EFFECTS OF PROMOTER, INTRON AND ENHANCER ELEMENTS ON TRANSIENT GENE-EXPRESSION IN SUGARCANE AND CARROT PROTOPLASTS

Various chimaeric promoter regions coupled to the uidA beta-glucuronid ase gene were evaluated for transient expression strength following el ectroporation into sugar-cane (monocot) and carrot (dicot) protoplasts . Multiple enhancer elements increased expression in sugar-cane, by up to 400-fold for the artificial Emu promoter relative to the CaMV 35S promoter. The relative expression strengths of promoters varied substa ntially between the species. Sugar-cane also differed in some respects from previously tested species in the family Poaceae. For example, in sugar-cane the nopaline synthase and CaMV 35S promoters were of equiv alent strength, and insertion of Adh1 intron 1 into the 5' transcribed region decreased expression strength.