Death proteases come alive

Cell death in plants exhibits morphological features comparable to caspase-mediated apoptosis in animals, suggesting that plant cell death is executed by (caspase-like) proteases. However, to date, no caspase homologues have been identified in plants and therefore the existence and nature of these plant caspase-like proteases is the subject of much debate. The recent characterization of cell death-associated plant proteases with aspartate-specific cleavage activity demonstrates the involvement in plant programmed cell death of proteolytic activities functionally resembling animal caspases. These findings might explain the observed similarity in cell death morphology between animal and plant cells.