Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Records 1 - 20 / 112

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: metisnummer==1024749
Check title to add to marked list
Shortening of Microtubule overlap regions defines membrane delivery sites during plant cytokinesis
Keijzer, J. de; Kieft, H. ; Ketelaar, T. ; Goshima, G. ; Janson, M.E. - \ 2017
Current Biology 27 (2017)4. - ISSN 0960-9822 - p. 514 - 520.
plant cytokinesis, microtubule, moss
Plants and animals synthesize and move large amounts of membraneous material to construct a division plane for cell division. We define short stretches of antiparallel microtubule overlap as membrane accumulation sites in moss plants. Dimensions of the dividing cell plate are set by kinesin-4-mediated shortening of these overlaps.
Characterization of polarity development through 2- and 3-D imaging during the initial phase of microspore embryogenesis in Brassica napus L.
Dubas, E. ; Custers, J. ; Kieft, H. ; Wedzony, M. ; Lammeren, A.A.M. van - \ 2014
Protoplasma 251 (2014)1. - ISSN 0033-183X - p. 103 - 113.
nuclear-dna synthesis - cv topas - extracellular-matrix - sporophytic development - cultured microspores - actin-filament - heat-shock - in-vitro - induction - pollen
Isolated microspores of B. napus in culture change their developmental pathway from gametophytic to sporophytic and form embryo-like structures (ELS) upon prolonged heat shock treatment (5 days at 32 °C). ELS express polarity during the initial days of endosporic development. In this study, we focussed on the analysis of polarity development of ELS without suspensor. Fluorescence microscopy and 3-D confocal laser scanning microscopy (CLSM) without tissue interfering enabled us to get a good insight in the distribution of nuclei, mitochondria and endoplasmic reticulum(ER), the architecture of microtubular (MT) cytoskeleton and the places of 5-bromo- 2'-deoxy-uridine (BrdU) incorporation in successive stages of microspore embryogenesis. Scanning electron microscopy (SEM) analysis revealed, for the first time, the appearance of a fibrillar extracellular matrix-like structure (ECM-like structure) in androgenic embryos without suspensor. Two types of endosporic development were distinguished based upon the initial location of the microspore nucleus. The polarity of dividing and growing cells was recognized by the differential distributions of organelles, by the organization of the MT cytoskeleton and by the visualization of DNA synthesis in the cell cycle. The directional location of nuclei, ER, mitochondria and starch grains in relation to theMTs configurations were early polarity indicators. Both exine rupture and ECMlike structure on the outer surfaces of ELS are supposed to stabilize ELS's morphological polarity. As the role of cell polarity during early endosporic microspore embryogenesis in apical–basal cell fate determination remains unclear, microspore culture system provides a powerful in vitro tool for studying the developmental processes that take place during the earliest stages of plant embryogenesis.
Arabidopsis VILLIN2 and VILLIN3 are required for the generation of thick actin filament bundles and for directional organ growth.
Honing, H.S. van der; Kieft, H. ; Emons, A.M.C. ; Ketelaar, T. - \ 2012
Plant Physiology 158 (2012)3. - ISSN 0032-0889 - p. 1426 - 1438.
pollen-tube growth - elongation-factor 1-alpha - root hair-cells - f-actin - binding-sites - plant villin - tip growth - severing protein - cytoskeleton - morphogenesis
In plant cells, actin filament bundles serve as tracks for myosin-dependent organelle movement and play a role in the organization of the cytoplasm. Although virtually all plant cells contain actin filament bundles, the role of the different actin-bundling proteins remains largely unknown. In this study, we investigated the role of the actin-bundling protein villin in Arabidopsis (Arabidopsis thaliana). We used Arabidopsis T-DNA insertion lines to generate a double mutant in which VILLIN2 (VLN2) and VLN3 transcripts are truncated. Leaves, stems, siliques, and roots of vln2 vln3 double mutant plants are twisted, which is caused by local differences in cell length. Microscopy analysis of the actin cytoskeleton showed that in these double mutant plants, thin actin filament bundles are more abundant while thick actin filament bundles are virtually absent. In contrast to full-length VLN3, truncated VLN3 lacking the headpiece region does not rescue the phenotype of the vln2 vln3 double mutant. Our results show that villin is involved in the generation of thick actin filament bundles in several cell types and suggest that these bundles are involved in the regulation of coordinated cell expansion.
