| Hormone | Location of Hormone | Major Functions |
|---|---|---|
| Auxin(IAA) | Embryo of seed, meristems of apical buds, young leaves | Stimulates stem elongation(low concentration only), root growth, cell differentiation, and branching, regulates developments of fruit; enhances apical dominance; functions in phototropism and gravitopism; promotes xylem differentiation; retards leaf abscission |
| Cytokinins | Synthesized in roots and transported to other organs | Affect root growth and differentiation; stimulate cell division and growth; stimulate germination; delay senescence |
| Gibberellins | Meristems of apical buds and roots, young leaves, embryo | Promote seed and bud germination, stem elongation, and leaf growth; stimulate flowering and development of fruit; affect root growth and differentiation |
| Abscisic acid | Leaves, stems, roots, green fruit | Inhibits growth, closes stomata during water stress; promotes seed dormacy |
| Ethylene | Tissues for ripening fruit, nodes of stems, aging leaves and flowers | Promotes fruit ripening, opposes some auxin effects; promotes or inhibits growth and development of roots, leaves and flowers, depending on species |