Analysis of isoenzyme patterns in embryogenic and non-embryogenic calli of coffee

Leaf sections of the coffee hybrid <<Catimor>> (Coffea arabica L. cv. Red Caturra x Hybrid of Timer) were cultivated in vitro to induce indirect somatic embryogenesis by the procedures previously described (11). With the goal of detecting characteristic biochemical patterns, associated with the embryogenic (E) and non-embryogenic (NE) calli of coffee; a study of the isoenzimatic patterns in those tissues was performed. These patterns would be potentially useful as markers of embryogenic tissues. For the analysis, extracts were prepared from E and NE calli, older than eight months. The extracts were separated by electrophoresis in 10% slab polyacrilamide gels, under nondenaturing conditions. Reactions to detect the enzymes diaphorase (DIA), acid phosphatase (ACP), malate dehydrogenase (MDH), esterase (EST) and peroxidase (PRX) were made on the gels. The profiles for PRX, EST, MDH and DIA were qualitatively the same for E and NE calli. However, these enzymes showed quantitative differences; the activity was always greater in E than in NE calli. By contrast, only the pattern of ACP showed qualitative differences between both tissues. In E calli four additional ACP bands, (absent in NE calli) appeared. According to the results of this research, in the group of enzymes studied, only the pattern of ACP differs in E and NE calli.