Summary
Changes in the density of nuclear chromatin in the shoot apical meristem ofSinapis alba L. during floral transition (floral evocation) are described using Feulgen-stained 2 μm thick semi-thin sections and scanning cytophotometric techniques. In both G1 and G2 nuclei the chromatin becomes less heterogeneous and less dense in evoked meristems compared to vegetative meristems. When chromatin is resolved into two fractions the “dispersed” fraction increases relative to the “condensed” fraction at evocation. This decondensation process occurs earlier in G1 than in G 2 nuclei. These chromatin changes are presumably closely related to the dramatic stimulation of biosynthetic activity and cell division during floral transition.
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Barlow, P. W., 1976: The integrity and organization of nuclear DNA in cells of the root cap ofZea mays probed by terminal deoxynucleotidyl transferase and microdensitometry. Z. Pflanzenphysiol.80, 271–278.
—, 1977: Determinants of nuclear chromatin structure in angiosperms. Ann. Sci. Nat., Bot., Paris 12e série,18, 193–206.
Bernier, G., Bronchart, R., Kinet, J. M., 1970: Nucleic acid synthesis and mitotic activity in the apical meristem ofSinapis alba during floral induction. In: Cellular and molecular aspects of floral induction (Bernier, G., ed.), pp. 51–75. London: Longman.
—,Kinet, J. M., Bronchart, R., 1967: Cellular events at the meristem during floral induction inSinapis alba L. Physiol. Vég.5, 311–324.
— —,Sachs, R. M., 1981: In: The physiology of flowering, Vol. II. Boca Raton, Florida: CRC Press.
Bodson, M., 1975: Variation in the rate of cell division in the apical meristem ofSinapis alba during transition to flowering. Amer. J. Bot.39, 547–554.
Bronchart, R., Bernier, G., Kinet, J. M., Havelange, A., 1970: RNA synthesis in the cells of the apical meristem ofSinapis alba during transition from the vegetative to the reproductive condition. Planta (Berl.)91, 255–269.
Brugal, G., Chassery, J. M., 1977: Un nouveau système d'analyse densitométrique et morphologique des préparations microscopiques. Application à la reconnaissance et au comptage automatique des cellules dans les différentes phases du cycle mitotique. Histochemistry52, 241–258.
Christov, K., Kiefer, G., Kiefer, R., Sandritter, W., 1974: Changes in the nuclear structure during thyroid carcinogenesis in rats. An image analysis study. Beitr. Path.152, 19.
Crèvecoeur, M., Deltour, R., Bronchart, R., 1976: Cytological study on water stress during germination ofZea mays. Planta132, 31–41.
Dela Torre, C., Navarette, M. H., 1974: Estimation of chromatin patterns at G1, S, and G2 of the cell cycle. Exp. Cell Res.88, 171–174.
Dhillon, S. S., Miksche, J. P., 1981: DNA changes during sequential leaf senescence of tobacco (Nicotiana tabacum). Physiol. Plant.51, 291–298.
— —, 1982: DNA content and heterochromatin variations in various tissues of peanut (Arachis hypogaea). Amer. J. Bot.69, 219–226.
Drumm, A., Nagl, W., 1982: Loss of DNA and euchromatin in senescing leaf cells ofAllium. Mechanisms of Ageing and Development18, 103–110.
Fakan, S., Bernhard, W., 1971: Localization of rapidly and slowly labelled nuclear RNA as visualized by high resolution autoradiography. Exp. Cell Res.67, 129–141.
Frenster, J. H., 1974: Ultrastructure and function of heterochromatin and euchromatin. In: The cell nucleus (Busch, H., ed.). New York-London: Academic Press.
Harris, H., 1970: Nucleus and cytoplasm, 2nd ed. Oxford: Clarendon Press.
Havelange, A., Bernier, G., 1974: Descriptive and quantitative study of ultrastructural changes in the apical meristems of mustard in transition to flowering. I. The cell and nucleus. J. Cell Sci.15, 633–644.
Jacqmard, A., Miksche, J. P., 1971: Cell population and quantitative changes of DNA in the shoot apex ofSinapis alba during floral induction. Bot. Gaz.132, 364–367.
— —,Bernier, G., 1972: Quantitative study of nucleic acids and proteins in the shoot apex ofSinapis alba during transition from the vegetative to the reproductive condition. Amer. J. Bot.59, 714–721.
