TaNTF2, a contributor for wheat resistance to the stripe rust pathogen

Nuclear Transport Factor 2 (NTF2) functions as a critical regulator in balancing the GTP-and GDP-bound forms of Ran, a class of evolutionarily conserved small GTP-binding protein. During the incompatible interaction between wheat-Puccinia striiformis f. sp. tritici (Pst), a cDNA fragment encoding a putative wheat NTF2 gene was found to be significantly induced, suggesting a potential role in wheat resistance to Pst. In this work, the full length of TaNTF2 was obtained, with three copies located on 7A, 7B and 7D chromosomes, respectively. QRT-PCR further verified the up-regulated expression of TaNTF2 in response to avirulent Pst. In addition, TaNTF2 was also induced by exogenous hormone applications, especially JA treatment. Transient expression of TaNTF2 in tobacco cells confirmed its subcellular localization in the cytoplasm, perinuclear area and nucleus. And virus induced gene silencing (VIGS) was used to identify the function of TaNTF2 during an incompatible wheat-Pst interaction. When TaNTF2 was knocked down, resistance of wheat to avirulentPst was decreased, with a bigger necrotic spots, and higher numbers of hyphal branches and haustorial mother cells. Our results demonstrated that TaNTF2 was a contributor for wheat resistance to the stripe rust pathogen, which will help to comprehensively understand the NTF2/Ran modulating mechanism in wheat-Pst interaction.