agrawal, Ganesh Kumar; Bourguignon, Jacques; Rolland, Norbert; Ephritikhine, Geneviève; Ferro, Myriam; Jaquinod, Michel; Alexiou, Konstantinos G; Chardot, Thierry; Chakraborty, Niranjan; Jolivet, Pascale; Doonan, John H; Rakwal, Randeep

    2011-01-01

    Organelle proteomics describes the study of proteins present in organelle at a particular instance during the whole period of their life cycle in a cell. Organelles are specialized membrane bound structures within a cell that function by interacting with cytosolic and luminal soluble proteins making the protein composition of each organelle dynamic. Depending on organism, the total number of organelles within a cell varies, indicating their evolution with respect to protein number and function. For example, one of the striking differences between plant and animal cells is the plastids in plants. Organelles have their own proteins, and few organelles like mitochondria and chloroplast have their own genome to synthesize proteins for specific function and also require nuclear-encoded proteins. Enormous work has been performed on animal organelle proteomics. However, plant organelle proteomics has seen limited work mainly due to: (i) inter-plant and inter-tissue complexity, (ii) difficulties in isolation of subcellular compartments, and (iii) their enrichment and purity. Despite these concerns, the field of organelle proteomics is growing in plants, such as Arabidopsis, rice and maize. The available data are beginning to help better understand organelles and their distinct and/or overlapping functions in different plant tissues, organs or cell types, and more importantly, how protein components of organelles behave during development and with surrounding environments. Studies on organelles have provided a few good reviews, but none of them are comprehensive. Here, we present a comprehensive review on plant organelle proteomics starting from the significance of organelle in cells, to organelle isolation, to protein identification and to biology and beyond. To put together such a systematic, in-depth review and to translate acquired knowledge in a proper and adequate form, we join minds to provide discussion and viewpoints on the collaborative nature of organelles in

  2. Fluids as Dynamic Templates for Cytoskeletal Proteins in Plant Cells

    CERN Document Server

    Lofthouse, J T

    2008-01-01

    The Dynamic Template model of biological cell membranes and the cytoplasm as spatially organised fluid layers is extended to plant cells, and is shown to offer a feasible shear driven mechanism for the co-alignment of internal and external fibres observed during growth and tropic responses

  3. Why should we study the plant cell cycle?

    Science.gov (United States)

    Inzé, Dirk

    2003-04-01

    Description of the molecular biology of plant and animal cell cycles highlights similarities and critical differences. The cell cycle is a point of control in both growth and development and deepening understanding of underlying processes and mechanisms may have many practical applications.

  4. A xylogalacturonan epitope is specifically associated with plant cell detachment

    DEFF Research Database (Denmark)

    Willats, William George Tycho; McCartney, L.; Steele-King, C.G.

    2004-01-01

    A monoclonal antibody (LM8) was generated with specificity for xyloglacturonan (XGA) isolated from pea (Pisum sativum L.) testae. Characterization of the LM8 epitope indicates that it is a region of XGA that is highly substituted with xylose. Immunocytochemical analysis indicates that this epitope...... that is specifically associated with a plant cell separation process that results in complete cell detachment....

  5. RIPK3-Mediated Necroptosis and Apoptosis Contributes to Renal Tubular Cell Progressive Loss and Chronic Kidney Disease Progression in Rats.

    Science.gov (United States)

    Zhu, Yongjun; Cui, Hongwang; Xia, Yunfeng; Gan, Hua

    2016-01-01

    Tubulointerstitial fibrosis (TIF) is caused by the progressive loss of renal tubular cells and the consequent replacement of the extracellular matrix. The progressive depletion of renal tubular cells results from apoptosis and necroptosis; however, the relative significance of each of these cell death mechanisms at different stages during the progression of chronic kidney disease (CKD) remains unclear. We sought to explore the mechanisms of renal tubular cell death during the early and intermediate stages of chronic renal damage of subtotal nephrectomied (SNx) rats. The results of tissue histological assays indicated that the numbers of necrotic dying cells and apoptotic cells were significantly higher in kidney tissues derived from a rat model of CKD. In addition, there was a significant increase in necroptosis observed by transmission electron microscopy (TEM) and an increase in the proportion of TUNEL-positive cells in kidney tissues from SNx rats compared with control rats, and necrostatin-1 (Nec-1) could inhibit necroptosis and reduce the proportion of TUNEL-positive cells. More importantly, we observed a significant increase in the incidence of necroptosis compared with apoptosis by TEM in vivo and in vitro and a significant increase in the proportion of TUNEL-positive tubular epithelial cells that did not express caspase-3 compared with those expressing cleaved caspase-3 in vitro. Furthermore, treatment with Nec-1 and zVAD strongly reduced necroptosis- and apoptosis-mediated renal tubular cell death and decreased the levels of blood urea nitrogen and serum creatinine and tubular damage scores of SNx rats. These results suggest that necroptotic cell death plays a more significant role than apoptosis in mediating the loss of renal tubular cells in SNx rats and that effectively blocking both necroptosis and apoptosis improves renal function and tubular damage at early and intermediate stages of CKD.

  6. Controlled production of cellulases in plants for biomass conversion. Progress report, June 15, 1996--March 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Danna, K.J.

    1997-06-01

    The goal of this project is to facilitate conversion of plant biomass to usable energy by developing transgenic plants that express genes for microbial cellulases, which can be activated after harvest of the plants. In particular, we want to determine the feasibility of targeting an endoglucanase and a cellobiohydrolase to the plant apoplast (cell wall milieu). The apoplast not only contains cellulose, the substrate for the enzymes, but also can tolerate large amounts of foreign protein. To avoid detrimental effects of cellulase expression in plants, we have chosen enzymes with high temperature optima; the genes for these enzymes are from thermophilic organisms that can use cellulose as a sole energy source.

  7. Controlled production of cellulases in plants for biomass conversion. Progress report, June 15, 1996--March 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Danna, K.J.

    1997-06-01

    The goal of this project is to facilitate conversion of plant biomass to usable energy by developing transgenic plants that express genes for microbial cellulases, which can be activated after harvest of the plants. In particular, we want to determine the feasibility of targeting an endoglucanase and a cellobiohydrolase to the plant apoplast (cell wall milieu). The apoplast not only contains cellulose, the substrate for the enzymes, but also can tolerate large amounts of foreign protein. To avoid detrimental effects of cellulase expression in plants, we have chosen enzymes with high temperature optima; the genes for these enzymes are from thermophilic organisms that can use cellulose as a sole energy source.

  8. 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.

  9. 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.

  10. Peroxisome Ca(2+) homeostasis in animal and plant cells.

    Science.gov (United States)

    Costa, Alex; Drago, Ilaria; Zottini, Michela; Pizzo, Paola; Pozzan, Tullio

    2013-01-01

    Ca(2+) homeostasis in peroxisomes has been an unsolved problem for many years. Recently novel probes to monitor Ca(2+) levels in the lumen of peroxisomes in living cells of both animal and plant cells have been developed. Here we discuss the contrasting results obtained in mammalian cells with chemiluminecsent (aequorin) and fluorescent (cameleon) probes targeted to peroxisomes. We briefly discuss the different characteristics of these probes and the possible pitfalls of the two approaches. We conclude that the contrasting results obtained with the two probes may reflect a heterogeneity among peroxisomes in mammalian cells. We also discuss the results obtained in plant peroxisomes. In particular we demonstrate that Ca(2+) increases in the cytoplasm are mirrored by similar rises of Ca(2+) concentration the lumen of peroxisomes. The increases in peroxisome Ca(2+) level results in the activation of a catalase isoform, CAT3. Other functional roles of peroxisomal Ca(2+) changes in plant physiology are briefly discussed.

  11. WNT5A modulates cell cycle progression and contributes to the chemoresistance in pancreatic cancer cells

    Institute of Scientific and Technical Information of China (English)

    Wei Wei; Hui-Hui Sun; Na Li; Hong-Yue Li; Xin Li; Qiang Li; Xiao-Hong Shen

    2014-01-01

    BACKGROUND: Although there are many studies on the mechanism of chemoresistance in cancers, studies on the relations between WNT5A and chemoresistance in pancreatic cancer are rare. The present study was to examine the role of WNT5A in the regulation of cell cycle progression and in chemoresistance in pancreatic cancer tissues and cell lines. METHODS: Fresh pancreatic cancer and paracarcinoma tissues were obtained from 32 patients. The expressions of WNT5A, AKT/p-AKT and Cyclin D1 were detected by immunohistochemistry, and the correlation between WNT5A expression and clinicopathological characteristics was analyzed. The relationship between WNT5A expression and gemcitabine resistance was studied in PANC-1 and MIAPaCa2 cell lines. The effect of WNT5A on the regulation of cell cycle and gemcitabine cytotoxicity were investigated. The associations among the expressions of p-AKT, Cyclin D1 and WNT5A were also analyzed in cell lines and the effect of WNT5A on restriction-point (R-point) progression was evaluated. RESULTS: WNT5A, p-AKT and Cyclin D1 were highly expressed in pancreatic cancer tissues, and the WNT5A expression was correlated with the TNM stages. In vitro, WNT5A expression was associated with gemcitabine chemoresistance. The percentage of cells was increased in G0/G1 phase and decreased in S phase after knockdown of WNT5A in PANC-1. WNT5A promoted Cyclin D1 expression through phosphorylation of AKT which consequently enhanced G1-S transition and gemcitabine resistance. Furthermore, WNT5A enhanced the cell cycle progression toward R-point through regulation of retinoblastoma protein (pRb) and pRb-E2F complex formation. CONCLUSIONS: WNT5A induced chemoresistance by regulation of G1-S transition in pancreatic cancer cells. WNT5A might serve as a predictor of gemcitabine response and as a potential target for tumor chemotherapy.

  12. Application of Stem Cells in Oral Disease Therapy: Progresses and Perspectives

    Science.gov (United States)

    Yang, Bo; Qiu, Yi; Zhou, Niu; Ouyang, Hong; Ding, Junjun; Cheng, Bin; Sun, Jianbo

    2017-01-01

    Stem cells are undifferentiated and pluripotent cells that can differentiate into specialized cells with a more specific function. Stem cell therapies become preferred methods for the treatment of multiple diseases. Oral and maxillofacial defect is one kind of the diseases that could be most possibly cured by stem cell therapies. Here we discussed oral diseases, oral adult stem cells, iPS cells, and the progresses/challenges/perspectives of application of stem cells for oral disease treatment. PMID:28421002

  13. Research progress in the treatment of small cell lung cancer

    Science.gov (United States)

    Qiu, Yan-fang; Liu, Zhi-gang; Yang, Wen-juan; Zhao, Yu; Tang, Jiao; Tang, Wei-zhi; Jin, Yi; Li, Fang; Zhong, Rui; Wang, Hui

    2017-01-01

    Small cell lung cancer (SCLC) accounts for approximately 10-15% of all lung cancers. No significant improvement has been made for patients with SCLC in the past several decades. The main progresses were the thoracic radiation and prophylactic cranial irradiation (PCI) that improved the patient survival rate. For patients with limited disease and good performance status (PS), concurrent chemoradiotherapy (CCRT) followed by PCI should be considered. For extensive disease, the combination of etoposide and platinum-based chemotherapy remains the standard treatment and consolidative thoracic radiotherapy is beneficial for patients who have a significant respond to initial chemotherapy. However, the prognosis still remains poor. Recently, efforts have been focused on molecular targets and immunotherapy. But numerous molecular targets methods have failed to show a significant clinical benefit in patients with SCLC. It is anticipated that further development of research will depend on the on-going trials for molecular targeted therapy and immunotherapy which are promising and may improve the outcomes for SCLC in the next decade.

  14. 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.

  15. Genistein sensitizes ovarian carcinoma cells to chemotherapy by switching the cell cycle progression in vitro

    Institute of Scientific and Technical Information of China (English)

    Huang Yanhong; Yuan Peng; Zhang Qinghong; Xin Xiaoyan

    2009-01-01

    Objective: To address how genistein sensitizes the chemotherapy-resistant ovarian carcinoma cells and promotes apoptosis in the respect of cell cycle and the regulation of survivin expression in the process. Methods: Ovarian SKOV-3 carcinoma cell line was treated with genistein or cisplatin either alone or in combination. Cell viability was showed by MTT method. Cell cycle and apoptosis were detected by flow cytometry. Survivin mRNA and protein were revealed by RT-PCR and immunocytochemistry, respectively. Results: Genistein could reduce the cell viability in a dose-dependent manner, while cisplatin did so at a much higher level. In contrast, if the two agents were treated in combination, half growth inhibition (IC50) value for cisplatin was reduced remarkably and the effect was synergistic as analyzed by isobologram. In particular, the reduced cell viability was exhibited by a switch in cell cycle progression, as the cells were arrested in G2/M phase and the G0/G1 phase-fraction was significantly decreased. The reduced cell viability appeared to involve apoptosis, based on our results from flow cytometry and Hoechst 33258 staining. In the meanwhile, genistein performed the inhibitory effect on cisplatin-induced survivin expression. Conclusion: Genistein can sensitize ovarian carcinoma cells to cisplatin therapy with the inhibition of survivin expression as the potential mechanism.

  16. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

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

  17. Effects of tyrosine kinase and phosphatase inhibitors on mitosis progression in synchronized tobacco BY-2 cells.

    Science.gov (United States)

    Sheremet, Ya A; Yemets, A I; Azmi, A; Vissenberg, K; Verbelen, J P; Blume, Ya B

    2012-01-01

    To test whether reversible tubulin phosphorylation plays any role in the process of plant mitosis the effects of inhibitors of tyrosine kinases, herbimycin A, genistein and tyrphostin AG 18, and of an inhibitor of tyrosine phosphatases, sodium orthovanadate, on microtubule organization and mitosis progression in a synchronized BY-2 culture has been investigated. It was found that treatment with inhibitors of tyrosine kinases of BY-2 cells at the G2/M transition did not lead to visible disturbances of mitotic microtubule structures, while it did reduce the frequency of their appearance. We assume that a decreased tyrosine phosphorylation level could alter the microtubule dynamic instability parameters during interphase/prophase transition. All types of tyrosine kinase inhibitors used caused a prophase delay: herbimycin A and genistein for 2 h, and tyrphostin AG18 for 1 h. Thereafter the peak of mitosis was displaced for 1 h by herbimycin A or genistein exposure, but after tyrphostin AG18 treatment the timing of the mitosis-peak was comparable to that in control cells. Enhancement of tyrosine phosphorylation induced by the tyrosine phosphatase inhibitor resulted in the opposite effect on BY-2 mitosis transition. Culture treatment with sodium orthovanadate during 1 h resulted in an accelerated start of the prophase and did not lead to the alteration in time of the mitotic index peak formation, as compared to control cells. We suppose that the reversible tyrosine phosphorylation can be involved in the regulation of interphase to M phase transition possibly through regulation of microtubule dynamics in plant cells.

  18. An Evolutionarily Conserved Plant RKD Factor Controls Germ Cell Differentiation.

    Science.gov (United States)

    Koi, Satoshi; Hisanaga, Tetsuya; Sato, Katsutoshi; Shimamura, Masaki; Yamato, Katsuyuki T; Ishizaki, Kimitsune; Kohchi, Takayuki; Nakajima, Keiji

    2016-07-11

    In contrast to animals, in which the germ cell lineage is established during embryogenesis, plant germ cells are generated in reproductive organs via reprogramming of somatic cells. The factors that control germ cell differentiation and reprogramming in plants are poorly understood. Members of the RKD subfamily of plant-specific RWP-RK transcription factors have been implicated in egg cell formation in Arabidopsis based on their expression patterns and ability to cause an egg-like transcriptome upon ectopic expression [1]; however, genetic evidence of their involvement is lacking, due to possible genetic redundancy, haploid lethality, and the technical difficulty of analyzing egg cell differentiation in angiosperms. Here we analyzed the factors that govern germ cell formation in the liverwort Marchantia polymorpha. This recently revived model bryophyte has several characteristics that make it ideal for studies of germ cell formation, such as low levels of genetic redundancy, readily accessible germ cells, and the ability to propagate asexually via gemma formation [2, 3]. Our analyses revealed that MpRKD, a single RWP-RK factor closely related to angiosperm RKDs, is preferentially expressed in developing eggs and sperm precursors in M. polymorpha. Targeted disruption of MpRKD had no effect on the gross morphology of the vegetative and reproductive organs but led to striking defects in egg and sperm cell differentiation, demonstrating that MpRKD is an essential regulator of germ cell differentiation. Together with previous findings [1, 4-6], our results suggest that RKD factors are evolutionarily conserved regulators of germ cell differentiation in land plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-07-01

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

  20. Are kinesins required for organelle trafficking in plant cells?

    Directory of Open Access Journals (Sweden)

    Giampiero eCai

    2012-07-01

    Full Text Available Plant cells exhibit active movement of membrane-bounded materials, which is more pronounced in large cells but is also appreciable in medium-sized cells and in tip-growing cells (such as pollen tubes and root hairs. Trafficking of organelles (such as Golgi bodies, endoplasmic reticulum, peroxisomes, and mitochondria and vesicles is essential for plant cell physiology and allows a more or less homogeneous distribution of the cell content. It is well established that the long-range trafficking of organelles is dependent essentially on the network of actin filaments and is powered by the enzyme activity of myosins. However, some lines of evidence suggest that microtubules and members of the kinesin microtubule-based motor superfamily might have a role in the positioning and/or short-range movement of cell organelles and vesicles. Data collected in different cells (such as trichomes and pollen tubes, in specific stages of the plant cell life cycle (for example during phragmoplast development and for different organelle classes (mitochondria, Golgi bodies and chloroplasts encourage the hypothesis that microtubule-based motors might play subtle yet unclarified roles in organelle trafficking. In some cases, this function could be carried out in cooperation with actin filaments according to the model of functional cooperation by which motors of different families are associated with the organelle surface. Since available data did not provide an unambiguous conclusion with regard to the role of kinesins in organelle transport, here we want to debate such hypothesis.

  1. 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.

  2. An imbalance in progenitor cell populations reflects tumour progression in breast cancer primary culture models.

    LENUS (Irish Health Repository)

    Donatello, Simona

    2011-01-01

    Many factors influence breast cancer progression, including the ability of progenitor cells to sustain or increase net tumour cell numbers. Our aim was to define whether alterations in putative progenitor populations could predict clinicopathological factors of prognostic importance for cancer progression.

