Wheat Dwarf Virus as a Modulator of Multi‐Stress Responses in Wheat

Wheat dwarf virus (WDV) is an emerging constraint to cereal production whose epidemiological significance has intensified under climate change. Rising temperatures, extended vector activity, and the expansion of Psammotettix alienus into new regions have increased both the frequency and severity of WDV outbreaks. Beyond its direct effects on plant development, WDV acts as a powerful regulator of host physiology, functioning as a host signalling hub that reprograms hormonal signalling, alters source-sink relationships, disrupts redox homeostasis, and modulates responses to both abiotic and biotic stress. Recent molecular studies have revealed how viral proteins manipulate the cell cycle, transcriptional machinery, and RNA silencing pathways to optimise viral replication while attenuating defence responses. These processes intersect with core stress-response networks, particularly those governed by abscisic acid, gibberellins, cytokinins, and auxin, positioning WDV as a model system for investigating hormonal crosstalk under combined stress. Despite advances in genomics, transcriptomics, and vector biology, major knowledge gaps persist regarding WDV interactions with co-occurring fungal pathogens, its impact on the plant microbiome, and its role in shaping cereal resilience under drought, heat, or nutrient limitations. This review synthesises current understanding of WDV biology from the molecular to the ecological scale, highlights mechanisms underpinning stress integration, and outlines future research priorities essential for developing sustainable management strategies in a changing climate.