Endosperm: food for humankind and fodder for scientific discoveries

Summary The endosperm is an essential constituent of seeds in flowering plants. It originates from a fertilization event parallel to the fertilization that gives rise to the embryo. The endosperm nurtures embryo development and, in some species including cereals, stores the seed reserves and represents a major source of food for humankind. Endosperm biology is characterized by specific features, including idiosyncratic cellular controls of cell division and epigenetic controls associated with parental genomic imprinting. This review attempts a comprehensive summary of our current knowledge of endosperm development and highlights recent advances in this field. Contents Summary 290 I. Introduction 290 II. Development of the endosperm 291 III. Patterning the endosperm 294 IV. Control of endosperm size and its influence on seed size 295 V. Hormonal physiology of the A. thaliana endosperm 298 VI. Epigenetic regulation of the endosperm 298 VII.