GUS Expression in Protoplasts of Immature cotyledons of Soybean

The E. coli beta-glucuronidase (GUS) gene was used in gene expression experiments with the protoplasts isolated from immature cotyledons of soybean (Glycine max L.). Transient expression of GUS gene could be detected in 1—6 days after DNA incorporation into soybean protoplasts by using a fluorogenic substrate MUG. Stable transformation was observed by histochemical localization with the use of a substrase X-Gluc. Some factors such as PEG toxicity and protoplast stability affecting PEG-mediated transformation were discussed.