TaELP2 Interacts With TaDCL1 and Negatively Regulates Wheat Resistance Against Stripe Rust

Wheat (Triticum aestivum) is an important staple food crop worldwide, playing a fundamental role in global food security. Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a highly destructive disease affecting this crop. The Elongator complex is known to be a key regulator of plant responses to stress; however, little is known about the function of its subunit 2, encoded by the TaELP2 gene, in the wheat-Pst interaction. In this study, we investigated the role of TaELP2 in the susceptibility of wheat to Pst. We found that the transient silencing of TaELP2 using a virus-induced gene silencing (VIGS) system markedly increased wheat resistance to the pathogen, whereas its overexpression exerted the opposite effect. Subsequently, yeast two-hybrid (Y2H), luciferase complementation imaging (LCI), pull-down and co-immunoprecipitation (Co-IP) assays demonstrated that TaELP2 directly interacts with DICER-LIKE (DCL1) protein. Notably, the knockdown of TaDCL1 expression greatly enhanced wheat resistance to stripe rust. Furthermore, Y2H and LCI assays indicated that TaELP2 also interacts with TaELP3. RNA-sequencing analysis revealed that TaELP2 overexpression downregulates NB-ARC genes and compromises disease resistance in wheat. Based on these findings, we propose that TaELP2 acts as a negative regulator of wheat stripe rust resistance, probably by interacting with TaDCL1 to modulate the transcription of key disease resistance genes.