The mature embryo is surrounded by a nutritive tissue called endosperm or perisperm. This tissue provides nourishment to the developing embryo. In some plants, the endosperm is formed by the fusion of two sperm cells with the central cell of the female gametophyte. In other plants, the perisperm is formed by the proliferation of the nucellus tissue surrounding the embryo sac.
The mature embryo is also protected by a coat, which is commonly referred to as a seed coat. This seed coat is derived from the integuments of the ovule and provides a protective covering for the embryo. The seed coat helps to prevent desiccation, mechanical damage, and fungal or bacterial infection. It may be thick and hard or thin and membranous, depending on the plant species. The seed coat often has specialized structures, such as micropyles or hilums, which serve as entry points for water and gases during germination.
Mature embryo surrounded by nutritive tissue and protected by a coat
1 answer