ABSTRACT Amino acids are important components of the soil organic nitrogen pool. There is, however, a current lack of knowledge concerning how exogenous C and N regulate amino acid uptake in the soil microorganism/plant system. We used a 13C,15N-glycine injection method to examine glycine-derived 13C and 15N partitioning in a planted or unplanted spring wheat pot experiment. Four treatments were used: control (CK), ammonium sulfate (N), glucose (C), and ammonium sulfate with glucose (NC). The results showed that amino acids were absorbed intact by soil microorganisms and plants at 4 h. An exogenous excess of C, rather than N, resulted in a reduced uptake of intact glycine by soil microorganisms, indicating that glycine was taken up primarily to fulfill their C requirement. Wheat was more effective in competing for glycine-C and N at 24 h. 13C and 15N partitioning in wheat was significantly influenced by exogenous C and N availability; uptake of 13C and 15N by wheat increased with increasing C and N availability. We concluded that amino acids are important not only for N but also for C to soil microorganisms and plants, which are able to respond quickly to exogenous C and N source application.

中文翻译：

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底物可用性影响植物和土壤微生物之间甘氨酸中 C 和 N 的分配

摘要 氨基酸是土壤有机氮库的重要组成部分。然而，目前缺乏关于外源 C 和 N 如何调节土壤微生物/植物系统中氨基酸吸收的知识。我们使用 13C,15N-甘氨酸注射方法在种植或未种植的春小麦盆栽实验中检查甘氨酸衍生的 13C 和 15N 分配。使用四种处理：对照 (CK)、硫酸铵 (N)、葡萄糖 (C) 和含葡萄糖的硫酸铵 (NC)。结果表明氨基酸在4 h内被土壤微生物和植物完整吸收。外源过量的 C 而不是 N，导致土壤微生物对完整甘氨酸的吸收减少，表明甘氨酸的吸收主要是为了满足它们的 C 需求。小麦在 24 小时时更有效地竞争甘氨酸-C 和 N。小麦中 13C 和 15N 的分配受外源 C 和 N 有效性的显着影响；小麦对 13C 和 15N 的吸收随着 C 和 N 可用性的增加而增加。我们得出结论，氨基酸不仅对 N 很重要，而且对 C 对土壤微生物和植物也很重要，这些微生物和植物能够快速响应外源 C 和 N 源的应用。