Tobacco BY-2 Cells Expressing Fission Yeast cdc25 Bypass a G2/M Block on the Cell Cycle

Herbert, Rob; Orchard, C.B.; Sorrell, D.A.; Marchbank, A.; Rogers, H.J.; Suchomelova, P.; Lipavska, H. and Azmi, A. (2005) Tobacco BY-2 Cells Expressing Fission Yeast cdc25 Bypass a G2/M Block on the Cell Cycle.

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Official URL: 10.1111/j.1365-313X.2005.02524.x


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.

Item Type: Article
Keywords: QK Botany
Members: University of Worcester
Depositing User: ULCC Admin
Date Deposited: 05 Oct 2011 09:19
Last Modified: 08 Nov 2016 13:09

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