对高铵胁迫下耐铵型水芹〔Oenanthe javanica (Blume) DC.〕与铵敏感型水芹根际细菌及根系代谢物的差异响应进行比较。结果表明：高铵处理9 d促进耐铵型水芹叶片生长，而铵敏感型水芹叶片萎蔫甚至死亡。铵敏感型水芹较耐铵型水芹受到了更严重的氧化胁迫。高铵处理改变了水芹根际细菌群落结构，各生态型水芹根际细菌群落的Margalef丰富度指数的降幅在37%以上。高铵处理9 d，耐铵型水芹根际细菌群落中戴氏菌属（Dyella）丰度较对照组明显上升，且明显高于铵敏感型水芹；根瘤菌科（未分类）〔Rhizobiaceae （unclassified）〕丰度为对照组的20余倍。代谢组学分析结果显示：高铵处理12 h，耐铵型水芹根系谷胱甘肽代谢、氮代谢和双组分系统等通路显著上调(P＜0.05)；高铵处理9 d，谷胱甘肽代谢、吲哚生物碱生物合成及氨基酸生物合成等通路显著上调。高铵处理12 h，铵敏感型水芹根系碳代谢相关的C5支链二元酸代谢通路显著上调；高铵处理9 d，三羧酸循环等碳代谢通路显著下调。相关性分析结果显示：耐铵型水芹中三萜酸类、酚类及吲哚生物碱类化合物含量与根瘤菌科（未分类）、戴氏菌属等属的丰度呈正相关；铵敏感型水芹中鞘氨醇单胞菌科（未分类）〔Sphingomonadaceae （unclassified）〕丰度与4-乙烯基苯酚、松柏醛和秦皮乙素含量呈正相关，而与皂苷类化合物含量呈负相关。综上，耐铵型水芹通过协同增强氮碳代谢与抗氧化代谢缓解铵毒害，并借助根际细菌与根系代谢物的互作提升有益菌的丰度，从而适应高铵环境。

The differential responses of rhizosphere bacteria and root metabolites of ammonium-tolerant Oenanthe javanica (Blume) DC. with ammonium-sensitive O. javanica under high ammonium stress were compared. The results show that high ammonium treatment for 9 d promotes leaf growth of ammonium-tolerant O. javanica, while leaves of ammonium-sensitive O. javanica wither or even die. The ammonium-sensitive O. javanica suffers more severe oxidative stress than ammonium-tolerant O. javanica. High ammonium treatment alters the rhizosphere bacterial community structure of O. javanica, with the Margalef richness index of the rhizosphere bacterial community of each ecotype decreasing by more than 37%. After 9 d of high ammonium treatment, the abundance of Dyella in the rhizosphere bacterial community of ammonium-tolerant O. javanica increases obviously compared with the control group, and is obviously higher than that of ammonium-sensitive O. javanica; the abundance of Rhizobiaceae (unclassified) is more than 20 times that of the control group. The metabolomics analysis result shows that after 12 h of high ammonium treatment,    pathways such as glutathione metabolism, nitrogen metabolism, and two-component system in the roots of ammonium-tolerant O. javanica are significantly upregulated (P＜0.05); after 9 d of high ammonium treatment, pathways such as glutathione metabolism, indole alkaloid biosynthesis, and biosynthesis of amino acids are significantly. After 12 h of high ammonium treatment, the  C5-branched dibasic acid metabolism pathway related to carbon metabolism in the roots of ammonium-sensitive O. javanica are significantly upregulated; after 9 d of high ammonium treatment, carbon metabolism pathways such as the tricarboxylic acid cycle are significantly downregulated. The correlation analysis result shows that the contents of triterpenoid acids, phenols, and indole alkaloids in ammonium-tolerant O. javanica are positively correlated with the abundance of genera such as Rhizobiaceae (unclassified) and Dyella; the abundance of Sphingomonadaceae (unclassified) in ammonium-sensitive O. javanica is positively correlated with the contents of 4-vinylphenol, coniferaldehyde, and esculetin, but negatively correlated with the contents of saponins. In conclusion, ammonium-tolerant O. javanica alleviates ammonium toxicity by synergistically enhancing nitrogen and carbon metabolism and antioxidant metabolism, and increases the abundance of beneficial bacteria through the interaction between rhizosphere bacteria and root metabolites, thereby adapting to high-ammonium environments.