During germination of grain seeds, they absorb water thereby the synthesis of auxin being start in embryos of seeds. Gibberellin stimulates the synthesis of proteases and ? - amylase enzymes. It activates inactive ? - amylase. Active ? and � - amylase combine to digest starch to form glucose. The energy is released by oxidation of glucose for embryo. Now cytokinin and auxin are also synthesised thereby cell division, differentiation and elongation become start and seedling is formed.