  3. How do filamentous pathogens deliver effector proteins into plant cells?

    Directory of Open Access Journals (Sweden)

    Benjamin Petre

    2014-02-01

    Full Text Available Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens.

  4. How Do Filamentous Pathogens Deliver Effector Proteins into Plant Cells?

    Science.gov (United States)

    Petre, Benjamin; Kamoun, Sophien

    2014-01-01

    Fungal and oomycete plant parasites are among the most devastating pathogens of food crops. These microbes secrete effector proteins inside plant cells to manipulate host processes and facilitate colonization. How these effectors reach the host cytoplasm remains an unclear and debated area of plant research. In this article, we examine recent conflicting findings that have generated discussion in the field. We also highlight promising approaches based on studies of both parasite and host during infection. Ultimately, this knowledge may inform future broad spectrum strategies for protecting crops from such pathogens. PMID:24586116

  5. Compost in plant microbial fuel cell for bioelectricity generation.

    Science.gov (United States)

    Moqsud, M A; Yoshitake, J; Bushra, Q S; Hyodo, M; Omine, K; Strik, David

    2015-02-01

    Recycling of organic waste is an important topic in developing countries as well as developed countries. Compost from organic waste has been used for soil conditioner. In this study, an experiment has been carried out to produce green energy (bioelectricity) by using paddy plant microbial fuel cells (PMFCs) in soil mixed with compost. A total of six buckets filled with the same soil were used with carbon fiber as the electrodes for the test. Rice plants were planted in five of the buckets, with the sixth bucket containing only soil and an external resistance of 100 ohm was used for all cases. It was observed that the cells with rice plants and compost showed higher values of voltage and power density with time. The highest value of voltage showed around 700 mV when a rice plant with 1% compost mixed soil was used, however it was more than 95% less in the case of no rice plant and without compost. Comparing cases with and without compost but with the same number of rice plants, cases with compost depicted higher voltage to as much as 2 times. The power density was also 3 times higher when the compost was used in the paddy PMFCs which indicated the influence of compost on bio-electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. A quantitative and dynamic model for plant stem cell regulation.

    Directory of Open Access Journals (Sweden)

    Florian Geier

    Full Text Available Plants maintain pools of totipotent stem cells throughout their entire life. These stem cells are embedded within specialized tissues called meristems, which form the growing points of the organism. The shoot apical meristem of the reference plant Arabidopsis thaliana is subdivided into several distinct domains, which execute diverse biological functions, such as tissue organization, cell-proliferation and differentiation. The number of cells required for growth and organ formation changes over the course of a plants life, while the structure of the meristem remains remarkably constant. Thus, regulatory systems must be in place, which allow for an adaptation of cell proliferation within the shoot apical meristem, while maintaining the organization at the tissue level. To advance our understanding of this dynamic tissue behavior, we measured domain sizes as well as cell division rates of the shoot apical meristem under various environmental conditions, which cause adaptations in meristem size. Based on our results we developed a mathematical model to explain the observed changes by a cell pool size dependent regulation of cell proliferation and differentiation, which is able to correctly predict CLV3 and WUS over-expression phenotypes. While the model shows stem cell homeostasis under constant growth conditions, it predicts a variation in stem cell number under changing conditions. Consistent with our experimental data this behavior is correlated with variations in cell proliferation. Therefore, we investigate different signaling mechanisms, which could stabilize stem cell number despite variations in cell proliferation. Our results shed light onto the dynamic constraints of stem cell pool maintenance in the shoot apical meristem of Arabidopsis in different environmental conditions and developmental states.

  7. Plant cell, tissue and organ culture: the most flexible foundations for plant metabolic engineering applications.

    Science.gov (United States)

    Ogita, Shinjiro

    2015-05-01

    Significant advances in plant cell, tissue and organ culture (PCTOC) have been made in the last five decades. PCTOC is now thought to be the underlying technique for understanding general or specific biological functions of the plant kingdom, and it is one of the most flexible foundations for morphological, physiological and molecular biological applications of plants. Furthermore, the recent advances in the field of information technology (IT) have enabled access to a large amount of information regarding all aspects of plant biology. For example, sequencing information is stored in mega repositories such as the National Center for Biotechnology Information (NCBI), which can be easily accessed by researchers worldwide. To date, the PCTOC and IT combination strategy for regulation of target plant metabolism and the utilization of bioactive plant metabolites for commercial purposes is essential. In this review, the advantages and the limitations of these methodologies, especially regarding the production of bioactive plant secondary metabolites and metabolic engineering in target plants are discussed mainly from the phenotypic view point.

  8. 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.

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

    Science.gov (United States)

    Hoson, Takayuki; Wakabayashi, Kazuyuki

    2015-04-01

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

  10. Optical Property Analyses of Plant Cells for Adaptive Optics Microscopy

    Science.gov (United States)

    Tamada, Yosuke; Murata, Takashi; Hattori, Masayuki; Oya, Shin; Hayano, Yutaka; Kamei, Yasuhiro; Hasebe, Mitsuyasu

    2014-04-01

    In astronomy, adaptive optics (AO) can be used to cancel aberrations caused by atmospheric turbulence and to perform diffraction-limited observation of astronomical objects from the ground. AO can also be applied to microscopy, to cancel aberrations caused by cellular structures and to perform high-resolution live imaging. As a step toward the application of AO to microscopy, here we analyzed the optical properties of plant cells. We used leaves of the moss Physcomitrella patens, which have a single layer of cells and are thus suitable for optical analysis. Observation of the cells with bright field and phase contrast microscopy, and image degradation analysis using fluorescent beads demonstrated that chloroplasts provide the main source of optical degradations. Unexpectedly, the cell wall, which was thought to be a major obstacle, has only a minor effect. Such information provides the basis for the application of AO to microscopy for the observation of plant cells.

  11. Nanosecond electric pulses trigger actin responses in plant cells.

    Science.gov (United States)

    Berghöfer, Thomas; Eing, Christian; Flickinger, Bianca; Hohenberger, Petra; Wegner, Lars H; Frey, Wolfgang; Nick, Peter

    2009-09-25

    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. Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

    Directory of Open Access Journals (Sweden)

    Qiong Liao

    2016-06-01

    Full Text Available AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3 make effect on outflow facility through the trabecular meshwork (TM. METHODS: Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC cells were determined, still were the collagen, type IV, alpha 1 (COL4A1 and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS: The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION: Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1. Reduced NOS3 restrains the TM cell cycle progression at the G2/M-phase transition and induced cell apoptosis.

  13. Control of division and differentiation of plant stem cells and their derivatives.

    Science.gov (United States)

    Nieuwland, Jeroen; Scofield, Simon; Murray, James A H

    2009-12-01

    The core mechanism of the plant cell cycle is conserved with all other eukaryotes but several aspects are unique to plant cells. Key characteristics of plant development include indeterminate growth and repetitive organogenesis derived from stem cell pools and they may explain the existence of the high number of cell cycle regulators in plants. In this review, we give an overview of the plant cell cycle and its regulatory components. Furthermore, we discuss the cell cycle aspects of plant stem cell maintenance and how the cell cycle relates to cellular differentiation during development. We exemplify this transition by focusing on organ initiation in the shoot.

  14. A stress-induced small RNA modulates alpha-rhizobial cell cycle progression.

    Directory of Open Access Journals (Sweden)

    Marta Robledo

    2015-04-01

    Full Text Available Mechanisms adjusting replication initiation and cell cycle progression in response to environmental conditions are crucial for microbial survival. Functional characterization of the trans-encoded small non-coding RNA (trans-sRNA EcpR1 in the plant-symbiotic alpha-proteobacterium Sinorhizobium meliloti revealed a role of this class of riboregulators in modulation of cell cycle regulation. EcpR1 is broadly conserved in at least five families of the Rhizobiales and is predicted to form a stable structure with two defined stem-loop domains. In S. meliloti, this trans-sRNA is encoded downstream of the divK-pleD operon. ecpR1 belongs to the stringent response regulon, and its expression was induced by various stress factors and in stationary phase. Induced EcpR1 overproduction led to cell elongation and increased DNA content, while deletion of ecpR1 resulted in reduced competitiveness. Computationally predicted EcpR1 targets were enriched with cell cycle-related mRNAs. Post-transcriptional repression of the cell cycle key regulatory genes gcrA and dnaA mediated by mRNA base-pairing with the strongly conserved loop 1 of EcpR1 was experimentally confirmed by two-plasmid differential gene expression assays and compensatory changes in sRNA and mRNA. Evidence is presented for EcpR1 promoting RNase E-dependent degradation of the dnaA mRNA. We propose that EcpR1 contributes to modulation of cell cycle regulation under detrimental conditions.

  15. 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

  16. Calcium signaling in plant cells in altered gravity

    Science.gov (United States)

    Kordyum, E. L.

    2003-10-01

    Changes in the intracellular Ca 2+ concentration in altered gravity (microgravity and clinostating) evidence that Ca 2+ signaling can play a fundamental role in biological effects of microgravity. Calcium as a second messenger is known to play a crucial role in stimulus - response coupling for many plant cellular signaling pathways. Its messenger functions are realized by transient changes in the cytosolic ion concentration induced by a variety of internal and external stimuli such as light, hormones, temperature, anoxia, salinity, and gravity. Although the first data on the changes in the calcium balance in plant cells under the influence of altered gravity have appeared in 80 th, a review highlighting the performed research and the possible significance of such Ca 2+ changes in the structural and metabolic rearrangements of plant cells in altered gravity is still lacking. In this paper, an attempt was made to summarize the available experimental results and to consider some hypotheses in this field of research. It is proposed to distinguish between cell gravisensing and cell graviperception; the former is related to cell structure and metabolism stability in the gravitational field and their changes in microgravity (cells not specialized to gravity perception), the latter is related to active use of a gravitational stimulus by cells presumebly specialized to gravity perception for realization of normal space orientation, growth, and vital activity (gravitropism, gravitaxis) in plants. The main experimental data concerning both redistribution of free Ca 2+ ions in plant cell organelles and the cell wall, and an increase in the intracellular Ca 2+ concentration under the influence of altered gravity are presented. Based on the gravitational decompensation hypothesis, the consequence of events occurring in gravisensing cells not specialized to gravity perception under altered gravity are considered in the following order: changes in the cytoplasmic membrane surface

  17. Cell cycle and epigenetic changes of plant DNA

    Directory of Open Access Journals (Sweden)

    Shevchenko G. V.

    2010-04-01

    Full Text Available Plants can apply various strategies to minimize environmental impact. One of the strategies is heritable modifications of gene expression which occur without changing original DNA sequence and are known as epigenetic. Signaling pathway Rb-E2F (retinoblastoma (Rb-transcription factor E2F/DP connects the cell cycle with factors, modifying structure of chromatin and DNA. It also coordinates cell proliferation and differentiation influenced by external stimuli. The article highlights the activity of Rb-E2F/DP signaling pathway and its connection with the epigenetic changes of DNA in plants.

  18. 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.

  19. 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.

  20. Genes and quantitative genetic variation involved with senescence in cells, organs and the whole plant

    Directory of Open Access Journals (Sweden)

    Benoit ePujol

    2015-02-01

    Full Text Available Senescence, the deterioration of morphological, physiological and reproductive functions with age that ends with the death of the organism, was widely studied in plants. Genes were identified that are linked to the deterioration of cells, organs and the whole plant. It is however unclear whether those genes are the source of age dependent deterioration or get activated to regulate such deterioration. Furthermore, it is also unclear whether such genes are active as a direct consequence of age or because they are specifically involved in some developmental stages. At the individual level, it is the relationship between quantitative genetic variation and age that can be used to detect the genetic signature of senescence. Surprisingly, the latter approach was only scarcely applied to plants. This may be the consequence of the demanding requirements for such approaches and/or the fact that most research interest was directed towards plants that avoid senescence. Here, I review those aspects in turn and call for an integrative genetic theory of senescence in plants. Such conceptual development would have implications for the management of plant genetic resources and generate progress on fundamental questions raised by ageing research.

  1. 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.

  2. DNA topoisomerase II-dependent control of the cell cycle progression in root meristems of Allium cepa.

    Science.gov (United States)

    Zabka, Aneta; Polit, Justyna Teresa; Bernasińska, Joanna; Maszewski, Janusz

    2014-03-01

    The catalytic ability of DNA topoisomerases (Topo) to generate short-term DNA breaks allow these enzymes to play crucial functions in managing DNA topology during S-phase replication, transcription, and chromatin-remodelling processes required to achieve commitment for the onset and transition through mitosis. Our experiments on root meristem cells of onion (Allium cepa) were designed to gain insight into the contribution of Topo II to plant-specific progression throughout interphase and mitosis. Irrespective of the position of the cell in interphase, the immunofluorescence of Topo II revealed similar nuclear labelling pattern with well defined signals dispersed in the nucleoplasm and the cortical zone of the nucleolus. Only weak labelling was detected in metaphase and anaphase chromosomes. Experiments with two potent anti-Topo II agents, doxorubicin (DOX, an anthracycline) and a bisdioxopiperazine derivative, ICRF-193, suggest that the inhibition-mediated increase in Topo II immunofluorescence may represent a compensatory mechanism, by which an up-regulated expression of the enzyme tends to counteract the drug-induced loss of indispensable catalytic and relaxation functions. γ-H2AX immunolabelling seems to indicate that both DOX- and ICRF-193-induced alterations in cell cycle progression reflect primarily the activity of the G2/M DNA damage checkpoint. Our findings provide evidence for the plant-specific cell cycle control mechanism induced by Topo II inhibitors under DNA stress conditions.

  3. The plant cell nucleus: a true arena for the fight between plants and pathogens.

    Science.gov (United States)

    Deslandes, Laurent; Rivas, Susana

    2011-01-01

    Communication between the cytoplasm and the nucleus is a fundamental feature shared by both plant and animal cells. Cellular factors involved in the transport of macromolecules through the nuclear envelope, including nucleoporins, importins and Ran-GTP related components, are conserved among a variety of eukaryotic systems. Interestingly, mutations in these nuclear components compromise resistance signalling, illustrating the importance of nucleocytoplasmic trafficking in plant innate immunity. Indeed, spatial restriction of defence regulators by the nuclear envelope and stimulus-induced nuclear translocation constitute an important level of defence-associated gene regulation in plants. A significant number of effectors from different microbial pathogens are targeted to the plant cell nucleus. In addition, key host factors, including resistance proteins, immunity components, transcription factors and transcriptional regulators shuttle between the cytoplasm and the nucleus, and their level of nuclear accumulation determines the output of the defence response, further confirming the crucial role played by the nucleus during the interaction between plants and pathogens. Here, we discuss recent findings that situate the nucleus at the frontline of the mutual recognition between plants and invading microbes.

  4. Specific organization of Golgi apparatus in plant cells.

    Science.gov (United States)

    Vildanova, M S; Wang, W; Smirnova, E A

    2014-09-01

    Microtubules, actin filaments, and Golgi apparatus are connected both directly and indirectly, but it is manifested differently depending on the cell organization and specialization, and these connections are considered in many original studies and reviews. In this review we would like to discuss what underlies differences in the structural organization of the Golgi apparatus in animal and plant cells: specific features of the microtubule cytoskeleton organization, the use of different cytoskeleton components for Golgi apparatus movement and maintenance of its integrity, or specific features of synthetic and secretory processes. We suppose that a dispersed state of the Golgi apparatus in higher plant cells cannot be explained only by specific features of the microtubule system organization and by the absence of centrosome as an active center of their organization because the Golgi apparatus is organized similarly in the cells of other organisms that possess the centrosome and centrosomal microtubules. One of the key factors determining the Golgi apparatus state in plant cells is the functional uniformity or functional specialization of stacks. The functional specialization does not suggest the joining of the stacks to form a ribbon; therefore, the disperse state of the Golgi apparatus needs to be supported, but it also can exist "by default". We believe that the dispersed state of the Golgi apparatus in plants is supported, on one hand, by dynamic connections of the Golgi apparatus stacks with the actin filament system and, on the other hand, with the endoplasmic reticulum exit sites distributed throughout the endoplasmic reticulum.

  5. New aspects of gravity responses in plant cells.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi

    2003-01-01

    Plants show two distinct responses to gravity: gravity-dependent morphogenesis (gravimorphogenesis) and gravity resistance. In gravitropism, a typical mechanism of gravimorphogenesis, gravity is utilized as a signal to establish an appropriate form. The response has been studied in a gravity-free environment, where plant seedlings were found to perform spontaneous morphogenesis, termed automorphogenesis. Automorphogenesis consists of a change in growth direction and spontaneous curvature in dorsiventral directions. The spontaneous curvature is caused by a difference in the capacity of the cell wall to expand between the dorsal and the ventral sides of organs, which originates from the inherent structural anisotropy. Gravity resistance is a response that enables the plant to develop against the gravitational force. To resist the force, the plant constructs a tough body by increasing the cell wall rigidity that suppresses growth. The mechanical properties of the cell wall are changed by modification of the cell wall metabolism and cell wall environment, especially pH. In gravitropism, gravity is perceived by amyloplasts in statocytes, whereas gravity resistance may be mediated by mechanoreceptors on the plasma membrane.

  6. Adult Stem Cell Therapy for Stroke: Challenges and Progress

    OpenAIRE

    Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

    2016-01-01

    Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell t...

  7. Adult Stem Cell Therapy for Stroke: Challenges and Progress

    OpenAIRE

    Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

    2016-01-01

    Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell t...

  8. Systemic inflammation in progressive multiple sclerosis involves follicular T-helper, Th17- and activated B-cells and correlates with progression.

