Bhatla SC, Kiessling J, Reski R (2002): Observation of polarity induction by cytochemical localization of phenylalkylamine-binding receptors in regenerating protoplasts of the moss Physcomitrella patens. Protoplasma 219, 99–105. Protoplasts may also be used for plant breeding, using a technique called protoplast fusion. Protoplasts from different species are induced to fuse by using an electric field or a solution of polyethylene glycol.
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The first meiotic division is then completed in the spores followed by a second meiotic division which leaves the spore with 4 nuclei. After dispersal, these four-nucleate spores germinate and naked protoplasts emerge. The protoplasts take in water upon emergence and enlarge to about 3 times the size of the spore from which they emerged. The protoplasts then form short thread-like filaments that later retract back into round globules.
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Introduction To Cytology. New York: McGraw Hill, p. 24. Protoplasts can be generated by stripping the cell wall from plant, bacterial, or fungal cells by mechanical, chemical or enzymatic means. Protoplasts differ from spheroplasts in that their cell wall has been completely removed.
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As the infection progresses, R. allomycis protoplasts will instead form resting spores with thick, spiny walls.
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Protoplasts of cells from a petunia's leaf Protoplasts of the moss Physcomitrella patens Protoplast, from ancient Greek (prōtóplastos, "first- formed"), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall.Hanstein, J (1880). Das Protoplasma. Heidelberg.Sharp, LW (1921).
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In the case of plant cells, protoplasts may be regenerated into whole plants first by growing into a group of plant cells that develops into a callus and then by regeneration of shoots (caulogenesis) from the callus using plant tissue culture methods. Growth of protoplasts into callus and regeneration of shoots requires the proper balance of plant growth regulators in the tissue culture medium that must be customized for each species of plant. Unlike protoplasts from vascular plants, protoplasts from mosses, such as Physcomitrella patens, do not need phytohormones for regeneration, nor do they form a callus during regeneration. Instead, they regenerate directly into the filamentous protonema, mimicking a germinating moss spore.
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Nature 318:285-287.Shimazaki K, Iino M, & Zeiger E (1986) Blue light-dependent proton extrusion by guard-cell protoplasts of Vicia faba. Nature 319:324-326.Schroeder JI, Raschke K, & Neher E (1987) Voltage dependence of K+ channels in guard cell protoplasts. Proc. Natl. Acad. Sci. USA 84:4108-4112.
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Instead, regenerating moss protoplasts behave like germinating moss spores.S.C. Bhatla, Justine Kiessling, Ralf Reski (2002): Observation of polarity induction by cytochemical localization of phenylalkylamine-binding receptors in regenerating protoplasts of the moss Physcomitrella patens. Protoplasma 219, 99-105. Of further note sodium nitrate and calcium ion at high pH can be used, although results are variable depending on the organism.Mahesh.
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Fused protoplast (on left), containing both chloroplasts (from a leaf cell) as well as a coloured vacuole (from a petal). Protoplasts can be used to study membrane biology, including the uptake of macromolecules and viruses . These are also used in somaclonal variation. Protoplasts are widely used for DNA transformation (for making genetically modified organisms), since the cell wall would otherwise block the passage of DNA into the cell.
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Some β1 integrin-like receptors on the root caps of Tabaco plants are found to play a role in the plant’s ability to detect gravitational pull and aid in root elongation in a process known as gravitropism. ILRs are found on the cellular membrane of plant protoplasts. The dispersion of the ILRs on these protoplasts can vary from species to species. The variation in the ILR surface placement has been correlated to species growth behavior.
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Streptomyces cyaneus is an actinobacterium species in the genus Streptomyces. S. cyaneus produces the alkylresorcinol adipostatin A (cardol). It also produces a chitinase A able to produce protoplasts from Schizophyllum commune cultured mycelia.
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Aoki, Y. and Kamei, Y. 2006 Preparation of recombinant polysaccharide-degrading enzymes from the marine bacterium, Pseudomonas sp. ND137 for the production of protoplasts of Porphyra yezoensis Eur. J. Phycol. 41: 321-328.
