Construction Of Expressing Vectors In Eukaryotic Cells For HMW-GS Genes And Gentic Transformation Of Triticum Aestivum

Common wheat (Triticum aestivum L.) is one of the most important crops in the world and it is the primary food for human. Up to now, more attention has been paid to wheat processing quality. High-Molecular-Weight glutenin subunits (HMW-GS) is present as a network in dough and confer the visco-elastic property, each subunit gives different contribution to the quality of wheat dough. The different composing and proportion of HMW-GS is able to result in different quality of wheat cultivars.With the development of molecular cloning and genetic transformation, many genes related to high quality have been cloned from wheat and other crop species. It is possible to improve the quality of wheat dough through gene engineering. If the HMW-GS genes for high quality were transferred into and expressed in low quality wheat cultivar, the number and proportion of HMW-GS in the acceptor will be increased and its quality will be improved.The sequence of HMW-GS gene of wheat- like either 1Bx13 or 1By16 cloned from a high quality hybrid 11-12, a high quality hybrid line, is linked with the promoter sequence of storage protein 1Bx17 gene from wheat seed. They were father constructed into plant transformation vector pBIN20 digested with the same enzyme-XbaI. Wheat cultivar Taian No. 23 was transformed by dipping shoot tip with Agrobatenum strain of AGL1 harboring pBIN20. Ninety-nine transforming seedlings resistant to Kanamycin generated. Total 23 positive plants were selected from the 99 resistant seedlings with PCR reaction. Southern blot of T₁ plant primarily confirmed that the HMW-SG gene had introducted into the acceptor wheat. The seed storage proteins of 42 transformed plants of T₁ generation were analyzed by SDS-PAGE. There are two new protein bands in 3 lines and one new band in other 4 lines, which represent the aim proteins expressed in the transgenic plants. In conclusion, we obtained transgenic wheat with new aim protein(s). T1 generation is planted further, and T2 pure lines, with high bread-making quality, will be selected and cultured.