A team of biologists from the National University of Singapore (NUS) has
found that some plants selectively kill part of their roots to survive under
cold weather conditions.
The team experimented on Arabidopsis roots to look at the effect of chilling
temperature on root development and growth. They found that a temperature of
four degree Celsius leads to
damage in the root stem cells of Arabidopsis, as well as their early
descendants. However, only the columella stem cell daughters die
preferentially, and the death of these daughter cells allows maintenance of
a functional stem cell niche. Inhibition of the DNA damage response in these
daughter cells prevents their death, but increases the probability that the
other stem cells in the root stem cell niche will die due to the cold,
leading to the plant's death.
Dr. Hong Jing Han, first author of the study, explains, "The sacrificial
mechanism improves the root's ability to withstand other low
temperature-related stresses. When optimal temperatures are restored, the
plant stem cells can divide at a faster rate, which will in turn enhance
recovery and survival of the plant."