Transformation of Wheat Thaumatin-Like Protein Gene and Analysis of Reactions to Powdery Mildew and Fusarium Head Blight in Transgenic Plants

A thaumatin-like protein gene, Ta-Tlp, was cloned from wheat in previous studies, which was expressed in a high level in wheat (Triticum aestivum L.) 6VS/6AL translocation line with high resistance to powdery mildew (Erysiphe graminis f.sp. tritici Em. Marchal.), implying its close relation to the resistance of the disease. To further understand the gene's function, Ta-Tlp was constructed into an expression vector driven by the strong ubi promoter. The vector pAHC-TlP constructed was transformed into immature embryo-derived calli of common wheat cultivar Yangmai 158 through particle bombardment. After two rounds of herbicide bialaphos selection and regeneration, herbicide-resistance plants were obtained. The Ta-Tlp proved to be integrated into the wheat genome and was expressed in T1 and T2 generations by PCR, Southern blot, and RT-PCR analysis. The transgenic plants of T0, T1, and T2 generations were inoculated by E. graminis and Fusarium graminearum for resistance identification. All plants of T0, T1, and T2 generations were resistant to wheat powdery mildew by delaying disease development, but no distinct resistance to Fusarium head blight.