Topic
Protoplast
About: Protoplast is a research topic. Over the lifetime, 5474 publications have been published within this topic receiving 122468 citations.
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TL;DR: Plants were regenerated from green leaf mesophyll protoplasts of diploid Gentiana decumbens L.f. through somatic embryogenesis and Flow cytometric analysis and chromosome counting revealed that all regenerants were tetraploid.
Abstract: Somaclonal variation, often manifested as the increased ploidy of plants observed following in vitro culture, can be advantageous in ornamental species or those used for secondary metabolite production. Polyploidy occurs especially when plantlets are produced by protoplast and callus cultures. Plants were regenerated from green leaf mesophyll protoplasts of diploid Gentiana decumbens L.f. through somatic embryogenesis. A yield of more than 9 × 105 protoplasts per gram of fresh weight was achieved by incubating fully expanded young leaves in an enzyme mixture containing 1.0% (w/v) cellulase and 0.5% (w/v) macerozyme. Protoplasts, cultured in agarose beads using a modified Murashige and Skoog medium, divided and formed microcalli, with the highest plating efficiency obtained on medium containing 2.0 mg l−1 1-naphthaleneacetic acid and 0.1 mg l−1 thidiazuron. Callus proliferation was also promoted by including thidiazuron in agar-solidified medium, while somatic embryogenesis was induced from microcalli on medium supplemented with 1.0 mg l−1 kinetin, 0.5 mg l−1 gibberellic acid, and 80 mg l−1 adenine sulfate. Flow cytometric analysis and chromosome counting revealed that all regenerants were tetraploid.
37 citations
TL;DR: Plant regeneration from protoplast culture of Crocus cancellatus was investigated using regenerable embryogenic calli obtained from shoot meristem culture on LS on medium supplemented with 4 mg l+1 kinetin and 1 mg l−1 2,4-dichlorophenoxyacetic acid.
Abstract: Plant regeneration from protoplast culture of Crocus cancellatus was investigated using regenerable embryogenic calli obtained from shoot meristem culture on LS (Linsmaier and Skoog, 1965) medium containing 4 mg l−1 kinetin and 1 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D). Protoplasts were isolated directly from embryogenic calli. The best protoplast growth was found on those embedded in Ca-alginate beads and cultured with nurse cells in MS (Murashige and Skoog, 1962) medium supplemented with 2 mg l−1 kinetin, 1 mg l−1 2,4-D and 100 mg l−1 ascorbic acid at 25 °C in darkness. After 4–5 weeks of culture, microcalli appeared on the surface of the Ca-alginate beads, but the protoplasts without immobilization in Ca-alginate beads showed very low cell division. Growth of the microcalli in the medium with nurse cells was much better than in the medium without nurse cells. Transferring beads onto half strength MS medium supplemented with 0.2 mg l−1 kinetin and 0.1 mg l−1 2,4-D, increased the growth of embryogenic calli. Somatic embryo development was observed either on half strength MS medium growth regulator free or with 1 mg l−1 abscisic acid. Matured embryos germinated on half strength MS medium containing 25 mg l−1 of gibberelic acid. Plantlet formation was obtained on half strength MS medium containing 1 mg l−1 6-benzyladenine and 1 mg l−1 α-naphthaleneacetic acid at 20 °C in a 16/8 h light/dark cycle.
37 citations
TL;DR: It appears that ribosomes physiologically attached to the membrane rapidly take up messenger RNA, and that during treatment with actinomycin there is a transfer of polyribosomes or of messenger RNA from the cytoplasmic fraction to the membranes.
37 citations
TL;DR: Stable protoplasts may be released from Micrococcus lysodeikticus and Sarcina lutea by digestion of the cell-wall with lysozyme in sucrose or NaCl solutions having an osmotic pressure of some 25 atmospheres, but not in glycerol solutions of the same osmosis pressure.
Abstract: SUMMARY: Stable protoplasts may be released from Micrococcus lysodeikticus and Sarcina lutea by digestion of the cell-wall with lysozyme in sucrose or NaCl solutions having an osmotic pressure of some 25 atmospheres, but not in glycerol solutions of the same osmotic pressure The stability of the protoplasts depends not only upon the depression of the water activity by the solute but upon an osmotic pressure exerted against the protoplast (plasma-) membrane The permeability of the protoplast membrane to a number of solutes resembles that of the osmotic barrier of intact Staphylococcus aureus
37 citations
TL;DR: The conditions for optimal formation and regeneration of protoplast of Streptomyces clavuligerus were established and the efficiencies of regeneration and transformation increased greatly when protoplasts were obtained from cultures in the early stationary phase of growth.
Abstract: The conditions for optimal formation and regeneration of protoplasts of Streptomyces clavuligerus were established. The optimal temperature for regeneration of protoplasts and for transformation was 26 degrees C in three different regeneration media. The best efficiency of transformation was obtained with 40% polyethylene glycol 1000. The efficiencies of regeneration and transformation increased greatly when protoplasts were obtained from cultures in the early stationary phase of growth. The number of transformants per assay increased linearly with rising concentrations of protoplasts. However, the number of transformants per protoplast decreased at concentrations of protoplasts above 1.5 X 10(9). The total number of transformants rose linearly at increasing plasmid DNA concentrations, but the number of the transformants per microgram of DNA became constant at concentrations above 1 microgram of DNA. Transformation frequencies as high as 5 X 10(5) transformants per microgram of DNA were obtained when plasmid pIJ702 was isolated from S. clavuligerus but not when isolated from Streptomyces lividans.
37 citations