The Estabablishment Of Maize Genetic Transformation Using Ghd7 And Gs5 Gene

Maize is the one of the most important crops in the world. But it's efficiency of transformation is very low and transformation is difficult. There are many methods about the maize transformation,for example,the particle gun method and agrobacterium-mediated method. It is not restricted by the genetype and could transferred the gene into the immature embryo, callus and cluster buds. although the agrobacterium method was late comparation with the particle gun method,but more and more people are pay attention to this method because the lower copy number, easy manipulate, stable and safe..Except these two method, the new methods are explored,for example shoot transformation method and pollen tube method.those method don't need the induce and subculture, this can reduce the time of transformation somaclonal variationThe rice gene Ghd7 and Gs5 are the important yield genes which were cloned recently. The Ghd7 gene controls many characters, such as the yield, height and heading date. It locates in the seventh chromosome. overexpression of Ghd7 gene under long-day conditions delays the heading and increases plant height and panicle size.Gs5 gene locates in the fifth chromosome and it controls the quality character.In our experiment, we constructed the Ghd7 gene into the pTF101.1 vector and transferred it into the maize callus using particle bombardment methods; the Gs5 gene were constructed into the binary vector pCAMBIA1301 and transferred it into maize immature embryo through Agrobacterium-mediated transformation. After selection and regeneration phases, we got the transgenic plants. These plants were detected by PCR and RT-PCR methods. We got 95 Ghd7 gene transgenic plants and all the plant were all positive. The number Gs5 transgenic plants were 25.Besides the two major methods, we also explored the stem tip method of maize, utilizing this method to transfer the Ghd7 gene into maize. This method crosses the phase of inducing callus and saves time. After the selection with the herbicide, we got some resistance plants.We established a genetic transformation system on the basic of previous and build a solid foundation for the next experiment.