, Volume 122, Issue 3, pp 222–232 | Cite as

Changes in density of chromatin in the meristematic cells ofSinapis alba during transition to flowering

  • A. Havelange
  • J. C. Jeanny


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.


Chromatin Floral evocation Shoot meristem Sinapis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 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.Google Scholar
  2. —, 1977: Determinants of nuclear chromatin structure in angiosperms. Ann. Sci. Nat., Bot., Paris 12e série,18, 193–206.Google Scholar
  3. 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.Google Scholar
  4. —,Kinet, J. M., Bronchart, R., 1967: Cellular events at the meristem during floral induction inSinapis alba L. Physiol. Vég.5, 311–324.Google Scholar
  5. — —,Sachs, R. M., 1981: In: The physiology of flowering, Vol. II. Boca Raton, Florida: CRC Press.Google Scholar
  6. 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.Google Scholar
  7. 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.Google Scholar
  8. 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.Google Scholar
  9. 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.Google Scholar
  10. Crèvecoeur, M., Deltour, R., Bronchart, R., 1976: Cytological study on water stress during germination ofZea mays. Planta132, 31–41.Google Scholar
  11. 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.Google Scholar
  12. Dhillon, S. S., Miksche, J. P., 1981: DNA changes during sequential leaf senescence of tobacco (Nicotiana tabacum). Physiol. Plant.51, 291–298.Google Scholar
  13. — —, 1982: DNA content and heterochromatin variations in various tissues of peanut (Arachis hypogaea). Amer. J. Bot.69, 219–226.Google Scholar
  14. Drumm, A., Nagl, W., 1982: Loss of DNA and euchromatin in senescing leaf cells ofAllium. Mechanisms of Ageing and Development18, 103–110.Google Scholar
  15. 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.Google Scholar
  16. Frenster, J. H., 1974: Ultrastructure and function of heterochromatin and euchromatin. In: The cell nucleus (Busch, H., ed.). New York-London: Academic Press.Google Scholar
  17. Harris, H., 1970: Nucleus and cytoplasm, 2nd ed. Oxford: Clarendon Press.Google Scholar
  18. 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.Google Scholar
  19. 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.Google Scholar
  20. — —,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.Google Scholar
  21. 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.Google Scholar
  22. —, 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.Google Scholar
  23. —,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.Google Scholar
  24. 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.Google Scholar
  25. 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.Google Scholar
  26. 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.Google Scholar
  27. Lai, V., Srivastava, L. M., 1976: Nuclear changes during differentiation of xylem vessel elements. Cytobiologia12, 220–243.Google Scholar
  28. 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).Google Scholar
  29. Maclean, N., Hilder, V. A., 1977: Mechanisms of chromatin activation and repression. Int. Rev. Cytology48, 1–54.Google Scholar
  30. Mitchison, J. M., 1971: The biology of the cell cycle (Mitchison, J. M., ed.). London: Cambridge University Press.Google Scholar
  31. Nagl, W., 1969: Puffing of polytene chromosomes in a plant (Phaseolus vulgaris). Naturwiss.56, 221–222.Google Scholar
  32. —, 1970: The mitotic and endomitotic nuclear cycle inAllium carinatum. II. Relations between DNA replication and chromatin structure. Caryologia23, 71–78.Google Scholar
  33. —, 1977: Early and late DNA replication in respectively condensed and decondensed heterochromatin ofAllium carinatum. Protoplasma91, 389–407.Google Scholar
  34. —, 1979: Condensed interphase chromatin in plant and animal cell nuclei: fundamental differences. Plant Syst. Evol., Suppl.2, 247–260.Google Scholar
  35. —,Fusenig, H. P., 1979: Types of chromatin organization in plant nuclei. Plant Syst. Evol., Suppl.2, 221–233.Google Scholar
  36. Pederson, T., Robbins, E., 1972: Chromatin structure and the cell division cycle. Actinomycin binding in synchronized Hela cells. J. Cell Biol.55, 322–327.Google Scholar
  37. 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.Google Scholar
  38. Pryke, J. A., Bernier, G., 1978: RNA synthesis in the apex ofSinapis alba in transition to flowering. J. exp. Bot.29, 953–961.Google Scholar
  39. Ruch, F., Rosselet, A., 1970: A cytochemical study of euchromatin and heterochromatin in roots ofRhoeo discolor. Exp. Cell Res.62, 219–227.Google Scholar
  40. Sadik, S., Ozbun, J. L., 1967: Histochemical changes in the shoot tip of cauliflower during floral induction. Can. J. Bot.45, 955–959.Google Scholar
  41. Sans, J., de la Torre, C., 1979: Proliferative index estimated by chromatin pattern analysis. Cell Biol. Int. Reports3, 227–235.Google Scholar
  42. 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.Google Scholar
  43. 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.Google Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • A. Havelange
    • 1
  • J. C. Jeanny
    • 2
  1. 1.Laboratoire de Physiologie végétale, Département de BotaniqueUniversité de LiègeLiègeBelgium
  2. 2.Faculté des Sciences de ReimsLaboratoire de Biologie cellulaireBelgeum

Personalised recommendations