Genome integrity of cells is threatened by DNA damage caused by environmental and endogenous stresses. To cope with these stress conditions, cells have developed a set of surveillance mechanisms that monitor the status and structure of DNA during cell cycle progression. In fission yeast and mammals, DNA damage activates the signalling kinases ataxia telangiectasia mutated (ATM) and Rad3-related (ATR) that simultaneously turn on DNA repair complexes and arrest cell division, allowing cells to repair damaged DNA before proceeding into mitosis.

During the course of their lives, immobile organisms are bound to encounter situations that put their structural integrity to the test. Attacks by predators, herbivores or harsh weather conditions all pose significant threats to the structure of an organism. For plants in particular, tissue damage or even the loss of an entire organ are possible outcomes. It is perhaps for this reason that plants have evolved an extraordinary capacity for regeneration.