TaERF109: A Novel ERF Transcription Factor Contributing to Enhanced Resistance to Puccinia graminis f. sp. tritici Infection in Wheat

Puccinia graminis f. sp. tritici (Pgt) is responsible for stem rust in wheat, a disease with worldwide occurrence. Ethylene response factors (ERFs), a group of transcription factors (TFs) responsive to ethylene, are essential for managing stress signaling under biotic and abiotic challenges. However, our understanding of ERF TFs’ function in wheat (Triticum aestivum L.) resistance against the obligate biotrophic Puccinia graminis f. sp. tritici remains limited. In this work, we report our findings of the TaERF109 gene, which is transcriptionally up-regulated by ethylene or Pgt infection. TaERF109 is localized in the nucleus of rice protoplasts. Results obtained using the yeast one-hybrid (Y1H) assay support the conclusion that TaERF109 interacts with the AGCCGCC sequence (GCC-box). Transient knockdown of TaERF109 via virus-induced gene silencing (VIGS) increased wheat susceptibility to Pgt, accompanied by the down-regulation of three pathogenesis-related (PR) genes, TaPR1, TaPR2, and TaPR10, as confirmed via real-time quantitative PCR. In contrast, the Agrobacterium-mediated overexpression of TaERF109 potentiated resistance of transgenic wheat against Pgt. Overall, these results expand the current understanding of the TaERF109 gene’s function in wheat resistance to Pgt.