Development and Characterization of Wheat Lines with Resistance to Take-All and Powdery Mildew Diseases

Abstract

Take-all, primarily caused by Gaeumannomyces graminis var. tritici (Ggt), and powdery mildew, mainly caused by Blumeria graminis f. sp. tritici (Bgt), are important diseases of wheat (Triticum aestivum L.) worldwide. The wheat cultivar Yangmai 18 carrying a powdery mildew resistance gene Pm21, shows broad-spectrum resistance to powdery mildew. We have isolated a lipid transfer protein gene TaLTP5 from wheat. To study the role of TaLTP5 in wheat defense responses to the major pathogens of take-all, we introduced this gene into Yangmai 18 via bombarding the particle containing the TaLTP5 expressing vector pA25-TaLTP5. The TaLTP5 transgenic wheat plants from T0 to T3 generations were subjected to PCR, Southern blot, RT-PCR, and Q-RT-PCR analyses. We also evaluated the disease resistances of the TaLTP5 transgenic plants against inoculating Ggt and Bgt. The PCR and Southern blotting results showed that the alien TaLTP5 was transferred and integrated into the genomes of three transgenic wheat lines, and inherited stably in the transgenic wheat lines. The RT-PCR and Q-RT-PCR results indicated that the introduced TaLTP5 was over-expressed in transgenic wheat lines, which showed significantly-enhanced resistance to take-all, suggesting that TaLTP5 gene is involved in the defense response to Ggt infection. In addition, the resistance of transgenic lines to powdery mildew was not influenced by the introduced gene TaLTP5. Thus, TaLTP5 transgenic wheat Yangmai 18 exhibits resistance to both Take-all and powdery mildew.