Agrobacterium Mediated Soybean Immature Cotyledons Genetic Transformation And Gmptfl Transcription Factor Expression In Soybean

Immature seeds of Jidou12were used as explants in order to research the impactof6-BA concentration, sampling time and the degree of development on adventitiousbuds induction. The results showed that the optimal regeneration conditions of thesoybean immature cotyledons section was the pod seed developed fully （afterflowering60-66d）, when pods began to turn yellow. When induced in the conditionthat6-BA concentration was1.0¹.5mg/L, budding rate reached to96.67%¹00%,and the average budding amount was1.6².57.Immature cotyledons node of Jidou7were used as explants to reserach theimpact of the low-temperature pretreatment of the explants, incubation temperature,co-medium pH and genotype on the efficiency of Agrobacterium-mediated genetictransformation. The results showed that, about60days after flowering when the sizeof seeds reached the full extent, more resistant shoots were produced. The Immaturecotyledons produced few resistant shoots when treated at4℃before infection. Underthe condition of24℃of incubation temperature, pH6.6of co-medium and24hoursillumination, the rate of resistant shoots reached the highest. The average number ofresistant shoots was higher in the Variety of Yudou22, Jidou7and Pinxi12thanother soybean varietis in this study.The transcription factor gene GmPTF1was transferred into soybean （Glycinemax L. Merr. c.v. Yudou22） by Agrobacterium-mediated soybean cotyledonary nodetransformation method, and11of T₁generation transgenic soybean strains wereobtained. The expression of gene GmPTF1in the transgenic plants was detected byFluorescent quantitative PCR. The biological functions of gene GmPTF1intransgenic soybeans were analyzed by determing the morphological, physiologicaland biochemical indexes of the transgenic and non-transgenic plants underlow-phosphorus stress. The experimental results showed that the GmPTF1expressionof transgenic soybeans was significantly higher than non-transgenic control, of whichthe T₁-32and T₁-40was the highest. The root length, root surface area, root volume,leaf area, photosynthetic pigment content, phosphorus absorption rate and phosphorus content of transgenic soybeans were significantly higher than these indexes ofnon-transgenic control. But the content of MDA of transgenic soybeans wassignificantly lower than the non-transgenic control. All the results indicate that thecapacity of P-deficiency tolerance of transgenic soybean was better thannon-transgenic control.