Gametophytic development of Brassica napus pollen in vitro enables examination of cytoskeleton and nuclear movements
Dubas, E. ; Wedzony, M. ; Custers, J.B.M. ; Kieft, H. ; Lammeren, A.A.M. van - \ 2012
Protoplasma 249 (2012)2. - ISSN 0033-183X - p. 369 - 377.
microspore embryogenesis - cv topas - induction - actin - cells - microtubules - differentiation - organization - arabidopsis - behavior
Isolated microspores and pollen suspension of Brassica napus “Topas” cultured in NLN-13 medium at 18°C follow gametophytic pathway and develop into pollen grains closely resembling pollen formed in planta. This culture system complemented with whole-mount immunocytochemical technology and novel confocal laser scanning optical technique enables detailed studies of male gametophyte including asymmetric division, cytoskeleton, and nuclear movements. Microtubular cytoskeleton configurationally changed in successive stages of pollen development. The most prominent role of microtubules (MTs) was observed just before and during nuclear migration at the early and mid-bi-cellular stage. At the early bi-cellular stage, parallel arrangement of cortical and endoplasmic MTs to the long axis of the generative cell (GC) as well as MTs within GC under the plasmalemma bordering vegetative cell (VC) were responsible for GC lens shape. At the beginning of the GC migration, endoplasmic microtubules (EMTs) of the VC radiated from the nuclear envelope. Most cortical and EMTs of the VC were found near the sporoderm. At the same time, pattern of MTs observed in GC was considerably different. Multiple EMTs of the GC, previously parallel aligned, reorganized, and start to surround GC, forming a basket-like structure. These results suggest that EMTs of GC provoke changes in GC shape, its detachment from the sporoderm, and play an important role in GC migration to the vegetative nucleus (VN). During the process of migration of the GC to the VC, multiple and thick bundles of MTs, radiating from the cytoplasm near GC plasma membrane, arranged perpendicular to the narrow end of the GC and organized into a “comet-tail” form. These GC “tail” MTs became shortened and the generative nucleus (GN) took a ball shape. The dynamic changes of MTs accompanied polarized distribution pattern of mitochondria and endoplasmic reticulum. In order to confirm the role of MTs in pollen development, a “whole-mount” immunodetection technique and confocal laser-scanning microscopy was essential.
Microtubule configurations and nuclear DNA synthesis during initiation of suspensor-bearing embryos from Brassica napus cv. Topas microspores
Dubas, E. ; Custers, J.B.M. ; Kieft, H. ; Wedzony, M. ; Lammeren, A.A.M. van - \ 2011
Plant Cell Reports 30 (2011)11. - ISSN 0721-7714 - p. 2105 - 2116.
heat-shock - sporophytic development - cultured microspores - rape embryogenesis - in-vitro - induction - pollen - organization - division - visualization
In the new Brassica napus microspore culture system, wherein embryos with suspensors are formed, ab initio mimics zygotic embryogenesis. The system provides a powerful in vitro tool for studying the diverse developmental processes that take place during early stages of plant embryogenesis. Here, we studied in this new culture system both the temporal and spatial distribution of nuclear DNA synthesis places and the organization of the microtubular (MT) cytoskeleton, which were visualized with a refined whole mount immunolocalization technology and 3D confocal laser scanning microscopy. A 'mild' heat stress induced microspores to elongate, to rearrange their MT cytoskeleton and to re-enter the cell cycle and perform a predictable sequence of divisions. These events led to the formation of a filamentous suspensor-like structure, of which the distal tip cell gave rise to the embryo proper. Cells of the developing pro-embryo characterized endoplasmic (EMTs) and cortical microtubules (CMTs) in various configurations in the successive stages of the cell cycle. However, the most prominent changes in MT configurations and nuclear DNA replication concerned the first sporophytic division occurring within microspores and the apical cell of the pro-embryo. Microspore embryogenesis was preceded by pre-prophase band formation and DNA synthesis. The apical cell of the proembryo exhibited a random organization of CMTs and, in relation to this, isotropic expansion occurred, mimicking the development of the apical cell of the zygotic situation. Moreover, the apical cell entered the S phase shortly before it divided transversally at the stage that the suspensor was 3-8 celled.
