Abstract: Ammopiptanthus mongolicus, the evergreen broadleaf shrub indigenous to the northwest desert of China, is a residual plant of the ancient subtropical area in the Tertiary Period and has been identified as the national tertiary protection species. This research was conducted to explore the relationship between DNA damage and telomerase activity of Ammopiptanthus mongolicus cells under salt stress. The results showed that telomerase activity was increased during the first 3 d of low salt（100 mmol/L NaCl）treatment. However, when culture cells were treated with 500 mmol/L NaCl, telomerase activity increased rapidly at the initial stage, while declined after 2 day salt stress. Telomerase activity increased 1.4-fold in the recovery phase when 500 mmol/L NaCl was removed from the growth medium. DNA damage was not obvious during the NaCl treatment time or in the phase when NaCl was removed from the growth medium. It is proposed that plants might have developed a highly efficient DNA repair system to cope with transient salt stress, and telomerase may play an important role in it.

Key words: Ammopiptanthus mongolicus, Salt stress, Telomerase, DNA damage