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| 2. |
- Brodelius, Peter, et al.
(författare)
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Permeabilization of Cultivated Plant Cells by Electroporation for Release of Intracellularly Stored Secondary Products
- 1988
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Ingår i: Plant Cell Reports. - 0721-7714 .- 1432-203X. ; 7:3, s. 186-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant cell suspension cultures producing secondary metabolites have been permeabilized for product release by electroporation. The two cell cultures studied, i.e. Thalictrum rugosum and Chenopodium rubrum, require about 5 and 10 kV cm–1, respectively, for complete permeabilization (release of all the intracellularly stored product). The number of electrical pulses and capacitance used had a relatively limited effect on product release while the viability of the cells was strongly influenced by the latter. Conditions for complete product release resulted in total loss of viability of the cells after treatment. The release of product from immobilized cells was also achieved by electroporation. Cells entrapped in alginate required less voltage for permeabilization than free or agarose entrapped cells.
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| 3. |
- Brodelius, Peter
(författare)
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Permeabilization of Plant Cells for Release of Intracellularly Stored Products: Viability Studies
- 1988
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Ingår i: Applied Microbiology and Biotechnology. - 0175-7598 .- 1432-0614. ; 27, s. 561-566
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Tidskriftsartikel (refereegranskat)abstract
- The effects of various chemical substanceson the permeability of plasma membranesand tonoplasts of three suspension cultures (Catharanthusroseus, Thalictrum rugosum and Chenopodiumrubrum) have been studied. The permeabilityof the plasma membrane is monitoredby measuring the activity of the cytosolic enzymeisocitrate dehydrogenase and the permeability ofthe tonoplast is measured by determining the releaseof substances stored in the vacuoles (inorganicphosphate, berberine and betanin for thethree cell lines, respectively). The minimum concentrationrequired for quantitative release of vacuolarproducts have been established for five differentpermeabilization agents. Cell viability islost upon permeabilization except for treatmentof Catharanthus roseus with DMSO and Triton X-100.
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| 4. |
- Gügler, K, et al.
(författare)
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Elicitor-induced Tyrosine Decarboxylase in Berberine Synthesizing Suspension Cultures of Thalictrum rugosum
- 1988
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 170:3, s. 661-666
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Tidskriftsartikel (refereegranskat)abstract
- Tyrosine decarboxylase (EC 4.1.1.25) was induced in suspension cultures of Thalictrum rugosum by treatment with a yeast glucan elicitor. Maximum induction was observed at a carbohydrate concentration of 0.4 mg/g fresh weight of cells and maximum enzyme activity was reached 20 h after addition of elicitor. The enzyme was inducible in late exponential and early stationary growth phases. A good correlation between induced tyrosine decarboxylase activity and berberine biosynthesis has been established. It is suggested that tyrosine decarboxylase may be a key enzyme between primary and secondary metabolisms in the biosynthesis of norlaudanosoline-derived alkaloids.
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| 5. |
- Hakman, Inger, et al.
(författare)
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An embryogenic cell-suspension culture of Picea glauca (White spruce)
- 1987
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Ingår i: Plant Cell Reports. - 0721-7714 .- 1432-203X. ; 6:1, s. 20-22
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Tidskriftsartikel (refereegranskat)abstract
- A cell suspension culture of Picea glauca (White spruce) which continuously produces somatic embryos has been established. Embryogenic callus derived from cultured zygotic embryos was used to initiate the culture. Numerous embryos at various early stages of development were recognized; they exhibited a meristematic embryonic region and suspensor consisting of elongate, vacuolated cells. The culture also contained clumps of meristematic cells and large irregular — shaped cells. The culture could be readily re-established on solid medium.
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| 6. |
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| 7. |
- Linsefors, L, et al.
(författare)
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Immobilization of Plant Protoplasts: Viability Studies
- 1985
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Ingår i: Plant Cell Reports. - 0721-7714 .- 1432-203X. ; 4:1, s. 23-27
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Tidskriftsartikel (refereegranskat)abstract
- Protoplasts of Daucus carota Ca68 and Catharanthusroseus have been inmobilized by entrapment in gelformingpolysaccharides (kappa-carrageenan, agarose andalginate). Uniform spherical beads of carrageenan andagarose containing the protoplasts have been preparedby utilizing an inert hydrophobic phase (vegetableoil). The entrapped protoplasts are viable and stabilizedtowards osmotic shock by the polymeric backbone.Standard methods have been used to study the viabilityand integrity of the entrapped protoplasts. Uponincubation in a relatively simple medium the inmobilizedprotoplasts show a much higher viability after14 days as compared to free protoplasts under the sameconditions. The viability of D. carota protoplasts hasalso been monitored by an enzyme activity present inthe cells (digitoxigenin 58-hydroxylase) .
