During the course of evolution, flowering plants have become one of the predominant life forms on earth. One reason of this evolutionary success is the rapid development of an embryo alongside a nutritive tissue called the endosperm. The embryo and the endosperm are surrounded by layers of maternal tissues, the seed integuments. The trinity of embryo, endosperm, and integuments form the plant seed. The seed is the embryo’s lifeboat in space and time, and stockpiled nutrients feed the germinating seedling. Likewise, seed-derived nutrients represent the major food source for mankind, and thus a comprehensive understanding of seed development is of utmost importance to ensure our sustenance in the decades to come.

In order to form a functional seed, all seed components have to develop in a highly coordinated manner, representing a paradigm for communication between cells and tissues. These communication events start with the double fertilization that generates the diploid embryo and the typically triploid endosperm. Although both embryo and endosperm are zygotic products, their fates differ fundamentally: While the embryo carries on to form the next plant generation, the endosperm’s destiny is to die during seed development, undergoing a developmentally regulated cell death. Our major focus is to unravel the molecular control of the terminal differentiation steps of the endosperm, culminating in cell death in Arabidopsis thaliana, as a dicotyledonous model, and corn (Zea mays) as a cereal system.