Nitrogen Metabolism of Arbuscular Mycorrhizal Symbiosis and Its Physiological and Ecological Regulation Mechanism

绝大多数陆生植物对丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)有着高度的依赖性，它们形成共生关系后植物为真菌提供光合C满足真菌生长发育基本需求，真菌帮助植物吸收更多的矿质营养(尤其是P和N)，促进植物生长发育。本文重点评述了AMF可吸收的土壤氮形态，氮素在丛枝菌根共生体(arbuscular mycorrhizal, AM)内外的传递路径、形态转化和降解过程，及AM中氮素转运和代谢相关的分子基础；分析了影响AMF吸收利用外源氮的可能因素以及AMF促进氮素在相邻植物间的传递和再分配功能，认为丛枝菌根共生体在土壤–真菌–植物氮循环中具有重要的生理生态学意义，并对AMF的未来研究进行了展望。 The most majority of terrestrial plants have a high dependence on arbuscular mycorrhizal fungi (AMF). When they form a symbiotic relationship plants provide carbon to the fungus to ensure the basic growth demand of fungi. And fungi can promote plants to absorb more nutrients (especially P and N) at the same time. This paper reviews the forms of nitrogen in soil uptake by AMF, the transportation pathway and degradation of nitrogen in AM symbiotic as well as the molecular basis of nitrogen transport and metabolism. The possible factors those can influence external nitrogen absorption were summarized. The external nitrogen transportation and redistribution pro- cesses in AM were analyzed. Arbuscular mycorrhizal symbiosis had physiological and ecological significance in the nitrogen cycling of soil-fungi-plant. And the future research of AMF is prospected.