Cytokinins (CK) belong to a class of plant growth substances (plant hormones) which promote cell deivision by means of local and long distance signalling.. Cytokinins are substances close to purine bases (substituted adenins). It is a family of phytohormones essential for the development of the plant as well as auxin, which acts as hormones in plants.

Thidiazuron (TDZ) is used in tissue culture and can promote or accelerate the organogenesis and plant regeneration. Thidiazuron (TDZ) was originally used as a defoliant but this phenyl-urea also has cytokinin activity. 

Thidiazuron (TDZ) is a plant growth regulator used in micropropagations to supplement media such as Murashige and Skoog medium. TDZ promotes plant organogenesis (shoot regeneration) and plant regeneration.

TDZ exhibits the unique property of mimicking both auxin and cytokinin effects on growth and differentiation of cultured explants, although structurally it is different from either auxins or purine-based cytokinins.