You have full text access to this OnlineOpen article

Tobacco BY-2 cells expressing fission yeast cdc25 bypass a G2/M block on the cell cycle

  1. Craig B. Orchard1,2,
  2. Ilario Siciliano1,2,
  3. David A. Sorrell1,3,
  4. Angela Marchbank1,
  5. Hilary J. Rogers1,
  6. Dennis Francis1,*,
  7. Robert J. Herbert2,
  8. Petra Suchomelova4,
  9. Helena Lipavska4,
  10. Abdelkrim Azmi5,
  11. Harry Van Onckelen5

Article first published online: 20 SEP 2005

DOI: 10.1111/j.1365-313X.2005.02524.x

Issue

The Plant Journal

The Plant Journal

Volume 44, Issue 2, pages 290–299, October 2005

Additional Information

How to Cite

Orchard, C. B., Siciliano, I., Sorrell, D. A., Marchbank, A., Rogers, H. J., Francis, D., Herbert, R. J., Suchomelova, P., Lipavska, H., Azmi, A. and Onckelen, H. V. (2005), Tobacco BY-2 cells expressing fission yeast cdc25 bypass a G2/M block on the cell cycle. The Plant Journal, 44: 290–299. doi: 10.1111/j.1365-313X.2005.02524.x

Author Information

  1. 1

    School of Biosciences, Cardiff University, PO Box 915, Cardiff CF10 3TL, UK,

  2. 2

    Department of Applied Sciences, Geography and Archaeology, University College, Worcester, Henwick Grove, Worcester WR2 6AJ, UK,

  3. 3

    Polgen Division, Cyclacel Ltd, Babraham Institute, Babraham, Cambridge, CB2 4AT, UK,

  4. 4

    Department of Plant Physiology, Faculty of Science, Charles University, Vinicna 5, Prague 2, Czech Republic, and

  5. 5

    Department of Biology, Universiteit Antwerpen (UIA), Universiteitsplein 1, B-2610 Antwerp, Belgium

* (fax +44 29 2087 4305; e-mail francisd@cardiff.ac.uk).

Publication History

  1. Issue published online: 20 SEP 2005
  2. Article first published online: 20 SEP 2005
  3. Received 1 June 2005; revised 15 July 2005; accepted 25 July 2005.

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article (HTML) Get PDF (350K)

Keywords:

  • Nicotiana tabacum;
  • cell size;
  • cytokinins;
  • BY-2 cell line CDKA/B;
  • plant cell cycle

Summary

The mitotic inducer gene from Schizosaccharomyces pombe, Spcdc25, was used as a tool to investigate regulation of G2/M in higher plants using the BY-2 (Nicotiana tabacum) cell line as a model. Spcdc25-expressing BY-2 cells exhibited a reduced mitotic cell size through a shortening of the G2 phase. The cells often formed isodiametric double files both in BY-2 cells and in cell suspensions derived from 35S::Spcdc25 tobacco plants. In Spcdc25-expressing cells, the tobacco cyclin-dependent kinase, NtCDKB1, showed high activity in early S phase, S/G2 and early M phase, whereas in empty vector cells CDKB1 activity was transiently high in early S phase but thereafter remained lower. Spcdc25-expressing cells also bypassed a block on G2/M imposed by the cytokinin biosynthetic inhibitor lovastatin (LVS). Surprisingly, cytokinins were at remarkably low levels in Spcdc25-expressing cells compared with the empty vector, explaining why these cells retained mitotic competence despite the presence of LVS. In conclusion, synchronised Spcdc25-expressing BY-2 cells divided prematurely at a small cell size, and they exhibited premature, but sustained, CDKB1 activity even though endogenous cytokinins were virtually undetectable.

View Full Article (HTML) Get PDF (350K)