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Similarly, in Rhizaria, the amoeboid, multinucleate protoplasts of some Cercozoan algae, e.g. Chlorarachniophyta, are called plasmodia. These lack cell walls; the syncytia are created by cell fusion. Some plasmodiophorids and haplosporidians are other multinucleated rhizarians.
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Applications of this process include: clonal propagation of genetically uniform plant material; elimination of viruses; provision of source tissue for genetic transformation; generation of whole plants from single cells called protoplasts; development of synthetic seed technology.
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Methodology varies depending on the organism to transform. While plants can be transformed with a construct introduced into Agrobacterium tumefaciens via agroinfiltration or floral dip, most animal cells would require a viral vector. Some fungi, like yeasts or zygomycota, are susceptible to transformation by dedifferentiating their hyphae to protoplasts and adding Cl2Ca 10–50 mM, Tris-HCl 10 mM, polyethylene glycol (40%) and the DNA construct (> 5µg/ml) to a 10^8 protoplast/ml solution. Under this pH conditions, PEG acts as a binder, promoting protoplasts to clump together and trap introduced DNA strands.
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The procedure for seed plants describe above, fusion of moss protoplasts can be initiated without electric shock but by the use of polyethylene glycol (PEG). Further, moss protoplasts do not need phytohormones for regeneration, and they do not form a callus.Solvey Rother, Birgit Hadeler, José M. Orsini, Wolfgang O. Abel, Ralf Reski (1994): Fate of a mutant macro chloroplast in somatic hybrids. when the potato is hybridized with tomato instead of getting any one character both character will exhibit and get a new plant called Pomato Journal of Plant Physiology 143, 72-77.
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A year later, during his studies of their osmotic behavior, he discovered and described the occasional fusion of naked protoplasts. This seminal paper in German immediately caught the attention of the bacterial geneticist Joshua Lederberg, who personally requested a copy.
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Hain R, Czernilofsky AP, et al. (1985). "Uptake, integration, expression and genetic transmission of a selectable chimaeric gene by plant protoplasts". Molecular and General Genetics 199:161–168. This technique may be used to generate somatic hybrids in tissue culture.
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Besson F., Peypoux F. & Michel G., 1978b. Action of mycosubtilin and of bacillomycin L on Micrococcus luteus cells and protoplasts: influence of the polarity of the antibiotics upon their action on the bacterial cytoplasmic membrane. FEBS Lett., 90, 36-40.
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Humble GD & Raschke K (1971) Stomatal opening quantitatively related to potassium transport. Evidence from electron probe analysis. Plant Physiol. 48:447-453.Schroeder JI, Hedrich R, & Fernandez JM (1984) Potassium- selective single channels in guard cell protoplasts of Vicia faba.
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W. H. Freeman and Company, New York, 2005. The sole method of reproduction is asexual and azosporic. The content of the cell divide into 2,4 (B), 8(C) sometimes daughter protoplasts. Each daughter protoplast rounds off to form a non-motile spore.
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After the spores' development, they first receive a diploid nucleus, and the meiosis takes place in the spore. At the germination, the spore shells open either alongside special germinal pores or chinks, or rip irregularly and then release one to four haploid protoplasts.
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For altering moss genes in a targeted way, the DNA-construct needs to be incubated together with moss protoplasts and with polyethylene glycol (PEG). As mosses are haploid organisms, the regenerating moss filaments (protonemata) can be directly assayed for gene targeting within 6 weeks when utilizing PCR-methods.
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2010 U.S. Patent. Fusion of Bacterial Protoplasts of Five Strains of Clostridium to Produce a Unique Thermophilic that Produces Bio-fuels and Other Chemicals Like Butanole in a Single Bioreactor. 2012 U.S Patent # 018293.00016 HIV replication inhibition using viral gene fragments and homologous microRNAs. 2014 U.S. Patent (#8,669,082 B1).
