The TaMADS2-TaTBL21 Module Enhances Wheat Resistance to Stripe Rust by Activating TaGKL-Mediated Immunity

Wheat stripe rust (Puccinia striiformis f. sp. tritici, Pst) poses a catastrophic threat to global food security. While MADS-box transcription factors regulate development and abiotic stress, their roles in plant-pathogen immunity remain enigmatic. In this study, we identified TaMADS2, a Pst-induced MADS-box gene, as a positive regulator of wheat resistance. Functional analyses demonstrated that TaMADS2 overexpression significantly enhanced Pst resistance, whereas its knockdown rendered wheat more susceptible. Further investigation revealed that TaMADS2 interacts with trichome birefringence-like protein 21 (TaTBL21) to activate glycerol kinase-like (TaGKL) expression. Silencing TaGKL in wild-type or TaMADS2-overexpressing lines compromised resistance, with elevated Pst biomass. Notably, dual silencing of TaMADS2 and TaGKL further heightened susceptibility, confirming their synergistic defence role. Mechanistically, the TaMADS2-TaTBL21 complex promotes wheat resistance to stripe rust disease by upregulating TaGKL expression, leading to the accumulation of the key defence metabolites salicylic acid (SA) and glycerol-3-phosphate (G3P). Our study unveils a novel TaMADS2-TaTBL21-TaGKL module that potentiates wheat resistance against stripe rust, offering strategic targets for breeding resistant wheat.