Nitrogen (N) deposition has been influencing ecological process, for instance N addition can affect plant growth and then alter plant community composition. Arbuscular mycorrhizal fungi (AMF) is one of the important soil microbiota, which play a key role in plant growth, especially under harsh environmental conditions. However, the effects of AMF on plant growth under N addition are still not well understood. To investigate the mechanism how AMF affect plant growth under N addition, a microcosm experiment was conducted with four N addition levels. The results showed that AMF increased aboveground biomass of Leymus chinensis by 21.5% and 4.8% under with and without N addition, respectively. AMF expressively improved the net photosynthetic rate by 44% and 29%, soluble protein by 65% and 40% under with and without N additions, respectively. The chlorophyll a, chlorophyll b, chlorophyll a + b and carotenoids content in leaves treated by AMF were greater than those without AMF treatment. AMF also significantly increased the metabolomics enzymes glutamate dehydrogenase, glutamine oxoglutarate aminotransferase, alanine transaminase and nitrogen reductase activity under N addition. However, the level of glutamine synthetase and soluble carbohydrates increased significantly under N addition in non‐inoculated AMF plants. The result showed that the response of AMF to L. chinensis was stronger than nitrogen deposition, which indicates that AMF could increase plant growth by improving photosynthetic characters and affecting metabolomics enzymes of L. chinensis under N addition.

中文翻译：

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丛枝菌根真菌通过增加氮添加下的代谢组学活性来促进羊草（Trin。）Tzvelev的植物生长

氮的沉积一直在影响生态过程，例如氮的添加会影响植物的生长，进而改变植物群落的组成。丛枝菌根真菌（AMF）是重要的土壤微生物区系之一，在植物生长（尤其是在恶劣的环境条件下）中起着关键作用。但是，AMF对添加N的植物生长的影响尚不十分清楚。为了研究AMF在添加N的情况下如何影响植物生长的机理，我们进行了4种N添加水平的微观实验。结果表明，AMF增加了羊草的地上生物量。在添加和不添加氮的情况下分别增加了21.5％和4.8％。在添加和不添加氮的情况下，AMF分别将净光合速率提高了44％和29％，将可溶性蛋白提高了65％和40％。AMF处理后的叶片中叶绿素a，叶绿素b，叶绿素a + b和类胡萝卜素含量均高于未使用AMF处理的叶片。在添加氮的情况下，AMF还显着提高了代谢组学酶谷氨酸脱氢酶，谷氨酰胺氧戊二酸氨基转移酶，丙氨酸转氨酶和氮还原酶的活性。但是，在未接种AMF的植物中，添加氮后，谷氨酰胺合成酶和可溶性碳水化合物的含量显着增加。结果表明，AMF对羊草的响应氮肥比氮沉降更强，这表明在添加氮的条件下，AMF可以通过改善光合特性和影响L. chinensis的代谢组学酶来增加植物的生长。