No-tillage practices mitigate warming-induced yield losses in wheat by enhancing source-sink coordination

Climate warming disrupts source-sink relationships that coordinate carbon acquisition and utilization in wheat. However, whether no-tillage practices can mitigate this warming-induced disruption, and how to modify source-sink coordination, remains poorly understood. We conducted a five-year field warming experiment, and systematically examined warming-induced alterations in source-sink coordination between conventional and no-tillage wheat systems. Principal component analysis revealed that source-sink relationships exhibited distinct physiological trade-offs, with significant correlations between carbon acquisition efficiency and reproductive structure traits, as well as between gas exchange and carbon allocation and yield components. Under ambient temperature conditions, source and sink processes contributed nearly equally to yield (44–47 % vs. 53–56 %, respectively). However, warming significantly shifted this balance towards source-domination (60 % vs. 40 %, respectively). Structural equation modeling indicated that yield responses to warming were negative under conventional tillage but positive under no-tillage, suggesting no-tillage practices modify resource allocation by maintaining photosynthetic activity under warming. The negative effect of warming on source-sink regulation in wheat yield formation was reversed under no-tillage through flexible temperature responses and integrated regulatory networks. The findings deepen impact and adaptation physiological mechanisms of climate warming on wheat systems, accelerating the development of climate-resilient agricultural practices.