Summary
Monthly collections from October to April revealed seasonal alterations in the structure of the nucleoli of the microsporangiate strobili of the Scotch pine (Pinus sylvestris L.). By classifying the nucleoli in five types, two of them with subtypes, it was possible to list the amount and the sequence of the changes. The results indicated that nucleoli with fully intermingled fibrillar and granular components dominated in actively proliferating tissues whereas this type was almost lacking during the so-called dormant period. The wintertime nuclei, although remaining at interphases, also underwent structural alterations. In the early part of the winter, the most prominent feature was the loosening of the nucleolar structure, but this phenomenon decreased towards midwinter. The chromatin became strongly condensed and synchronous with this, the nucleolar organizer regions became visible as distinct, often ball-like entities. These were located at the surface of nucleoli, sometimes almost separated from them, and they were often partly, or fully, buried in condensed chromatin. Chromatin condensation relaxed transiently during the latter part of winter and at the same time, the granulation of the nucleoplasm increased. Nucleolar segregation disappeared before any mitoses began. The start of active cell divisions was accompanied by growth in the size of the nucleoli and by their increased stainability.
Similar content being viewed by others
References
Ashraf, M., Godward, M. B. E., 1980: The nucleolus in telophase, interphase and prophase. J. Cell Sci.41, 321–329.
Chaly, N., Setterfield, G., 1975: Organization of the nucleus, nucleolus and proteinsynthesizing apparatus in relation to cell development in roots ofPisum sativum. Canad. J. Bot.53, 200–218.
—,Lord, A., Lafontaine, J. G., 1979: Nucleolar organization in the euglenoidAstasia longa as disclosed by selective staining, actinomycin D treatment, and cold shock. Canad. J. Bot.57, 2031–2043.
Deltour, R., Gautier, A., Fakan, J., 1979: Ultrastructural cytochemistry of the nucleus inZea mays embryos during germination. J. Cell Sci.40, 43–62.
Feldman, L. J., Torrey, J. G., 1977: Nuclear changes associated with cellular dedifferentiation in pea root cortical cells culturedin vitro. J. Cell Sci.28, 87–105.
Fransolet, S., Deltour, R., Bronchart, R., van de Walle, C., 1979: Changes in ultrastructure and transcription induced by elevated temperature inZea mays embryonic root cells. Planta146, 7–18.
Giménez-Martin, G., de la Torre, C., Lopez-Saez, J. F., Espona, P., 1977: Plant nucleolus: Structure and physiology. Cytobiologie14, 421–462.
Goessens, G., 1978: Nucleolar ultrastructure during reversible inhibition of RNA synthesis in chick fibroblasts cultivatedin vitro. J. Ultrastruct. Res.65, 83–89.
—,Lepoint, A., 1974: The fine structure of the nucleolus during interphase and mitosis in Ehrlich tumour cells cultivatedin vitro. Exp. Cell Res.87, 63–72.
—, 1979: The nucleolus-organizing regions (NOR's): Recent data and hypotheses. Biol. Cellulaire35, 211–220.
Hernandez-Verdun, D., Bouteille, M., Ege, T., Ringertz, N. R., 1979: Fine structure of nucleoli in micronucleated cells. Exp. Cell Res.124, 223–235.
Jordan, E. G., Chapman, J. M., 1971: Ultrastructural changes in the nucleoli of Jerusalem artichoke (Helianthus tuberosus) tuber discs. J. exp. Bot.22, 627–634.
— —, 1973: Nucleolar and nuclear envelope ultrastructure in relation to cell activity in discs of carrot root (Daucus carota L.). J. exp. Bot.24, 197–209.
Kupila-Ahvenniemi, S., Hohtola, A., 1979: Structure of the nucleoli of developing microsporangiate strobili and root tips of Scotch pine. Protoplasma100, 289–301.
—,Pihakaski, S., Pihakaski, K., 1978: Wintertime changes in the ultrastructure and metabolism of the microsporangiate strobili of the Scotch pine. Planta144, 19–29.
Lafontaine, J. G., Lord, A., 1974: A correlated light- and electronmicroscope investigation of the structural evolution of the nucleolus during the cell cycle in plant meristematic cells (Allium porrum). J. Cell Sci.16, 63–93.
—,Luck, B. T., Dontigny, D., 1979: A cytochemical and radioautographic study of the ultrastructural organization of puff-like fibrillar structures in plant interphase nuclei (Allium porrum). J. Cell Sci.39, 13–27.
Martin, B., Öquist, G., 1979: Seasonal and experimentally induced changes in the ultrastructure of chloroplasts ofPinus silvestris. Physiol. Plant.46, 42–49.
Morcillo, G., Krimer, D. B., de la Torre, C., 1978: Modification of nucleolar components by growth temperature in meristems. Exp. Cell Res.115, 95–102.
Nougarède, A., 1977: On the infrastructural localization of basic proteins in the nucleus and nucleolus of cells in pea axillary meristems submitted to or released from apical dominance. Protoplasma93, 341–356.
Puvion, E., Bachellerie, J.-P., Burglen, M.-J., 1979: Nucleolar perichromatin granules induced by dichlorobenzimidazole riboside. J. Ultrastruct. Res.69, 1–12.
Raveh, D., Friedländer, M., Eyal-Giladi, H., 1976: Nucleolar ontogenesis in the uterine chick germ correlated with morphogenetic events. Exp. Cell Res.100, 195–203.
Rose, R. J., 1974: Changes in nucleolar activity during the growth and development of the wheat coleoptile. Protoplasma79, 127–143.
—,Setterfield, G., Fowke, L. C., 1972: Activation of nucleoli in tuber slices and the function of nucleolar vacuoles. Exp. Cell Res.71, 1–16.
Senser, M., Beck, E., 1979: Kälteresistenz der Fichte. II. Einfluß von Photoperiode und Temperatur auf die Struktur und photochemischen Reaktionen von Chloroplasten. Ber. deutsch, bot. Ges.92, 243–259.
Widmer, R., Fuhrer, S., Parish, R. W., 1979: Biochemical evidence for a distinctive chromatin structure in nucleoli ofDictyostelium. FEBS Lett.106, 363–369.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kupila-Ahvenniemi, S., Hohtola, A. Nucleoli of the overwintering strobilal cells of scotch pine. Protoplasma 105, 107–119 (1980). https://doi.org/10.1007/BF01279853
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01279853