paljudes kasvu- ja arenguprotsessides (embrüogenees, juurte ja juhtkudede moodustumine, rakkude venimiskasv, rakutsükli regulatsioon, lehtede ja viljade langemine) osalev meristeemides sünteesitav taimehormoonide rühm, Auxins are a class of plant hormones, have a cardinal role in coordination of many growth and behavioral processes in the plant's life cycle and are essential for plant body development and cell cycle regulation. The most widely used auxin by plants is indole-3-acetic acid (IAA).