Inheritance Analysis And Insects Resistance Of The Transgenic Rice Harboring GNA+SBTi Double Gene

Plant genetic engineering has a great impact on the modern agriculture, and recombinant DNA technology provides a novel and powerful way to the high efficiency of transformation. Although the number of transgenic insect resistance rice (Oryza Sativa L.) plants generated through genetic engineering is increasing, many studies have been focused on whether the genes were transferred and integrated or not, and there is lack of detailed information concerning the nature of DNA integration events. However, the success of contemporary breeding programs involving genetic engineering depends on the stability of transgenic insect resistance genes inheritance and expression over many generations. Some articles involved relative studies, but because of a lack of molecule biology evidence, especially the stability of transgenes in different and higher generations, so many scientists suspect the results.In this research, we report here molecular genetic analyses and insect resistance of transgenic plants, revealing the integration and inheritance of transgenes in the progeny (R2 and R3) of these plants, which delivered by particle bombardment, by cotransformation the SBT1 (soy bean trypsin inhibitor) gene and GNA (snowdrop lectin) gene and hpt (hygromycin phosphotransferase) gene into Indica rice (Oryza saliva L. cvs. Zhuxian B) with three plasmids, carrying a total of three genes.DNA dot blotting and PCR analysis showed that 45.5% of the transgenic plants carried GNA gene in the R2 progeny. Valued by X2 test of all transgenic lines, approximately 21.7% of the lines demonstrated Mendelian 3:1 (positivernegative for transgene) inheritance, suggesting integration at a single locus, 1.7% demonstrated Mendelian 15:1 inheritance, suggesting integration at double locus, and 20. 0% were pure lines, 21.7% were GNA":GNA". In addition, the selfed progeny of some independent plants show the segregation ratio of 1:1 and other aberrant segregation ratio (number of positive was less than negative as expected). We also further evaluated the molecular profiles of 27 independently derived transgenic lines of R3 progeny. The integration of GNA and SBTi genes were 59.4% and 43.8% respectively. GNA gene segregation analysis of R3 plantsrevealed that transgenes were stably transmitted to their progenies, 37.0% of the lines demonstrated Mendelian 3:1 inheritance, 11.3% were 15:1, 18.5% were pure lines, 3.7% were negative lines and other aberrant segregation ratio lines. Segregation patterns of SBTi genes in the R3 progeny were 23.0% as 3:1, 3.8% as 15:1, 11.5% as pure lines and other aberrant segregation lines. In addition, The GNA and SBTi genes cointegrated with a frequency of 34.2%. Furthermore, 2 pure lines of the transgenic plants carried all two genes. Southern blotting analysis further proved those insectcidal genes had been integrated into the genome of transgenic rice, and the number of integrated copies ranged from 1 to 15.Insect resistance test shows that 83.3% and 76.9% of the R2 and R3 progeny of GNA transgenic Zhuxian B plants displayed enhanced insecticidal effect on rice planthopper respectively.78.6% of the 28 lines of R3L generation SBTi transgenic Zhuxian B plants indicated enhanced insecticidal effect on rice leaffold. Also, we obtained 10 lines of R3 generation of transgenic plants, which had better resistance effect on both rice planthopper and rice leaffold than the resistant-control.