Enzyme Markers for Somatic Embryogenesis in Vitis

A protocol has been detailed for somatic embryogenesis from leaf- and petiole-derived callus of Vitis rupestris. Isozymic patterns of acid phosphatase, alcohol dehydrogenase, esterase, gluconate-6-phosphate dehydrogenase and phosphoglucomutase were analyzed during precise steps of somatic embryogenesis from callus to plantlet. Among the five enzymes investigated, alcohol dehydrogenase, acid phosphatase and esterase gave different results, either in their specific activity, as in the case of alcohol dehydrogenase, or in the number and isoelectric point of the isoforms expressed, as in that of acid phosphatase and esterase. Non-morphogenic calli were clearly different from embryogenic calli, and from embryos. Moreover, the calli dedifferentiated from somatic embryos did not retain the level and types of isozymes that characterize the embryo state. Our analysis of the electrophoretic patterns of specific enzymes proves to be an effective approach to the characterization of the main steps of Vitis rupestris somatic embryogenesis.