REGULATION OF THE ENZYMES OF UDP-SUGAR METABOLISM DURING DIFFERENTIATION OF FRENCH BEAN

A study has been made of changes in the enzymes of UDP-sugar metabolis m in suspension cultured cells of French bean during their normal grow th following subculture. These are compared to cells of the same cell suspension subcultured into a cytokinin enriched media which induces c hanges in their cell walls that resemble xylogenesis. The same enzymes have also been measured in seedling hypocotyls undergoing elongation growth and differentiation. Evidence was obtained for sucrose synthase and possibly amylase for having roles in the mobilization of sugar re serves during growth changes in suspension cultures. Furthermore, UDP- glucose dehydrogenase showed characteristic increased activity that in dicated a key role in the provision of sugar nucleotides for cell wall biosynthesis. Less significant changes were observed for other enzyme s involved in sugar nucleotide interconversion.