Protoplast

About: Protoplast is a research topic. Over the lifetime, 5474 publications have been published within this topic receiving 122468 citations.

Transgenic Rice: Characterization of Protoplast derived Plants and their Seed Progeny

Abstract: Thirty eight green and 2 albino plants were regenerated from 400 kanamycin-resistant colonies derived from protoplasts isolated from cell suspensions of Oryza sativa variety Taipei 309 and electroporated with pCaMVNEO carrying the neomycin phosphotransferase II {nptll) gene. Twenty of the green transgenic R0 plants were transferred to the glasshouse, where 3 flowered after 7 months. Of 15 plants analysed by DNA hybridization, all carried the nptll gene, but only 2 of 11 plants assayed for NPTII activity expressed the nptll gene. One transgenic R0 plant produced 59 seeds following self-pollination. The seeds, when germinated on medium containing kanamycin sulphate, gave 16 green transgenic R, plants. Five transgenic Rt plants flowered and set seed, 7 flowered but failed to produce seeds, while 4 did not produce panicles. Transgenic R0 and R! plants were shorter, required longer to flower, and had reduced pollen viability compared to non-transformed R, protoplast-derived plants. The nptll gene was present in all 16 transgenic R, plants, but NPTII activity was detected in only 8 of these plants.

Inhibitory protein controls the reversion of protoplasts and L forms of Bacillus subtilis to the walled state.

Abstract: When the cell wall of Bacillus subtilis is removed by lysozyme and the resultant protoplasts are plated on hypertonic soft agar medium, each protoplast forms an L colony L bodies from such L colonies again plate as L-colony-forming units (CFU) However, if protoplasts or L bodies are "conditioned" by 1 h of incubation in 04% casein hydrolysate medium and then incubated in 25% gelatin medium for 1 h, 60 to 100% of the formerly naked cells give rist to bacillary colonies The present experiments largely explain the mechanism responsible for the "heritable" persistence of the wall-less state in B subtilis It is shown that protoplasts produce a reversion inhibitory factor (RIF) which blocks reversion when the cell concentration exceeds 5 x 105 CFU/ml This inhibitor is nondialyzable and sensitive to trypsin, heat, and detergent Efficient reversion at 2 x 107 CFU/ml is obtained if the protoplasts are treated with trypsin after conditioning and chloramphenicol is incorporated into the gelatin reversion medium In the presence of 500 mug of trypsin per ml, the requirement for gelatin is sharply reduced, and reversion occurs rapidly in liquid medium containing only 10% gelatin Trypsin also stimulates reversion in L colonies growing on soft agar Latent RIF is activated by beta-mercaptoethanol This reagent blocks reversion of protoplast suspensions at densities of 5 x 105 CFU/ml Comparison of the autolytic behavior of B subtilis and of the RIF revealed that several or the properties of the two activities coincide: both are inhibited by high concentrations of gelatin, both are activated by beta-mercaptoethanol, and both have high affinity for cell wall Going on the assumption that RIF is autolysin, models for protoplast reversion is suggested by the finding that mutants with altered teichoic acid show altered reversion behavior

Protoplast Isolation and Culture

Abstract: Protoplasts can be isolated from plant tissues or cultured cells by enzymatic digestion to remove the cell walls. The enzymes for this purpose are preparations which are commercially available. The success of protoplast isolation depends especially on the condition of the tissue and the combination of enzymes being used. There is no standard method for the isolation and culture of protoplasts. However, the procedure follows a general pattern. The individual cell or tissue source may require special conditions for successful isolation or for culture. Protoplasts from cell suspension cultures generally are the most readily obtained and usually regenerate into dividing cells at a reasonable frequency. Moreover, if plant regeneration is possible from the cells of the suspension culture, the same is often true for the cells regenerated from the protoplasts derived from the culture. Leaf mesophyll cells from a wide range of plants also have been used as protoplast sources with success.