Jeanny, J. C., Gontcharoff, M., 1978: Etude en microscopie électronique et par cytophotométrie à balayage de la structure et de la distribution de la chromatine dans les noyaux des cellules cartilagineuses deTriturus cristatus au cours de la sénescence. Biol. Cellulaire32, 233–244.
—, 1980: Utilisation des caractéristiques morphométriques et densitométriques des noyaux en vue de l'identification et du dénombrement des cellules cartilagineuses en G0 et G1 au cours du vieillissement et de la régénération chezTriturus cristatus. Biol. Cellulaire39, 305–316.
—,Gontcharoff, M., 1981: Analysis of the changes in the morphology and staining density characteristics of cartilagenous cell nuclei fromTriturus cristatus during ageing and regeneration. J. Histochem. Cytochem.29, 1281–1288.
Kiefer, G., Kiefer, R., Moore, G. W., Salm, R., Sandritter, W., 1974: Nuclear images of cells in different functional states. J. Histochem. Cytochem.22, 569–576.
Knox, R. B., Evans, L. T., 1966: Inflorescence initiation inLolium temulentum L. VIII. Histochemical changes at the shoot apex during induction. Austr. J. biol. Sci.19, 233–245.
Kwiatkowska, M., Maszewski, J., 1979: Changes in the content of condensed chromatin during the cell cycle in antheridial filaments ofChara vulgaris L. as related to DNA and RNA synthesis,3H-actinomycin-D binding and RNA polymerase activity. Protoplasma78, 363–367.
Lai, V., Srivastava, L. M., 1976: Nuclear changes during differentiation of xylem vessel elements. Cytobiologia12, 220–243.
Lyndon, R. F.,Jacqmard, A.,Bernier, G., 1983: Changes in protein composition of the shoot meristem during floral evocation inSinapis alba. Physiol. Plant. (in press).
Maclean, N., Hilder, V. A., 1977: Mechanisms of chromatin activation and repression. Int. Rev. Cytology48, 1–54.
Mitchison, J. M., 1971: The biology of the cell cycle (Mitchison, J. M., ed.). London: Cambridge University Press.
Nagl, W., 1969: Puffing of polytene chromosomes in a plant (Phaseolus vulgaris). Naturwiss.56, 221–222.
—, 1970: The mitotic and endomitotic nuclear cycle inAllium carinatum. II. Relations between DNA replication and chromatin structure. Caryologia23, 71–78.
—, 1977: Early and late DNA replication in respectively condensed and decondensed heterochromatin ofAllium carinatum. Protoplasma91, 389–407.
—, 1979: Condensed interphase chromatin in plant and animal cell nuclei: fundamental differences. Plant Syst. Evol., Suppl.2, 247–260.
—,Fusenig, H. P., 1979: Types of chromatin organization in plant nuclei. Plant Syst. Evol., Suppl.2, 221–233.
Pederson, T., Robbins, E., 1972: Chromatin structure and the cell division cycle. Actinomycin binding in synchronized Hela cells. J. Cell Biol.55, 322–327.
Piérard, D., Jacqmard, A., Bernier, G., Salmon, J., 1980: Appearance and disappearance of proteins in the shoot apical meristem ofsinapis alba in transition to flowering. Planta (Berl.)150, 397–405.
Pryke, J. A., Bernier, G., 1978: RNA synthesis in the apex ofSinapis alba in transition to flowering. J. exp. Bot.29, 953–961.
Ruch, F., Rosselet, A., 1970: A cytochemical study of euchromatin and heterochromatin in roots ofRhoeo discolor. Exp. Cell Res.62, 219–227.
Sadik, S., Ozbun, J. L., 1967: Histochemical changes in the shoot tip of cauliflower during floral induction. Can. J. Bot.45, 955–959.
Sans, J., de la Torre, C., 1979: Proliferative index estimated by chromatin pattern analysis. Cell Biol. Int. Reports3, 227–235.
Sauter, J. J., Ulrich, H., 1977: Cytophotometric investigation of DNA and RNA content in nuclei of active Strasburger cells inPinus nigra var.austriaca (Hoess) Badoux. Planta (Berl.)137, 5–11.
Schmalenberger, B., Nagl, W., 1979: Different DNA content, chromatin condensation and transcription activity in retina cell nuclei of the Guinea pig. Plant Syst. Evol., Suppl.2, 119–125.
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Havelange, A., Jeanny, J.C. Changes in density of chromatin in the meristematic cells ofSinapis alba during transition to flowering. Protoplasma 122, 222–232 (1984). https://doi.org/10.1007/BF01281699
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DOI: https://doi.org/10.1007/BF01281699