    Directory of Open Access Journals (Sweden)

    Jeppe Romme Christensen

    Full Text Available Pathology studies of progressive multiple sclerosis (MS indicate a major role of inflammation including Th17-cells and meningeal inflammation with ectopic lymphoid follicles, B-cells and plasma cells, the latter indicating a possible role of the newly identified subset of follicular T-helper (TFH cells. Although previous studies reported increased systemic inflammation in progressive MS it remains unclear whether systemic inflammation contributes to disease progression and intrathecal inflammation. This study aimed to investigate systemic inflammation in progressive MS and its relationship with disease progression, using flow cytometry and gene expression analysis of CD4(+ and CD8(+T-cells, B-cells, monocytes and dendritic cells. Furthermore, gene expression of cerebrospinal fluid cells was studied. Flow cytometry studies revealed increased frequencies of ICOS(+TFH-cells in peripheral blood from relapsing-remitting (RRMS and secondary progressive (SPMS MS patients. All MS subtypes had decreased frequencies of Th1 TFH-cells, while primary progressive (PPMS MS patients had increased frequency of Th17 TFH-cells. The Th17-subset, interleukin-23-receptor(+CD4(+T-cells, was significantly increased in PPMS and SPMS. In the analysis of B-cells, we found a significant increase of plasmablasts and DC-SIGN(+ and CD83(+B-cells in SPMS. ICOS(+TFH-cells and DC-SIGN(+B-cells correlated with disease progression in SPMS patients. Gene expression analysis of peripheral blood cell subsets substantiated the flow cytometry findings by demonstrating increased expression of IL21, IL21R and ICOS in CD4(+T-cells in progressive MS. Cerebrospinal fluid cells from RRMS and progressive MS (pooled SPMS and PPMS patients had increased expression of TFH-cell and plasmablast markers. In conclusion, this study is the first to demonstrate the potential involvement of activated TFH-cells in MS. The increased frequencies of Th17-cells, activated TFH- and B-cells parallel findings

  9. The cell biology of lignification in higher plants.

    Science.gov (United States)

    Barros, Jaime; Serk, Henrik; Granlund, Irene; Pesquet, Edouard

    2015-06-01

    Lignin is a polyphenolic polymer that strengthens and waterproofs the cell wall of specialized plant cell types. Lignification is part of the normal differentiation programme and functioning of specific cell types, but can also be triggered as a response to various biotic and abiotic stresses in cells that would not otherwise be lignifying. Cell wall lignification exhibits specific characteristics depending on the cell type being considered. These characteristics include the timing of lignification during cell differentiation, the palette of associated enzymes and substrates, the sub-cellular deposition sites, the monomeric composition and the cellular autonomy for lignin monomer production. This review provides an overview of the current understanding of lignin biosynthesis and polymerization at the cell biology level. The lignification process ranges from full autonomy to complete co-operation depending on the cell type. The different roles of lignin for the function of each specific plant cell type are clearly illustrated by the multiple phenotypic defects exhibited by knock-out mutants in lignin synthesis, which may explain why no general mechanism for lignification has yet been defined. The range of phenotypic effects observed include altered xylem sap transport, loss of mechanical support, reduced seed protection and dispersion, and/or increased pest and disease susceptibility. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Amygdalin delays cell cycle progression and blocks growth of prostate cancer cells in vitro.

    Science.gov (United States)

    Makarević, Jasmina; Tsaur, Igor; Juengel, Eva; Borgmann, Hendrik; Nelson, Karen; Thomas, Christian; Bartsch, Georg; Haferkamp, Axel; Blaheta, Roman A

    2016-02-15

    Despite impressive survival benefits from new agents to treat metastasized prostate cancer (PCa), progressive drug resistance hinders long-term response and restricts the efficacy of subsequent therapy. Due to reported antitumor activity of amygdalin and growing popularity for complementary and alternative medicine the potential of this natural, widely used substance to exert antineoplastic effects on prostate cancer cells has been assessed. LNCaP (castration-sensitive), DU-145 and PC3 cells (castration-resistant) were exposed to different concentrations of amygdalin for 24h or 2weeks. Cell growth was measured by the MTT test, clonal formation by the clonogenic assay. Flow cytometry served to investigate apoptosis and cell cycle phases. Cell cycle regulating proteins and the mTOR-akt signaling axis were analyzed by western blotting. Amygdalin dose-dependently diminished tumor cell growth with maximum effects at 10mg/ml. Apoptosis of PC3 and LNCaP but not of DU-145 cells was reduced, whereas colony formation was suppressed in all cell lines. A decrease in the number of G2/M- and S-phase cells along with an elevated number of G0/G1-phase cells was recorded. The cell cycle proteins cdk 1, cdk 2 and cdk 4 as well as cyclin A, cyclin B and cyclin D3 were modulated by amygdalin after both 24h and 2weeks. Distinct effects on p19 and p27 expression and on Akt, Rictor and Raptor activation became evident only after 2weeks. Amygdalin exhibits significant antitumor activity in both castration-sensitive and castration-resistant PCa cell lines and merits further evaluation for therapeutic purposes. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Pluripotent stem cells for Parkinson's disease: progress and challenges

    National Research Council Canada - National Science Library

    Zeng, Xianmin; Couture, Larry A

    2013-01-01

    Parkinson's disease (PD) is a common debilitating neurodegenerative disease. The motor symptoms of PD are caused mainly by a progressive loss of dopaminergic neurons from the substania nigra, resulting in a loss of dopamine production...

  12. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Bergstrom Gary C

    2011-02-01

    Full Text Available Abstract Background The discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for the production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly cellulolytic and is a major industrial microbial source for commercial cellulases, xylanases and other cell wall degrading enzymes. However, enzyme-prospecting research continues to identify opportunities to enhance the activity of T. reesei enzyme preparations by supplementing with enzymatic diversity from other microbes. The goal of this study was to evaluate the enzymatic potential of a broad range of plant pathogenic and non-pathogenic fungi for their ability to degrade plant biomass and isolated polysaccharides. Results Large-scale screening identified a range of hydrolytic activities among 348 unique isolates representing 156 species of plant pathogenic and non-pathogenic fungi. Hierarchical clustering was used to identify groups of species with similar hydrolytic profiles. Among moderately and highly active species, plant pathogenic species were found to be more active than non-pathogens on six of eight substrates tested, with no significant difference seen on the other two substrates. Among the pathogenic fungi, greater hydrolysis was seen when they were tested on biomass and hemicellulose derived from their host plants (commelinoid monocot or dicot. Although T. reesei has a hydrolytic profile that is highly active on cellulose and pretreated biomass, it was less active than some natural isolates of fungi when tested on xylans and untreated biomass. Conclusions Several highly active isolates of plant pathogenic fungi were identified, particularly when tested on xylans and untreated biomass. There were statistically significant preferences for biomass type reflecting the monocot or dicot host preference of the

  13. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

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

  14. Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

    Science.gov (United States)

    Discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly c...

  15. Hypersensitive cell death in plants : its mechanisms and role in plant defense against pathogens

    NARCIS (Netherlands)

    Iakimova, E.T.; Michalczuk, L.; Woltering, E.J.

    2005-01-01

    This review is a recent update in the understanding of the hypersensitive response (HR) of plants with special consideration to the physiological and biochemical determinants in different model systems. Hypersensitive response is reviewed as a form of programmed cell death (PCD) representing one of

  16. Progress in the Classification of Plant Programmed Cell Death and the Regulatory Protein for Membrane Permeabilization%植物细胞程序性死亡的分类和膜通透性调控蛋白研究进展

    Institute of Scientific and Technical Information of China (English)

    蒋丽; 孔莹莹; 韩凝; 边红武; 朱睦元; 王君晖

    2012-01-01

    程序性细胞死亡是由基因调控的贯穿于真核细胞生理和发育过程的细胞自杀行为.动物细胞的程序性死亡分成3类:凋亡、自噬和坏死;线粒体和溶酶体分别在前两个过程中起关键作用.关于植物细胞程序性死亡的分类还存在很多争议,焦点是植物是否有细胞凋亡这种形式,核心问题是植物细胞的线粒体外膜上没有Bcl-2家族的膜通透性调控蛋白.近年,程序性细胞死亡也在细菌中发现,LrgAB家族的膜通透性调控蛋白起着重要作用.最近的研究表明,植物叶绿体外被膜上也有LrgAB家族的同源蛋白,它们在控制叶绿体发育和程序性细胞死亡方面起重要作用.因此,叶绿体在植物细胞死亡调控中的作用应该更加受到关注.%Programmed cell death (PCD) is a genetically controlled process of cell suicide, which can be induced in physiology and development of eukaryotic cells. Currently, three types of PCD have been noticed in animal cells: apoptosis, autophagy and necrosis. Mitochondria and lysosomes play a vital role in apoptosis and autophagy, respectively. However, there exists controversy on the categories of plant PCD, focusing on whether apoptosis occurs in plant cells, due to the apparent absence of the Bcl-2 family proteins, the key regulators of membrane permeability in outer membrane of mitochondria. Recently, PCD was identified in bacteria, and the LrgAB family proteins was found to play a cental role in the regulation of membrane permeability. In the envelope membrane of chloroplasts, homologues of LrgAB family proteins have been identified, and their role in chloroplast development and plant PCD control have been revealed. Thus, we should pay more attention on chloroplast which may have a prominent role in plant PCD control.

  17. Adult Stem Cell Therapy for Stroke: Challenges and Progress.

    Science.gov (United States)

    Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

    2016-09-01

    Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell therapies include (a) the limited source of engraftable stem cells, (b) the presence of optimal time window for stem cell therapies, (c) inherited limitation of stem cells in terms of growth, trophic support, and differentiation potential, and (d) possible transplanted cell-mediated adverse effects, such as tumor formation. Here, we discuss recent advances that overcome these hurdles in adult stem cell therapy for stroke.

  18. Plant cells use auxin efflux to explore geometry.

    Science.gov (United States)

    Zaban, Beatrix; Liu, Wenwen; Jiang, Xingyu; Nick, Peter

    2014-07-28

    Cell movement is the central mechanism for animal morphogenesis. Plant cell development rather relies on flexible alignment of cell axis adjusting cellular differentiation to directional cues. As central input, vectorial fields of mechanical stress and gradients of the phytohormone auxin have been discussed. In tissue contexts, mechanical and chemical signals will always act in concert; experimentally it is difficult to dissect their individual roles. We have designed a novel approach, based on cells, where directionality has been eliminated by removal of the cell wall. We impose a new axis using a microfluidic set-up to generate auxin gradients. Rectangular microvessels are integrated orthogonally with the gradient. Cells in these microvessels align their new axis with microvessel geometry before touching the wall. Auxin efflux is necessary for this touch-independent geometry exploration and we suggest a model, where auxin gradients can be used to align cell axis in tissues with minimized mechanical tensions.

  19. 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.

  20. 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.

  1. Plant recombinant erythropoietin attenuates inflammatory kidney cell injury.

    Science.gov (United States)

    Conley, Andrew J; Mohib, Kanishka; Jevnikar, Anthony M; Brandle, Jim E

    2009-02-01

    Human erythropoietin (EPO) is a pleiotropic cytokine with remarkable tissue-protective activities in addition to its well-established role in red blood cell production. Unfortunately, conventional mammalian cell cultures are unlikely to meet the anticipated market demands for recombinant EPO because of limited capacity and high production costs. Plant expression systems may address these limitations to enable practical, cost-effective delivery of EPO in tissue injury prevention therapeutics. In this study, we produced human EPO in tobacco and demonstrated that plant-derived EPO had tissue-protective activity. Our results indicated that targeting to the endoplasmic reticulum (ER) provided the highest accumulation levels of EPO, with a yield approaching 0.05% of total soluble protein in tobacco leaves. The codon optimization of the human EPO gene for plant expression had no clear advantage; furthermore, the human EPO signal peptide performed better than a tobacco signal peptide. In addition, we found that glycosylation was essential for the stability of plant recombinant EPO, whereas the presence of an elastin-like polypeptide fusion had a limited positive impact on the level of EPO accumulation. Confocal microscopy showed that apoplast and ER-targeted EPO were correctly localized, and N-glycan analysis demonstrated that complex plant glycans existed on apoplast-targeted EPO, but not on ER-targeted EPO. Importantly, plant-derived EPO had enhanced receptor-binding affinity and was able to protect kidney epithelial cells from cytokine-induced death in vitro. These findings demonstrate that tobacco plants may be an attractive alternative for the production of large amounts of biologically active EPO.

  2. 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.

  3. Categorizing Cells on the Basis of their Chemical Profiles: Progress in Single-Cell Mass Spectrometry

    Science.gov (United States)

    2017-01-01

    The chemical differences between individual cells within large cellular populations provide unique information on organisms’ homeostasis and the development of diseased states. Even genetically identical cell lineages diverge due to local microenvironments and stochastic processes. The minute sample volumes and low abundance of some constituents in cells hinder our understanding of cellular heterogeneity. Although amplification methods facilitate single-cell genomics and transcriptomics, the characterization of metabolites and proteins remains challenging both because of the lack of effective amplification approaches and the wide diversity in cellular constituents. Mass spectrometry has become an enabling technology for the investigation of individual cellular metabolite profiles with its exquisite sensitivity, large dynamic range, and ability to characterize hundreds to thousands of compounds. While advances in instrumentation have improved figures of merit, acquiring measurements at high throughput and sampling from large populations of cells are still not routine. In this Perspective, we highlight the current trends and progress in mass-spectrometry-based analysis of single cells, with a focus on the technologies that will enable the next generation of single-cell measurements. PMID:28135079

  4. Compost in plant microbial fuel cell for bioelectricity generation

    NARCIS (Netherlands)

    Moqsud, M.A.; Yoshitake, J.; Bushra, Q.S.; Hyodo, M.; Omine, K.; Strik, D.P.B.T.B.

    2015-01-01

    Recycling of organic waste is an important topic in developing countries as well as developed countries. Compost from organic waste has been used for soil conditioner. In this study, an experiment has been carried out to produce green energy (bioelectricity) by using paddy plant microbial fuel cells

  5. 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

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  7. Protease signaling in animal and plant-regulated cell death.

    Science.gov (United States)

    Salvesen, Guy S; Hempel, Anne; Coll, Nuria S

    2016-07-01

    This review aims to highlight the proteases required for regulated cell death mechanisms in animals and plants. The aim is to be incisive, and not inclusive of all the animal proteases that have been implicated in various publications. The review also aims to focus on instances when several publications from disparate groups have demonstrated the involvement of an animal protease, and also when there is substantial biochemical, mechanistic and genetic evidence. In doing so, the literature can be culled to a handful of proteases, covering most of the known regulated cell death mechanisms: apoptosis, regulated necrosis, necroptosis, pyroptosis and NETosis in animals. In plants, the literature is younger and not as extensive as for mammals, although the molecular drivers of vacuolar death, necrosis and the hypersensitive response in plants are becoming clearer. Each of these death mechanisms has at least one proteolytic component that plays a major role in controlling the pathway, and sometimes they combine in networks to regulate cell death/survival decision nodes. Some similarities are found among animal and plant cell death proteases but, overall, the pathways that they govern are kingdom-specific with very little overlap. © 2015 FEBS.

  8. Reprogramming of human cancer cells to pluripotency for models of cancer progression

    Science.gov (United States)

    Kim, Jungsun; Zaret, Kenneth S

    2015-01-01

    The ability to study live cells as they progress through the stages of cancer provides the opportunity to discover dynamic networks underlying pathology, markers of early stages, and ways to assess therapeutics. Genetically engineered animal models of cancer, where it is possible to study the consequences of temporal-specific induction of oncogenes or deletion of tumor suppressors, have yielded major insights into cancer progression. Yet differences exist between animal and human cancers, such as in markers of progression and response to therapeutics. Thus, there is a need for human cell models of cancer progression. Most human cell models of cancer are based on tumor cell lines and xenografts of primary tumor cells that resemble the advanced tumor state, from which the cells were derived, and thus do not recapitulate disease progression. Yet a subset of cancer types have been reprogrammed to pluripotency or near-pluripotency by blastocyst injection, by somatic cell nuclear transfer and by induced pluripotent stem cell (iPS) technology. The reprogrammed cancer cells show that pluripotency can transiently dominate over the cancer phenotype. Diverse studies show that reprogrammed cancer cells can, in some cases, exhibit early-stage phenotypes reflective of only partial expression of the cancer genome. In one case, reprogrammed human pancreatic cancer cells have been shown to recapitulate stages of cancer progression, from early to late stages, thus providing a model for studying pancreatic cancer development in human cells where previously such could only be discerned from mouse models. We discuss these findings, the challenges in developing such models and their current limitations, and ways that iPS reprogramming may be enhanced to develop human cell models of cancer progression. PMID:25712212

  9. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

  10. [The cell theory. Progress in studies on cell-cell communications].

    Science.gov (United States)

    Brodskiĭ, V Ia

    2009-01-01

    Current data confirm the fundamental statement of the cell theory concerning the cell reproduction in a series of generations (omnis cellula e cellula). Cell communities or ensembles integrated by the signaling systems established in prokaryotes and protists and functioning in multicellular organisms including mammals are considered as the structural and functional unit of a multicellular organism. The cell is an elementary unit of life and basis of organism development and functioning. At the same time, the adult organism is not just a totality of cells. Multinucleated cells in some tissues, syncytial structure, and structural-functional units of organs are adaptations for optimal functioning of the multicellular organism and manifestations of cell-cell communications in development and definitive functioning. The cell theory was supplemented and developed by studies on cell-cell communications; however, these studies do not question the main generalizations of the theory.

  11. Stem cells: progressions and applications in clinical medicine

    OpenAIRE

    2016-01-01

    Stem cells are undifferentiated and multi pluripotent cells which can differentiate into a variety of mature cells and tissues such as nervous tissue, muscle tissue, epithelial tissue, skeletal tissue and etc. Stem cells from all different source have three unique features: 1) Proliferative capability: Stem cells are capable of self dividing and self renewing for long periods or more than six months at least that called immortalization. 2) Undifferentiated nature: It’s considered as one...

  12. Geothermal commercial power plant study. Monthly progress report, January 29, 1977-February 25, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-04-15

    Conceptual designs and capital cost estimates were completed for the six different Heber power plants in this study. The six plants involve two types of operating modes, constant geothermal fluid flow rate and constant power output, each for net capacities of 50, 100, and 200 MWe. Conceptual designs were completed for the six plants by modifying and scaling-up the base case design. The capital costs for all six plants were estimated in fourth-quarter 1976 dollars.

  13. 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

    2016-08-23

    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.

