Transferring CycD2 Gene Into Wheat Via Micro-projectile Bombardment And Floral-dipping With Agrobacterium Tumefaciens

The plant D-type cyclin CycD2 is a cell cycle related protein gene. In the year of 2000, Cockcroft transformed CycD2 gene into the tobacco and discovered that, the rate of cell-division in the transgenic tobacco plants is increased by the over-expression of the plant D-type cyclin CycD2. In addition, the overall plant growth rate is extremely significant than the untransfomed wild-type plant. At present, we also hadn't seen the related report about the transgenic wheat plants yet. This research transformed CycD2 gene into wheat via Micro-projectile bombardmentand and floral-dipping wheat with Agrobacterium tumefaciens. Main findings are as follows:In the foundation work of Wang xiaoxia who is graduated from our laboratory, we carried on the molecular biology analysis to the T₁ generation of transgenic plant which obtains the CycD2 gene via particle bombardment, the result of PCR analysis revealed that part of the transgenic T₁ seedlings contained the CycD2 gene fragment. but the result of Southern-blot showed that the CycD2 gene has not been integrated into wheat nucleus genome. In addition, the agronomic characters of the transgenic T₂ generation were analyzed, the result showed that most of the T₂ plants tended to normol phenotype and were sensitive to the powdery mildew, but there are four plants which is different from the other plants in plant height, and the ear of neck length of these four plants were obviously shortened. The multiple comparison result showed the difference in plant heigh has achieved the remarkable level between the transgenic T₂ plants. We also tansformed the CycD2 gene into wheat by floral-dipping wheat ears with Agrobacterium tumefaciens and made some improvements and comparision to the floral-dipping method. Furthermore, We found the right selection concentration of G418 solution and had got twenty-five G418-resistant T₁ seedlings, but the result of PCR analysis showed that these T₁ seedlings hadn't contain the CycD2 gene fragment. Howervr, the result of agronomic characters observation showed the growth status of T₁ plants is similar to transgenic plants which has been reported by the other researchers. In addition, the partial leaf of T₁ plants presented the random curl, and the ear of neck length of some T₁ plants were also shortened. This kind of phenomenon may due to physiological and cultivated conditions or caused by inheritance unconventionality. At present, the right reasons are also waiting for the further research to confirm.