With the development of techniques applied to plant products, studies on plant components have recently developed tremendously. Plant components have been used for many purposes: industries based on the use of lignin or cellulose are well-known, while proteins represent a major source of food for men and animals. Recently, studies have focused on plant growth factors or hormones for two main purposes: (1) to gain more knowledge of plant growth regulatory mechanisms: (2) to increase some specific hormone production and other products of use in human pharmacology.