Regeneration of Transgenic Oil Palm Carrying GFP Gene Used as a Visual Selectable Marker

Green fluorescent protein (GFP) has been widely used as a visual selectable marker for plant transformation. Transformed cells could be easily screened directly under ultraviolet/blue light without the need for any solution or substrate. In this study, oil palm embryogenic calli were bombarded with a transformation vector, p35SCaMV-sgfpS65T, carrying a modified version of gfp gene driven by the 35S promoter. Upon bombardment, the expression of gfp in embryogenic calli was monitored visually while the regeneration of the embryogenic calli was on-going. Regenerated plantlets on medium without selection agent demonstrated that only some parts of the plants showed GFP expression. When gfp gene was co-bombarded with plasmid pAHC25 carrying Basta resistant gene (bar), and the transformed embryogenic calli were regenerated on medium containing herbicide Basta, regenerated plantlets obtained also showed GFP expression in some parts of the plantlets instead of in the whole plant. Molecular analysis revealed the presence of gfp transgene in the transgenic plants. The possible reasons for the failure to obtain the whole plant expressing gfp gene will be discussed. (author)