Abstract:

The thaumatin-like protein in plants, an important member of pathogenesis-related proteins (PRs), involves in plant resistant reaction to many fungi. A series of thaumatin-like protein genes have been isolated and transformed to potato(Solanum tuberosum L.), rice (Oryza sativa L.), and wheat (Triticum aestivum L.) resulting in resistance improvement to plant diseases. We have cloned a thaumantin-like protein gene, Ta-Tlp, from wheat in our earlier studies. The Ta-Tlp gene expresses in high level in wheat 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, we constructed Ta-Tlp into a expression vector driven by the strong ubi promoter in the present study. The constructed vector pAHC-TlP was transformed into immature embryo-derived calli of a 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 was confirmed having been integrated into the wheat genome and expressed in T1 and T2 generations by PCR, Southern blot, and RT-PCR. The transgenic plants of T0, T1, and T2 generations were inoculated by E. graminis f.sp. tritici and F. graminearum for resistance identification. All plants of T0, T1, (183 individuals derived from 6 positive T0 lines), and T2 (241 individuals derived from 6 positive T0 lines) generations appeared some resistance to wheat powdery mildew by delaying disease development, but no distinct resistance to scab (F. graminearum).

Key words: Wheat thaumatin-like protein gene (Ta-Tlp), Particle bombardment, Genetic transformation, Powdery mildew, Resistance identification