Analysis And Characterization Of Transgenic Wheat Plants Resistant To Fusarium Head Blight

Fusarium head blight(FHB) is an important wheat disease that has caused huge losses to wheat production world widely.Seven million hectares of wheat crops have been influenced every year and 10%～40%of the wheat yields had been lost in the Yangtze River area,winter wheat area of southern China and spring wheat area of northeast China all together.In the middle and down stream areas of Yangtze River,FHB often reaches to epidemical level more than anywhere causing severe yield losses and mycotoxin contamination,which is poisonous to both human and the livestock.Crucial food security problems were also arisen.However,as no wheat cultivar has absolute innate immunity to FHB,the chemical fungicides are used to control FHB now,but they are not only ineffective but also have caused severe environmental pollutions.In this study,molecular analysis and FHB resistance assays have been used to identify the foreign gene integration,expression and FHB resistance of the transgenic wheat lines harboring the fusion protein genes of the fusarium specific antibody linked to antifungal proteins.The PCR detection and Southern blotting analysis of the T2 and T3 transgenic wheat lines showed that the fusion genes had been integrated into the wheat genome.The RT-PCR detection of the T3 transgenic wheat lines showed that the fusion protein genes had been well expressed.Point inoculation showed that T2 and T3 transgenic wheat lines were significantly better than the nontransformed wheat line in FHB resistance in all three evaluations.Meanwhile,no significant difference had been found between the transgenic wheat lines and Sumai3 that was well documented to be the best FHB resistant wheat cultivar against disease spread.The relative grain weight per spikelet(RGWSp) and the relative grain thousand weights(RGTW) of the transgenic wheat lines were significantly higher than the nontransformed wheat line and were comparable to that of Sumai3.Spray inoculation showed that the AUDPC values of T3 transgenic wheat lines were significantly lower than that of the nontransformed wheat line and slightly lower compared to the Sumai3.The transgenic wheat lines displayed significantly higher relative grain thousand weights(RGTW) than the nontransformed wheat line and comparable RGTWs compared to Sumai3.These results indicated that strong FHB resistant transgenic wheat lines had been selected out.The FHB resistance of the transgenic wheat lines harboring the fusion protein genes of the fusarium specific antibody and antifungal proteins has been improved. This novel strategy could be used to breed FHB resistant wheat.