Multiplexed Engineering of Disease Resistance and Lodging Tolerance in Wheat Via a Single Xylan Modifying Glycosyltransferase.

Breeding crops with robust disease resistance often compromises yield, a persistent challenge in agricultural improvement. We report that modifying cell wall architecture through a xylan-specific glycosyltransferase successfully breaks this trade-off in wheat. TaXAX1, a pathogen-induced member of the glycosyltransferase (GT)61 family, catalyses arabinose modification of xylan and is predominantly localized to the Golgi apparatus. CRISPR/Cas9 knockout mutants of Taxax1 exhibited enhanced susceptibility to three major fungal diseases: Fusarium head blight (FHB), Fusarium crown rot (FCR) and stripe rust. Conversely, overexpression of TaXAX1 significantly enhanced resistance to all three pathogens concurrently. Remarkably, this multi-disease resistance was achieved without any reduction in grain yield. Mechanistically, TaXAX1 mediates cell wall fortification by increasing xylan arabinose modification arabinosylation, upregulating the phenylpropanoid pathway and enhancing the deposition of lignin, cellulose and phenolic cross-linkers. This resulted in a thicker and more reinforced secondary cell wall, which also translated into superior stem strength. Our study identifies TaXAX1 as a master regulator of cell wall remodelling and provides a compelling strategy for designing wheat varieties with integrated resilience against multiple diseases and environmental stresses, while safeguarding yield potential.