Herbert, Rob and Orchard, C.B. and Sorrell, D.A. and Marchbank, Angela and Rogers, H.J. and Suchomelova, P and Lipavska, H and AZmi, A (2005) Tobacco BY-2 Cells Expressing Fission Yeast cdc25 Bypass a G2/M Block on the Cell Cycle. The Plant Journal, 44 (2). pp. 290-299. ISSN 0960-7412Full text not available from this repository. (Request a copy)
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.
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|Uncontrolled Keywords:||Nicotiana tabacum, cell size, cytokinins, BY-2 cell line CDKA/B, plant cell cycle.|
|Subjects:||Q Science > QK Botany|
|Divisions:||Academic Departments > Institute of Science and the Environment|
|Depositing User:||Rob Herbert|
|Date Deposited:||27 Nov 2009 14:03|
|Last Modified:||24 Dec 2012 09:58|
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