Functions of Auxin : Cell enlargement, apical dominance, prevention from bending; promote xylem differentiation, healing of wounds of plants.
Function of Cytokinin : promote cell division, apical dominance, delay in senescenes ( aging ), phloem transport, accumulation of salts in cells, production of female flowers, increase resistance to extreme temperatures and diseases.
Functions of Gibberellin : promote increase in fruit size, inter-nodal elongation, seed germination
Functions of Abscisic Acid : abscission of leaves, reduce transpiration, inhibit cambium activity, bud dormancy in seed during winter, seed development and maturation, induce flowering in some SDPs, synthesis of carotenoids in green organs
Functions of Ethylene : inhibit stem elongation; promote fruit ripening, increase girth of stem, speed of senescence, abscission of leaves