SUNY at Albany
June 19-23, 2001
Reversibility of cadmium-induced apoptosis is associated with increased level of telomerase activity in tobacco TBY-2 cells.
A prolonged exposure of tobacco BY-2 suspension culture to cadmium (Cd2+) leads to apoptosis (Fojtova and Kovarik 2000). In this study we demonstrate that apoptotic process can be fully reversed if cadmium is removed from cell culture after three days of incubation.
To monitor apoptotic changes, we followed several parameters including cell viability, DNA integrity and telomerase activity. Preapoptotic phase has been achieved by exposure of cells to 50mM cadmium for 3 days. At that time the cell culture retains more than 95% viability although the majority of DNA is fragmented into 50-200 kb. Integrity of DNA is reestablished within two days after cadmium removal suggesting that an efficient DNA repair process has occurred. In parallel, a significant increase of telomerase activity in cell extracts is observed. The data suggest an involvement of telomerase in plant chromosome healing in response to damage caused by genotoxic agents.
Fojtova, M. and Kovarik, A. (2000) Genotoxic effect of cadmium is associated with apoptotic changes in tobacco cells. Plant Cell Environm. 23, 531-537.
The work was supported by the Grant Agency of the Czech Republic (grant no. 521/01/P042) and the Ministry of Education of the Czech Republic (CEZ J07/98:143100008).
Miloslava Fojtova, Jana Fulneckova*, Jir? Fajkus* and Ales Kovarik
Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolsk? 135, Brno, 612 65, Czech Republic
*Analysis of Biologically Important Molecular Complexes, Masaryk University, Brno