PROGRESS IN THE DEVELOPMENT OF TRANSGENIC PAPAYA: TRANSFORMATION OF SOLO PAPAYA USING ACC SYNTHASE ANTISENSE CONSTRUCT

Papaya (cv. Solo) somatic embryos were produced, squashed and used for transient stable transformation. Conditions for transforming somatic embryos were optimized using transient expression of GUS. A total of 11,900 immature zygotic embryos were isolated and 7,730 (65%) produced somatic embryos. All the somatic embryos were squashed, placed in an osmotic medium and bombarded with the antisense ACC synthase construct placed in a co-transformation vector. A total of 160 bombardments were made. The bombarded tissues were subjected to a selection medium containing half-strength MS with 150 mg L^-1, then with 300 mg L^-1 kanamycin. Embryos surviving kanamycin-selection were regenerated on a full strength De Fossard medium supplemented with 0.25 μM each of BAP and NAA and 10.0 μM GA₃.