Planta

, Volume 211, Issue 3, pp 370–375

The frequency of plasmodesmata increases early in the whole shoot apical meristem of Sinapis alba L. during floral transition

Authors

  • Sandra Ormenese
    • Laboratoires de Physiologie et de Morphologie, Département de Biologie végétale, Université de Liège, Sart-Tilman, 4000 Liège, Belgium
  • Andrée Havelange
    • Laboratoires de Physiologie et de Morphologie, Département de Biologie végétale, Université de Liège, Sart-Tilman, 4000 Liège, Belgium
  • Roger Deltour
    • Laboratoires de Physiologie et de Morphologie, Département de Biologie végétale, Université de Liège, Sart-Tilman, 4000 Liège, Belgium
  • Georges Bernier
    • Laboratoires de Physiologie et de Morphologie, Département de Biologie végétale, Université de Liège, Sart-Tilman, 4000 Liège, Belgium

DOI: 10.1007/s004250000294

Cite this article as:
Ormenese, S., Havelange, A., Deltour, R. et al. Planta (2000) 211: 370. doi:10.1007/s004250000294

Abstract.

 The frequency of plasmodesmata increases in the shoot apical meristem of plants of Sinapis alba L. induced to flower by exposure to a single long day. This increase is observed within all cell layers (L1, L2, L3) as well as at the interfaces between these layers, and it occurs in both the central and peripheral zones of the shoot apical meristem. The extra plasmodesmata are formed only transiently, from 28 to 48 h after the start of the long day, and acropetally since they are detectable in L3 4 h before they are seen in L1 and L2. These observations indicate that (i) in the Sinapis shoot apical meristem at floral transition, there is an unfolding of a single field with increased plasmodesmatal connectivity, and (ii) this event is an early effect of the arrival at this meristem of the floral stimulus of leaf origin. Since (i) the wave of increased frequency of plasmodesmata is 12 h later than the wave of increased mitotic frequency (A. Jacqmard et al. 1998, Plant cell proliferation and its regulation in growth and development, pp. 67–78; Wiley), and (ii) the increase in frequency of plasmodesmata is observed in all cell walls, including in walls not deriving from recent divisions (periclinal walls separating the cell layers), it is concluded that the extra plasmodesmata seen at floral transition do not arise in the forming cell plate during mitosis and are thus of secondary origin.

Key words: Floral transitionPlasmodesmata formationSecondary plasmodesmataShoot apical meristemSinapis (floral transition)

Copyright information

© Springer-Verlag Berlin Heidelberg 2000