  14. Molecular mechanisms of cholangiocarcinoma cell inhibition by medicinal plants

    Science.gov (United States)

    Leelawat, Surang; Leelawat, Kawin

    2017-01-01

    Cholangiocarcinoma (CCA) is one of the most common causes of cancer-associated mortality in Thailand. Certain phytochemicals have been demonstrated to modulate apoptotic signaling pathways, which may be targeted for the prevention and treatment of cancer. Therefore, the aim of the present study was to investigate the effect of specific medicinal plants on the inhibition of CCA cell proliferation, and to identify the molecular mechanisms underlying this. A WST-1 cell proliferation assay was performed using an RMCCA1 cell line, and apoptotic signaling pathways were also investigated using a PathScan Stress and Apoptosis Signaling Antibody Array Kit. The cell proliferation assay indicated that extracts from the Phyllanthus emblica fruit pulp (PEf), Phyllanthus emblica seed (PEs), Terminalia chebula fruit pulp (TCf), Terminalia chebula seed (TCs), Areca catechu seed (ACs), Curcuma longa (CL) and Moringa oleifera seed (MOs) exerted anti-proliferative activity in RMCCA1 cells. In addition, the PathScan assay revealed that certain pro-apoptotic molecules, including caspase-3, poly (ADP-ribose) polymerase, checkpoint kinase 2 and tumor protein 53, exhibited increased activity in RMCCA1 cells treated with the aforementioned selected plant extracts, with the exception of PEf. The mitogen-activated protein kinase (MAPK) pathways (including ERK1/2 and p38 MAPK) expression level was significantly increased in RMCCA1 cells pre-treated with extracts of PEs, TCf, CL and MOs. The activation of protein kinase B (Akt) was significantly demonstrated in RMCCA1 cells pre-treated with extracts of TCf, ACs and MOs. In summary, the present study demonstrated that extracts of PEs, TCf, TCs, ACs, CL and MOs exhibited anti-proliferative effects in CCA cells by inducing pro-apoptotic signals and modulating signal transduction molecules. Further studies in vivo are required to demonstrate the potential applications of specific plant extracts for the treatment of human cancer.

  15. Progresses and challenges in optimization of human pluripotent stem cell culture.

    Science.gov (United States)

    Lin, Ge; Xu, Ren-He

    2010-09-01

    The pressing demand to elucidate the biology of human embryonic stem (ES) cells and to realize their therapeutic potential has greatly promoted the progresses in the optimization of the culture systems used for this highly promising cell type. These progresses include the characterization of exogenous regulators of pluripotency and differentiation, the development of animal-free, defined, and scalable culture systems, and some pioneering efforts to establish good manufactory practice facilities to derive and expand clinical-grade human ES cells and their derivatives. All of these advancements appear to be also applicable to the derivation and culture of human induced pluripotent stem cells, an ES cell-like cell type derived from somatic cells via reprogramming. This review attempts to summarize these progresses and discuss some of the remaining challenges.

  16. A role for ADAM12 in breast tumor progression and stromal cell apoptosis

    DEFF Research Database (Denmark)

    Kveiborg, Marie; Frohlich, Camilla; Albrechtsen, Reidar;

    2005-01-01

    of stromal fibroblasts in tumor initiation and progression has been elucidated. Here, we show that stromal cell apoptosis occurs in human breast carcinoma but is only rarely seen in nonmalignant breast lesions. Furthermore, we show that ADAM12, a disintegrin and metalloprotease up-regulated in human breast...... cancer, accelerates tumor progression in a mouse breast cancer model. ADAM12 does not influence tumor cell proliferation but rather confers both decreased tumor cell apoptosis and increased stromal cell apoptosis. This dual role of ADAM12 in governing cell survival is underscored by the finding that ADAM......12 increases the apoptotic sensitivity of nonneoplastic cells in vitro while rendering tumor cells more resistant to apoptosis. Together, these results show that the ability of ADAM12 to influence apoptosis may contribute to tumor progression....

  17. 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...

  18. Effect of PKC pathway on G1/S progression control in HeLa cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of PKC activity on G1/S progression in HeLa cells has been studied.The result shows that (ⅰ) PKC activity alteration in G1 phase affects G1/S progression in HeLa cells.It has been observed that G1/S progression is stimulated by PKC agonist TPA and inhibited by PKC inhibitor GF-109203X.(ⅱ) The expression of c-myc and c-jun is stimulated by TPA and inhibited by GF-109203X treatment in early G1 phase.(ⅲ) During G1/S progression,the expression of CyclinD1 is stimulated by TPA treatment and inhibited by GF-109203X treatment.There is no effect on the expression of CDK4.It is likely that PKC pathway regulates G1/S progression through regulating the expression of some early response genes and engine molecules in HeLa cells.

  19. 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

  20. 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.

  1. 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.

  2. Gene therapy progress and prospects: stem cell plasticity.

    Science.gov (United States)

    Kashofer, K; Bonnet, D

    2005-08-01

    With the identification of stem cell plasticity several years ago, multiple reports raised hopes that tissue repair by stem cell transplantation could be within reach in the near future. Krause et al reported that a single purified hematopoietic stem cell not only repopulated the bone marrow of a host animal, but also integrated into unrelated tissues. Lagasse et al demonstrated that in a genetic model of liver disease, purified hematopoietic stem cells can give rise to hepatocytes and rescue fatal liver damage. More recent work by Jiang et al demonstrated that cultured cells can retain their stem cell potential. There are a number of possible mechanisms that could explain these phenomena, and recent experiments have raised controversy about which mechanism is prevalent. One possibility is transdifferentiation of a committed cell directly into another cell type as a response to environmental cues. Transdifferentiation has been shown mainly in vitro, but some in vivo data also support this mechanism. Direct transdifferentiation would clinically be limited by the number of cells that can be introduced into an organ without removal of resident cells. If bone marrow cells could on the other hand give rise to stem cells of another tissue, then they could in theory repopulate whole organs from a few starting cells. This model of dedifferentiation is consistent with recent data from animal models. Genetic analysis of cells of donor origin in vivo and in vitro has brought to light another possible mechanism. The fusion of host and donor cells can give rise to mature tissue cells without trans- or dedifferentiation. The resulting heterokaryons are able to cure a lethal genetic defect and do not seem to be prone to give rise to cancer. All these models will clinically face the problem of accessibility of healthy primary cells for transplantation. This underlines the importance of the recent identification of a population of mesenchymal stem cells (MSCs) with stem cell

  3. Chick stem cells: Current progress and future prospects

    Science.gov (United States)

    Intarapat, Sittipon; Stern, Claudio D.

    2013-01-01

    Chick embryonic stem cells (cESCs) can be derived from cells obtained from stage X embryos (blastoderm stage); these have the ability to contribute to all somatic lineages in chimaeras, but not to the germ line. However, lines of stem cells that are able to contribute to the germ line can be established from chick primordial germ cells (cPGCs) and embryonic germ cells (cEGCs). This review provides information on avian stem cells, emphasizing different sources of cells and current methods for derivation and culture of pluripotent cells from chick embryos. We also review technologies for isolation and derivation of chicken germ cells and the production of transgenic birds. PMID:24103496

  4. NPAT expression is regulated by E2F and is essential for cell cycle progression

    DEFF Research Database (Denmark)

    Gao, Guang; Bracken, Adrian P; Burkard, Karina

    2003-01-01

    NPAT is an in vivo substrate of cyclin E-Cdk2 kinase and is thought to play a critical role in coordinated transcriptional activation of histone genes during the G(1)/S-phase transition and in S-phase entry in mammalian cells. Here we show that NPAT transcription is up-regulated at the G(1)/S...... by small interfering RNA duplexes impedes cell cycle progression and histone gene expression in tissue culture cells. Thus, NPAT is an important E2F target that is required for cell cycle progression in mammalian cells. As NPAT is involved in the regulation of S-phase-specific histone gene transcription...

  5. Homotypic fusion of endoplasmic reticulum membranes in plant cells

    Directory of Open Access Journals (Sweden)

    Junjie eHu

    2013-12-01

    Full Text Available The endoplasmic reticulum (ER is a membrane-bounded organelle whose membrane comprises a network of tubules and sheets. The formation of these characteristic shapes and maintenance of their continuity through homotypic membrane fusion appears to be critical for the proper functioning of the ER. The atlastins (ATLs, a family of ER-localized dynamin-like GTPases, have been identified as fusogens of the ER membranes in metazoans. Mutations of the ATL proteins in mammalian cells cause morphological defects in the ER, and purified Drosophila ATL mediates membrane fusion in vitro. Plant cells do not possess ATL, but a family of similar GTPases, named root hair defective 3 (RHD3, are likely the functional orthologs of ATLs. In this review, we summarize recent advances in our understanding of how RHD3 proteins play a role in homotypic ER fusion. We also discuss the possible physiological significance of forming a tubular ER network in plant cells.

  6. 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)

  7. 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.

  8. 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...

  9. Introducing the Cell Concept with Both Animal and Plant Cells: A Historical and Didactic Approach

    Science.gov (United States)

    Clement, Pierre

    2007-01-01

    In France, as well as in several other countries, the cell concept is introduced at school by two juxtaposed drawings, a plant cell and an animal cell. After indicating the didactic obstacles associated with this presentation, this paper focuses on the reasons underlying the persistence of these two prototypes, through three complementary…

  10. Introducing the Cell Concept with Both Animal and Plant Cells: A Historical and Didactic Approach

    Science.gov (United States)

    Clement, Pierre

    2007-01-01

    In France, as well as in several other countries, the cell concept is introduced at school by two juxtaposed drawings, a plant cell and an animal cell. After indicating the didactic obstacles associated with this presentation, this paper focuses on the reasons underlying the persistence of these two prototypes, through three complementary…

  11. Profilin as a regulator of the membrane-actin cytoskeleton interface in plant cells

    Directory of Open Access Journals (Sweden)

    Tiantian eSun

    2013-12-01

    Full Text Available Membrane structures and cytoskeleton dynamics are intimately inter-connected in the eukaryotic cell. Recently, the molecular mechanisms operating at this interface have been progressively addressed. Many experiments have revealed that the actin cytoskeleton can interact with membranes through various discrete membrane domains. The actin-binding protein, profilin has been proven to inhibit actin polymerization and to promote F-actin elongation. This is dependent on many factors, such as the profilin/G-actin ratio and the ionic environment of the cell. Additionally, profilin has specific domains that interact with phosphoinositides and poly-L-proline rich proteins; theoretically, this gives profilin the opportunity to interact with membranes, and a large number of experiments have confirmed this possibility. In this article, we summarize recent findings in plant cells, and discuss the evidence of the connections among actin cytoskeleton, profilin and biomembranes through direct or indirect relationships.

  12. Research progress of pharmacological activities and analytical methods for plant origin proteins.

    Science.gov (United States)

    Li, Chun-hong; Chen, Cen; Xia, Zhi-ning; Yang, Feng-qing

    2015-07-01

    As one of the important active components of traditional Chinese medicine (TCM), plant origin active proteins have many significant pharmacological functions. According to researches on the plant origin active proteins reported in recent years, pharmacological effects include anti-tumor, immune regulation, anti-oxidant, anti-pathogeny microorganism, anti-thrombus, as well as hypolipidemic and hypoglycemic activities of plant origin were reviewed, respectively. On the other hand, the analytical methods including chromatography, spectroscopy, electrophoresis and mass spectrometry for plant origin proteins analysis were also summarized. The main purpose of this paper is providing a reference for future development and application of plant active proteins.

  13. ROS-mediated redox signaling during cell differentiation in plants.

    Science.gov (United States)

    Schmidt, Romy; Schippers, Jos H M

    2015-08-01

    Reactive oxygen species (ROS) have emerged in recent years as important regulators of cell division and differentiation. The cellular redox state has a major impact on cell fate and multicellular organism development. However, the exact molecular mechanisms through which ROS manifest their regulation over cellular development are only starting to be understood in plants. ROS levels are constantly monitored and any change in the redox pool is rapidly sensed and responded upon. Different types of ROS cause specific oxidative modifications, providing the basic characteristics of a signaling molecule. Here we provide an overview of ROS sensors and signaling cascades that regulate transcriptional responses in plants to guide cellular differentiation and organ development. Although several redox sensors and cascades have been identified, they represent only a first glimpse on the impact that redox signaling has on plant development and growth. We provide an initial evaluation of ROS signaling cascades involved in cell differentiation in plants and identify potential avenues for future studies. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Production of therapeutic proteins through plant tissue and cell culture

    Directory of Open Access Journals (Sweden)

    Reza S. Gharelo

    2016-04-01

    Full Text Available Nowadays, pharmaceutical recombinant protein is increasingly used in treatment of many diseases such as hepatitis, anemia, diabetes and cancer. Different protein expression systems have been used for the expression of recombinant proteins in which each of them face obstacles that make utilizing them as comprehensive expression system in order to express wide variety of proteins difficult. Plant cell as a eukaryotic expression system have many advantages compared to other hosts. They are very "safe" and significantly decrease concerns about the contamination of recombinant proteins with human pathogens. In addition to this, plants as eukaryotic expression system perform proper post-translational modification, in case of eukaryotic proteins, and appropriate folding resulting in right function in biological environments. Therefore, the production of pharmaceutical protein through plant cells can be absolutely promising approach. In this review, the production of pharmaceutical protein in plant cells, advantages and disadvantages, offered methods and techniques for developing recombinant protein yields, and affective factors on the whole process of pharmaceutical protein expression in the molecular level will be reviewed.

  15. HMGA1: a master regulator of tumor progression in triple-negative breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Sandeep N Shah

    Full Text Available Emerging evidence suggests that tumor cells metastasize by co-opting stem cell transcriptional networks, although the molecular underpinnings of this process are poorly understood. Here, we show for the first time that the high mobility group A1 (HMGA1 gene drives metastatic progression in triple negative breast cancer cells (MDA-MB-231, Hs578T by reprogramming cancer cells to a stem-like state. Silencing HMGA1 expression in invasive, aggressive breast cancer cells dramatically halts cell growth and results in striking morphologic changes from mesenchymal-like, spindle-shaped cells to cuboidal, epithelial-like cells. Mesenchymal genes (Vimentin, Snail are repressed, while E-cadherin is induced in the knock-down cells. Silencing HMGA1 also blocks oncogenic properties, including proliferation, migration, invasion, and orthotopic tumorigenesis. Metastatic progression following mammary implantation is almost completely abrogated in the HMGA1 knock-down cells. Moreover, silencing HMGA1 inhibits the stem cell property of three-dimensional mammosphere formation, including primary, secondary, and tertiary spheres. In addition, knock-down of HMGA1 depletes cancer initiator/cancer stem cells and prevents tumorigenesis at limiting dilutions. We also discovered an HMGA1 signature in triple negative breast cancer cells that is highly enriched in embryonic stem cells. Together, these findings indicate that HMGA1 is a master regulator of tumor progression in breast cancer by reprogramming cancer cells through stem cell transcriptional networks. Future studies are needed to determine how to target HMGA1 in therapy.

  16. Novel functions of plant cyclin-dependent kinase inhibitors, ICK1/KRP1, can act non-cell-autonomously and inhibit entry into mitosis

    DEFF Research Database (Denmark)

    Weinl, Christina; Marquardt, Sebastian; Kuijt, Suzanne J H

    2005-01-01

    numbers of cells consistent with a function of CKIs in blocking the G1-S cell cycle transition. Here, we demonstrate that at least one inhibitor from Arabidopsis, ICK1/KRP1, can also block entry into mitosis but allows S-phase progression causing endoreplication. Our data suggest that plant CKIs act...... independently from ICK1/KRP1-induced endoreplication. Strikingly, we found that endoreplicated cells were able to reenter mitosis, emphasizing the high degree of flexibility of plant cells during development. Moreover, we show that in contrast with animal CDK inhibitors, ICK1/KRP1 can move between cells...

  17. 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.

  18. Patterns of expression of cell cycle/apoptosis genes along the spectrum of thyroid carcinoma progression

    NARCIS (Netherlands)

    B. Saltman; B. Singh; C.V. Hedvat; V.B. Wreesmann; R. Ghossein

    2006-01-01

    Background. Genetic screening studies suggest that genetic changes underlie progression from well differentiated, to anoplastic thyroid cancers. The aim of this study is to determine to what extent cell cycle/apoptosis regulators contribute to cancer progression. Methods. Tissue microarrarys (TMAs)

  19. Mitochondrial regulation of cell cycle progression through SLC25A43

    Energy Technology Data Exchange (ETDEWEB)

    Gabrielson, Marike; Reizer, Edwin [School of Health and Medical Sciences, Faculty of Medicine and Health, Örebro University, SE 70182 Örebro (Sweden); Stål, Olle [Department of Clinical and Experimental Medicine, Linköping University, SE 58185 Linköping (Sweden); Department of Oncology, Linköping University, SE 58185 Linköping (Sweden); Tina, Elisabet, E-mail: elisabet.tina@regionorebrolan.se [Department of Clinical Research Laboratory, Faculty of Medicine and Health, Örebro University, SE 70182 Örebro (Sweden)

    2016-01-22

    An increasing body of evidence is pointing towards mitochondrial regulation of the cell cycle. In a previous study of HER2-positive tumours we could demonstrate a common loss in the gene encoding for the mitochondrial transporter SLC25A43 and also a significant relation between SLC25A43 protein expression and S-phase fraction. Here, we investigated the consequence of suppressed SLC25A43 expression on cell cycle progression and proliferation in breast epithelial cells. In the present study, we suppressed SLC25A43 using siRNA in immortalised non-cancerous breast epithelial MCF10A cells and HER2-positive breast cancer cells BT-474. Viability, apoptosis, cell proliferation rate, cell cycle phase distribution, and nuclear Ki-67 and p21, were assessed by flow cytometry. Cell cycle related gene expressions were analysed using real-time PCR. We found that SLC25A43 knockdown in MCF10A cells significantly inhibited cell cycle progression during G{sub 1}-to-S transition, thus significantly reducing the proliferation rate and fraction of Ki-67 positive MCF10A cells. In contrast, suppressed SLC25A43 expression in BT-474 cells resulted in a significantly increased proliferation rate together with an enhanced G{sub 1}-to-S transition. This was reflected by an increased fraction of Ki-67 positive cells and reduced level of nuclear p21. In line with our previous results, we show a role for SLC25A43 as a regulator of cell cycle progression and proliferation through a putative mitochondrial checkpoint. These novel data further strengthen the connection between mitochondrial function and the cell cycle, both in non-malignant and in cancer cells. - Highlights: • Proposed cell cycle regulation through the mitochondrial transporter SLC25A43. • SLC25A43 alters cell proliferation rate and cell cycle progression. • Suppressed SLC25A43 influences transcription of cell cycle regulatory genes.

