Glycine-rich RNA-binding proteins (GR-RBPs) play pivotal roles in regulating plant responses to abiotic and biotic stresses. However, the involvement of GR-RBPs in wheat immune responses to Puccinia striiformis f. sp. tritici (Pst) remains poorly understood. Here, we report the identification of 58 GR-RBP genes in wheat and provide a functional characterization of TaGR-RBP, which exhibits significant upregulation during wheat-Pst interactions. Subcellular localization analysis demonstrated that TaGR-RBP localizes in both the cytoplasm and the nucleus. Virus-induced gene silencing (VIGS) using Barley Stripe Mosaic Virus (BSMV) revealed that transient silencing of TaGR-RBP compromises wheat resistance to Pst. Furthermore, CRISPR-Cas9-mediated knockout of TaGR-RBP resulted in reduced resistance to Pst, as evidenced by diminished hydrogen peroxide (H2O2) accumulation and enhanced fungal proliferation, confirming its positive regulatory role in wheat immunity. Transient expression of TaGR-RBP in Nicotiana benthamiana induced Reactive Oxygen Species (ROS) accumulation. AlphaFold3 predictions and an RNA electrophoretic mobility shift assay (REMSA) validated the RNA-binding activity of TaGR-RBP. Overall, these findings imply the functional significance of GR-RBPs in wheat resistance against Pst. Deciphering the function of TaGR-RBP in plant immunity provides a theoretical basis for engineering disease-resistant wheat and guides the development of sustainable strategies for disease control.
He et al. (Tue,) studied this question.