Season-specific changes in telomere length and telomerase activity in Chinese pine (Pinus tabulaeformis Carr.)

Telomeres have lately received considerable attention in the development of deciduous tree species. In order to determine season-specific changes in telomere length and telomerase activity in evergreen tree species, Chinese pine trees (Pinus tabulaeformis Carr.) were used as experimental materials. In this study, we examined the correlation among telomere length, telomerase activity, and temperature in P. tabulaeformis during the course of an annual developmental cycle. A statistical analysis showed that the lengths of telomeres were significantly different between new and old leaves in each month. During the annual developmental cycle, the telomere lengths in Chinese pine tree leaves increased from May to June 2012, remained stable or increased slightly from June to August 2012, decreased sharply from August 2012 to January 2013, and then increased from January to April 2013. Telomerase activities could be detected in both new and old leaves from May 2012 to April 2013 and the telomerase activities in new leaves are higher than in the old each month. Additionally, there were similar trends between the changes in telomere length and mean monthly temperature from May 2012 to April 2013, and opposite trends were shown between the changes in telomerase activity and mean monthly temperature. Therefore, telomere length and telomerase activity varied with the season. Telomere length was positively correlated with temperature and telomerase activity was negatively correlated with temperature during the annual developmental cycle.