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In 2005 a two hybrid system in plants was developed. Using protoplasts of A. thaliana protein-protein interactions can be studied in plants. This way the interactions can be studied in their native context. In this system the GAL4 AD and BD are under the control of the strong 35S promoter.
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Additionally, protoplasts of plants expressing fluorescent proteins in certain cells may be used for Fluorescence Activated Cell Sorting (FACS), where only cells fluorescing a selected wavelength are retained. Among other things, this technique is used to isolate specific cell types (e.g., guard cells from leaves, pericycle cells from roots) for further investigations, such as transcriptomics.
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124: 911–919. The hormones IAA and ABA are also involved in the process and play antagonistic roles, with IAA inducing pulvinar swelling and ABA inducing pulvinar shrinking. Blue light has also been shown to induce rapid pulvinar shrinking.Wang, X., Haga, K., Nishizaki, Y. and Iino, M. (2001) Blue-light- dependent osmoregulation in protoplasts of Phaseolus vulgaris pulvini.
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Hybrids may also be produced by a technique called protoplast fusion. In this case protoplasts are fused, usually in an electric field. Viable recombinants can be regenerated in culture. Chemical mutagens like EMS and DMS, radiation and transposons are used to generate mutants with desirable traits to be bred with other cultivars – a process known as Mutation Breeding.
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DNA Nanostructures Coordinate Gene Silencing in Mature Plants. DNA Nanostructures Coordinate Gene Silencing in Mature Plants: Supplemental Information, 538678. doi: 10.1101/538678. A recent study utilizing DNA loaded CNTs was able to successfully express desired traits in various mature model plant systems- and even isolated Eruca sativa protoplasts while managing to protect and maintain the fidelity of the transferred genetic material.
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The production of cyanotoxins is facultative, and strains that do not produce microcystins are commonly found in nature. Apart from microcystins, they can produce several other cyclic peptides including oscillapeptin J. Planktothrix organisms house gas vesicles called protoplasts which play an important role in their buoyancy as the gas within the vesicle is nearly only one tenth the density of water making the organism less dense overall.
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While all mechanistic aspects of this behavior have yet to be elucidated (e.g., evidence indicates differential gene expression is involved, but the specifics have yet to be determined), many of the physiological aspects of paraheliotropic movement, at least in Phaseolus vulgaris (the common bean), are well understood.Iino, M., Long, C., and Wang, X. (2001). Auxin- and Abscisic Acid-Dependent Osmoregulation in Protoplasts of Phasoleus vulgaris Pulvini.
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Astrephomene gubernaculifera has two mating types that reproduce to form zygotes. Schematic diagrams of the two mechanisms of spheroidal colony formation in the volvocine algae. In Astrephomene, rotation of daughter protoplasts occurs in conjunction with the movement of basal bodies during successive cell divisions. In Eudorina, protoplast rotation is lacking during successive divisions; a spheroidal colony is formed by means of inversion after successive divisions.
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For each plant, an overview (upper row, scale bar corresponds to 1 mm) and a close-up (bottom row, scale bar equals 0.5 mm) is shown. A, Haploid wild-type moss plant completely covered with leafy gametophores and close-up of wild- type leaf. B-D, Different Mutants. To target genes in moss, the DNA is incubated together with freshly isolated protoplasts and with polyethylene glycol.
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These algae are capable of forming two types of dormant diploid zygospores. Some populations form zygospores within single clones of cells (homothallic), whereas others form zygospores between different clones of cells (heterothallic). The heterothallic strains have two mating types, mt(-) and mt(+). When cells of opposite mating types are mixed in a nitrogen- deficient mating medium, mt(-) and mt(+) cells pair with each other and release protoplasts.
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Somatic embryos are formed from plant cells that are not normally involved in the development of embryos, i.e. ordinary plant tissue. No endosperm or seed coat is formed around a somatic embryo. Applications of this process include: clonal propagation of genetically uniform plant material; elimination of viruses; provision of source tissue for genetic transformation; generation of whole plants from single cells called protoplasts; development of synthetic seed technology.