  20. Metabolism of fluoranthene in different plant cell cultures and intact plants

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, M.; Harms, H.

    2000-05-01

    The metabolism of fluoranthene was investigated in 11 cell cultures of different plant species using a [{sup 14}C]-labeled standard. Most species metabolized less than 5% of fluoranthene to soluble metabolites and formed less than 5% nonextractable residues during the standardized 48-h test procedure. Higher metabolic rates were observed in lettuce (Lactuca sativa, 6%), wheat (Tricitum aestivum, 9%), and tomato (Lycopersicon esculentum, 15%). A special high metabolic rate of nearly 50% was determined for the rose species Paul's Scarlet. Chromatographic analysis of metabolites extracted from aseptically grown tomato plants proved that the metabolites detected in the cell cultures were also formed in the intact plants. Metabolites produced in tomato and rose cells from [{sup 14}C]-fluoranthene were conjugated with glucose, glucuronic acid, and other cell components. After acid hydrolyses, the main metabolite of both species was 1-hydroxyfluoranthene as identified by gas chromatography-mass spectrometry and high-performance liquid chromatography with diode array detection. The second metabolite formed by both species was 8-hydroxyfluoranthene. A third metabolite in tomatoes was 3-hydroxyfluoranthene.

  1. Mast cells mediate neutrophil recruitment during atherosclerotic plaque progression

    NARCIS (Netherlands)

    Wezel, Anouk; Lagraauw, H Maxime; van der Velden, Daniël; de Jager, Saskia C A; Quax, Paul H A; Kuiper, Johan; Bot, Ilze

    2015-01-01

    AIMS: Activated mast cells have been identified in the intima and perivascular tissue of human atherosclerotic plaques. As mast cells have been described to release a number of chemokines that mediate leukocyte fluxes, we propose that activated mast cells may play a pivotal role in leukocyte recruit

  2. Recent progresses in stem cell research and hearing restoration

    Institute of Scientific and Technical Information of China (English)

    YANG Hua; CHEN Xiao-wei; GAO Zhi-qiang

    2008-01-01

    @@ Serious hearing and balance impairments can occur as a result of loss of hair cells related to aging, environmental stresses (such as noises exposure) or exposure to chemotherapeutic drugs(such as cisplatin and aminoglycoside antibiotics). Because a large portion of hearing impair-ment involves loss of hair cells, regeneration or replacement of these cells is a possible alternative to prosthetic devices1.

  3. Evolution of plant conducting cells: perspectives from key regulators of vascular cell differentiation.

    Science.gov (United States)

    Ohtani, Misato; Akiyoshi, Nobuhiro; Takenaka, Yuto; Sano, Ryosuke; Demura, Taku

    2017-01-01

    One crucial problem that plants faced during their evolution, particularly during the transition to growth on land, was how to transport water, nutrients, metabolites, and small signaling molecules within a large, multicellular body. As a solution to this problem, land plants developed specific tissues for conducting molecules, called water-conducting cells (WCCs) and food-conducting cells (FCCs). The well-developed WCCs and FCCs in extant plants are the tracheary elements and sieve elements, respectively, which are found in vascular plants. Recent molecular genetic studies revealed that transcriptional networks regulate the differentiation of tracheary and sieve elements, and that the networks governing WCC differentiation are largely conserved among land plant species. In this review, we discuss the molecular evolution of plant conducting cells. By focusing on the evolution of the key transcription factors that regulate vascular cell differentiation, the NAC transcription factor VASCULAR-RELATED NAC-DOMAIN for WCCs and the MYB-coiled-coil (CC)-type transcription factor ALTERED PHLOEM DEVELOPMENT for sieve elements, we describe how land plants evolved molecular systems to produce the specialized cells that function as WCCs and FCCs. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Local circadian clock gates cell cycle progression of transient amplifying cells during regenerative hair cycling.

    Science.gov (United States)

    Plikus, Maksim V; Vollmers, Christopher; de la Cruz, Damon; Chaix, Amandine; Ramos, Raul; Panda, Satchidananda; Chuong, Cheng-Ming

    2013-06-04

    Regenerative cycling of hair follicles offers an unique opportunity to explore the role of circadian clock in physiological tissue regeneration. We focused on the role of circadian clock in actively proliferating transient amplifying cells, as opposed to quiescent stem cells. We identified two key sites of peripheral circadian clock activity specific to regenerating anagen hair follicles, namely epithelial matrix and mesenchymal dermal papilla. We showed that peripheral circadian clock in epithelial matrix cells generates prominent daily mitotic rhythm. As a consequence of this mitotic rhythmicity, hairs grow faster in the morning than in the evening. Because cells are the most susceptible to DNA damage during mitosis, this cycle leads to a remarkable time-of-day-dependent sensitivity of growing hair follicles to genotoxic stress. Same doses of γ-radiation caused dramatic hair loss in wild-type mice when administered in the morning, during mitotic peak, compared with the evening, when hair loss is minimal. This diurnal radioprotective effect becomes lost in circadian mutants, consistent with asynchronous mitoses in their hair follicles. Clock coordinates cell cycle progression with genotoxic stress responses by synchronizing Cdc2/Cyclin B-mediated G2/M checkpoint. Our results uncover diurnal mitotic gating as the essential protective mechanism in highly proliferative hair follicles and offer strategies for minimizing or maximizing cytotoxicity of radiation therapies.

  5. Improving human reliability through better nuclear power plant system design: Program for advanced nuclear power studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Golay, M.W.

    1993-10-10

    The project on ``Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performance`` was been undertaken in order to address the problem of human error in advanced nuclear power plant designs. Lack of a mature theory has retarded progress in reducing likely frequencies of human errors. Work being pursued in this project is to perform a set of experiments involving human subjects who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants, which are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds.

  6. MMP13 mediates cell cycle progression in melanocytes and melanoma cells: in vitro studies of migration and proliferation.

    NARCIS (Netherlands)

    Meierjohann, S.; Hufnagel, A.; Wende, E.; Kleinschmidt, M.A.; Wolf, K. van der; Friedl, P.H.A.; Gaubatz, S.; Schartl, M.

    2010-01-01

    BACKGROUND: Melanoma cells are usually characterized by a strong proliferative potential and efficient invasive migration. Among the multiple molecular changes that are recorded during progression of this disease, aberrant activation of receptor tyrosine kinases (RTK) is often observed. Activation o

  7. Can plant oncogenes inhibit programmed cell death? The rolB oncogene reduces apoptosis-like symptoms in transformed plant cells.

    Science.gov (United States)

    Gorpenchenko, Tatiana Y; Aminin, Dmitry L; Vereshchagina, Yuliya V; Shkryl, Yuri N; Veremeichik, Galina N; Tchernoded, Galina K; Bulgakov, Victor P

    2012-09-01

    The rolB oncogene was previously identified as an important player in ROS metabolism in transformed plant cells. Numerous reports indicate a crucial role for animal oncogenes in apoptotic cell death. Whether plant oncogenes such as rolB can induce programmed cell death (PCD) in transformed plant cells is of particular importance. In this investigation, we used a single-cell assay based on confocal microscopy and fluorescent dyes capable of discriminating between apoptotic and necrotic cells. Our results indicate that the expression of rolB in plant cells was sufficient to decrease the proportion of apoptotic cells in steady-state conditions and diminish the rate of apoptotic cells during induced PCD. These data suggest that plant oncogenes, like animal oncogenes, may be involved in the processes mediating PCD.

  8. Mesenchymal Stem Cell Therapy in Diabetes Mellitus: Progress and Challenges

    Directory of Open Access Journals (Sweden)

    Nagwa El-Badri

    2013-01-01

    Full Text Available Advanced type 2 diabetes mellitus is associated with significant morbidity and mortality due to cardiovascular, nervous, and renal complications. Attempts to cure diabetes mellitus using islet transplantation have been successful in providing a source for insulin secreting cells. However, limited donors, graft rejection, the need for continued immune suppression, and exhaustion of the donor cell pool prompted the search for a more sustained source of insulin secreting cells. Stem cell therapy is a promising alternative for islet transplantation in type 2 diabetic patients who fail to control hyperglycemia even with insulin injection. Autologous stem cell transplantation may provide the best outcome for those patients, since autologous cells are readily available and do not entail prolonged hospital stays or sustained immunotoxic therapy. Among autologous adult stem cells, mesenchymal stem cells (MSCs therapy has been applied with varying degrees of success in both animal models and in clinical trials. This review will focus on the advantages of MSCs over other types of stem cells and the possible mechanisms by which MSCs transplant restores normoglycemia in type 2 diabetic patients. Sources of MSCs including autologous cells from diabetic patients and the use of various differentiation protocols in relation to best transplant outcome will be discussed.

  9. Hydrogen peroxide homeostasis and signaling in plant cells

    Institute of Scientific and Technical Information of China (English)

    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.

  10. Progress in spondylarthritis immunopathogenesis of spondyloarthritis: which cells drive disease?

    OpenAIRE

    2009-01-01

    Spondyloarthritides, or SpA, form a cluster of chronic inflammatory diseases with the axial skeleton as the most typical disease localisation, although extra-articular manifestations such as intestinal inflammation may frequently occur during the course of the disease. This review summarises recent progress in our understanding of the immunopathogenesis of SpA with special emphasis on the cellular constituents considered to be responsible for the initiation and/or perpetuation of inflammation...

  11. Andrographolide Ameliorates Abdominal Aortic Aneurysm Progression by Inhibiting Inflammatory Cell Infiltration through Downregulation of Cytokine and Integrin Expression.

    Science.gov (United States)

    Ren, Jun; Liu, Zhenjie; Wang, Qiwei; Giles, Jasmine; Greenberg, Jason; Sheibani, Nader; Kent, K Craig; Liu, Bo

    2016-01-01

    Abdominal aortic aneurysm (AAA), characterized by exuberant inflammation and tissue deterioration, is a common aortic disease associated with a high mortality rate. There is currently no established pharmacological therapy to treat this progressive disease. Andrographolide (Andro), a major bioactive component of the herbaceous plant Andrographis paniculata, has been found to exhibit potent anti-inflammatory properties by inhibiting nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activity in several disease models. In this study, we investigated the ability of Andro to suppress inflammation associated with aneurysms, and whether it may be used to block the progression of AAA. Whereas diseased aortae continued to expand in the solvent-treated group, daily administration of Andro to mice with small aneurysms significantly attenuated aneurysm growth, as measured by the diminished expansion of aortic diameter (165.68 ± 15.85% vs. 90.62 ± 22.91%, P Andro decreased infiltration of monocytes/macrophages and T cells. Mechanistically, Andro inhibited arterial NF-κB activation and reduced the production of proinflammatory cytokines [CCL2, CXCL10, tumor necrosis factor α, and interferon-γ] in the treated aortae. Furthermore, Andro suppressed α4 integrin expression and attenuated the ability of monocytes/macrophages to adhere to activated endothelial cells. These results indicate that Andro suppresses progression of AAA, likely through inhibition of inflammatory cell infiltration via downregulation of NF-κB-mediated cytokine production and α4 integrin expression. Thus, Andro may offer a pharmacological therapy to slow disease progression in patients with small aneurysms.

  12. Molecular aspects of allergic contact dermatitis to plants. Recent progress in phytodermatochemistry.

    Science.gov (United States)

    Benezra, C; Ducombs, G

    1987-01-01

    A classification of plants based on the chemical structures of their skin sensitizers is presented. A whole range of chemical structures of contact sensitizers exists in plants containing sesquiterpene lactones (Compositae, Frullania, Lauraceae etc.), tulipalin (Tulipa, Alstroemeria etc.), quinones (Primula and tropical woods), long chain phenols (Anacardiaceae, Ginkgoaceae) and miscellaneous structures such as aldehydes, ketones, terpene hydrocarbons etc. Knowledge of allergens in various plants allows prediction of cross-reactivity.

  13. [Research progress of chemistry and anti-cancer activities of natural products from Chinese Garcinia plants].

    Science.gov (United States)

    Fu, Wen-Wei; Tan, Hong-Sheng; Xu, Hong-Xi

    2014-02-01

    Garcinia plants are one of the rich sources of natural xanthones and benzophenones which have attracted a great deal of attention from the scientists in the fields of chemistry and pharmacology. Recently, many structurally unique constituents with various bioactivities, especially anti-tumor activity, have been isolated from Garcinia plants. This concise review focused on the anti-cancer activity natural products isolated from Chinese Garcinia plants, and the research finding by authors and collaborators over the past several years were cited.

  14. Cell physiology of plants growing in cold environments.

    Science.gov (United States)

    Lütz, Cornelius

    2010-08-01

    The life of plants growing in cold extreme environments has been well investigated in terms of morphological, anatomical, and ecophysiological adaptations. In contrast, long-term cellular or metabolic studies have been performed by only a few groups. Moreover, a number of single reports exist, which often represent just a glimpse of plant behavior. The review draws together the literature which has focused on tissue and cellular adaptations mainly to low temperatures and high light. Most studies have been done with European alpine plants; comparably well studied are only two phanerogams found in the coastal Antarctic. Plant adaptation in northern polar regions has always been of interest in terms of ecophysiology and plant propagation, but nowadays, this interest extends to the effects of global warming. More recently, metabolic and cellular investigations have included cold and UV resistance mechanisms. Low-temperature stress resistance in plants from cold environments reflects the climate conditions at the growth sites. It is now a matter of molecular analyses to find the induced genes and their products such as chaperones or dehydrins responsible for this resistance. Development of plants under snow or pollen tube growth at 0 degrees C shows that cell biology is needed to explain the stability and function of the cytoskeleton. Many results in this field are based on laboratory studies, but several publications show that it is not difficult to study cellular mechanisms with the plants adapted to a natural stress. Studies on high light and UV loads may be split in two parts. Many reports describe natural UV as harmful for the plants, but these studies were mainly conducted by shielding off natural UV (as controls). Other experiments apply additional UV in the field and have had practically no negative impact on metabolism. The latter group is supported by the observations that green overwintering plants increase their flavonoids under snow even in the absence of

  15. Myelin restoration: progress and prospects for human cell replacement therapies.

    Science.gov (United States)

    Potter, Gregory B; Rowitch, David H; Petryniak, Magdalena A

    2011-06-01

    Oligodendrocytes are the primary source of myelin in the adult central nervous system (CNS), and their dysfunction or loss underlies several diseases of both children and adults. Dysmyelinating and demyelinating diseases are thus attractive targets for cell-based strategies since replacement of a single presumably homogeneous cell type has the potential to restore functional levels of myelin. To understand the obstacles that cell-replacement therapy might face, we review oligodendrocyte biology and emphasize aspects of oligodendrocyte development that will need to be recapitulated by exogenously transplanted cells, including migration from the site of transplantation, axon recognition, terminal differentiation, axon wrapping, and myelin production and maintenance. We summarize studies in which different types of myelin-forming cells have been transplanted into the CNS and highlight the continuing challenges regarding the use of cell-based therapies for human white matter disorders.

  16. Recent progress in stability of perovskite solar cells

    Science.gov (United States)

    Qin, Xiaojun; Zhao, Zhiguo; Wang, Yidan; Wu, Junbo; Jiang, Qi; You, Jingbi

    2017-01-01

    Perovskite solar cells have attracted significant attention in just the past few years in solar cell research fields, where the power conversion efficiency was beyond 22.1%. Now, the most important challenge for perovskite solar cells in practical applications is the stability issue. In this mini-review, we will summarize the degradation mechanism of perovskite solar cells, including the perovskite material itself and also the interfaces. While we also provide our opinion on improving the stability of perovskite solar cells. Project supported by China Huaneng Group Project High Performance Perovskite Solar Cells (No. TW-15-HJK01), the National Key Research and Development Program of China (No. 2016YFB0700700), the National 1000 Young Talent Awards, and the National Natural Science Foundation of China (No. 61574133).

  17. Recent progress of dopant-free organic hole-transporting materials in perovskite solar cells

    Science.gov (United States)

    Dongxue, Liu; Liu, Yongsheng

    2017-01-01

    Organic–inorganic hybrid perovskite solar cells have undergone especially intense research and transformation over the past seven years due to their enormous progress in conversion efficiencies. In this perspective, we review the latest developments of conventional perovskite solar cells with a main focus on dopant-free organic hole transporting materials (HTMs). Regarding the rapid progress of perovskite solar cells, stability of devices using dopant-free HTMs are also discussed to help readers understand the challenges and opportunities in high performance and stable perovskite solar cells. Project supported by the Scientific Research Starting Foundation for Overseas Introduced Talents of College of Chemistry, Nankai University.

  18. Recent progress on quantum dot solar cells: a review

    Science.gov (United States)

    Sogabe, Tomah; Shen, Qing; Yamaguchi, Koichi

    2016-10-01

    Semiconductor quantum dots (QDs) have a potential to increase the power conversion efficiency in photovoltaic operation because of the enhancement of photoexcitation. Recent advances in self-assembled QD solar cells (QDSCs) and colloidal QDSCs are reviewed, with a focus on understanding carrier dynamics. For intermediate-band solar cells using self-assembled QDs, suppression of a reduction of open circuit voltage presents challenges for further efficiency improvement. This reduction mechanism is discussed based on recent reports. In QD sensitized cells and QD heterojunction cells using colloidal QDs well-controlled heterointerface and surface passivation are key issues for enhancement of photovoltaic performances. The improved performances of colloidal QDSCs are presented.

  19. Plant Phosphoglycerolipids: The Gatekeepers of Vascular Cell Differentiation.

    Science.gov (United States)

    Gujas, Bojan; Rodriguez-Villalon, Antia

    2016-01-01

    In higher plants, the plant vascular system has evolved as an inter-organ communication network essential to deliver a wide range of signaling factors among distantly separated organs. To become conductive elements, phloem and xylem cells undergo a drastic differentiation program that involves the degradation of the majority of their organelles. While the molecular mechanisms regulating such complex process remain poorly understood, it is nowadays clear that phosphoglycerolipids display a pivotal role in the regulation of vascular tissue formation. In animal cells, this class of lipids is known to mediate acute responses as signal transducers and also act as constitutive signals that help defining organelle identity. Their rapid turnover, asymmetrical distribution across subcellular compartments as well as their ability to rearrange cytoskeleton fibers make phosphoglycerolipids excellent candidates to regulate complex morphogenetic processes such as vascular differentiation. Therefore, in this review we aim to summarize, emphasize and connect our current understanding about the involvement of phosphoglycerolipids in phloem and xylem differentiation.

