α- amylase activity by GA₃ - Dormancy

Of the enzymes required for the digestion of starch α-amylase appears immediately after the start of germination. It was found that if the embryo was removed no a-amylase appeared, however, if very low concentations of GA₃ were added to the seed the production of digestive enzyme proceeds. The work over the last 30 years proved the fact that GA₃ initiates action at transcriptional and translational levels. Not only activation of pre-existing m-RNAs coding for a-amylase but synthesis of m-RNA also takes place after the exposure of seeds to GA₃.

Cytokinins and Cell Division

Cell division involves synthesis of new DNA, RNA and a host of cell proteins in interphase (cell cycle S₁ and S₂). All these events are promoted by cytokinins. Cell division also means synthesis of a number of enzymes that are needed for the synthesis of cell wall and middle lamella.