| Wheat is the most widely cultivated crop in the world, and with an annual production of more than 500 million ton it is clearly a major component of the human diet. It is due to insect pests that decreases the world crop production. Wheat cultivation was also threatened by the pests, such as aphid, armyworn, and so no. Because of the rare insect-resistant wheat germplasm resources and the reproduction isolation that is a utilizable limitation of heterogenic gene, conventional breeding programs have led to little improvement in term of increased resistance to pests. Pest control has been largely dominated by chemical pesticides, but often these are impra'ctical or not effective because of specific weather conditions. Moreover, some environment problems related to the use of these chemicals were reported, such as pollution of land and water tables, toxicity to non-target organisms, accumulation in food chain, and related health problems. Introducing into to wheat the gna gene that encoding snowdrop lectin (Galanthus nivalis agglutinin; GNA) , a toxic protein to Homoptera, or cry IA gene that encoding Bacillus thuringiensis insecticidal protein for Lepidoptera (Cry I A) by genetic transformation will produce new germplasm that maybe produce resistant to some kinds of pests. In this study, transgenic wheat plants with insect-resisting gene gna or cry I A had been obtained by three independent genetic transformation systems and some experience had been provided for improvement of the systems.In the report, the maize ubiquitin 1 promoter Ubi. a high efficiency promoter in gramineous crop, had been introduced into the original plasmids. Expression box of bar gene had been also inserted as a selectable marker. In order to improve the expression level of the target genes, Q- kozak sequence and poly(A) sequence were added to the 5'-end and 3 "-end of the target genes, respectively. The insect-resisting gene wheat expression vectors pGU4ABBar,pGU4AGBar and pGBIU4AGBar had been constructed. pGU4ABBar contains isodirectional expression box of Ubi-cry 1A and Ubi-bar. pGU4AGBar contains isodirectional expression box of Ubi-gna and Ubi-bar. They are suitable for genetic transformation of wheat mediated by microprjectile or pollen-tube pathway. pGBIU4AGBar contains T-DNA boundary sequence, and isodirectional expression box of CaMV35S-npt II, Ubi-gna and Ubi-bar had been inserted within the T-DNA boundary sequence. It can be used in genetic transformation of wheat mediated by microprjectile or pollen-tube pathway, and Agrobacterium tumefaciens.A new Agrobacterium tumefaciens-mediated transformation system for wheat was developed using one-week-precultured immature embryos. The explants were pretreatment with higher-osmotic pressure medium before inoculation. Two transgenic plants with gna_gene were obtained from 380 one-week-precultured immature embryos of Yangmail58. Thetransformation efficiency was about 0.5%. Southern bolt analysis showed expression box of Ubi-gna gene was integrated into the transgenic plants genome. GNA protein expression were detected in the transgenic plants by Western blot analysis. The result showed proper pretreatment with higher-osmotic pressure medium can improve genetic tansformation system of wheat mediated by Agrobacterium tumefaciens.Six transgenic plants, two with gna gene and four with cry IA gene, were obtained from one-week-precultured immature embryos of Yangmail58 by microprojectile-mediated transformation. The transformation efficiency were about 0.3% and 0.7%. respectively. Southern bolt analysis showed expression box of target gene was integrated into the transgenic plants genome. GNA and Cry I A protein expression in the transgenic plants were detected by Western blot analyses, respectively. The result showed lower gold particle concentration and smaller vector size may be more profitable for genetic tansformation system of wheat mediated by microprojectile because all transgenic plants came from the relevant process .Two wheat lines, Xinongl32 and Xinong 2208. were use...
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