Transformation of wheat with insecticide gene of arrowhead proteinase inhibitor by pollen tube pathway and analysis of transgenic plants

Arrowhead Proteinase Inhibitor(API), one kind of pure natural material, was derived from storage organ of Sagittaria trifolia. It belongs to serine proteinase inhibitor, and can inhibit trypsin, chemotrypsin and kallikrein. Furthermore, API is toxical to some species of insects such as lepidotera, Coleoptera and Diptrea etc. By means of pollen tube pathway, plasmid pBIAH-A(B) containing insect-resistant genes of API-A, API-B and selective marker gene of NPT-II were transferred into three lines of local winter wheat - JD-1, 8866, 866554. Then, Kanamycin-resistant screening and PCR analysis of genetic transformed plants showed that three of Km^r green plants (two from 866554, one from JD-1) were PCR positive with the positive rate of 0.29%. When the fragment of API gene was used as probe to hybrid with genomic DNA of Km^r green plants separately, all of three PCR positive ones displayed a single strong hybridizing band. Such results demonstrated that foreign target gene had been integrated into wheat genome already. Simultaneously, PCR analysis and Southern hybridization were carried out among selfiedoffsprings of transformed positive plant of the line 899554-3, some of them were PCR and Southern blotting positive, indicating that foreign gene integrated into wheat genome could stably transmitted into next generation. In addition, the expression level of NPT-II gene was checked via ELISA in our study, all of three PCR and Southern blot positive plants could yield high level of NPT-II. This data provided a more powerful evidence for integration of insecticide gene into wheat genome.