Excessive amounts of omega-6 polyunsaturated fatty acids and a very high omega-6/omega-3 ratio, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, inflammatory and autoimmune diseases. For the successful transfer of a gene to a plant, gene transfer optimization is needed. Sesame is an ancient oilseed plant known for its medicinally important lignans and its high quality edible oil. The increase of omega 3 in this plant helps to improve the quality of the oil. In this research, in order to optimize the transfer conditions of FAD3 gene isolated from flax plant to sesame plant, the effects of cultivar (Darab and Dashtestan), pre-culture time (5, 6 and 7 days), Agrobacterium concentration (0.1, 0.5, 0.25 OD600), inoculation time (10, 20 and 30 minutes), co-cultivation time (zero, 24, 48 and 72 hours) and light effect (darkness and 16 hours of light) and acetosyringone concentration (0, 50 and 100 µM)) were investigated separately in a completely randomized design in 4 replications. The results showed that the 7-day pre-culture duration in the Dashtestan variety and 5-day pre-culture duration in the Darab variety, Agrobacterium concentration OD600= 1, inoculation time of 30 minutes, co-culture time of 24 hours in the dark and 100 μM acetosyringone had an important role in gene transfer efficiency. In this study, the Dashtestan cultivar showed a better regeneration percentage than the Darab cultivar. Finally, shoots were transferred into rooting media. Preliminary investigations of regenerated plants in the selected environment and PCR tests were done using specific primers and transgenic plants were selected.
