Requirements for seed to germinate:
1. Absorption of water by imbibition, (physical process)
2. Hydrolysis of reserve foods like - in cereals & milletes reserve food by amylase, in pulses by proteases, in oil seeds by lipase. (Biochemical process)
3. Enzymes are activated by water.
4. Meanwhile the seed coat ruptures and growing embryo is exposed to the light and air.
5. The primary axis synthesizes proteins rapidly.