Cell proliferation, cell shape, and microtubule and cellulose microfibril organization of tobacco BY-2 cells are not altered by exposure to near weightlessness in space
Sieberer, B. ; Kieft, H. ; Franssen-Verheijen, M.A.W. ; Emons, A.M.C. ; Vos, J.W. - \ 2009
Planta 230 (2009)6. - ISSN 0032-0935 - p. 1129 - 1140.
random-positioning machine - cortical microtubules - self-organization - soyuz-missions - plant-cells - arabidopsis - growth - microgravity - gravity - actin
The microtubule cytoskeleton and the cell wall both play key roles in plant cell growth and division, determining the plant’s final stature. At near weightlessness, tubulin polymerizes into microtubules in vitro, but these microtubules do not self-organize in the ordered patterns observed at 1g. Likewise, at near weightlessness cortical microtubules in protoplasts have difficulty organizing into parallel arrays, which are required for proper plant cell elongation. However, intact plants do grow in space and therefore should have a normally functioning microtubule cytoskeleton. Since the main difference between protoplasts and plant cells in a tissue is the presence of a cell wall, we studied single, but walled, tobacco BY-2 suspension-cultured cells during an 8-day space-flight experiment on board of the Soyuz capsule and the International Space Station during the 12S mission (March–April 2006). We show that the cortical microtubule density, ordering and orientation in isolated walled plant cells are unaffected by near weightlessness, as are the orientation of the cellulose microfibrils, cell proliferation, and cell shape. Likely, tissue organization is not essential for the organization of these structures in space. When combined with the fact that many recovering protoplasts have an aberrant cortical microtubule cytoskeleton, the results suggest a role for the cell wall, or its production machinery, in structuring the microtubule cytoskeleton
Rapportage onderzoek aantasting van de bast bij laanbomen
Lammeren, A.A.M. van; Ruiter, N.C.A. ; Kieft, H. - \ 2009
Wageningen : Wageningen UR, Leerstoelgroep Plantencelbiologie
straatbomen - afwijkingen, planten - deformiteiten - knobbelvorming - schors - korstmossen - schimmels - landbouwkundig onderzoek - boomverzorging - openbaar groen - street trees - plant disorders - deformities - nodulation - cortex - lichens - fungi - agricultural research - tree care - public green areas
In dit verslag zijn aantastingen op de stam onderzocht van Carpinus betulus ‘Frans Fontaine’, Fagus sylvatica “ Atropurpurea”, Fraxinus excelsior ‘Atlas’, Quercus palustris, Quercus robur, Sorbus latifolia “Henk Vink” en Ulmus ‘Clusius’ Daarbij is aandacht besteed aan het voorkomen en de aard en ontwikkeling van bastknobbels, baststrepen, bastscheuren, verkleuringen en het effect van epifyten zoals schimmels en korstmossen
Rapportage onderzoek aan bastknobbels en aantasting van bast door korstmossen aantasting van bast door korstmossen
Lammeren, A.A.M. van; Kieft, H. ; Donkers, J. - \ 2008
Wageningen : Wageningen Universiteit en Research Centrum
bomen - fraxinus - afwijkingen - deformiteiten - korstmossen - knobbelvorming - schors, bomen - cedrus - straatbomen - landbouwkundig onderzoek - boomkwekerijen - gemeenten - openbaar groen - trees - abnormalities - deformities - lichens - nodulation - bark - street trees - agricultural research - forest nurseries - municipalities - public green areas
In het hier beschreven onderzoek is nagegaan wat de aard en oorzaak is van het pokdalig uiterlijk van de stam van de es, wat het effect is van korstmosbegroeiing op de essenbast en hoe de reeds eerder beschreven bastknobbels ontstaan. Het is een voortgangsrapportage van een grotere studie naar oorzaak en gevolg van boomaantastingen. Hier worden verschijnselen beschreven maar er is vooralsnog geen uitspraak over hoe de aantastingen zoals bastknobbels zijn veroorzaakt
Polymer Microcapsules with a Fiber-Reinforced Nanocomposite Shell
Sagis, L.M.C. ; Ruiter, R. de; Rossier Miranda, F.J. ; Ruiter, J. de; Schroën, C.G.P.H. ; Aelst, A.C. van; Kieft, H. ; Boom, R.M. ; Linden, E. van der - \ 2008
Langmuir 24 (2008)5. - ISSN 0743-7463 - p. 1608 - 1612.
human serum-albumin - amyloid fibrils - vesicles - nanocapsules - stability - ph - permeability - fabrication - emulsions - capsules
Polymer microcapsules can be used as controlled release systems in drugs or in foods. Using layer-by-layer adsorption of common food proteins and polysaccharides, we produced a new type of microcapsule with tunable strength and permeability. The shell consists of alternating layers of pectin and whey protein fibrils, yielding a fiber-reinforced nanocomposite shell. The strength can be tightly controlled by varying the number of layers or the density and length of the fibrils in the protein layers. The mechanical stability of these microcapsules appears to be superior to that of currently available multilayer capsules. The method involves only standard unit operations and has the potential for scaling up to industrial production volumes.
