Plant genomics and the regulation of programmed cell death and aging

During their life cycle, plants are continuously challenged by a variety of internal and external factors and often respond by local cell death decisions, i.e., the controlled ablation of cells or cell groups. As in animals, cell death is regulated genetically also in plants. Evidence is accumulating that there are resemblances between the cell death mechanisms in either case and that the key gene products mediating these pathways are conserved. However, recent work also has led to the discovery of plant-specific cell death pathways in which chloroplasts and photoreactive porphyrins are involved.