Study On Agrobacterium-mediated Transformation Of Sesame With Binary Insect Resistant Genes

Sesame(Sesamum indicum L.)belongs to the genus sesamum, family Pedaliaceae.It is an annual plant and one of the oldest oil crops in the world [1].Moreover, both sesame seeds and sesame oil are important raw materials for food industry. Sesame,especially the black sesame, is also considered an health food. Therefore,the breeding for new sesame varieties with high and stable yield, and insect-resistant traits has become an inevitable requirement in sesame industry. With the development of science and technology, transgenic technology has provides a new way for the cultivation of new varieties of sesame seeds.In this study, the Jinzhi No.3 and plasmid pBI101-Chi-Bmk was selected as experimental materials.The Agrobacterium tumefaciens-mediated method was applied to introduce the bivalent insect-resistant genes into the sesame cultivar. The aim is to obtain new varieties with insect-resistance and provide technical support for breeding new varieties.Contents and results of this study are as follows:1.We studied the impact of different explants, various hormone concentrations and their combination ratios on the regeneration of the sesame. The hypocotyls of 5-8 day plantlets were used as explants.The effect that these explants were induced in MS+6-BA 2.0mg/L+IAA 0.2mg/L medium and differentiated into adventitious buds was the best. These explants could root in 1/2MS+NAA 0.1mg/L medium, rooting rate up to 100%.2.This study explored the impact of the bacterial concentrations, co-culture conditions and duration on Sesame transformation. The results showed that:the highest transformation efficiency of up to 30.52% was reached when the bacterial culture concentration of OD6oo was 0.4 to 0.6 in the logarithmic growth phase, the hypocotyls of 5-8day seedlings were used as explants,and they were co-cultured for 2 days in dark.3.PCR was employed to detect transgenic sesame plants,and the specific amplified bands demonstrated that the foreign genes had been introduced into the sesame variety. Afterwards, the natural occurrence of insect damage the were observed in the field, and the less damage on transgenic plants may be related to the expression of introduced target genes in the sesame plants.