Cell differentiation in the pericarp and endosperm of developing maize kernels (Zea mays L.)
Lammeren, A.A.M. van; Kieft, H. ; Schel, J.H.N. - \ 2006
In: Embryology of flowering plants: terminology and concepts. Volume 2: Seed / Batygina, T.B., Enfield, NH, USA : Science Publishers - ISBN 1578082633 - p. 131 - 139.
Light microscopic study of endosperm formation in Brassica napus L.
Lammeren, A.A.M. van; Kieft, H. ; Ma, F. ; Veenendaal, W.L.H. van - \ 2006
In: Embryology of flowering plans: terminology and concepts. Volume 2: Seed / Batygina, T.B., Enfield, NH, USA : Science Publishers - ISBN 1578082633 - p. 128 - 131.
Visualisation of microtubules and actin filaments in fixed BY-2 suspension cells using an optimised whole mount immunolabelling protocol
Szechynska-Hebda, M. ; Wedzony, M. ; Dubas, E. ; Kieft, H. ; Lammeren, A.A.M. van - \ 2006
Plant Cell Reports 25 (2006)8. - ISSN 0721-7714 - p. 758 - 766.
living plant-cells - mill h-duval - pollen development - cytoskeleton - reorganization - organization - cytokinesis - tubulin - microinjection - dynamics
Excellent visualisation of microtubules and actin filaments was obtained in fixed tobacco BY-2 suspension cells after optimising a protocol for whole mount immunolabelling. The procedure is based on modification of fixation, cell wall digestion, dimethyl sulfoxide (DMSO) treatment, post fixation, and blocking. The most critical aspects of successful preservation and visualization of cytoskeletal elements appeared to be: a two-step fixation with paraformaldehyde and glutaraldehyde before enzymatic cell wall digestion and a post fixation with aldehydes thereafter. The method allows the improved visualization of the organisation of the microtubular and actin filament arrays during the successive stages of cell division and at interphase. Although we present the application of our protocols for cytoskeleton labelling, the excellent results show the potential of using this method for the analysis of various proteins and molecules in plant cells
Intrusive growth of flax phloem fibers is of intercalary type
Ageeva, M. ; Petrovská, B. ; Kieft, H. ; Sal'nikov, V.V. ; Snegireva, A.V. ; Dam, J.E.G. van; Veenendaal, W.L.H. van; Emons, A.M.C. ; Gorshkova, T.A. ; Lammeren, A.A.M. van - \ 2005
Planta 222 (2005)4. - ISSN 0032-0935 - p. 565 - 574.
arabidopsis root hairs - cell expansion - tip growth - cytoskeleton - plant - microtubules - polarity
Flax (Linum usitatissimum L.) phloem fibers elongate considerably during their development and intrude between existing cells. We questioned whether fiber elongation is caused by cell tip growth or intercalary growth. Cells with tip growth are characterized by having two specific zones of cytoplasm in the cell tip, one with vesicles and no large organelles at the very tip and one with various organelles amongst others longitudinally arranged cortical microtubules in the subapex. Such zones were not observed in elongating flax fibers. Instead, organelles moved into the very tip region, and cortical microtubules showed transversal and helical configurations as known for cells growing in intercalary way. In addition, pulse-chase experiments with Calcofluor White resulted in a spotted fluorescence in the cell wall all over the length of the fiber. Therefore, it is concluded that fiber elongation is not achieved by tip growth but by intercalary growth. The intrusively growing fiber is a coenocytic cell that has no plasmodesmata, making the fibers a symplastically isolated domain within the stem.
Novel approach to quantify immobilized-enzyme distributions
Roon, J.L. van; Groenendijk, E. ; Kieft, H. ; Schroën, C.G.P.H. ; Tramper, J. ; Beeftink, H.H. - \ 2005
Biotechnology and Bioengineering 89 (2005)6. - ISSN 0006-3592 - p. 660 - 669.
