Functional characterization of the Wrab17 gene in the interaction process between wheat and Puccinia triticina

In the interaction between wheat and Puccinia triticina, wheat resists the invasion of P. triticina by producing hypersensitive reaction-programmed cell death (HR-PCD). To better understand the mechanism of wheat resistance to P. triticina, it is important to identify the defensive genes involved in wheat resistance to leaf rust. This paper systematically presented the role of Wrab17 in the HR-PCD process in wheat after infection by P. triticina. The subcellular location analysis is performed using the full length of Wrab17 coding sequences and Wrab17 is found to be localized in cell nucleus and cytoplasm. Quantitative RT-PCR (RT-qPCR) and western blot analysis showed that expression of Wrab17 at both mRNA and protein levels increased by P. triticina infection, indicating that the Wrab17 gene participated in the interaction between wheat and P. triticina. Wrab17 knockdown plants were generated by RNA-mediated gene silencing technology (RNA interference, RNAi) and confirmed by southern blot. Further analysis with P. triticina inoculation found that knockdown of Wrab17 exhibited decreased HR expansion area in incompatible combination (L10×260) and significant higher sensitivity to the compatible pathogen P. triticina race 165. In all, this work reports that Wrab17 is a new defensive gene playing a role in wheat resistance to leaf rust.