ABSTRACT
This chapter explores some of the processes which lead to development and differentiation in the plant. In essence, development encompasses both growth and differentiation. In practice, the terms development and differentiation are often used interchangeably. Development is the broad change that takes place in a plant during its life cycle. Auxin was the first plant growth regulator to be investigated. Auxin shows polar movement, that is, it is produced in apical meristem and young leaves and is translocated down the plant in the phloem to the roots in one direction only. Cell elongation and enlargement is stimulated by auxin in the region behind the apical meristem so leads to growth of the stem. Cell division and differentiation also involves auxin where it promotes cell division in cambium tissue favouring xylem production. Promotion of cell division which is one of cytokinin's main effects. In micropropagation, it is used to stimulate shoot production in tissue culture.