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| 8. |
- Lundberg, Peter, et al.
(författare)
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Permeabilization of Plant Cells: 31P NMR Studies of the Permeability of the Tonoplast
- 1986
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Ingår i: Plant Cell Reports. - : Springer. - 0721-7714 .- 1432-203X. ; 5, s. 13-16
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Tidskriftsartikel (refereegranskat)abstract
- A suspension culture of Catharanthus roseus has been used to study the permeability of cell membranes after treatment with various concentrations of a permeabilizing agent (DMSO). The uptake and release (after permeabilization) of inorganic phosphate (Pi) by cells have been investigated by 32P radiotracer and non-invasive phosphorus-31 NMR experiments. These studies have demonstrated that measurements of the Pi-efflux from plant cells provide a reliable measure of the permeability of the tonoplast.
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| 9. |
- Ohlsson, LG, et al.
(författare)
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Postembryonic development of Arg-Phe-amide-like and cholecystokinin-like immunoreactive neurons in the blowfly optic lobe
- 1989
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Ingår i: Cell and Tissue Research. - 0302-766X .- 1432-0878. ; 256, s. 199-211
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Tidskriftsartikel (refereegranskat)abstract
- The adult optic lobes of the blowfly Calliphoraerythrocephala were found to be innervated by more than2000 neurons immunoreactive to antisera raised against theneuropeptides FMRFamide, its fragment RFamide, andgastrin/cholecystokinin (CCK). All of the CCK-like immunoreactive(CCK-IR) neurons also reacted with antisera toRFamide, FMRFamide and pancreatic polypeptide. A fewRFamide/FMRFamide-like immunoreactive (RF-IR) neuronsdid not react with CCK antisera; they reacted insteadwith antisera to Leu-enkephalin and Met-enkephalin-Arg 6-Phe 7. The RF-IR neurons are, thus, heterogeneous withrespect to their contents of immunoreactive peptides. Twoof the RF-IR neuron types innervating the adult optic lobescould be traced in their entirety only after following theirpostembryonic development, because of the complexity ofthe trajectories of the immunoreactive neuronal process inthe adult insect. The majority of the cell bodies of the RFIRand CCK-IR neurons lie within the optic lobes andare derived from imaginal neuroblasts of the inner and outeroptic anlagen. Six of the peptidergic neurons are, however,metamorphosing larval neurons with their cell bodiesin the central part of the protocerebrum. The full extentof immunoreactivitiy is not attained in some of the neuronsuntil the late pupal or early adult stage. The larval opticcenter was also found to be innervated by neurons immunoreactivewith both RFamide and CCK antisera. The cellbodies of these RF-IR/CCK-IR neurons are located nearthe developing lamina (one on each side). In the 24 h pupa,the cell bodies of these neurons are still immunoreactive,but thereafter they cannot be immunolabeled apparentlydue to cell death or a change in transmitter phenotype.
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| 10. |
- Sode, K, et al.
(författare)
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Continuous Production of Somatomedin C with Immobilized Transformed Yeast Cells
- 1988
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Ingår i: Applied Microbiology and Biotechnology. - 0175-7598 .- 1432-0614. ; 28:3, s. 215-221
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Tidskriftsartikel (refereegranskat)abstract
- Yeast cells producing the growth hormonesomatomedin C (SMC) were constructedand applied in the immobilized form continuouslyfor a period of over 10 days in a flowthroughbioreactor. The construction of theMF~I-SMC fusion vector p336/l is given as wellas the results of the influence of various nutrientseffecting hormone production. Immobilization ofthe transformed yeast cells is described and theirapplication in a continuous bioreactor system.This study demonstrates the feasibility of a longtermand high-level hormone production by immobilizedtransformed yeast. The SMC productivitiesof free cells in batch and immobilized cellsunder continuous conditions were 0.2--0.3 and0.5--0.6 mg per g wet cells and day, respectively.
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