Improved electroporation buffer enhances transient gene expression in Arachis hypogaea protoplasts

An electroporation medium containing 50 mM glycine or 10 mM glycylglycine (glygly), 70 mM potassium glutamate, and 0.4 M mannitol was evaluated for its ability to improve transient β-glucuronidase (GUS) expression in immature cotyledonary protoplasts of Arachis hypogaea L. GUS activity in electroporated protoplasts was 8- to 430-fold greater than that obtained using any of other four commonly employed poration media. Analysis of viability and histochemical staining of protoplasts indicated that electroporation using the glycine- or glygly-based poration medium resulted in increased protoplast viability and GUS expression when compared with other poration media. Replacement of glygly with MES or HEPES buffers significantly reduced the level of GUS expression in electroporated protoplasts.