المؤلفون: H.J. Wilms

المصدر: Acta Societatis Botanicorum Poloniae 50 (1981)
Acta Societatis Botanicorum Poloniae, Vol 50, Iss 1-2, Pp 165-168 (2014)
Acta Societatis Botanicorum Poloniae, 50, 165-168

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Egg cell, Nucleolus, Endoplasmic reticulum, Embryo, Plant Science, Vacuole, Filiform apparatus, Biology, lcsh:QK1-989, Cell biology, Laboratory of Plant Cell Biology, medicine.anatomical_structure, lcsh:Botany, Botany, medicine, Ultrastructure, Life Science, Nucleus

الوصف: The egg apparatus of Spinacia was studied from the time the embryo sac reaches its maximal size to just before fertilization, i.e., until about 8-9 hours after pollination. At maturity each synergid has a large elongated nucleus and prominent chalazal vacuoles, Numerous mitochondria, plastids, dictyosomes, free ribosomes, rough endoplasmic reticulum (RER), and lipid bodies are present. The cell wall exists only around the micropylar half of the synergids and each cell has a distinct, striated filiform apparatus. In general, degeneration of one synergid starts after pollination. The egg cell has a spherical nucleus and nucleolus and a large micropylar vacuole. Numerous mitochondria, some plastids with starch grains, dictyosomes, free ribosomes, and HER are present. A continuous cell wall is absent around the chalazal end of the egg cell.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::90b6d0f302e3254006916c1972f4f446Test
https://doi.org/10.5586/asbp.1981.024Test

المؤلفون: J. L. Van Went

المصدر: Acta Societatis Botanicorum Poloniae, Vol 50, Iss 1-2, Pp 249-252 (2014)
Acta Societatis Botanicorum Poloniae 50 (1981)
Acta Societatis Botanicorum Poloniae, 50, 249-252

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Tapetum, biology, Sterility, Cytoplasmic male sterility, Plant Science, biology.organism_classification, lcsh:QK1-989, Laboratory of Plant Cell Biology, lcsh:Botany, Botany, Ultrastructure, Life Science, Impatiens

الوصف: Some cytological and ultrastructural aspects of tapetum and sporogenic cells, in both male-fertile and male-sterile Impatiens, were investigated and compared in order to find the cause of cytoplasmic male sterility.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ac8ff319fed34a3019fc2957967e35eeTest
https://doi.org/10.5586/asbp.1981.039Test

المؤلفون: Franck Lhuissier, Antonius C.J. Timmers, Björn J. Sieberer, Anne Mie C. Emons

المصدر: Plant Physiology, 130, 977-988
Plant Physiology 130 (2002)

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Cytoplasm, Paclitaxel, Physiology, Green Fluorescent Proteins, Population, Plant Science, Biology, Root hair, Endoplasmic Reticulum, Microtubules, Plant Roots, chemistry.chemical_compound, Microtubule, Sulfanilamides, Botany, Medicago, Genetics, medicine, Life Science, Cytoskeleton, education, education.field_of_study, integumentary system, Cell Polarity, Oryzalin, Immunohistochemistry, Cell biology, Laboratory of Plant Cell Biology, Dinitrobenzenes, Luminescent Proteins, medicine.anatomical_structure, chemistry, Ultrastructure, Cell Surface Extensions, EPS, Carrier Proteins, Nucleus, Cell Division, Research Article

الوصف: To investigate the configuration and function of microtubules (MTs) in tip-growing Medicago truncatularoot hairs, we used immunocytochemistry or in vivo decoration by a GFP linked to a MT-binding domain. The two approaches gave similar results and allowed the study of MTs during hair development. Cortical MTs (CMTs) are present in all developmental stages. During the transition from bulge to a tip-growing root hair, endoplasmic MTs (EMTs) appear at the tip of the young hair and remain there until growth arrest. EMTs are a specific feature of tip-growing hairs, forming a three-dimensional array throughout the subapical cytoplasmic dense region. During growth arrest, EMTs, together with the subapical cytoplasmic dense region, progressively disappear, whereas CMTs extend further toward the tip. In full-grown root hairs, CMTs, the only remaining population of MTs, converge at the tip and their density decreases over time. Upon treatment of growing hairs with 1 μm oryzalin, EMTs disappear, but CMTs remain present. The subapical cytoplasmic dense region becomes very short, the distance nucleus tip increases, growth slows down, and the nucleus still follows the advancing tip, though at a much larger distance. Taxol has no effect on the cytoarchitecture of growing hairs; the subapical cytoplasmic dense region remains intact, the nucleus keeps its distance from the tip, but growth rate drops to the same extent as in hairs treated with 1 μm oryzalin. The role of EMTs in growing root hairs is discussed.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2947eb1becd95293b399f959141856bdTest
https://doi.org/10.1104/pp.004267Test