  20. Plant phosphoglycerolipids: the gatekeepers of vascular cell differentiation

    Directory of Open Access Journals (Sweden)

    Bojan eGujas

    2016-02-01

    Full Text Available In higher plants, the plant vascular system has evolved as an inter-organ communication network essential to deliver a wide range of signaling factors among distantly separated organs. To become conductive elements, phloem and xylem cells undergo a drastic differentiation program that involves the degradation of the majority of their organelles. While the molecular mechanisms regulating such complex process remain poorly understood, it is nowadays clear that phosphoglycerolipids display a pivotal role in the regulation of vascular formation. In animal cells, this class of lipids is known to mediate acute responses as signal transducers and also act as constitutive signals that help defining organelle identity. Their rapid turnover, asymmetrical distribution across subcellular compartments as well as their ability to rearrange cytoskeleton fibers make phosphoglycerolipids excellent candidates to regulate complex morphogenetic processes such as vascular differentiation. Therefore, in this review we aim to summarize, emphasize and connect our current understanding about the involvement of phosphoglycerolipids in phloem and xylem differentiation.

  1. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

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

  2. 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.

  3. Host cell modulation by human, animal and plant pathogens.

    Science.gov (United States)

    Andersson, Siv G E; Kempf, Volkhard A J

    2004-04-01

    Members of the alpha-proteobacteria display a broad range of interactions with higher eukaryotes. Some are pathogens of humans, such as Rickettsia and Bartonella that are associated with diseases like epidemic typhus, trench fever, cat scratch disease and bacillary angiomatosis. Others like the Brucella cause abortions in pregnant animals. Yet other species have evolved elaborate interactions with plants; in this group we find both plant symbionts and parasites. Despite radically different host preferences, extreme genome size variations and the absence of toxin genes, similarities in survival strategies and host cell interactions can be recognized among members of the alpha-proteobacteria. Here, we review some of these similarities, with a focus on strategies for modulation of the host target cell.

  4. 天然植物单体抗结肠癌 SW480细胞活性的研究进展%Research Progress of the Antitumor Activity of Monomer from Natural Plant for Human SW480 Colon Cancer Cells in Vitro

    Institute of Scientific and Technical Information of China (English)

    肖忠华; 李晶; 黄海兵; 苗加伟; 李毓强

    2015-01-01

    Human colon cancer is one of the most common malignant tumors. The current treatment of chemical drugs still has serious side effects and toxicity, therefore, it is very urgent to develop drugs with low side effects and toxicity for colon cancer patients. Enriched with active ingredients, Chinese herbal medicine becomes an important resource to screen anti-cancer drugs. Compounds of polyphenols, glycoside, organic sulfide and isoprenoids from natural plants are mark-edly characterized by their antitumor activities in vitro for human SW480 colon cancer cells, by killing tumor cells directly, blocking the cell cycle, affecting the gene expression and apoptosis signal pathways and induction of cell differentiation. This article makes a brief summary of monomers in anti-activity of SW480 cells from natural plant.%结肠癌是临床上常见的恶性肿瘤,当前的化学药物治疗仍具有严重的毒、副作用,开发毒性低、副作用小的抗结肠癌药物的任务十分迫切。中草药的有效活性成分是筛选抗癌药物的重要来源,从天然植物中提取的多酚类、苷类、有机硫化物及异戊二烯类等物质可通过直接杀伤肿瘤细胞、阻滞细胞周期、影响基因表达、作用于凋亡信号传导途径和诱导细胞分化等机制在体外表现出显著的抑制人结肠癌 SW480细胞生长的活性。本文综述了近年来发现的具有体外抗 SW480细胞活性的天然植物单体。

  5. Research progress of plant receptor like kinase CR4%植物受体样激酶CR4家族

    Institute of Scientific and Technical Information of China (English)

    姚清国; 肖颖; 魏青; 崔文广; 于宏伟

    2011-01-01

    Receptor like kinases play important roles in the development of plants.CRINKLY4 (CR4) is a growth factor-like plant receptor kinase including ZmCR4 in Zea mays, ACR4 in Arabidopsis and OsCR4 in rice.They exert a great influence on a wide array of developmental processes including plant cell proliferation and differentiation, cell fate and pattern.ZmCR4 affects the pattern leaf epidermis and in the aleurone of the endosperm.ACR4 promots formative cell divisions in the pericycle and controls in the number of the division cells when organogenesis has been started.This paper summarized the research progress of CR4 family.%受体样激酶在植物的生长发肯中发挥着重要的功能.CRINKLY4(简称CR4)属于生长因子类的受体激酶,包括玉米中的ZmCR4、拟南芥中的ACR4和水稻中的OsCR4,参与了植物细胞的增殖和分化,包括细胞分化命运和发育方向.ZmCR4影响了玉米表皮细胞的形态和糊粉层的发育,ACR4启动拟南芥根中形成层细胞的分化,而且器官发生开始后可以控制细胞分化的数目.本文对植物受体样激酶CR4家族近年的研究进展进行了总结.

  6. SON controls cell-cycle progression by coordinated regulation of RNA splicing.

    Science.gov (United States)

    Ahn, Eun-Young; DeKelver, Russell C; Lo, Miao-Chia; Nguyen, Tuyet Ann; Matsuura, Shinobu; Boyapati, Anita; Pandit, Shatakshi; Fu, Xiang-Dong; Zhang, Dong-Er

    2011-04-22

    It has been suspected that cell-cycle progression might be functionally coupled with RNA processing. However, little is known about the role of the precise splicing control in cell-cycle progression. Here, we report that SON, a large Ser/Arg (SR)-related protein, is a splicing cofactor contributing to efficient splicing of cell-cycle regulators. Downregulation of SON leads to severe impairment of spindle pole separation, microtubule dynamics, and genome integrity. These molecular defects result from inadequate RNA splicing of a specific set of cell-cycle-related genes that possess weak splice sites. Furthermore, we show that SON facilitates the interaction of SR proteins with RNA polymerase II and other key spliceosome components, suggesting its function in efficient cotranscriptional RNA processing. These results reveal a mechanism for controlling cell-cycle progression through SON-dependent constitutive splicing at suboptimal splice sites, with strong implications for its role in cancer and other human diseases.

  7. Regulation of polyamine synthesis in plants. Final progress report, July 1, 1991--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Malmberg, R.L.

    1995-07-01

    This research focused on unusual post-translational modifications occuring in a arginine decarboxylase cDNA clone in oats. A novel regulatory mechanism for polyamines was explored and an attempt was made to characterize it. A plant ornithine decarboxylase cDNA was identified in Arabidopsis. Further work remains on the mechanisms of polyamine regulation and function in plants.

  8. Vacuolar processing enzyme in plant programmed cell death

    Directory of Open Access Journals (Sweden)

    Noriyuki eHatsugai

    2015-04-01

    Full Text Available Vacuolar processing enzyme (VPE is a cysteine proteinase originally identified as the proteinase responsible for the maturation and activation of vacuolar proteins in plants, and it is known to be an orthologue of animal asparaginyl endopeptidase (AEP/VPE/legumain. VPE has been shown to exhibit enzymatic properties similar to that of caspase 1, which is a cysteine protease that mediates the programmed cell death (PCD pathway in animals. Although there is limited sequence identity between VPE and caspase 1, their predicted three-dimensional structures revealed that the essential amino-acid residues for these enzymes form similar pockets for the substrate peptide YVAD. In contrast to the cytosolic localization of caspases, VPE is localized in vacuoles. VPE provokes vacuolar rupture, initiating the proteolytic cascade leading to PCD in the plant immune response. It has become apparent that the VPE-dependent PCD pathway is involved not only in the immune response, but also in the responses to a variety of stress inducers and in the development of various tissues. This review summarizes the current knowledge on the contribution of VPE to plant PCD and its role in vacuole-mediated cell death, and it also compares VPE with the animal cell death executor caspase 1.

  9. 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.

  10. Conservation and sustainable use of medicinal plants: problems, progress, and prospects.

    Science.gov (United States)

    Chen, Shi-Lin; Yu, Hua; Luo, Hong-Mei; Wu, Qiong; Li, Chun-Fang; Steinmetz, André

    2016-01-01

    Medicinal plants are globally valuable sources of herbal products, and they are disappearing at a high speed. This article reviews global trends, developments and prospects for the strategies and methodologies concerning the conservation and sustainable use of medicinal plant resources to provide a reliable reference for the conservation and sustainable use of medicinal plants. We emphasized that both conservation strategies (e.g. in situ and ex situ conservation and cultivation practices) and resource management (e.g. good agricultural practices and sustainable use solutions) should be adequately taken into account for the sustainable use of medicinal plant resources. We recommend that biotechnical approaches (e.g. tissue culture, micropropagation, synthetic seed technology, and molecular marker-based approaches) should be applied to improve yield and modify the potency of medicinal plants.

  11. 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.

  12. 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.

  13. Recent Progress Towards Quantum Dot Solar Cells with Enhanced Optical Absorption

    OpenAIRE

    Zheng, Zerui; Ji, Haining; Yu, Peng; Wang, Zhiming

    2016-01-01

    Quantum dot solar cells, as a promising candidate for the next generation solar cell technology, have received tremendous attention in the last 10 years. Some recent developments in epitaxy growth and device structures have opened up new avenues for practical quantum dot solar cells. Unfortunately, the performance of quantum dot solar cells is often plagued by marginal photon absorption. In this review, we focus on the recent progress made in enhancing optical absorption in quantum dot solar ...

  14. Human POLD1 modulates cell cycle progression and DNA damage repair

    OpenAIRE

    Song, Jing; Hong, Ping; Liu, Chengeng; Zhang, Yueqi; Wang, Jinling; Wang, Peichang

    2015-01-01

    Background The activity of eukaryotic DNA polymerase delta (Pol ?) plays an essential role in genome stability through its effects on DNA replication and repair. The p125 catalytic subunit of Pol ? is encoded by POLD1 gene in human cells. To clarify biological functions of POLD1, we investigated the effects of POLD1 overexpression or downregulation on cell proliferation, cell cycle progression, DNA synthesis and oxidative DNA damage induced by H2O2. Methods HEK293 cells were transfected with ...

  15. [Research progress in chemical communication among insect-resistant genetically modified plants, insect pests and natural enemies].

    Science.gov (United States)

    Liu, Qing-Song; Li, Yun-He; Chen, Xiu-Ping; Peng, Yu-Fa

    2014-08-01

    Semiochemicals released by plants or insects play an important role in the communication among plants, phytophagous insects and their natural enemies. They thus form a chemical information network which regulates intra- and inter-specific behaviors and sustains the composition and structure of plant and insect communities. The application of insect-resistant genetically modified (IRGM) crops may affect the chemical communication within and among the tritrophic levels, and thus cause disturbances to the biotic community structure and the stability of the farmland ecosystem. This has raised concerns about the environmental safety of IRGM crops and triggered research worldwide. In the current article we provided a brief summary of the chemical communication among plants, herbivores and natural enemies; analyzed the potential of IRGM crops to affect the chemical communication between plants and arthropods and the related mechanisms; and discussed the current research progress and the future prospects in this field. We hope that this will promote the research in this field by Chinese scientists and increase our understanding of the potential effects of growing of IRGM crops on the arthropod community structure.

  16. Apoptotic cell signaling in cancer progression and therapy.

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2011-04-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the development and maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Impairment of this native defense mechanism promotes aberrant cellular proliferation and the accumulation of genetic defects, ultimately resulting in tumorigenesis, and frequently confers drug resistance to cancer cells. The regulation of apoptosis at several levels is essential to maintain the delicate balance between cellular survival and death signaling that is required to prevent disease. Complex networks of signaling pathways act to promote or inhibit apoptosis in response to various cues. Apoptosis can be triggered by signals from within the cell, such as genotoxic stress, or by extrinsic signals, such as the binding of ligands to cell surface death receptors. Various upstream signaling pathways can modulate apoptosis by converging on, and thereby altering the activity of, common central control points within the apoptotic signaling pathways, which involve the BCL-2 family proteins, inhibitor of apoptosis (IAP) proteins, and FLICE-inhibitory protein (c-FLIP). This review highlights the role of these fundamental regulators of apoptosis in the context of both normal apoptotic signaling mechanisms and dysregulated apoptotic pathways that can render cancer cells resistant to cell death. In addition, therapeutic strategies aimed at modulating the activity of BCL-2 family proteins, IAPs, and c-FLIP for the targeted induction of apoptosis are briefly discussed.

  17. Apoptotic cell signaling in cancer progression and therapy†

    Science.gov (United States)

    Plati, Jessica; Bucur, Octavian; Khosravi-Far, Roya

    2011-01-01

    Apoptosis is a tightly regulated cell suicide program that plays an essential role in the development and maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Impairment of this native defense mechanism promotes aberrant cellular proliferation and the accumulation of genetic defects, ultimately resulting in tumorigenesis, and frequently confers drug resistance to cancer cells. The regulation of apoptosis at several levels is essential to maintain the delicate balance between cellular survival and death signaling that is required to prevent disease. Complex networks of signaling pathways act to promote or inhibit apoptosis in response to various cues. Apoptosis can be triggered by signals from within the cell, such as genotoxic stress, or by extrinsic signals, such as the binding of ligands to cell surface death receptors. Various upstream signaling pathways can modulate apoptosis by converging on, and thereby altering the activity of, common central control points within the apoptotic signaling pathways, which involve the BCL-2 family proteins, inhibitor of apoptosis (IAP) proteins, and FLICE-inhibitory protein (c-FLIP). This review highlights the role of these fundamental regulators of apoptosis in the context of both normal apoptotic signaling mechanisms and dysregulated apoptotic pathways that can render cancer cells resistant to cell death. In addition, therapeutic strategies aimed at modulating the activity of BCL-2 family proteins, IAPs, and c-FLIP for the targeted induction of apoptosis are briefly discussed. PMID:21340093

  18. Progress on the Electrolytes for Dye-sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results The development of a new type of solar cell has been promoted by public concern about pollution and energy consumption.Since the prototype of a dye-sensitized solar cell (DSC) was reported in 1991 by M.Gratzel,it has aroused intensive interest over the past decade due to its low cost and simple preparation procedure.The typical cell is a sandwiched structure consisting of a dye-sensitized TiO2 electrode,a platinized counter electrode and a filled redox couple electrolyte between the electrodes...

  19. Mammalian cryptochromes impinge on cell cycle progression in a circadian clock-independent manner.

    Science.gov (United States)

    Destici, Eugin; Oklejewicz, Małgorzata; Saito, Shoko; van der Horst, Gijsbertus T J

    2011-11-01

    By gating cell cycle progression to specific times of the day, the intracellular circadian clock is thought to reduce the exposure of replicating cells to potentially hazardous environmental and endogenous genotoxic compounds. Although core clock gene defects that eradicate circadian rhythmicity can cause an altered in vivo genotoxic stress response and aberrant proliferation rate, it remains to be determined to what extent these cell cycle related phenotypes are due to a cell-autonomous lack of circadian oscillations. We investigated the DNA damage sensitivity and proliferative capacity of cultured primary Cry1(-/- )|Cry2(-/-) fibroblasts. Contrasting previous in vivo studies, we show that the absence of CRY proteins does not affect the cell-autonomous DNA damage response upon exposure of primary cells in vitro to genotoxic agents, but causes cells to proliferate faster. By comparing primary wild-type, Cry1(-/-) |Cry2(-/-), Cry1(+/-)|Cry2(-/-) and Cry1(-/-)|Cry2(+/-) fibroblasts, we provide evidence that CRY proteins influence cell cycle progression in a cell-autonomous, but circadian clock-independent manner and that the accelerated cell cycle progression of Cry-deficient cells is caused by global dysregulation of Bmal1-dependent gene expression. These results suggest that the inconsistency between in vivo and in vitro observations might be attributed to systemic circadian control rather than a direct cell-autonomous control.

  20. How to let go: pectin and plant cell adhesion

    Science.gov (United States)

    Daher, Firas Bou; Braybrook, Siobhan A.

    2015-01-01

    Plant cells do not, in general, migrate. They maintain a fixed position relative to their neighbors, intimately linked through growth and differentiation. The mediator of this connection, the pectin-rich middle lamella, is deposited during cell division and maintained throughout the cell’s life to protect tissue integrity. The maintenance of adhesion requires cell wall modification and is dependent on the actin cytoskeleton. There are developmental processes that require cell separation, such as organ abscission, dehiscence, and ripening. In these instances, the pectin-rich middle lamella must be actively altered to allow cell separation, a process which also requires cell wall modification. In this review, we will focus on the role of pectin and its modification in cell adhesion and separation. Recent insights gained in pectin gel mechanics will be discussed in relation to existing knowledge of pectin chemistry as it relates to cell adhesion. As a whole, we hope to begin defining the physical mechanisms behind a cells’ ability to hang on, and how it lets go. PMID:26236321

  1. How to let go: pectin and plant cell adhesion

    Directory of Open Access Journals (Sweden)

    Firas eBou Daher

    2015-07-01

    Full Text Available Plant cells do not, in general, migrate. They maintain a fixed position relative to their neighbours, intimately linked through growth and differentiation. The mediator of this connection, the pectin-rich middle lamella, is deposited during cell division and maintained throughout the cell’s life to protect tissue integrity. The maintenance of adhesion requires cell wall modification and is dependent on the actin cytoskeleton. There are developmental processes that require cell separation, such as organ abscission, dehiscence, and ripening. In these instances, the pectin-rich middle lamella must be actively altered to allow cell separation, a process which also requires cell wall modification. In this review, we will focus on the role of pectin and its modification in cell adhesion and separation. Recent insights gained in pectin gel mechanics will be discussed in relation to existing knowledge of pectin chemistry as it relates to cell adhesion. As a whole, we hope to begin defining the physical mechanisms behind a cells’ ability to hang on, and how it lets go.

