Cell regeneration and sustained division have been observed in protoplasts from carrot cell suspension cultures. Carrot plants were produced from the protoplasts by embryogenesis.

Cell division and plant development from protoplasts of carrot cell suspension cultures.

1 When I encountered tobacco BY-2 cell line T. Nagata Cell Cycle 2 Improvements of the molecular toolbox for cell cycle studies in tobacco BY-2 cells J. Joubes, D. Inze and D. Geelen 3 Transcriptional regulation during the plant cell cycle: Involvement of Myb proteins in cyclin B transcription M. Ito 4 Control of the G1/S phase transition in tobacco BY-2 cells M. Sekine and A. Shinmyo 5 Expression, localization and stability of mitotic cyclins in tobacco BY-2 cells Y. Parmentier, M.C. Crique, T. Potuschak and P. Genschik Cell Biology and Cytoskeleton 6 Molecular mechanisms of microtubule nucleation in tobacco BY-2 cells A.-C. Schmit, J. Canaday, V. Seltzer, S. Campagne, E. Herzog, J.-L. Evradrd and A.-M. Lambert 7 Dynamic behavior of microtubules and vacuoles at M/G1 interface observed in living tobacco BY-2 cells F. Kumagai, A. Yoneda, N. Kutsuna and S. Hasezawa 8 Tobacco BY-2 cells as an ideal material for biochemical studies of plant cytoskeletal proteins S. Sonobe, E. Yokata and T. Shimmen 9 Cell plate formation in plant cells as visualized using the model plant cells of tobacco BY-2 T. Asada and Y. Yasuhara Physiological and Developmental Aspects 10 Hormonal control of plant cell cycle L. Roef and H. Van Onckelen 11 Block points in the cell cycle progression of plant cells: deduced lessons from tobacco BY-2 cells T. Sano, T. Shimizu, K. Sakamoto and T. Nagata 12 Growth and physiology of suspension-cultured plant cells: the contribution of tobacco BY-2 cells to the study of auxin action J.-P. Renaudin 13 Dual pathways for auxin regulation of cell division and expansion A. Jones, H. Ullah and J. Chen 14 Studies on dynamic changes of organelles using tobacco BY-2 as the model plant cell line A. Sakai, Y.Miyazawa and T. Kuroiwa 15 Cell wall dynamics in tobacco BY-2 cells R. Yokoyama, D. Tanaka, T. Fujino, T. Itoh and K. Nishitani 16 Regulation of secondary metabolism in tobacco cell cultures S. Salonvaara and K.-M. Oksman 17 Boron nutrition of cultured tobacco BY-2 M. Kobayashi and T. Matoh Molecular Biological Aspects 18 In vitro transcription system from tobacco BY-2 cells Y. Yukawa and M. Sugiura 19 Protein sorting and protein modification along the secretary pathway in tobacco BY-2 cells K. Matsuoka 20 Characterization of the TGV inducible/repressible gene expression system in tobacco BY-2 cells S. Planchais, G. Kuna, G.. Armstrong and J.A.H. Murray 21 Tobacco BY-2 cell line as a model system to understand in planta coactivator interactions R.A. Bhat and R. Thompson 22 Tobacco BY-2 proteomics K. Laukens and E. Witters

Tobacco by-2 cells

SUMMARY Protoplasts isolated from soybean (Glycine max (L.) Merr.) callus and cultured for 40 h developed a wall which could be seen on plasmolysis. They changed shape, producing buds, and became osmotically stable. Analysis after feeding radioactive glucose showed that the regenerated wall was devoid of pectin which was in the medium. Budding occurs because of the loss of pectin and the observations assist understanding of wall expansion and growth in normal plant cells. The complete molecule of weakly acidic pectinic acid was secreted, precluding the possibility of its assembly in the wall.

Cell wall formation by soybean callus protoplasts.

Publisher Summary This chapter presents the basic information about the isolation, fusion, and culture of plant protoplasts, in pointing out some of the new research approaches that may be useful in the production of better varieties of crop plants, and in understanding the basic processes involved in the growth and differentiation of higher plants. Protoplasts can be isolated from a variety of plant tissues and cultured cells. The nutrition and age of the plants, as well as the temperature and illumination at which they are grown, directly affect the isolation of protoplasts and their suitability for further growth. The chapter describes two methods for the isolation of protoplasts: mechanical methods and enzymatic methods. The stability and further growth of protoplasts are largely dependent on the procedures used for their isolation and the nutritional, physiological, and physical conditions of their culture. The chapter discusses the techniques for the culture of protoplasts, including (1) suspension and drop cultures, (2) plating, and (3) microculture chambers.

The Progress. Problems, and Prospects of Plant Protoplast Research

Protoplasts were isolated from seedlings of Zea mays L, roots of Convolvulus arvensis L, and root callus of C arvensis L. (filamentous strain of root callus) and Allium cepa L. by cellulase treatment They were maintained for over 3 weeks in liquid medium containing either 0.4 M sorbitol or a mixture of sorbitol and 1% sucrose. Protoplasts of C. arvensis L were observed to form protuberances or "buds"; such protoplasts demonstrated regenerated wall formation within 2-3 days of culture A few protoplasts exhibited nuclear divisions on the second day of culture About 4%-5% became binucleate, and 2% became three- to four-nucleate In experiments on the effect of "Sendai" virus on plant protoplasts, no agglutination or fusion was observed

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"Budding" and Nuclear Division in Cultured Protoplasts of Corn, Convolvulus, and Onion

: Somatic cell hybridization is a potentially useful technique for the introduction of genetic variability into plant species. One proposed method involves fusion of plant protoplasts (which is a cell lacking its wall--defined here on the basis of light microscope examination) to form a hybrid cell which can be induced to form a plant. Plant protoplasts produced by the use of crude commercial lytic enzymes are not always healthy (as defined by consideration of factors such as cytoplasmic streaming, presence of cytoplasmic strands and position of the nucleus within the cell, in relation to survival time). Peroxidase, basic proteins and ribonuclease have been implicated as possible deleterious agents. The use of purified enzymes offers a more rigorously defined system for obtaining healthy protoplasts. Purified preparations of cellulase (EC 3.2.1.4), pectate lyase (EC 4.2.99.3) and endopolygalacturonase (EC 3.2.1.15) have been used to prepare protoplasts from a range of plant cell suspension cultures. Inducible streptomycete enzymes lytic towards plant cell walls have also been prepared. (Author)

W. A. Keller

Papers

Plant protoplasts for use in somatic cell hybridization.