Cytokinins are group of plant hormones that influence cell division and shoot formation.
They are also involved primarily in cell growth and differentiation, but also affect apical dominance, axillary bud growth, and leaf senescence.
Cytokinins or CKs are a group of chemicals that influence cell division and shoot formation.
The first of the cytokinins to be discovered was zeatin, which was isolated from corn kernels in 1964. Since then, three others have been identified, including kinetin. When coupled with other hormones, cytokinins appear to promote cell division in meristematic tissues.
Cytokinins also appear to play a role in preventing senescence (aging) in plants. If picked leaves are coated with cytokinins, they stay fresh longer. Cytokinins are also used to promote lateral bud growth of flower crops. Cytokinins are responsible for mediating auxin transport throughout the plant, and affect internodal length and leaf growth. They have a highly–synergistic effect in concert with auxins and the ratios of these two groups of plant hormones affect most major growth periods during a plant's lifetime. Cytokinins counter the apical dominance induced by auxins; they in conjunction with ethylene promote abscission of leaves, flower parts and fruits. Cytokinins are also used to promote lateral bud growth in flowering plants.