Molecular Characterization And Inheritance Stability Analysis Of An Insect-resistant And Herbicide-tolerant Transgenic Maize

Maize(Zea mays L.)is one of the most important food,feed as well as energy crop worldwide.Genetic engineering(GE)technology has been an effective way to increase production in the past 20 years.GE maize lines stacked with insect-resistant and herbicide-tolerant genes have been developed and implemented rapidly.However,it is important to evaluated the inhitance stability of transgenes for a transgenic event before commercial planting,as inactivation or silencing may threat to the long-term use of a transgenic event.We developed a novel transgenic Bt maize events ZD 12-6 which contained fusion Bt insecticidal gene CrylAb/Cry2Aj and a modified EPSPS gene(G10).This fusion gene could provide enhanced toxicity against major corn lepidopteran pests,and effective strategy to overcome the resistance to CrylAb,which was widely utilized in first generation GE products of corn and cotton.In this study,we report the molecular characterization and stability analysis of the T-DNA insertion and expression over several generations in ZD 12-6.The results of molecular detection showed that ZD 12-6 were single copy inserted event.The insert site was determined to be at chromosome 1.Bioinformatic analysis indicated that the T-DNA insertion on maize did not disrupt known or putataive genes.The ELISA analysis showed that the fusion gene CrylAb/Cry2Aj and GIO was expressed stably at high levels in maize and inherited stably over generations.Insect resistance assays indicated that ZD 12-6 have high toxicity to the Asian corn borer,cotton bollworm and oriental armyworm.Therefore,we recommended ZD 12-6 to serve as breeding sources for the development of insect resistance and glyphosate-tolerant transgenic maize.