Which layer secretes the enzymes that mobilise stored reserves when a cereal grain germinates?

1. Reserves stored in the endosperm are useless to the embryo until they are broken down. 2. The aleurone is a single layer of cells just inside the seed coat, surrounding the endosperm and embryo. 3. On germination it secretes the enzymes that degrade the stored carbohydrates, proteins and lipids. 4. The products are then absorbed by the scutellum and transported to the developing embryo. 5. So the scutellum takes up what the aleurone releases, and confusing the two reverses the sequence. 6. The testa is the outer seed coat and the coleorhiza is the covering of the emerging root tip. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 32 "Plant Reproduction", section 32.2 Pollination and Fertilization_