Scorched earth strategy: Grim Reaper saves the plant.

Programmed cell death is a common feature of developmental processes and responses to environmental cues in many multicellular organisms. Examples of programmed cell death in plants are leaf abscission in autumn and the hypersensitive response during pathogen attack. Reactive oxygen species (ROS) have been implicated in the regulation of various types of cell death. However, the precise mechanics of the involvement of ROS in the processes leading to initiation of cell death and subsequent containment are currently unknown. We recently showed the involvement of an Arabidopsis protein GRIM REAPER in the regulation of ROS-induced cell death under stress conditions. Our results indicated that the presence of a truncated protein primes plants for cell death in the presence of ROS leading to ozone sensitivity and increased resistance to hemibiotrophic pathogens.