endospermi

Endospermi, or endosperm, is a nutrient-rich tissue formed inside the seeds of most angiosperms during seed development. It arises as a result of double fertilization, when one sperm fuses with the central cell to form a triploid nucleus that divides to create endosperm tissue. The endosperm surrounds and nourishes the developing embryo and, in many species, fuels germination.

The endosperm can develop in different cellular patterns. It may become cellular early, with distinct cell walls forming between nuclei, or it may be predominantly coenocytic (multinucleate) for a period before cellularization. In many cereal crops, the endosperm persists after seed maturity and serves as the main storage tissue, providing starch, storage proteins, and lipids to support seedling growth. In other seeds, the endosperm is consumed by the embryo during maturation, resulting in exalbuminous seeds where the mature seed contains little or no endosperm.

Two broad categories describe its persistence: albuminous seeds retain a substantial endosperm at maturity (examples include maize, wheat, barley), whereas exalbuminous seeds lack substantial endosperm in the mature seed (examples include many legumes such as beans and peas).

Composition typically includes starch as the primary carbohydrate, along with storage proteins and lipids. The exact composition varies among species and influences seed size, germination rate, and seedling vigor.

Endosperm plays a central role in plant reproduction and agriculture, particularly for cereal crops, where its nutritious reserves are critical for human and animal food supplies. In gymnosperms and most non-angiosperm lineages, a true endosperm as defined in flowering plants is not present.