المؤلفون: Anne Mie C. Emons, Tijs Ketelaar

المصدر: New Phytologist, 152, 409-418
New Phytologist 152 (2001)

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Physiology, Cortical actin cytoskeleton, Microtubule, Plant Science, Root hair, Biology, Plant cell, Microfilament, Exocytosis, Cell biology, Laboratory of Plant Cell Biology, Cell expansion, Cytoplasm, Botany, Calcium, EPS, Cytoskeleton, Actin

الوصف: In this review, we compare expansion of intercalary growing cells, in which growth takes place over a large surface, and root hairs, where expansion occurs at the tip only. Research that pinpoints the role of the cytoskeleton and the cytoplasmic free calcium in both root hairs and intercalary growing cells is reviewed. From the results of that research, we suggest experiments to be carried out on intercalary growing cells to test our hypotheses on plant cell expansion. Our main hypothesis is that instability of the cortical actin cytoskeleton determines the location where expansion takes place and the amount of expansion. Contents Summary 409 I. How do plant cells expand their surface? 409 II. Immunolocalization of epitopes in fixed root hairs for light-microscopy 410 III. The cytoskeleton in growing root hairs 412 1. Microtubules 412 2. Actin filaments 413 3. Free cytoplasmic calcium concentration 413 IV. The role of cytoskeletal elements and cytoplasmic free alcium in intercalary expanding root cells 414 1. Microtubules 414 2. Actin filaments 415 3. Free cytoplasmic calcium concentration 416 Acknowledgements 416 References 416.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f29f65ed0d161bc4c6dad438cf6c16daTest
https://doi.org/10.1046/j.0028-646x.2001.00278.xTest

المؤلفون: J.H.N. Schel, K.R. Straatman

المصدر: Protoplasma 216 (2001)
Protoplasma, 216, 191-200

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Pollen development, Nucleolus, Coiled Bodies, Plant Science, Biology, medicine.disease_cause, environment and public health, Microspore, Pollen, Botany, medicine, snRNP, Cell Nucleus, Nucleoplasm, Microspore embryogenesis, Brassica napus, food and beverages, Cell Biology, General Medicine, Ribonucleoproteins, Small Nuclear, Immunohistochemistry, Coiled body, Cell biology, Laboratory of Plant Cell Biology, Spliceosome, medicine.anatomical_structure, RNA splicing, EPS, Nucleus, Small nuclear ribonucleoprotein

الوصف: Small nuclear ribonucleoprotein particles (snRNPs) are subunits of splicing complexes, which show a transcription-dependent localization pattern. We have analyzed the labelling pattern of snRNPs during pollen development and microspore and pollen embryogenesis in Brassica napus with an antibody which recognizes protein D of U1, U2, U4, U5, and U6 snRNPs. It was found that nuclei were labelled almost uniformly for snRNPs in microspores and young bicellular pollen. In the generative nuclei of late-bicellular pollen and in the vegetative nuclei and sperm nuclei of mature pollen no snRNPs could be detected. The snRNP-positive nuclei contained mostly one or two brightly labelled nuclear bodies, most likely coiled bodies, often closely related to the nucleolus. These nuclear bodies increased in size from 0.5 micron in nuclei of young microspores up to 2 microns in nuclei of late microspores and the vegetative nucleus of early-bicellular pollen. Also their number increased during these developmental stages. After induction of embryogenesis the size of the coiled bodies decreased to about 0.5 micron and in several occasions the coiled body was found free in the nucleoplasm, away from the nucleolus. The results support the idea that the size and number of coiled bodies coincide with changes in general nuclear activity. They also indicate that, in nuclei of Brassica napus, at least assembly and disassembly of coiled bodies takes place in the nucleoplasm, whereas mature coiled bodies are located adjacent to the nucleolus.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3bbfb7c5b5a8b47bf07cb41f0177b084Test
https://doi.org/10.1007/bf02673871Test

المؤلفون: Elena A. Golovina, Folkert A. Hoekstra, Adriaan C. van Aelst

المصدر: Journal of Experimental Botany 52 (2001)
Journal of Experimental Botany, 52, 1015-1027

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Physiology, Triticum aestivum, Morphogenesis, Plant Science, Biology, Endosperm, Desiccation tolerance, Anthesis, Botany, Laboratorium voor Plantenfysiologie, Triticum, Electron Spin Resonance Spectroscopy, Water, food and beverages, Embryo, Meristem, Adaptation, Physiological, Cellular desiccation tolerance, EPR spin probe, Cell biology, Laboratory of Plant Cell Biology, Premature drying, Germination, Seeds, Embryogenesis, SEM, EPS, Desiccation, Laboratory of Plant Physiology

