Logo
 Home | Sitemap | Contact us | Search | Language
Left Right
Home >> Plant Biotechnology and Genomics >>Tissue Culture, Micropropagation and Somaclonal Variation >>Cytodifferentiation

Cytodifferentiation
Since an undifferentiated callus is always parenchymatous in nature, the differentiation of these cells into a variety of cells is required during redifferentiation of these cells into whole plants. This is described as Cytodifferentiation. In this connection, a study of differentiation into vascular tissue has received maximum attention. It has been shown that auxin and sucrose play a major role in vascular differentiation and also that cytokinins and gibberellins promote differentiation into xylem tissue. At low concentration (0.5mg. l-1), auxin stimulates xylem formation and there is inverse relationship between auxin concentration and the degree of xylem differentiation.

This effect of auxin is dependent on the presence of sugar, since the relative amounts of xylem and phloem formed can be altered by varying the sucrose concentration. In some studies (e.g. in syringa), 1% sucrose (with 0.55 mg l-1 of auxin or IAA) induced little xylem formation; 2.5-3% sucrose induced equal xylem and phloem differentiation and 4% sucrose induced only xylem formation (with little or no phloem). Sugars, other than sucrose (e.g. maltose, glucose, fructose, etc.) have also been used to stimulate vascular differentiation. Besides auxin and sucrose, cytokinins and gibberellins have also been shown to play a role in xylem differentiation.

 

Left Right