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Ernst Haeckel, in his 1866 Generelle Morphologie der Organismen, asserted that all living things were monophyletic (had a single evolutionary origin), being divided into plants, protista, and animals. His protista were divided into moneres, protoplasts, flagellates, diatoms, myxomycetes, myxocystodes, rhizopods, and sponges. His animals were divided into groups with distinct body plans: he named these phyla. Haeckel's animal phyla were coelenterates, echinoderms, and (following Cuvier) articulates, molluscs, and vertebrates.
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One can disrupt the membrane and demonstrate a heterogeneous range of composition in the population of the resulting vesicles or fragments. Electron microscopy can also be used to demonstrate lateral inhomogeneities in biomembranes. Often, lateral heterogeneity has been inferred from biophysical techniques where the observed signal indicates multiple populations rather than the expected homogenous population. An example of this is the measurement of the diffusion coefficient of a fluorescent lipid analogue in soybean protoplasts.
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Crick at Cambridge University Applying magnetic theory to the study of biology is a biophysical technique that started to appear in Germany in the early 1920s. Possibly the first demonstration was published by Alfred Heilbronn in 1922; his work looked at viscosity of protoplasts. The following year, Freundlich and Seifriz explored rheology in echinoderm eggs. Both studies included insertion of magnetic particles into cells and resulting movement observations in a magnetic field gradient.
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Ion channels and pumps regulating stomatal opening and closure. Ion uptake into guard cells causes stomatal opening: The opening of gas exchange pores requires the uptake of potassium ions into guard cells. Potassium channels and pumps have been identified and shown to function in the uptake of ions and opening of stomatal apertures.Assmann SM, Simoncini L, & Schroeder JI (1985) Blue light activates electrogenic ion pumping in guard cell protoplasts of Vicia faba.
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When living conditions become less favourable, many species of the genus Tetraspora also have the ability to form into hypanospores called akineties. Akineties are thick-walled spores that are brown in colour with a diameter of 12.9-15.80 μm and a cell wall thickness of 0.6-1.10 μm. They function as resting cells which are resistant to cold temperatures and desiccation. The process of division of mature akineties is done by amoeboid protoplasts located inside the mucilaginous envelopes.
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Photosynthesis, plant water transport (xylem) and gas exchange are regulated by stomatal function which is important in the functioning of plants. Stomata are responsive to light with blue light being almost 10 times as effective as red light in causing stomatal response. Research suggests this is because the light response of stomata to blue light is independent of other leaf components like chlorophyll. Guard cell protoplasts swell under blue light provided there is sufficient availability of potassium.
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E. calopteni only produces resting spores, which are available to infect grasshoppers the following year. E. macleodii and E. praxibuli produce both resting spores and asexual conidia. Large numbers of conidia are produced under wet, humid conditions, and several cycles of infection can then occur in a single season. After landing on a potential host, a conidium produces a germ tube which can grow through the cuticle into the hemocoel; once there, it produces amoeboid protoplasts.
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Colony inversion is believed to have arisen twice in the order Chlamydomonadales. Spheroidal colony formation differs between the two lineages: rotation of daughter protoplasts during successive cell divisions in Astrephomene, and inversion after cell divisions in Eudorina. Schematic representation of the phylogenetic relationships of the volvocine algae and the parallel evolution of the spheroidal colony. Volvocine algae range from the unicellular Chlamydomonas to the multicellular Volvox through various intermediate forms and are used as a model for research into the evolution of multicellularity.
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This is in contrast to the glycopeptide antibiotics vancomycin and teicoplanin, which are both much larger than the penicillins. Gram-positive bacteria are called protoplasts when they lose their cell walls. Gram-negative bacteria do not lose their cell walls completely and are called spheroplasts after treatment with penicillin. Penicillin shows a synergistic effect with aminoglycosides, since the inhibition of peptidoglycan synthesis allows aminoglycosides to penetrate the bacterial cell wall more easily, allowing their disruption of bacterial protein synthesis within the cell.
