Gibberellins have been shown to be effective in breaking the dormancy in potato tubers and in tree buds in winter.
Cytokinins have been found to be effective in breaking the dormancy of seeds. They also promote the germination of the seeds. The cytokinins substitute the red light requirement for breaking the dormancy of seed, while in combination with red light kinetin reverses the effect of certain naturally occurring inhibitors of seed germination as coumarin.
ABA regulates the dormancy of buds and seeds by inhibiting the growth processes. Bud dormancy is regulated by a balance between gibberellins and ABA.