Protoplast

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

Plant tissue and protoplast culture: applications to stress physiology and biochemistry.

Abstract: Introduction Salinity and drought, two environmental stresses frequently found together, are major barriers to productivity of agricultural crops throughout the world. Crops exposed to these stressful environments are observed initially to have reduced growth rates. If the stress is more severe the response is manifested visually in a number of specific and recognisable symptoms, many of which are common to both salinity and drought. However, specific ion toxicity responses (e.g. marginal leaf burn) are observed in plants exposed to excess salinity. Since salinity and drought have many common responses some of the information presented in this review will be combined under the general umbrella of environmental stress. This chapter discusses the use of tissue and protoplast culture as a means to understand better the cellular processes related to stress tolerance with the expectation that these techniques will provide alternative methods for screening germplasm and assist in identifying useful material for incorporation into crop improvement programmes. Of equal importance is the ability to compare physiological and biochemical processes of cells and protoplasts selected for stress tolerance against unselected (wild-type) lines and to relate this to genetic regulation at the molecular level. The techniques of tissue and protoplast culture are important for application of molecular biology to genetic manipulation of plants. The field of plant pest-host interactions has been significantly advanced by the use of protoplasts and subsequent tissue culture and regeneration of pest-resistant plants (Harrison & Mayo, 1983). Somaclonal variation has provided important genetic material both for genetic studies and for selection of desired traits in plants (Scowcroft, Larkin & Brettell, 1983; Maddock & Semple, 1986).

Resistance, germination, and permeability correlates of Bacillus megaterium spores successively divested of integument layers.

Abstract: A variant strain that produced spores lacking exosporium was isolated from a culture of Bacillus megaterium QM-B1551. Two additional spore morphotypes were obtained from the parent and variant strains by chemical removal of the complex of coat and outer membrane. Among the four morphotype spores, heat resistance did not correlate with total water content, wet density, refractive index, or dipicolinate or cation content, but did correlate with the volume ratio of protoplast to protoplast plus cortex. The divestment of integument layers exterior to the cortex had little influence on heat resistance. Moreover, the divestment did not change the response of either the parent or the variant spores to various germination-initiating agents, except for making the spores susceptible to germination by lysozyme. The primary permeability barrier to glucose for the intact parent and variant spores was found to be the outer membrane, whereas the barrier for the divested spores was the inner membrane.

Regeneration of Aspergillus nidulans protoplasts.

Abstract: SUMMARY: The process of regeneration of mycelial protoplasts from Aspergillus nidulans wild-type and strain p76 has been investigated. In liquid media two patterns of regeneration were observed. In the first, the protoplasts produced chains of yeast-like cells and eventually the terminal cell produced a hypha. In the second wall ‘shells’ were formed into which the cytoplasm migrated. It is suggested that the mechanism of regeneration reflects the site of origin of the protoplast from the parent hypha.

Polyethylene glycol-assisted transfection of Streptomyces protoplasts.

Abstract: In the presence of polyethylene glycol (concentration optimum 20%), protoplasts of appropriate Streptomyces strains could be transfected by deoxyribonucleic acid (DNA) of five temperate phages (phi C31, VP5, R4, phi 448, and S14) belonging to four different immunity groups. Quantitation of transfection was made possible by plating the transfection mixture with excess uninfected protoplasts in soft agar overlays on protoplast regeneration medium so that plaques were easily detected. Optimum frequencies of transfection in the ranges of 10(-6)/DNA molecule and 10(-5)/viable protoplast were invariably obtained. It appeared that single DNA molecules initiated transfection events, and that the conformation of the DNA (i.e., circular or linear) was not important. Inhibition of transfection by ethylenediaminetetraacetic acid suggested that divalent cations were also observed. A minor subpopulation of protoplasts appeared to be particularly sensitive to transfection (i.e., "competent") in some DNA-host combinations. In such cases the size of this subpopulation was the major limiting factor in obtaining high transfection frequencies. The same protoplast

Plant tissue culture manual : fundamentals and applications

Abstract: Tobacco protoplast isolation, culture and regeneration, I. Negrutiu culture, regeneration and transformation of barley protoplasts, P. Lazzeri et al in vitro fertilization of maize, E. Kranz monoclonal antibodies against marker protein for somatic embryogenesis, S. Stirn and H-J. Jacobsen endosperm culture, B.M. Johri and P.S. Srivastava.