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Coprinopsis cinerea can be transformed with exogenous DNA by transformation when the fungus is a protoplast. It was found that disrupting (knockout or RNAi silencing) ku70 homologue can increase gene targeting via increased homologous recombination. Either protoplasts derived from oidia or vegetative mycelium can be used, however, gene targeting was found to be higher by 2% (based on phenotyping) when using vegetative mycelium. Otherwise, insertion of integrative vectors ectopically and with small homologous regions can be used, likely with low transformation efficiency.
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At Yale, Galston continued to do research in the areas of auxin physiology, photobiology, plant hormones, protoplasts and polyamines. Using microspectrophotometric measurements, he was the first researcher to report that phytochromes were located in plant nuclei, a result that would be confirmed using molecular techniques over 30 years later. At Yale, increasing amounts of Galston's time were spent in administrative roles. He served as chair of the Departments of Botany and Biology, the university-wide Course of Study Committee, and the Committee on Teaching and Learning.
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During asexual reproduction of Astrephomene, rotation of daughter protoplasts occurs in conjunction with the movement of basal bodies during successive cell divisions, ending with the anterior end of all cells of the daughter colony outside after the first nuclear and cytoplasmic division.Yamashita S, Arakaki Y, Kawai-Toyooka H, Noga A, Hirono M, Nozaki H. Alternative evolution of a spheroidal colony in volvocine algae: developmentalanalysis of embryogenesis in Astrephomene (Volvocales, Chlorophyta). BMC Evol Biol. 2016 Nov 9;16(1):243. PubMed PMID: 27829356; PubMed Central PMCID: PMC5103382.
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More specifically, ACC signaling promotes secretion of the pollen tube chemoattractant LURE1.2 in ovular sporophytic tissue thus enhancing pollen tube attraction. Additionally, ACC activates Ca2+-containing ion currents via glutamate receptor-like (GLR) channels in root protoplasts. ACC can be used by soil microorganisms (both bacteria and fungi) as a source of nitrogen and carbon. As such, using ACC to incubate soils has been proven to induce the gene abundance encoding ACC- deaminases, which may have positive consequences on plant growth and stress tolerance.
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Pectin affects the expression of WAK2 dependent genes such as those involved in cell wall integrity and external response; WAK2 is suggested to be important in cellular events and gene expression in Arabidopsis mesophyll. Gene expression using Affymetrix expression arrays with RNA from wild-type or wak2-1 (null mutation) protoplasts treated or not treated with pectin reveals a variety of things. In pectin-treated wild type protoplasts, there was a change in the expression of over 200 genes, with almost 50 of the upregulated genes being those involved in cell-wall synthesis such as pectin esterase, leucine-rich transmembrane kinase, plant defensin. The remainder of the downregulated genes comprised those involved in multiple functions through the plant; however, only one gene in the pectin-treated WAK2-1 was differentially expressed. In comparison to wak2-1, 13 out of the 50 upregulated genes in the wild-type was suppressed in wak2-1 and 37 were expressed similarly to the wild type. 20 genes within those downregulated showed reduced expression in wak2-1 cells, 24 were activated and the remainder had levels similar to the wild type.
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Microfibrils are held together by hydrogen bonds to provide a high tensile strength. The cells are held together and share the gelatinous membrane called the middle lamella, which contains magnesium and calcium pectates (salts of pectic acid). Cells interact though plasmodesmata, which are inter-connecting channels of cytoplasm that connect to the protoplasts of adjacent cells across the cell wall. In some plants and cell types, after a maximum size or point in development has been reached, a secondary wall is constructed between the plasma membrane and primary wall.
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Both Stähelin's parents were medical doctors. After preparatory school and a classical education with the emphasis on Greek and Latin, Stähelin studied medicine in Basel, Zürich and Florence (1944–1950). His first position after graduation was at the Institute of Microbiology of the University of Basel (1951–1954) where he investigated the morphology and sporulation of anthrax bacilli with the help of the then-new phase-contrast microscope. In May 1951, Stähelin was the first to observe naked anthrax bacilli protoplasts, called gymnoplasts, which had left behind their empty cell walls.
