Abstract
Embryogeny in the nasturtium is characterized by the development of a large, tripartite suspensor and storing cotyledons. A light and electron microscopic study revealed an early diversification of the plastids in the various regions of the suspensor and the embryo proper. Amyloplasts are found in the developing cotyledons of the heart-like embryo, while chloroplasts occur within the meristematic part of the embryo and the adjacent portion of the suspensor. The cells between the meristem and the storing cotyledons display undifferentiated leukoplasts, whereas leukoplasts with an electron-dense matrix occur in the basal cell mass of the embryo-suspensor. Etioplasts develop in several cells of the placental haustorium of the suspensor. The carpel haustorium shows rather undifferentiated leukoplasts, which are transformed into electron-dense plastids during autolysis of the suspensor. This early plastidal differentiation in discussed with respect to its control and functional significance.
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Alpi, A., Tognoni, F., D'Amato, F.: Growth regulator levels in embryo and suspensor of Phaseolus coccineus at two stages of development. Planta (Berl.) 127, 153–162 (1975)
Butterfass, Th.: Control of plastid division by means of nuclear DNA amount. Protoplasma 76, 167–195 (1973)
Chapman, E.A., Bain, J.M., Gove, D.W.: Mitochondria and chloroplast peripheral reticulum in the C4 plants Amaranthus edulis and Atriplex spongiosa. Austral. J. Plant Physiol. 2, 207–223 (1975)
Cionini, P.G., Bennici, A., Alpi, A., D'Amato, F.: Suspensor, gibberellin and in vitro development of Phaseolus coccineus embryos. Planta (Berl.) 131, 115–117 (1976)
Dumas, A.: The secretory tissue of Umbelliferae: occurrence of plastidial secretion in the nectaries of Conium maculatum. C.R. Acad. Sci. (Paris) D, 280, 1983–1986 (1975)
Evans, A., Smith, H.: Localization of phytochrome in etioplasts and its regulation in vitro of gibberellin levels. Proc. Nat. Acad. Sci. 73, 138–142 (1976)
Fougere-Rifot, M.: L'edification de l'appareil filiforme et l'évolution cytoplasmique des synergides du sac embryonnaire d'Aquilegia vulgaris. C.R. Acad. Sci. (Paris) D, 280, 2445–2447 (1975)
Lee, L.P., Hecht, A.: Chloroplasts of monoploid and diploid Oenothera hookeri. Amer. J. Bot. 62, 268–272 (1975)
Marinos, N.G.: Embryogenesis of the pea (Pisum sativum). II. An unusual type of plastid in the suspensor cells. Protoplasma 71, 227–233 (1970)
Nagl, W.: Über Endopolyploidie, Restitutionskernbildung und Kernstrukturen im Suspensor von Angiospermen und einer Gymnosperme. Osterr. Bot. Z. 109, 431–494 (1962)
Nagl, W.: DNA synthesis in tissue and cell cultures. In: Tissue culture and plant science, pp. 19–42. Street, H.E., Ed. London, New York: Academic Press, 1974
Nagl, W.: Zellkern und Zellzyklen. Stuttgart: Ulmer 1976a
Nagl, W.: Early embryogenesis in Tropaeolum majus L.: Evolution of DNA content and polyteny in the suspensor. Plant Sci. Lett. 7, 1–8 (1976b)
Nagl, W.: Early embryogenesis in Tropaeolum majus L.: Ultrastructure of the embryo-suspensor. Biochem. Physiol. Pflanzen (in press)
Nagl, W., Peschke, C., van Gyseghem, R.: Heterochromatin underreplication in Tropaeolum embryogenesis. Naturwissenschaften 63, 198 (1976)
Newcomb, W., Fowke, L.C.: Stellaria media embryogenesis: the development and ultrastructure of the suspensor. Canad. J. Bot. 52, 607–614 (1974)
Ponzi, R., Pizzolongo, P.: Ultrastructure of plastids in the suspensor cells of Ipomoea purpurea Roth. J. Submicr. Cytol. 5, 257–263 (1973)
Schnepf, E., Nagl, W.: Über einige Strukturbesonderheiten der Suspensorzellen von Phaseolus vulgaris. Protoplasma 69, 133–143 (1970)
Seyer, P., Marty, D., Lescure, A.M., Peaud-Lenoel, C.: Effect of cytokinin on chloroplast cyclic differentiation in cultured tobacco cells. Cell Diff 4, 187–197 (1975)
Spurr, A.R.: A low viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res. 26, 31–43 (1969)
Stetler, D.A., Laetsch, W.M.: Kinetin-induced chloroplast maturation in cultures of tobacco tissue. Science 149, 1387–1388 (1965)
Walker, R.I.: Megasporogenesis and embryo development in Tropaeolum majus L. Bull. Torrey Bot. Club 74, 240–249 (1947)
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Nagl, W., Kühner, S. Early embryogenesis in Tropaeolum majus L.: Diversification of plastids. Planta 133, 15–19 (1976). https://doi.org/10.1007/BF00386000
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DOI: https://doi.org/10.1007/BF00386000