Publication details

Recovery of tobacco cells from cadmium stress is accompanied by DNA repair and increased telomerase activity

Authors

FOJTOVÁ Miloslava FULNEČKOVÁ Jana FAJKUS Jiří KOVAŘÍK Aleš

Year of publication 2002
Type Article in Periodical
Magazine / Source Journal of Experimental Botany
MU Faculty or unit

Faculty of Science

Citation
Field Genetics and molecular biology
Keywords apoptosis; cadmium; DNA domain fragmentation; telomerase; tobacco BY-2 cells
Description It has been shown previously that apoptosis of tobacco cells induced by cadmium ions shows a relatively long lag period between exposure and ceel death. This lag phase lasts for 3 d in TBY-2 cell cultures and is characterized by the maintenance of full cell viability despite extensive fragmentation of DNA into pieces of chromatin loop size. Experiments reported here demonstrate that cell death can be prevented if CdSO4 is removed from the growth medium during the lag phase, suggesting that an irreversible apoptotic trigger is delivered within 24 h, between the third and fourth days of cadmium treatment. The post-cadmium recovery phase was characterized by DNA repair at the level of 50-200 kb and increased telomerase activity. Analysis of high-molecular-weight DNA by pulsed-field-gel electrophoresis revealed that the majority of DNA strand breaks was repaired within 48 h after cadmium withdrawal. Telomerase activity increased 2.5-fold in the recovery phase, but elevated levels were also found in cell extracts from apoptotic cells suggesting that telomerase might be associated with DNA repair, but it is not capable of inhibiting ongoing apoptosis. Limited exposure of TBY-2 cells to cadmium elicits non-random DNA damage of relatively high magnitude that can be repaired. It is proposed that plants might have developed a highly efficient DNA repair system to cope with transient genotoxic stress.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info