scanning laser microscopy - confocal microscopy - diffusion limitation - protein diffusion - methacrylate - acylase
The quantitative intraparticle enzyme distribution of Assemblase, an industrially employed polydisperse immobilized penicillin-G acylase, was measured. Because of strong autofluorescence of the carrier, the generally applied technique of confocal scanning microscopy could not be used; light microscopy was our method of choice. To do so, Assemblase particles of various sizes were sectioned, labeled with antibodies specifically against the enzyme, and analyzed light microscopically. Image analysis software was developed and used to determine the intraparticle enzyme distribution, which was found to be heterogeneous, with most enzyme located in the outer regions of the particles. Larger particles showed steeper gradients than smaller ones. A mathematical representation of the intraparticle profiles, based on in-stationary enzyme diffusion into the particles, was validated successfully for a broad range of particle sizes using data for volume-averaged particle size and enzyme loading. The enzyme gradients determined in this work will be used as input for a physical model that quantitatively describes the complex behavior of Assemblase. Such a physical model will lead to identification of the current bottlenecks in Assemblase and can serve as a starting point for the design of improved biocatalysts that also may be based on intelligent use of enzyme gradients. (C) 2005 Wiley Periodicals, Inc.
Configuration of the microtubule cytoskeleton in elongating fibers of flax (Linum usitatissimum L.)
Lammeren, A.A.M. van; Ageeva, M. ; Kieft, H. ; Lhuissier, F.G.P. ; Vos, J. ; Gorshkova, T. ; Emons, A.M.C. - \ 2003
Cell Biology International 27 (2003)3. - ISSN 1065-6995 - p. 225 - 225.
There are three basic types of plant cell growth: isodiametric, unidirectional diffuse, and tip growth. During plant cell growth, microtubules are present in the cell cortex, appressed against the plasma membrane. It is well documented that these cortical microtubules determine the orientation of cell growth in unidirectional intercalary, growing cells, in which the microtubules are always found perpendicular to the axis of cell elongation. There are indications that bast fiber cells of flax have two types of cell growth within one single cell: unidirectional intercalary and tip growth. Since the ultimate length of fiber cells determines the quality of the flax fiber for industry, we study the growth of these cells. In order to determine whether tip growth occurs or not, we use the following tip growth indicators: the type of cell wall at the cell tip, vesicle accumulation at the cell tip, calcium gradient at the cell tip, configuration of the actin cytoskeleton, and configuration of the microtubule cytoskeleton. Here we report on the microtubule cytoskeleton. We started to study the microtubules in fixed flax fiber cells using immunocytochemistry. Both, sections, as well as enzymatically isolated fibers, were analyzed at increasing distances from the shoot apex. Young fibers from the subapical region exhibit microtubules that are positioned approximately perpendicular to the cell's long axis. After prolonged elongation they are found in a helical orientation. In the two tapering regions of the elongating fiber, the microtubules are more often in a perpendicular orientation than in the middle zone of the cell indicating that within a single fiber more than one growth rate might occur. After elongation ceased, all cortical MTs are positioned approximately parallel to the long axis of the fiber. Based on the changes of the configurations of MTs in growing fibers, it is concluded that flax fibers exhibit coordinated growth first, and then also begin to exhibit intrusive growth at both ends as well. Until now, no observations support tip growth.
Phloem fibre elongation in flax (Linum ussitatissimum L. cv Belinka) and the role of the microtubular cytoskeleton
Petrovska, B. ; Kieft, H. ; Ageeva, M. ; Emons, A.M.C. ; Lammeren, A.A.M. van - \ 2003
Early development of flax (Linum usitatissimum L. c.v. Belinka) bast fibres
Petrovska, B. ; Kieft, H. ; Ageeva, M. ; Emons, A.M.C. ; Lammeren, A.A.M. van - \ 2003
In: 5th International Symposium in the Series - Recent Advances in Plant Biotechnology, Stara Lesna, September 7-13, 2003, High Tatras Slovak Republic Stara Lesna : S.n. - p. 165 - 165.
Abnormalities in architecture of the microtubular cytoskeleton during meiosis in haploid Brassica juncea Czern and Coss
Lammeren, A.A.M. van; Deineko, E. ; Kieft, H. ; Custers, J.B.M. ; Shamina, N.V. - \ 2002
- 167 p.
T-DNA insertion leads to male sterility in tobacco
Deineko, E. ; Kieft, H. ; Emons, A.M.C. ; Lammeren, A.A.M. van - \ 2002
Microtubule dynamics during preprophase band formation and configuration of the microtubule cytoskeleton in elongating fibres of flax (Linum usitatissimum L.)
Lammeren, A.A.M. van; Ageeva, M. ; Kieft, H. ; Lhuissier, F. ; Emons, A.M.C. - \ 2002
In: Book of abstracts, Nato advanced research workshop 'The plant cytoskeleton: functional diversity and biotechnological implications' Kiev, Ukraïne :
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.