Plasticity in ploidy: a generalized response to stress

• Endoreduplication is the process of genome replication without mitotic cell division.
• Endoreduplication occurs in many taxa in response to numerous environmental stresses.
• Increasing ploidy by endoreduplication has cellular, metabolic, and genetic effects.
• Endoreduplication may be integrated into the generalized stress response of plants.

Endoreduplication, the replication of the genome without mitosis, leads to an increase in the cellular ploidy of an organism over its lifetime, a condition termed ‘endopolyploidy’. Endopolyploidy is thought to play significant roles in physiology and development through cellular, metabolic, and genetic effects. While the occurrence of endopolyploidy has been observed widely across taxa, studies have only recently begun to characterize and manipulate endopolyploidy with a focus on its ecological and evolutionary importance. No compilation of these examples implicating endoreduplication as a generalized response to stress has thus far been made, despite the growing evidence supporting this notion. We review here the recent literature of stress-induced endopolyploidy and suggest that plants employ endoreduplication as an adaptive, plastic response to mitigate the effects of stress.