Construction Of Cotton (Gossypium Hirsutum L) Transformation System And Transgene Of AtABA2

Excellent germplasm resources are necessary for cotton breeding. Biological technology could be used to create new germplasm resources and promoted the development of cotton genetic breeding. Especially, being one of the most important techniques, genetic modification with trasgening method is efficient and developing achievements on cotton.The regeneration and transformation system of cotton was optimized by adjusting the parameters of somatic embryogenesis and agrobacterium-based transformation. It had been found that MSB5 medium with IAA, 2, 4-D, KT equal to 0.1 mg/L at pH6.0 conditions could be used to induce the best callus. Callus were sub-cultured once every three weeks on MSB5 medium with IAA, KT, 2, 4-D compared sub-culture medium a decline of 0.01 mg/L, till the concentration come to 0.05 mg/L, subculture 2-3 times, embryogenic callus appear. Increase pH of medium progressively and adding glutamine to it can induce somatic embryogenesis. Keeping IAA; 6-BA at the level of 0.01 mg/L and adding 0.1 g/L glutamine to the medium, after 3-4 times sub-culture somatic embryo can emerge. Survival rate of the regeneration plants can come to 90% by grafting.Embryogenic callus induced from hypocotyls of Jihe713 was used as explants in process of agrobacterium-based transformation. The best parameters were found by setting a series of gradients, such as co-culture time and temperature, bacteria concentration, infection time, and concentration of kanamycin. Results showed that the best transformation ratio could be attained, when OD600 of bacteria was 0.3, infection time was 3 min, co-culture time for 26 h at 24℃, and kanamycin concentration was 50 mg/L. Moreover, we have got some transgenic lines for AtABA2 being transmitted to jihe713, through this system above.Pollen tube pathway was used in this study. We set a series of experiments including the self intersection time, injection time, and method of injection to optimize parameters of injection. The highest transformation efficiency of exogenous DNA could be attended when plasmid concentration was 0.02 mg/mLAtABA2 encodes COX-zeaxanthin of ABA synthesize way. This study successfully transmitted AtABA2 over expression vector into Jihe713 through the system mentioned above. Over expression of AtABA2 in cotton result in advanced flowering. decreased stomata aperture, reduced water loss rate, increased leaf surface temperature which showed a drought resistance phenotype.