[Construction and identification of vectors containing maize plasmid-like DNA S1 and reporter genes]

The reporter Gene GUS with CaMV 35S promoter was inserted into plasmid pBS[1] in reversal direction of integration, and two kinds of recombinant plasmids were obtained. These results were verified by restriction endonuclease analysis and southern hybridization. A piece of 10.8kb fragment containing NPT II reporter gene from digested pBI121.1 by BamHI and EcoRI was ligated together with 3.9 kb fragment of plasmid-like DNA S1. Then generate a recombinant plasmid pBIS5 was generated. These three vectors can be used to transform maize protoplasts. High frequency of transformation may be expected due to homology between plasmid-like DNA S1 and maize nuclear DNA.