The young plant individual after fertilization or parthenogenesis when the * proembryo has differentiated into embryo and suspensor. Embryo cells are typically thin walled with dense cytoplasm and maintain mitotic activity. Cells exhibit polarity from early on, and in higher plants a plumule, radicle, and cotyledons may be identified. In seed-bearing plants the embryo is protected by integuments, which later form the seed coat. Further embryo development in the seed is usually controlled until environmental conditions are appropriate. Compare zygote. See embryogeny. |