  2. Integrating cell biology and proteomic approaches in plants.

    Science.gov (United States)

    Takáč, Tomáš; Šamajová, Olga; Šamaj, Jozef

    2017-04-22

    Significant improvements of protein extraction, separation, mass spectrometry and bioinformatics nurtured advancements of proteomics during the past years. The usefulness of proteomics in the investigation of biological problems can be enhanced by integration with other experimental methods from cell biology, genetics, biochemistry, pharmacology, molecular biology and other omics approaches including transcriptomics and metabolomics. This review aims to summarize current trends integrating cell biology and proteomics in plant science. Cell biology approaches are most frequently used in proteomic studies investigating subcellular and developmental proteomes, however, they were also employed in proteomic studies exploring abiotic and biotic stress responses, vesicular transport, cytoskeleton and protein posttranslational modifications. They are used either for detailed cellular or ultrastructural characterization of the object subjected to proteomic study, validation of proteomic results or to expand proteomic data. In this respect, a broad spectrum of methods is employed to support proteomic studies including ultrastructural electron microscopy studies, histochemical staining, immunochemical localization, in vivo imaging of fluorescently tagged proteins and visualization of protein-protein interactions. Thus, cell biological observations on fixed or living cell compartments, cells, tissues and organs are feasible, and in some cases fundamental for the validation and complementation of proteomic data. Validation of proteomic data by independent experimental methods requires development of new complementary approaches. Benefits of cell biology methods and techniques are not sufficiently highlighted in current proteomic studies. This encouraged us to review most popular cell biology methods used in proteomic studies and to evaluate their relevance and potential for proteomic data validation and enrichment of purely proteomic analyses. We also provide examples of

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

    Science.gov (United States)

    Tucker, Matthew R; Koltunow, Anna M G

    2014-02-01

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

  4. Stem cell models of Alzheimers disease: progress and challenges

    National Research Council Canada - National Science Library

    Charles Arber; Christopher Lovejoy; Selina Wray

    2017-01-01

    .... Induced pluripotent stem cell (iPSC) technology, together with advances in 2D and 3D neuronal differentiation, offers a unique opportunity to overcome this challenge and generate a limitless supply of human neurons for in vitro studies...

  5. Research progresses in the pathogenesis of anaplastic large cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    Xiao-Lan Shi; Xiao-Wen Tang; De-Pei Wu

    2011-01-01

    Anaplastic large cell lymphoma (ALCL) is a distinct subset of T-cell non-Hodgkin's lymphoma. As a consequence of its low incidence, general pathogenic consideration of ALCL is lacking. In this review, we summarize the pathogenesis, epidemiology, clinical manifestations, and treatment of ALCL, so as to better understand key stages of the development of this disease and provide valuable information for future treatment.

  6. Dendritic cell targeted vaccines: Recent progresses and challenges.

    Science.gov (United States)

    Chen, Pengfei; Liu, Xinsheng; Sun, Yuefeng; Zhou, Peng; Wang, Yonglu; Zhang, Yongguang

    2016-03-01

    Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches.

  7. A mixture of peptides and sugars derived from plant cell walls increases plant defense responses to stress and attenuates ageing-associated molecular changes in cultured skin cells.

    Science.gov (United States)

    Apone, Fabio; Tito, Annalisa; Carola, Antonietta; Arciello, Stefania; Tortora, Assunta; Filippini, Lucio; Monoli, Irene; Cucchiara, Mirna; Gibertoni, Simone; Chrispeels, Maarten J; Colucci, Gabriella

    2010-02-15

    Small peptides and aminoacid derivatives have been extensively studied for their effect of inducing plant defense responses, and thus increasing plant tolerance to a wide range of abiotic stresses. Similarly to plants, these compounds can activate different signaling pathways in mammalian skin cells as well, leading to the up-regulation of anti-aging specific genes. This suggests the existence of analogous defense response mechanisms, well conserved both in plants and animal cells. In this article, we describe the preparation of a new mixture of peptides and sugars derived from the chemical and enzymatic digestion of plant cell wall glycoproteins. We investigate the multiple roles of this product as potential "biostimulator" to protect plants from abiotic stresses, and also as potential cosmeceutical. In particular, the molecular effects of the peptide/sugar mixture of inducing plant defense responsive genes and protecting cultured skin cells from oxidative burst damages were deeply evaluated.

  8. 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.

  9. Accelerating progress toward operational excellence of fossil energy plants with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Zitney, S.; Liese, E.; Mahapatra, P.; Turton, R. Bhattacharyya, D.

    2012-01-01

    To address challenges in attaining operational excellence for clean energy plants, the National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training And Research (AVESTARTM). The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This paper will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of an integrated gasification combined cycle power plant (IGCC) with carbon dioxide capture.

  10. 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.

  11. Nitration of plant apoplastic proteins from cell suspension cultures.

    Science.gov (United States)

    Szuba, Agnieszka; Kasprowicz-Maluśki, Anna; Wojtaszek, Przemysław

    2015-04-29

    Nitric oxide causes numerous protein modifications including nitration of tyrosine residues. This modification, though one of the greatest biological importance, is poorly recognized in plants and is usually associated with stress conditions. In this study we analyzed nitrotyrosines from suspension cultures of Arabidopsis thaliana and Nicotiana tabacum, treated with NO modulators and exposed to osmotic stress, as well as of BY2 cells long-term adapted to osmotic stress conditions. Using confocal microscopy, we showed that the cell wall area is one of the compartments most enriched in nitrotyrosines within a plant cell. Subsequently, we analyzed nitration of ionically-bound cell-wall proteins and identified selected proteins with MALDI-TOF spectrometry. Proteomic analysis indicated that there was no significant increase in the amount of nitrated proteins under the influence of NO modulators, among them 3-morpholinosydnonimine (SIN-1), considered a donor of nitrating agent, peroxynitrite. Moreover, osmotic stress conditions did not increase the level of nitration in cell wall proteins isolated from suspension cells, and in cultures long-term adapted to stress conditions; that level was even reduced in comparison with control samples. Among identified nitrotyrosine-containing proteins dominated the ones associated with carbon circulation as well as the numerous proteins responding to stress conditions, mainly peroxidases. High concentrations of nitric oxide found in the cell wall and the ability to produce large amounts of ROS make the apoplast a site highly enriched in nitrotyrosines, as presented in this paper. Analysis of ionically bound fraction of the cell wall proteins indicating generally unchanged amounts of nitrotyrosines under influence of NO modulators and osmotic stress, is noticeably different from literature data concerning, however, the total plant proteins analysis. This observation is supplemented by further nitroproteome analysis, for cells long

  12. Quantitative imaging with Fucci and mathematics to uncover temporal dynamics of cell cycle progression.

    Science.gov (United States)

    Saitou, Takashi; Imamura, Takeshi

    2016-01-01

    Cell cycle progression is strictly coordinated to ensure proper tissue growth, development, and regeneration of multicellular organisms. Spatiotemporal visualization of cell cycle phases directly helps us to obtain a deeper understanding of controlled, multicellular, cell cycle progression. The fluorescent ubiquitination-based cell cycle indicator (Fucci) system allows us to monitor, in living cells, the G1 and the S/G2/M phases of the cell cycle in red and green fluorescent colors, respectively. Since the discovery of Fucci technology, it has found numerous applications in the characterization of the timing of cell cycle phase transitions under diverse conditions and various biological processes. However, due to the complexity of cell cycle dynamics, understanding of specific patterns of cell cycle progression is still far from complete. In order to tackle this issue, quantitative approaches combined with mathematical modeling seem to be essential. Here, we review several studies that attempted to integrate Fucci technology and mathematical models to obtain quantitative information regarding cell cycle regulatory patterns. Focusing on the technological development of utilizing mathematics to retrieve meaningful information from the Fucci producing data, we discuss how the combined methods advance a quantitative understanding of cell cycle regulation.

  13. Silicon space solar cells: progression and radiation-resistance analysis

    Science.gov (United States)

    Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2016-02-01

    In this paper, an overview of the solar cell technology based on silicon for applications in space is presented. First, the space environment and its effects on the basis of satellite orbits, such as geostationary earth orbit (GEO) and low earth orbit (LEO), are described. The space solar cell technology based on silicon-based materials, including thin-film silicon solar cells, for use in space was appraised. The evolution of the design for silicon solar cell for use in space, such as a backsurface field (BSF), selective doping, and both-side passivation, etc., is illustrated. This paper also describes the nature of radiation-induced defects and the models proposed for understanding the output power degradation in silicon space solar cells. The phenomenon of an anomalous increase in the short-circuit current ( I sc) in the fluence irradiation range from 2 × 1016 cm-2 to 5 × 1016 cm-2 is also described explicitly from the view point of the various presented models.

  14. [Research progress of the bHLH transcription factors involved in genic male sterility in plants].

    Science.gov (United States)

    Yongming, Liu; Ling, Zhang; Jianyu, Zhou; Moju, Cao

    2015-12-01

    Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application. As one of the largest transcription factor families in plants, basic helix-loop-helix proteins (bHLHs) play a crucial role in regulating plant growth and development. This paper introduces the mechanism of bHLH regulating stamen development in several important model plants. Furthermore, we discuss the molecular mechanisms of genic male sterility resulting from bHLH dysfunction to provide references for crop breeding and theoretical studies.

  15. O-acetylation of Plant Cell Wall Polysaccharides

    Directory of Open Access Journals (Sweden)

    Sascha eGille

    2012-01-01

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

  16. Singlet Fission: Progress and Prospects in Solar Cells.

    Science.gov (United States)

    Xia, Jianlong; Sanders, Samuel N; Cheng, Wei; Low, Jonathan Z; Liu, Jinping; Campos, Luis M; Sun, Taolei

    2016-12-14

    The third generation of photovoltaic technology aims to reduce the fabrication cost and improve the power conversion efficiency (PCE) of solar cells. Singlet fission (SF), an efficient multiple exciton generation (MEG) process in organic semiconductors, is one promising way to surpass the Shockley-Queisser limit of conventional single-junction solar cells. Traditionally, this MEG process has been observed as an intermolecular process in organic materials. The implementation of intermolecular SF in photovoltaic devices has achieved an external quantum efficiency of over 100% and demonstrated significant promise for boosting the PCE of third generation solar cells. More recently, efficient intramolecular SF has been reported. Intramolecular SF materials are modular and have the potential to overcome certain design constraints that intermolecular SF materials possess, which may allow for more facile integration into devices.

  17. Recent Progress Towards Quantum Dot Solar Cells with Enhanced Optical Absorption.

    Science.gov (United States)

    Zheng, Zerui; Ji, Haining; Yu, Peng; Wang, Zhiming

    2016-12-01

    Quantum dot solar cells, as a promising candidate for the next generation solar cell technology, have received tremendous attention in the last 10 years. Some recent developments in epitaxy growth and device structures have opened up new avenues for practical quantum dot solar cells. Unfortunately, the performance of quantum dot solar cells is often plagued by marginal photon absorption. In this review, we focus on the recent progress made in enhancing optical absorption in quantum dot solar cells, including optimization of quantum dot growth, improving the solar cells structure, and engineering light trapping techniques.

  18. Recent Progress Towards Quantum Dot Solar Cells with Enhanced Optical Absorption

    Science.gov (United States)

    Zheng, Zerui; Ji, Haining; Yu, Peng; Wang, Zhiming

    2016-05-01

    Quantum dot solar cells, as a promising candidate for the next generation solar cell technology, have received tremendous attention in the last 10 years. Some recent developments in epitaxy growth and device structures have opened up new avenues for practical quantum dot solar cells. Unfortunately, the performance of quantum dot solar cells is often plagued by marginal photon absorption. In this review, we focus on the recent progress made in enhancing optical absorption in quantum dot solar cells, including optimization of quantum dot growth, improving the solar cells structure, and engineering light trapping techniques.

  19. Mesenchymal Stem Cells for Ischemic Stroke: Progress and Possibilities.

    Science.gov (United States)

    Maria Ferri, Anna Lucia; Bersano, Anna; Lisini, Daniela; Boncoraglio, Giorgio; Frigerio, Simona; Parati, Eugenio

    2016-05-27

    Stroke is the most common neurological cause of morbidity and mortality in industrialized countries, afflicting 15 million people every year. The numbers are expected to increase, mostly due to aging populations. One in five stroke patients dies, and one in three are left with permanent disabilities. Although some acute phase therapies such as intravenous recombinant tissue plasminogen activator (rt-PA) andendovascular treatment have been shown to improve ischemic stroke outcome, these therapies are available only for a small proportion of patients. The use of stem cells to replace brain cells lost during stroke is a long-term goal, and one which is difficult to achieve given that transplanted cells must integrate and restore neural pathways to regain function of damaged parts of the brain. Over the past decade the use of mesenchymal stromal cells (MSCs) as therapy has emerged as a particularly attractive option. MSCs are a class of multipotent, self-renewing cells that give rise to differentiated progeny when implanted into appropriate tissues. Herein, we present a review of the application of MSCs in ischemic stroke, including the source of MSCs, the route and timing of their delivery into the brain and the endpoints measured. Experimental data of transplantation of MSCs in animal stroke models suggest an improved functional recovery. The transplantation of MSCs influences a wide range of events by modulating the inflammatory environment, stimulating endogenous neurogenesis and angiogenesis and reducing the formation of glial scar, although the precise, underlying mechanism of this phenomenon remains unknown. The results from early clinical trials highlight the need to optimize variables such as cell selection and route of administration in order to translate these results into safe and successful clinical applications.

  20. Intermediate band solar cells: Recent progress and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Y., E-mail: okada@mbe.rcast.u-tokyo.ac.jp; Tamaki, R.; Farrell, D. J.; Yoshida, K.; Ahsan, N.; Shoji, Y.; Sogabe, T. [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Ekins-Daukes, N. J., E-mail: n.ekins-daukes@imperial.ac.uk; Yoshida, M.; Pusch, A.; Hess, O.; Phillips, C. C. [Department of Physics, Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Kita, T. [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan); Guillemoles, J.-F. [Institute of Research and Development of Energy from Photovoltaics (IRDEP-CNRS), Chatou 78401 (France); NextPV, Joint RCAST-CNRS Laboratory, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

    2015-06-15

    Extensive literature and publications on intermediate band solar cells (IBSCs) are reviewed. A detailed discussion is given on the thermodynamics of solar energy conversion in IBSCs, the device physics, and the carrier dynamics processes with a particular emphasis on the two-step inter-subband absorption/recombination processes that are of paramount importance in a successful implementation high-efficiency IBSC. The experimental solar cell performance is further discussed, which has been recently demonstrated by using highly mismatched alloys and high-density quantum dot arrays and superlattice. IBSCs having widely different structures, materials, and spectral responses are also covered, as is the optimization of device parameters to achieve maximum performance.

  1. Progress of Large-scale Culture of Plant Cells and Organs Methods for Large-scale and Long-term Animal Cell Culture%轮状病毒疫苗研究进展及其转基因植物疫苗的开发前景

    Institute of Scientific and Technical Information of China (English)

    杨国峰; 周鹏; 王健伟

    2001-01-01

    Human rotavirusesHRV are the major cause of diarrhea in infants and young children in the autumn and winter. In this papers many kinds of rotavirus vaccine are reviewed including live replicating attenuated rotaviruses subunit vaccine DNA vaccine synthesized peptides vaccine and so on. And many antigens of rotavirus are discribed such as VP7 VP4 VP6 and NSP4. Particular consideration is given to the prospects of the transgenic plant-derived rotavirus vaccine.%轮状病毒是目前婴幼儿秋冬季腹泻的最主要病原物。作者通过对轮状病毒减毒株疫苗、亚单位疫苗和DNA疫苗研究进展的综合分析,指出了减毒株疫苗在实际应用中存在的弊端,论述了开发新型轮状病毒疫苗,特别是转基因植物疫苗的必要性和可行性。

  2. 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.

  3. Estimation of turgor pressure through comparison between single plant cell and pressurized shell mechanics

    Science.gov (United States)

    Durand-Smet, P.; Gauquelin, E.; Chastrette, N.; Boudaoud, A.; Asnacios, A.

    2017-10-01

    While plant growth is well known to rely on turgor pressure, it is challenging to quantify the contribution of turgor pressure to plant cell rheology. Here we used a custom-made micro-rheometer to quantify the viscoelastic behavior of isolated plant cells while varying their internal turgor pressure. To get insight into how plant cells adapt their internal pressure to the osmolarity of their medium, we compared the mechanical behavior of single plant cells to that of a simple, passive, pressurized shell: a soccer ball. While both systems exhibited the same qualitative behavior, a simple mechanical model allowed us to quantify turgor pressure regulation at the single cell scale.

  4. Recent progressions in stem cell research: breakthroughs achieved and challenges faced.

    Science.gov (United States)

    Tani, Jowy; Umbas, Rainy

    2009-01-01

    Stem cell studies have been conducted to study characteristics of stem cells, to develop better techniques for patient-specific stem cell lines generation, and to explore the therapeutic potential of stem cells. Techniques that enable efficient generation of new stem cell lines would facilitate research and allow generation of patient-specific stem cell lines for transplantation therapy. Somatic-Cell Nuclear Transfer (SCNT), which involves injection of donor cell nucleus into enucleated ovum, is the standard technique for new embryonic stem (ES) cell lines generation; presently its efficiency is low. A newer technique, pluripotent stem cell induction, reprograms somatic cells into induced pluripotent stem (iPS) cells by introducing certain factors into somatic cells. While certain adult stem cell treatments have been investigated on human participants, most ES cell or iPS cell treatments were still experimented on animal models. Recently, therapeutic potential of stem cell for several disorders was demonstrated. Researchers demonstrated stem cell's potential for treating hematologic disorders by correcting sickle cell anemia in rat model with iPS cells. Its potential role in treating cardiovascular disorder was demonstrated as injection of damaged rat heart with human ES cells derived cardiomyocyte plus "prosurvival" cocktail improved heart function. It might also treat nervous system disorders; injected into brain, ES cells derived neurons replace some loss cells in stroke rats and iPS cells derived neurons improved Parkinsonian syndrome in rats. Progress was also seen in other aspects of regenerative medicine. To overcome controversies caused by embryo destruction for obtaining ES cells, single blastomer stem cell derivation, Cdx2-inactivation, and parthenogenesis were proposed. All ES cell, iPS cell, and adult stem cell research should be continued with support from all sides.

