Stable Transformation of Gladiolus Using Suspension Cells and Callus

Abstract

More than 100 transgenic Gladiolus plants were recovered after particle bombardment of regenerable suspension cells and callus. For transformation, Gladiolus callus and suspension cells were co-bombarded with phosphinothricin acetyltransferase-(PAT) and ß- glucuronidase (GUS) -expressing plasmids. Stably transformed calli were selected on medium containing either phosphinothricin (PPT) or bialaphos followed by transfer to a regeneration medium to recover transgenic plants. Stable transformation was confirmed by detection of the PAT gene by DNA gel blot analysis and by enzymatic assays to measure GUS activity. In general, particle bombardment of regenerable suspension cells rather than callus resulted in the largest number of transformants. The rate of co-expression for GUS in PPT-resistant plants was high (≈ 70%). Promoters that are typically more efficient in dicotyledonous plants were very active in Gladiolus, a monocotyledonous bulb plant. Establishment of an efficient transformation protocol for Gladiolus will now allow the introduction of transgenes to confer resistance to the viral and fungal pathogens that decrease Gladiolus production.