Establishment And Optimization Of Agrobacterium-mediated Soybean Transformation Using Embryonic Meristem Regeneration System

Soybean is one of the most important crops, which is the primary source of vegetable oils and vegetable proteins, and so on. Transgenic soybean has greatly contributed to yield increase, quality improvement, and reduction of production cost. To date,75%of the world soybean arcrage is transgenic soybean. However, China is still at the early stage of development of transgenic soybean. The bottleneck is lack of efficient soybean transformation system. The aim of research is to establish a robustic and efficient soybean transformation system.Firstly, an effective soybean embryonic meristems transformation system was established in this research by analyzing and optimizing influencing factors. Using this system, five excellent soybean cultivars were compared for susceptibility to Agrobacterium infection, the regenerative ability and transformation efficiency. Secondly, we studied the effects of two acdS genes, encoding for1-Aminocyclopropane-l-carboxylate deaminase (ACDS), which are expected to alleviate the negative effect of Agrobacterium-infection on the soybean tissue culture. Finally, we established protocols for greenhouse care of transgenic soybean, and screening of glyphosate tolerance of transgenic soybean.By optimization of mutiple factors of transformation system, we were able to achieve1.5-3%of the transformation efficiency using Agrobacterium-mediated soybean embryonic meristems transformation system. Among the five genotypes tested, Tianlong1showed the best response to Agrobacterium-infection, tissue regeneration and transformation efficiency totally. Moreover, we confirmed acdS genes could promote soybean transformation in Huachun3. At last, we affirmed spraying one time with glyphosate concentration of1/200(v/v) was the best combination for identification of herbicide tolerance of the transgenic soybean plants. Single T-box vector and single trangene copy transformant had better inheritability and stability. Black and loess soil mixure with1:1ratio was the best choice for transgenic soybean growth. In conclusion, the results of this study provide important basis for the breeding new soybean cultivars and exploring soybean functional genomics.