Poster: Cell Cycle & Cytokinesis

Abs # 1099: The effects of polyamine and environmental stresses on cell cycling in BY-2 tobacco cells

Presenter:	Park, Ky Young , plpm@sunchon.ac.kr
Authors	Park, Ky Young  (A)   Jang, Su Jin  (A)
Affiliations:	(A): Department of Biology, Sunchon National University, Sunchon, Chonnam 540-742, South Korea

The polyamines putrescine, spermidine and spermine are positively charged, low molecular weight compounds that occur in both prokaryotic and eukaryotic cells. We have chosen tobacco as the experimental system because of the high degree of synchronization attainable in the tobacco Bright Yellow-2 (BY-2) cell line. There were determined the effects of exogenous polyamines on cell divisions in synchronized BY-2 cell cultures. The cell cycle profile of cells treated with 1mM putrecine, spermidine, and spermine was essentially unchanged compared with control cells until 24h. But, DNA content of S phase before reaching the G2 phase constantly increased after 24h of treatment polyamines, suggesting polyamines increased the continuity of cell cycling. Also, polyamine induced more amounts of transcripts for cyclins. Other plant growth regulators, kinetin, auxin, brassinosteroid, abscisic acid, jasmonic acid, and gibberellin, were differently changed the profile of cell cycling in BY2 cells. Cell cycle arrest was associated with inhibition of the activity of cyclin-dependent kinase and of gene expression for cyclins after treatment with a various stresses such as salt, cold, heat, etc. Possibly, this dual response to osmotic and oxidative stress could mirror an evolutionarily conserved response to environmental stresses and thereby provide a good model to study the molecular events induced by specific environmental stresses that influence cell division.