Author/Editor		Herbert, RJ; Vilhar, B; Evett, C; Orchard, CB; Rogers, HJ; Davies, MS; Francis, D
Title		Ethylene induces cell death at particular phases of the cell cycle in the tobacco TBY-2 cell line
Type		članek
Source		J Exp Bot
Vol. and No.		Letnik 52, št. 361
Publication year		2001
Volume		str. 1615-23
Language		eng
Abstract		It was examined whether ethylene induces programmed cell death in a cell cycle-specific manner. Following synchronization of the tobacco TBY-2 cell line with aphidicolin and its subsequent removal, ethylene was injected into the head space of 300 cm3 culture flasks at 0 h or 3.5 h later and cells were sampled for 26 h. There were significant increases in cell mortality at G2/M in both the 0 h and 3.5 h ethylene treatments, and for the latter treatment, another peak in S-phase. The effect at G2/M was greater in the 3.5 h treatment, but was ameliorated by the simultaneous addition of silver nitrate (1.2microM). In addition, the 3.5 h ethylene treatment resulted in a 1 h delay in the characteristic rise in the mitotic index following aphidicolin-induced synchrony. The addition of silver nitrate alone (1.2microM), also delayed the entry of cells into mitosis but had no effect on cell cycle length compared with the controls (14 h throughout all treatments) but it induced a peak of mortality 2.5 h after its addition. Nuclear shrinkage was also a characteristic feature of dying cells at G2/M. Using Apoptag, an in situ apoptosis detection kit, nuclear DNA fragmentation was observed in the TBY-2 cells which were often isolated on the end of a filament of normal cells. In the 3.5 h ethylene treatment, a marked increase was noted in the percentage of such cells at the G2/M transition compared with the controls. Hence, the data show cell death occurring at a major phase transition of the cell cycle and the observations of nuclear shrinkage, isolation of dying cells and nuclear DNA fragmentation suggest a programmed mechanism of cell death exacerbated by ethylene treatment.
Descriptors		TOBACCO CELL LINE ETHYLENES APHIDICOLIN CELL CYCLE CELL DEATH MITOTIC INDEX SILVER NITRATE APOPTOSIS RNA HISTONES