Table of Contents
Cover image

It is well established that in the female gametophyte of higher plants, both egg and central cells are fertilized to generate the embryo and the endosperm, respectively. It is not clear, however, how these fertilization events activate seed development. Indeed, in efforts to identify genes that control the onset of reproductive development, a number of mutations that allow for fertilization-independent endosperm formation have been identified. A seed of one such mutant-fie-is illustrated on the cover. This seed, which is comprised of an endosperm surrounded by a seed coat, was formed without fertilization. On pages 407-415 of this issue, Ohad et al. show that the FIE protein is most closely related to a family of animal WD polycomb-group proteins that operate as repressors of homeotic genes. These results suggest that FIE functions in the female gametopohyte to suppress a critical aspect of plant reproduction-endosperm development-until fertilization occurs.