During seed germination especially of cereals gibberellins stimulate the production of some mRNA and than hydrolytic enzymes like amylases, lipases ribonucleases and protreases These enzymes solubilize the reserve food of the seed. The same are transferred to embryo axis for its growth.
Auxins stimulate respiration most probably by increasing the availability of respiratory substrate.
Cytokinins help in phloem transport. Abscisic acid inhibits gibberellin mediated amylase formation during germination of cereal grains.