الوصف: Acquisition of desiccation tolerance and the related changes at the cellular level in wheat (Triticum aestivum cv. Priokskaya) kernels during normal development and premature drying on the ear were studied using a spin probe technique and low temperature scanning electron microscopy. During normal development, the ability of embryos to germinate after rapid drying and rehydration was acquired after completion of morphological development, which is a few days before mass maturity. The acquisition of desiccation tolerance, as assessed by germination, was associated with an upsurge in cytoplasmic viscosity, the onset of accumulation of protein and oil bodies, and the retention of membrane integrity upon dehydration/rehydration. These features were also used to assess cellular desiccation tolerance in the cases when germination could not occur. Slow premature drying was used to decouple the acquisition of cellular desiccation tolerance from morphogenesis. Upon premature drying of kernels on the ears of plants cut at 5 d after anthesis, desiccation-tolerant dwarf embryos were formed that were able to germinate. When plants were cut at earlier stages poorly developed embryos were formed that were unable to germinate, but cellular desiccation tolerance was nevertheless acquired. In such prematurely dried kernels, peripheral meristematic endosperm cells had already passed through similar physiological and ultrastructural changes associated with the acquisition of cellular desiccation tolerance. It is concluded that despite the apparent strong integration in seed development, desiccation tolerance can be acquired by the meristematic cells in the developing embryo and cambial layer of endosperm, independently of morphological development.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::244128aeb66d23ed9607c5eed1ad1fc4Test
https://doi.org/10.1093/jexbot/52.358.1015Test

المؤلفون: Marcelle Holsters, Koen Goethals, Mondher El Jaziri, Tita Ritsema, Jaap Nijsse, Karen Cornelis

المصدر: Molecular Plant-Microbe Interactions 14 (2001)
Scopus-Elsevier
Molecular Plant-Microbe Interactions, 14, 599-608

مصطلحات موضوعية: DNA, Bacterial, Laboratorium voor Plantencelbiologie, Physiology, Nicotiana tabacum, Arabidopsis, Cytokinin, Microbiology, Shoot induction, Rhodococcus fascians, Tobacco, Botany, Rhodococcus, Colonization, Leafy, Plant Diseases, Microscopy, Confocal, biology, Slime layer, Cryoelectron Microscopy, fungi, Nucleic Acid Hybridization, food and beverages, General Medicine, Meristem, biology.organism_classification, Plant Leaves, Laboratory of Plant Cell Biology, Colonisation, Plants, Toxic, Microscopy, Fluorescence, Microscopy, Electron, Scanning, Agronomy and Crop Science, Bacteria

الوصف: Rhodococcus fascians is a plant-pathogenic bacterium that causes malformations on aerial plant parts, whereby leafy galls occur at axillary meristems. The colonization behavior on Nicotiana tabacum and Arabidopsis thaliana plants was examined. Independent of the infection methods, R. fascians extensively colonized the plant surface where the bacteria were surrounded by a slime layer. R. fascians caused the collapse of epidermal cells and penetrated intercellularly into the plant tissues. The onset of symptom development preceded the extensive colonization of the interior. The meristematic regions induced by pathogenic strain D188 were surrounded by bacteria. The nonpathogenic strain, D188-5, colonized the exterior of the plant equally well, but the linear plasmid (pFiD188) seemed to be involved in the penetration efficiency and colonization of tobacco tissues.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c30fdc2eb284270dbe5fda63d6dcd1f8Test
https://doi.org/10.1094/mpmi.2001.14.5.599Test

المؤلفون: N.C.A. de Ruijter, Björn J. Sieberer, Franck Lhuissier, J.J. Esseling, Anne Mie C. Emons

المصدر: Annals of Botany, 87, 289-302
Annals of Botany 87 (2001)

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, Plant Science, Nod, Review, Biology, Root hair, Nod factor, Botany, Tip growth, Cytoskeleton, Symbiosis, integumentary system, Depolarization, Actin cytoskeleton, biology.organism_classification, Cell biology, Legume, Laboratory of Plant Cell Biology, Rhizobium, Calcium, sense organs, EPS

الوصف: In many common legumes, when host-specific nodule bacteria meet their legume root they attach to it and enter through root hairs. The bacteria can intrude these cells because they instigate in the hairs the formation of an inward growing tube, the infection thread, which consists of wall material. Prior to infection thread formation, the bacteria exploit the cell machinery for wall deposition by inducing the hairs to form a curl, in which the dividing bacteria become entrapped. In most species, Nod factor alone (a lipochito-oligosaccharide excreted by bacteria) induces root hair deformation, though without curling, thus most aspects of the initial effects of Nod factor can be elucidated by studying root hair deformation. In this review we discuss the cellular events that host-specific Nod factors induce in their host legume root hairs. The first event, detectable only a few seconds after Nod factor application, is a Ca 2+ influx at the root hair tip, followed by a transient depolarization of the plasma membrane potential, causing an increase in cytosolic [Ca 2+ ] at the root hair tip. Also within minutes, Nod factors change the cell organization by acting on the actin cytoskeleton, enhancing tip cell wall deposition so that root hairs become longer than normal for their species. Since the remodelling of the actin cytoskeleton precedes the second calcium event, Ca 2+ spiking, which is observed in the perinuclear area, we propose that the initial cytoskeleton events taking place at the hair tip are related to Ca 2+ influx in the hair tip and that Ca 2+ spiking serves later events involving gene expression.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::30c51bb27791996ff3c8d8a95d8abd16Test
https://doi.org/10.1006/anbo.2000.1333Test