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Two main tapetum types are recognised, secretory (glandular) and plasmodial (amoeboid). In the secretory type a layer of tapetal cells remains around the anther locule, while in the plasmodial type the tapetal cell walls dissolve and their protoplasts fuse to form a multinucleate plasmodium. A third, less common type, the invasive non- syncytial tapetum has been described in Canna, where the tapetal cell walls break down to invade the anther locule but do not fuse to form a plasmodium. Amongst the monocots Acorales, the first branching clade has a secretory tapetum, while the other alismatid clade, Alismatales are predominantly plasmodial.
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Green peach aphid, Myzus persicae, killed by the fungus Pandora neoaphidis (Zygomycota: Entomophthorales) Scale bar = 0.3 mm. These fungi usually attach to the external body surface of insects in the form of microscopic spores (usually asexual, mitosporic spores also called conidia). Under the right conditions of temperature and (usually high) humidity, these spores germinate, grow as hyphae and colonize the insect's cuticle; which they bore through by way of enzymatic hydrolysis, reaching the insects' body cavity (hemocoel). Then, the fungal cells proliferate in the host body cavity, usually as walled hyphae or in the form of wall-less protoplasts (depending on the fungus involved).
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There is not a lot known about plant virus and host cell interaction due to the difficulty of studying organisms with cell walls. One study examined the interactions between CCMV and cowpea protoplasts and found that it was dependent on aspecific binding, mostly relying on electrostatic interactions between the plasma membrane and virus particles, specifically negatively charged vesicles and the positively charged N-terminal arm of viral coat proteins, further labelling CCMV as an endocytic virus. It also takes advantage of membrane lesions to introduce viral particles into the cell. Overall, the most effective infection occurred by internalization through membrane lesions of the host.
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While chromosomal integration of genes creates a stable transformant, transient expression allows short-term experiments to be done using labeled or modified genes in C. merolae. Transient expression can be achieved using a polyethylene glycol (PEG) based method in protoplasts (plant cells with the rigid cell wall enzymatically eliminated), and because C. merolae lacks a cell wall, it behaves much as a protoplast would for transformation purposes. To transform, cells are briefly exposed to 30% PEG with the DNA of interest, resulting in transient transformation. In this method, the DNA is taken up as a circular element and is not integrated into the genome of the organism because no homologous regions exist for integration.
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According to some studies, the Casparian strip begins as a localized deposition of phenolic and unsaturated fatty substances in the middle lamella between the radial walls, as partly oxidized films. The primary wall becomes encrusted with and later thickened by deposits of similar substances on the inside of that wall. The encrustation of the cell wall by the material constituting the Casparian strip presumably plugs the pores that would have otherwise allowed the movement of water and nutrients via capillary action along that path. The cytoplasm of the endodermal cell is firmly attached to the Casparian strip so that it does not readily separate from the strip when the cells are subjected to contraction of the protoplasts.
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540-547 It is an additional gene whose only biological function is to block pollen formation. It is involved in gynodoecia (a species composed of females and hermaphrodites) in the genus Raphanus. The discovery of the gene responsible for male sterility, its transfer to Brassica by fusion of protoplasts, and the selection of mitochondrial recombinants with improved agronomic characteristics have enabled this male sterility to be widely distributed and exploited in Europe and North America for the production of hybrid varieties in rapeseed and various cabbage.Pelletier G. and Budar F., Brassica Ogu-INRA Cytoplasmic Male sterility: an example of successful plant somatic fusion for hybrid seed production; In X-Q Li, D.J. Donnelly and T.G.Jensen eds.
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The fruit's size has not been shown to increase appreciably by girdling the vines or by applying gibberellic acid when the berries set. The aborted seeds of Thomcord are small, but in some years they can become sclerified (a thickening and lignification of the walls of plant cells and the subsequent dying off of the protoplasts), making them more noticeable inside the medium-soft flesh. There are usually two aborted seeds per berry, which averaged between 14 and 22.3 mg in 2001 and 2002. This varied in comparison to Venus depending on the year and location, was comparable to the Sovereign Coronation, and was significantly smaller than the Sovereign Rose and Saturn varieties.
