(a) Gibberellins : Stem elongation.Abscissic acid : Acts as a growth inhibitor.
(b) Cytokinin : Counteract the dominance of apical buds.
Ethylene : Causes apical dominance and fruit ripening.
(c) Auxin: It inhibits the above functions.
Ethylene : It breaks seed and bud dormancy and induces respiration rate during fruit ripening. Rise
in respiration rate is termed as the respiratory climatic.