4. Development of Embryo_2.pptx embryo beginning

How embryo develops

1. Embryogenesis

2. After double fertilization – Each ovule develops into a seed seed ( s)

3. De v elopment a l St a g es Early Mid Late 19.36 pre- g l o b ular globular transition heart t o r p e do ma t ure Buchanan et al, 2000, Biochemistry and Molecular Biology of Plants

4. S implified Structure of A Mature Seed Seed coat is dead tissue. It protects everything inside it. Embryo is a minute plant . Endosperm provides energy for seed germination and early seedling growth. In a common garden bean, a eudicot

5. – The embryo consists of the hypocotyl, radicle, and thick cotyledons (a) Common garden bean, a eudicot with thick cotyledons. The fleshy cotyledons store food absorbed from the endosperm before the seed germinates. The seeds of other eudicots, such as castor beans – Have similar structures, but thin cotyledons S e e d c o a t Radicle E p i c ot y l Hypocotyl Cotyledons

6. H y p oc ot y l Radicle S e e d c o a t Endosperm Cotyledons Epicotyl Hypocotyl Radicle (b) Castor bean, a eudicot with thin cotyledons. The narrow, membranous cotyledons (shown in edge and flat views) absorb food from the endosperm when the seed germinates. The embryo of a monocot – Has a single cotyledon, a coleoptile, and a coleorhiza

7. (c) Maize, a monocot. Like all monocots, maize has only one cotyledon. Maize and other grasses have a large cotyledon called a scutellum. The rudimentary shoot is sheathed in a structure called the coleoptile, and the coleorhiza covers the young root. Embryogenesis &Seed development Embryo development: Establishment of patterns Establishment of meristem regions Scutellum (cotyledon) Coleoptile Coleorhiza Pe r i c a r p f u s e d w ith seed coa t E nd osp e r m E pic o t y l H y poc ot y l Radicle