  5. Rho/ROCK signaling in regulation of corneal epithelial cell cycle progression.

    Science.gov (United States)

    Chen, Jian; Guerriero, Emily; Lathrop, Kira; SundarRaj, Nirmala

    2008-01-01

    The authors' previous study showed that the expression of a Rho-associated serine/threonine kinase (ROCK) is regulated during cell cycle progression in corneal epithelial cells. The present study was conducted to determine whether and how Rho/ROCK signaling regulates cell cycle progression. Rabbit corneal epithelial cells (RCECs) in culture were arrested in the G(0) phase of the cell cycle by serum deprivation and then allowed to re-enter the cell cycle in the presence or absence of the ROCK inhibitor (Y27632) in serum-supplemented medium. The number of cells in the S phase, the relative levels of specific cyclins and CDKs and their intracellular distribution, and the relative levels of mRNAs were determined by BrdU labeling, Western blot and immunocytochemical analyses, and real-time RT-PCR, respectively. ROCK inhibition delayed the progression of G(1) to S phase and led to a decrease in the number of RCECs entering the S phase between 12 and 24 hours from 31.5% +/- 4.5% to 8.1% +/- 2.6%. During the cell cycle progression, protein and mRNA levels of cyclin-D1 and -D3 and cyclin-dependent kinases CDK4 and CDK6 were significantly lower, whereas the protein levels of the CDK inhibitor p27(Kip1) were higher in ROCK-inhibited cells. Intracellular mRNA or protein levels of cyclin-E and protein levels of CDK2 were not significantly affected, but their nuclear translocation was delayed by ROCK inhibition. ROCK signaling is involved in cell cycle progression in RCECs, possibly by upregulation of cyclin-D1 and -D3 and CDK4, -6, and -2; nuclear translocation of CDK2 and cyclin-E; and downregulation of p27(Kip1).

  6. PIAS1-FAK Interaction Promotes the Survival and Progression of Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Jerfiz D. Constanzo

    2016-05-01

    Full Text Available The sequence of genomic alterations acquired by cancer cells during tumor progression and metastasis is poorly understood. Focal adhesion kinase (FAK is a non-receptor tyrosine kinase that integrates cytoskeleton remodeling, mitogenic signaling and cell survival. FAK has previously been reported to undergo nuclear localization during cell migration, cell differentiation and apoptosis. However, the mechanism behind FAK nuclear accumulation and its contribution to tumor progression has remained elusive. We report that amplification of FAK and the SUMO E3 ligase PIAS1 gene loci frequently co-occur in non-small cell lung cancer (NSCLC cells, and that both gene products are enriched in a subset of primary NSCLCs. We demonstrate that endogenous FAK and PIAS1 proteins interact in the cytoplasm and the cell nucleus of NSCLC cells. Ectopic expression of PIAS1 promotes proteolytic cleavage of the FAK C-terminus, focal adhesion maturation and FAK nuclear localization. Silencing of PIAS1 deregulates focal adhesion turnover, increases susceptibility to apoptosis in vitro and impairs tumor xenograft formation in vivo. Nuclear FAK in turn stimulates gene transcription favoring DNA repair, cell metabolism and cytoskeleton regulation. Consistently, ablation of FAK by CRISPR/Cas9 editing, results in basal DNA damage, susceptibility to ionizing radiation and impaired oxidative phosphorylation. Our findings provide insight into a mechanism regulating FAK cytoplasm-nuclear distribution and demonstrate that FAK activity in the nucleus promotes NSCLC survival and progression by increasing cell-ECM interaction and DNA repair regulation.

  7. 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.

  8. Esau's Plant anatomy: meristems, cells, and tissues of the plant body : their structure, function, and development

    National Research Council Canada - National Science Library

    Evert, Ray Franklin; Esau, Katherine; Eichhorn, Susan E

    2006-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix Chapter 1 Structure and Development of the Plant Body- An Overview . . . . . . . . . . . . . . . . . . . . . . . . 1 Internal Organization of the Plant Body...

  9. Rapid G0/1 transition and cell cycle progression in CD8(+) T cells compared to CD4(+) T cells following in vitro stimulation.

    Science.gov (United States)

    Mishima, Takuya; Fukaya, Shotaro; Toda, Shoko; Ando, Yoshiaki; Matsunaga, Tsukasa; Inobe, Manabu

    2017-04-01

    T cell population consists of two major subsets, CD4(+) T cells and CD8(+) T cells, which can be distinguished by the expression of CD4 or CD8 molecules, respectively. Although they play quite different roles in an immune system, many of their basic cellular processes such as proliferation following stimulation are presumably common. In this study, we have carefully analyzed time course of G0/1 transition as well as cell cycle progression in the two subsets of quiescent T cell population following in vitro growth stimulation. We found that CD8(+) T cells promote G0/1 transition more rapidly and drive their cell cycle progression faster compared to CD4(+) T cells. In addition, expression of CD25 and effects of its blockade revealed that IL-2 is implicated in the rapid progression, but not the earlier G0/1 transition, of CD8(+) T cells.

  10. Progress on stem cell research towards the treatment of Parkinson's disease.

    Science.gov (United States)

    Gibson, Stuart A J; Gao, Guo-Dong; McDonagh, Katya; Shen, Sanbing

    2012-04-03

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive accumulation of Lewy body inclusions along with selective destruction of dopaminergic (DA) neurons in the nigrostriatal tract of the brain. Genetic studies have revealed much about the pathophysiology of PD, enabling the identification of both biomarkers for diagnosis and genetic targets for therapeutic treatment, which are evolved in tandem with the development of stem cell technologies. The discovery of induced pluripotent stem (iPS) cells facilitates the derivation of stem cells from adult somatic cells for personalized treatment and thus overcomes not only the limited availability of human embryonic stem cells but also ethical concerns surrounding their use. Non-viral, non-integration, or non-DNA-mediated reprogramming technologies are being developed. Protocols for generating midbrain DA neurons are undergoing constant refinement. The iPS cell-derived DA neurons provide cellular models for investigating disease progression in vitro and for screening molecules of novel therapeutic potential and have beneficial effects on improving the behavior of parkinsonian animals. Further progress in the development of safer non-viral/non-biased reprogramming strategies and the subsequent generation of homogenous midbrain DA neurons shall pave the way for clinical trials. A combined approach of drugs, cell replacement, and gene therapy to stop disease progression and to improve treatment may soon be within our reach.

  11. A comparative mechanical analysis of plant and animal cells reveals convergence across kingdoms.

    Science.gov (United States)

    Durand-Smet, Pauline; Chastrette, Nicolas; Guiroy, Axel; Richert, Alain; Berne-Dedieu, Annick; Szecsi, Judit; Boudaoud, Arezki; Frachisse, Jean-Marie; Bendahmane, Mohammed; Bendhamane, Mohammed; Hamant, Oliver; Asnacios, Atef

    2014-11-18

    Plant and animals have evolved different strategies for their development. Whether this is linked to major differences in their cell mechanics remains unclear, mainly because measurements on plant and animal cells relied on independent experiments and setups, thus hindering any direct comparison. In this study we used the same micro-rheometer to compare animal and plant single cell rheology. We found that wall-less plant cells exhibit the same weak power law rheology as animal cells, with comparable values of elastic and loss moduli. Remarkably, microtubules primarily contributed to the rheological behavior of wall-less plant cells whereas rheology of animal cells was mainly dependent on the actin network. Thus, plant and animal cells evolved different molecular strategies to reach a comparable cytoplasmic mechanical core, suggesting that evolutionary convergence could include the internal biophysical properties of cells.

  12. Sinorhizobium meliloti CpdR1 is critical for co-ordinating cell cycle progression and the symbiotic chronic infection.

    Science.gov (United States)

    Kobayashi, Hajime; De Nisco, Nicole J; Chien, Peter; Simmons, Lyle A; Walker, Graham C

    2009-08-01

    ATP-driven proteolysis plays a major role in regulating the bacterial cell cycle, development and stress responses. In the nitro -fixing symbiosis with host plants, Sinorhizobium meliloti undergoes a profound cellular differentiation, including endoreduplication of the ome. The regulatory mechanisms governing the alterations of the S. meliloti cell cycle in planta are largely unknown. Here, we report the characterization of two cpdR homologues, cpdR1 and cpdR2, of S. meliloti that encode single-domain response regulators. In Caulobacter crescentus, CpdR controls the polar localization of the ClpXP protease, thereby mediating the regulated proteolysis of key protein(s), such as CtrA, involved in cell cycle progression. The S. meliloti cpdR1-null mutant can invade the host cytoplasm, however, the intracellular bacteria are unable to differentiate into bacteroids. We show that S. meliloti CpdR1 has a polar localization pattern and a role in ClpX positioning similar to C. crescentus CpdR, suggesting a conserved function of CpdR proteins among alpha-proteobacteria. However, in S. meliloti, free-living cells of the cpdR1-null mutant show a striking morphology of irregular coccoids and aberrant DNA replication. Thus, we demonstrate that CpdR1 mediates the co-ordination of cell cycle events, which are critical for both the free-living cell division and the differentiation required for the chronic intracellular infection.

  13. Role of acyl carrier protein isoforms in plant lipid metabolism: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Ohlrogge, J.B.

    1989-01-01

    Previous research from my lab has revealed that several higher plant species have multiple isoforms of acyl carrier protein (ACP) and therefore this trait appears highly conserved among higher plants. This level of conservation suggests that the existence of ACP isoforms is not merely the results of neutral gene duplications. We have developed techniques to examine a wider range of species. Acyl carrier proteins can be labelled very specifically and to high specific activity using H-palmitate and the E. coli enzyme acyl-ACP synthetase. Isoforms were then resolved by western blotting and native PAGE of H-palmitate labelled ACP's. Multiple isoforms of ACP were observed the leaf tissue of the monocots Avena sativa and Hordeum vulgare and dicots including Arabidopsis thallina, Cuphea wrightii, and Brassica napus. Lower vascular plants including the cycad, Dioon edule, Ginkgo biloba, the gymnosperm Pinus, the fern Anernia phyllitidis and Psilotum nudum, the most primitive known extant vascular plant, were also found to have multiple ACP isoforms as were the nonvascular liverwort, Marchantia and moss, Polytrichum. Therefore, the development of ACP isoforms occurred early in evolution. However, the uniellular alge Chlamydomonas and Dunaliella and the photosynthetic cyanobacteria Synechocystis and Agmnellum have only a single elecrophotetic form of ACP. Thus, multiple forms of ACP do not occur in all photosynthetic organisms but may be associated with multicellular plants.

  14. Fuel Cell Balance-of-Plant Reliability Testbed Project

    Energy Technology Data Exchange (ETDEWEB)

    Sproat, Vern [Stark State College of Technology, North Canton, OH (United States); LaHurd, Debbie [Lockheed Martin Corp., Oak Ridge, TN (United States)

    2016-10-29

    Reliability of the fuel cell system balance-of-plant (BoP) components is a critical factor that needs to be addressed prior to fuel cells becoming fully commercialized. Failure or performance degradation of BoP components has been identified as a life-limiting factor in fuel cell systems.1 The goal of this project is to develop a series of test beds that will test system components such as pumps, valves, sensors, fittings, etc., under operating conditions anticipated in real Polymer Electrolyte Membrane (PEM) fuel cell systems. Results will be made generally available to begin removing reliability as a roadblock to the growth of the PEM fuel cell industry. Stark State College students participating in the project, in conjunction with their coursework, have been exposed to technical knowledge and training in the handling and maintenance of hydrogen, fuel cells and system components as well as component failure modes and mechanisms. Three test beds were constructed. Testing was completed on gas flow pumps, tubing, and pressure and temperature sensors and valves.

  15. Rapid burst of H2O2 by plant growth regulators increases intracellular Ca2+ amounts and modulates CD4+ T cell activation.

    Science.gov (United States)

    Ahmed, Asma; Mukherjee, Sambuddho; Deobagkar, Mukta; Naik, Tanushree; Nandi, Dipankar

    2010-11-01

    The identification of small molecules that affect T cell activation is an important area of research. Three molecules that regulate plant growth and differentiation, but not their structurally similar analogs, were identified to enhance primary mouse CD4(+) T cell activation in conjunction with soluble anti-CD3 stimulation: Indoleacetic acid (natural plant auxin), 1-Napthaleneacetic acid (synthetic plant auxin) and 2,4-Dichlorophenoxyacetic acid (synthetic plant auxin and herbicide). These effects are distinct in comparison to Curcumin, the well known phenolic immunomodulator, which lowers T cell activation. An investigation into the mechanisms of action of the three plant growth regulators revealed a rapid induction of reactive oxygen species (ROS), mainly comprising H(2)O(2). In addition, these three molecules synergize with soluble anti-CD3 signaling to enhance intracellular Ca(2+) concentrations [Ca(2+)](i), leading to greater T cell activation, e.g. induction of CD25 and IL-2. Enhanced production of TNFα and IFNγ by CD4(+) T cells is also observed upon plant growth regulator treatment with soluble anti-CD3. Interestingly, maximal IL-2 production and CD4(+) T cell cycle progression are observed upon activation with soluble anti-CD3 and phorbol 12-myristate 13-acetate (PMA), a phorbol ester. Additionally, stimulation with PMA and Ionomcyin (a Ca(2+) ionophore), which activates T cells by circumventing the TCR, and plant growth regulators also demonstrated the role of the strength of signal (SOS): T cell cycle progression is enhanced with gentle activation conditions but decreased with strong activation conditions. This study demonstrates the direct effects of three plant growth regulators on CD4(+) T cell activation and cycling.

  16. Luminescence imaging of polymer solar cells: visualization of progressing degradation

    Energy Technology Data Exchange (ETDEWEB)

    Seeland, Marco; Roesch, Roland; Hoppe, Harald [Institute of Physics, Ilmenau University of Technology, Ilmenau (Germany)

    2011-07-01

    We apply luminescence imaging as tool for the non-destructive visualization of degradation processes within bulk heterojunction polymer solar cells. The imaging technique is based on luminescence detection with a highly sensitive silicon-ccd camera and is able to visualize the with time advancing degradation patterns of polymer solar cells. The devices investigated have been aged under defined conditions and were characterized periodically with current-voltage-sweeps. This allows determining the time evolution of the photovoltaic parameters and - in combination with the luminescence images - understanding differences in the observed degradation behaviour. The versatile usability of the method is demonstrated in a correlation between local reduction of lateral luminescence and a fast decrease of the short-circuit-current due to the loss of active area. Differences in the degradation of photovoltaic parameters under varied aging conditions are discussed.

  17. Progress in amorphous silicon solar cells produced by reactive sputtering

    Science.gov (United States)

    Moustakas, T. D.

    The photovoltaic properties of reactively sputtered amorphous silicon are reviewed and it is shown that efficient PIN solar cells can be fabricated by the method of sputtering. The photovoltaic properties of the intrinsic films correlate with their structural and compositional inhomogeneities. Hydrogen incorporation and small levels of phosphorus and boron impurities also affect the photovoltaic properties through reduction of residual dangling bond related defects and modification of their occupation. The optical and transport properties of the doped P and N-films were found to depend sensitively on the amount of hydrogen and boron or phosphorus incorporation into the films as well as on their degree of crystallinity. Combination of the best intrinsic and doped films leads to PIN solar cell structures generating J(sc) of 13 mA/sq cm and V(oc) of between 0.85 to 0.95 volts. The efficiency of these devices, 5 to 6 percent, is limited by the low FF, typically about 50 percent. As a further test to the potential of this technology efficient tandem solar cell structures were fabricated, and device design concepts, such as the incorporation of optically reflective back contacts were tested.

  18. A radioimmunoassay for lignin in plant cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Dawley, R.M.

    1989-01-01

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

  19. Plant rhizosphere effects on metal mobilization and transport. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Fan, T.W.M.

    1998-06-01

    'Information on the mechanism of how plants mobilize, uptake, and metabolize metal ions is very limited. Especially deficient is the understanding of these processes involving pollutant metal ions and interactions among these ions. Based on the current knowledge regarding nutrient ions, it is clear that elucidation of rhizospheric processes such as exudation of organic ligands by plant roots and plant metabolism/adaptation involving these biogenic chelators is critically important. A mechanistic insight into these processes will advance knowledge in microbe-plant host interactions and how metal ions are mobilized, immobilized, and sequestered by these interactions. This, in turn, is essential to applications such as phytobioremediation and microbioremediation of metal ion pollution. Root exudation also serves many other important rhizosphere functions including energy supply for microbial degradation of organic pollutants, structuring of microbial community, and the formation of soil humic materials which are considered to be a major sink for both organic and inorganic pollutants. How root exudates function is critically dependent on the chemical nature of exudate components. Therefore, a comprehensive characterization of all major exudate components, regardless of their chemical class, should facilitate the development and implementation of bioremediation for both organic and inorganic pollutants. Therefore, the objectives of this project are: (1) To obtain a comprehensive composition of major organic components in plant root exudates as a function of different metal ions; (2) To examine plant metabolic response(s) to these metal ion treatments, with emphasis on biosynthetic pathways of organic ligands; and (3) To investigate the effect(s) of soil microbial (e.g. mycorrhizae) association on (1) and (2).'

  20. Investigating the regulation of stem and progenitor cell mitotic progression by in situ imaging.

    Science.gov (United States)

    Gerhold, Abigail R; Ryan, Joël; Vallée-Trudeau, Julie-Nathalie; Dorn, Jonas F; Labbé, Jean-Claude; Maddox, Paul S

    2015-05-01

    Genome stability relies upon efficacious chromosome congression and regulation by the spindle assembly checkpoint (SAC). The study of these fundamental mitotic processes in adult stem and progenitor cells has been limited by the technical challenge of imaging mitosis in these cells in situ. Notably, how broader physiological changes, such as dietary intake or age, affect mitotic progression in stem and/or progenitor cells is largely unknown. Using in situ imaging of C. elegans adult germlines, we describe the mitotic parameters of an adult stem and progenitor cell population in an intact animal. We find that SAC regulation in germline stem and progenitor cells is distinct from that found in early embryonic divisions and is more similar to that of classical tissue culture models. We further show that changes in organismal physiology affect mitotic progression in germline stem and progenitor cells. Reducing dietary intake produces a checkpoint-dependent delay in anaphase onset, and inducing dietary restriction when the checkpoint is impaired increases the incidence of segregation errors in mitotic and meiotic cells. Similarly, developmental aging of the germline stem and progenitor cell population correlates with a decline in the rate of several mitotic processes. These results provide the first in vivo validation of models for SAC regulation developed in tissue culture systems and demonstrate that several fundamental features of mitotic progression in adult stem and progenitor cells are highly sensitive to organismal physiological changes.