Glycosidases in Carrot Cells in Suspension Culture: Localization and Activity Change during Growth

Localization of four glycosidases, -galactosidase (-Gal), ß-galactosidase(ß-Gal), -glucosidase (-Glu) and ß-glucosidase(ß-Glu) in suspension-cultured carrot cells was studied.Wall-bound enzymes were made soluble when the cells were convertedto protoplasts by cellulase and pectinase. -Gal was separatedinto two forms, designated I and II, by chromatography on aSephadex G-200 colunm. -Gal I was located exclusively in thecytoplasm whereas -Gal II was found in both the cytoplasmicand cellwall fractions. The pH optimum was in the neutral regionfor -Gal I and in the acidic region for the other glycosidases,including -Gal II. Both intact cells and protoplasts in suspensionculture secreted these glycosidases, except -Gal I, into themedium. Specific activities of the glycosidases, especiallythe activity of ß-Gal, decreased in the early logarithmicgrowth phase and increased as cells went through late logarithmicand stationary phases. In protoplast culture, glycosidase activitygradually increased as cell wall regeneration proceeded. (Received December 13, 1980; Accepted February 10, 1981)