How do auxin and cytokinin work in apical dominance?

When a shoot is lengthening at the tip, its lateral buds are typically dormant, an effect called apical dominance. Auxin maintains apical dominance by regulating production and transport of cytokinin in a stem, and by promoting expression of an enzyme that breaks it down. If a shoot's tip breaks off, its source of auxin disappears, so the cytokinin level rises in the stem. The cytokinin moves into lateral buds and stimulates cell divisions of apical meristem inside them. These newly active meristem cells produce auxin, which is transported away from the bud tips and down the stem. The movement causes the lateral buds to lengthen and form new shoots.