The synthesis of a plant hormone is not localized to a specific tissue, but occurs in many different tissues, particularly in the meristematic regions. Furthermore, plant hormones are transported from the site of synthesis to act in distant tissues. Plant hormones influence a wide range of processes. Auxins, for example, have been found to influence a myriad of processes within a cell, including cell elongation, cell division, induction of primary vascular tissue, adventitious root formation, senescence, fruit growth, outgrowth of axillary buds and flower development. In some cases, the levels of endogenous hormones have been determined. All of PlantMedia™'s hormones and growth regulators are tested for use in plant tissue culture.