PCD processes are an integral part of vegetative and reproductive plant development. They occur during xylem and tapetum differentiation, in various tissues during seed development and germination, and during plant organ senescence. We indicate proteases that have been implicated with aspects of these cell death processes in the individual tissues. For some of the PCD processes listed, no functional data for protease involvement exists to date. Abbreviations are: A, aleurone layer; E, endosperm; ESR, embryo-surrounding region of the endosperm; I, seed integuments; S, suspensor.