CHANGES IN PEROXIDASE AND IAA-OXIDASE ACTIVITIES DURING ADVENTITIOUS BUD FORMATION FROM SMALL ROOT EXPLANTS OF CICHORIUM-INTYBUS L - INFLUENCE OF GLUCOSE

Root explants of Cichorium intybus were cultured on Heller medium supplemented with different glucose concentrations, in light or in darkness. Capacity of bud formation was strongly diminished by darkness and the average number of buds formed by explants, was not modified by glucose treatment. When explants were illuminated adventitious bud formation was strongly dependent upon the glucose concentrations. Glucose was not necessary for budding and glucose concentrations above 0.01 M decreased bud forming capacity. During differenciation of bud meristems peroxidase activity remained highest in explants wich will produce more buds, i.e. when glucose concentration was weak. Glucose effects were similar on IAA-oxidase activity, but this activity cannot be detected without PVP in the extraction buffer. The hypothesis of the regulation of bud formation by a relationship between phenolic compounds and enzymes involved in IAA catabolism, i.e. peroxidase, is discussed.