Role of host nitrogen use efficiency in determining arbuscular mycorrhizal fungi responses to nitrogen enrichment.

Host nitrogen use efficiency (NUE) determines whether arbuscular mycorrhizal fungi (AMF) responses to nitrogen enrichment are linear or hump-shaped, with implications for ecosystem management.

• Why it matters: Understanding how plant traits like NUE influence AMF responses to nitrogen is crucial for predicting ecosystem resilience and guiding sustainable agriculture amid increasing N inputs.
• What they did: A global meta-analysis, greenhouse experiments with maize cultivars, and a long-term field study involving low- and high-NUE varieties examined AMF responses across different NUE levels, N addition rates, and soil conditions.
• The result: High-NUE plants showed a hump-shaped AMF response mediated by soil acidification, while low-NUE plants experienced linear declines, revealing NUE as a key biological filter shaping mycorrhizal dynamics under N enrichment.