المؤلفون: C.J. Keijzer, G.W.A.M. van der Heijden, U. van Meeteren, W. van Ieperen, J. Nijsse

المصدر: Journal of Experimental Botany 52 (2001)
Journal of Experimental Botany, 52, 319-327

مصطلحات موضوعية: Digital image analysis, Laboratorium voor Plantencelbiologie, Horticultural Supply Chains, Materials science, Water transport, Vessel length distribution, Hydraulic conductance, Physiology, Xylem, Leerstoelgroep Tuinbouwproductieketens, Soil science, Plant Science, Soil surface, Hydraulic resistance, PE&RC, Laboratory of Plant Cell Biology, Electrical conduit, Hydraulic conductivity, Plant Research International, Botany, Length distribution, Xylem conduit anatomy, Dendranthema xgrandiflorum Tzvelev

الوصف: The stem xylem conduit dimensions and hydraulic conductivity of chrysanthemum plants (Dendranthemaxgrandiflorum Tzvelev cv. Cassa) were analysed and quantified. Simple exponential relations describe conduit length distribution, height dependency of conduit length distribution, and height dependency of stem hydraulic conductivity. These mathematical descriptions can be used to model the xylem water transport system. Within a chrysanthemum stem of 1.0 m, the conduit half-length (the length within which 50␘f the conduits have their end) was 0.029 m at soil surface and decreased by half at a height of 0.6 m. With each 0.34 m increase in height up the stem, the hydraulic conductivity decreased by 50ÐThe resistance calculated from conduit lumen characteristics was 70␘f the measured resistance. The remaining unexplained part of the hydraulic resistance is at least partly caused by inter-conduit connections

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f4bc527b23b8e576000aff465aa8e816Test
https://doi.org/10.1093/jexbot/52.355.319Test

المؤلفون: J.H.N. Schel, A. Iwanowska, I.R. von Recklinghausen, A. P. Mordhorst, A.A.M. van Lammeren, Henk Kieft

المصدر: Protoplasma, 211, 217-224
Protoplasma 211 (2000)

مصطلحات موضوعية: Laboratorium voor Plantencelbiologie, animal structures, Arabidopsis thaliana, Somatic embryogenesis, Callus formation, Plant Science, Biology, Hypocotyl, Auxin, Botany, Laboratorium voor Moleculaire Biologie, Primordium, chemistry.chemical_classification, Microscopy, fungi, Primordia timing, Structure, food and beverages, In vitro culture, Cell Biology, General Medicine, Meristem, biology.organism_classification, Cell biology, Laboratory of Plant Cell Biology, chemistry, Seedling, Callus, embryonic structures, Laboratory of Molecular Biology, EPS

الوصف: Seeds of the Arabidopsis thaliana mutant primordia timing (pt) were germinated in 2,4-dichlorophenoxyacetic acid- containing liquid medium. The seedlings formed somatic embryos and nonembryogenic and embryogenic callus in vitro in a time period of approximately two to three weeks. Embryogenesis and callus formation were monitored with respect to origin, structure, and development. Ten days after germination globular structures appeared in close vicinity of and on the shoot apical meristem (SAM). Somatic embryos formed either directly on the SAM region of the seedling or indirectly on embryogenic callus that developed at the SAM zone. Globular structures developed along the vascular tissue of the cotyledons as well, but only incidentally they formed embryos. Upon deterioration, the cotyledons formed callus. Regular subculture of the embryogenic callus gave rise to high numbers of somatic embryos. Such primary somatic embryos, grown on callus, originated from meristematic cell clusters located under the surface of the callus. Embryos at the globular and heart-shape stage were mostly hidden within the callus. Embryos at torpedo stage appeared at the surface of the callus because their axis elongated. Secondary somatic embryos frequently formed directly on primary ones. They preferentially emerged from the SAM region of the primary somatic embryos, from the edge of the cotyledons, and from the hypocotyl. We conclude that the strong regeneration capacity of the pt mutant is based on both recurrent and indirect embryogenesis.

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الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::56b4efc81d599c5150d1c80c4228e122Test
https://doi.org/10.1007/bf01304489Test