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In enzymology, a pectin lyase also known as pectolyase is a naturally occurring pectinase a type of enzyme that degrades pectin. It is produced commercially for the food industry from fungi and used to destroy residual fruit starch, known as pectin, in wine and cider. In plant cell culture, it is used in combination with the enzyme cellulase to generate protoplasts by degrading the plant cell walls. Pectin lyase is an enzyme that catalyzes the chemical reaction :Eliminative cleavage of (1->4)-alpha-D-galacturonan methyl ester to give oligosaccharides with 4-deoxy-6-O-methyl-alpha-D- galact-4-enuronosyl groups at their non-reducing ends This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on polysaccharides.
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Beside his main research stream, he worked collaboratively as a visiting scientist with many famous scientists from different parts of the world: He was very lucky to be involved in research with a very active research group at London University led by both Dr. R.H.A. Coutts and Prof. R.K.S. Wood (FRS), Virology laboratory, Imperial College of Science. The work was centred on elucidating the molecular basis of gene expression in terms of protein synthesis and enzyme activities in plant tissues exposed to biotic (necrosis-eliciting viruses or fungal infections) or abiotic stresses. He was also privileged by working as a visiting scientist in 1981, with Dr. R.H.A. Coutts on the replication and gene expression of single stranded DNA viruses (Geminiviruses) in protoplasts.
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Osbourn went on to study at the Queens' College, Cambridge where she obtained a 1st class degree in Natural Sciences (Biochemistry). She was recognised in 1986 for playing Netball at Queens, and was also awarded both a third year Foundation Scholarship and The Henry Mosseri prize. She then went on to complete a PhD degree at the John Innes Centre for Plant Science Research in Norwich which resulted in the publication of Evidence that nucleocapsid disassembly and a later step in virus replication are inhibited in transgenic tobacco protoplasts expressing TMV coat protein. Following this she completed a post-doctoral position at Rutgers University, New Jersey, undertaking research directed towards clarification of the sequence elements responsible for the translational enhancement effect conferred by the 5' untranslated region of Tobacco Mosaic Virus known as omega.
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Section two establishes various definitions, including section 2(3)(a) which strictly defines "genetically engineered" by specific genetic engineering techniques, and differentiated from selective breeding. These specific genetic engineering techniques include various recombinant DNA and RNA methods such as micro- injection, electroporation, micro-encapsulation, liposome fusion, protoplast fusion or other "hybridization techniques that overcome natural physiological, reproductive or recombination barriers, where the donor cells or protoplasts do not fall within the same taxonomic family, in a way that does not occur by natural multiplication or natural recombination." Section three requires that "any food offered for retail sale" be labeled "clearly and conspicuously" if it contains genetically-engineered ingredients, with certain exceptions. Exemptions consistent with current federal regulations include prepared foods such as those coming from a restaurant, meat from animals fed genetically engineered feeds, alcoholic beverages and foods processed with GE enzymes.
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Video of high-frequency irreversible electroporation (H-FIRE) for non-thermal ablation without muscle Electroporation, or electropermeabilization, is a microbiology technique in which an electrical field is applied to cells in order to increase the permeability of the cell membrane, allowing chemicals, drugs, or DNA to be introduced into the cell (also called electrotransfer). In microbiology, the process of electroporation is often used to transform bacteria, yeast, or plant protoplasts by introducing new coding DNA. If bacteria and plasmids are mixed together, the plasmids can be transferred into the bacteria after electroporation, though depending on what is being transferred cell-penetrating peptides or CellSqueeze could also be used. Electroporation works by passing thousands of volts across a distance of one to two millimeters of suspended cells in an electroporation cuvette (1.0 – 1.5 kV, 250 – 750 V/cm).
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