Labile Carbon Input Mitigates the Negative Legacy Effects of Nitrogen Addition on Arbuscular Mycorrhizal Symbiosis in a Temperate Grassland

• Published in: Plants (Basel) Vol. 14; no. 3; p. 456
• Main Authors: Liu, Sitong, Zhang, Yuxiao, Yu, Xiaoqian, Cui, Meng, Jiang, Liangchao, Zhang, Tao, Gao, Yingzhi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.02.2025; MDPI
• Subjects: Analysis; arbuscular mycorrhizal fungi; Arbuscular mycorrhizas; Carbon; Climate change; Ecological effects; Ecological restoration; Ecosystems; Enrichment; Environmental restoration; Enzymes; Flowers & plants; Fungi; Grasses; Grasslands; Infections; Influence; labile carbon input; Mutualism; Nitrogen; nitrogen deposition; Nitrogen enrichment; nutrient cycling; Nutrients; Phosphorus; Plant growth; Plant roots; Plant species; plant–microbe interactions; soil management; Stoichiometry; Symbiosis; Massachusetts; China; soil management; arbuscular mycorrhizal fungi; plant–microbe interactions; labile carbon input; nutrient cycling; nitrogen deposition
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants14030456

Nitrogen (N) deposition and carbon (C) addition significantly influence the dynamics of plant–microbe interactions, particularly altering the symbiotic relationship between plants and arbuscular mycorrhizal fungi (AMF). However, the effects and underlying mechanisms of labile C input on the relationship between AMF and various plant species in a nitrogen-enriched environment remain a knowledge gap. A seven-year field experiment was conducted to examine how six levels of N and three levels of labile C addition impact AMF colonization in four key plant species: Leymus chinensis (Trin. ex Bunge) Tzvelev, Stipa baicalensis Roshev., Thermopsis lanceolata R. Br. and Potentilla bifurca Linn. Our results showed that N and C additions exert significantly different effects on the relationship between AMF and various plant species. Labile C addition mitigated historical N negative effects, particularly for S. baicalensis, enhancing AMF infection and promoting nutrient exchange under high-N and low-C conditions. The relationship between AMF and both L. chinensis and T. lanceolata changed to weak mutualism under low-N and high-C conditions, with significant decreases in vesicular and arbuscular abundance. Plant root stoichiometry plays a critical role in modulating AMF symbiosis, particularly under high-N and -C conditions, as reflected in the increased AMF infection observed in T. lanceolata and P. bifurca. Our findings emphasize the species-specific and nutrient-dependent AMF symbiosis, revealing that targeted C input can mitigate the legacy effects of N enrichment. Effective nutrient management is of crucial importance for ecological restoration efforts in temperate grasslands affected by long-term N enrichment.