中文摘要：

植物能够在不经矿化的情况下直接吸收利用环境中的分子态氨基酸.氨基酸作为植物和微生物的优良碳源和氮源,二者对其吸收存在着激烈竞争,氨基酸态氮来源广、半衰期短的特点使其具有巨大的流通量.运用氮同位素示踪方法研究氨基酸对植物的氮营养贡献一直是国内外学者研究的热点,对揭示土壤肥力本质具有重要意义.本文对不同生态系统中氨基酸形态特征、代谢机制及营养贡献进行了简要综述,分析了氨基酸态氮在植物-土壤-微生物系统中的循环机制及生物有效性等方面研究现状和发展趋势,并提出了土壤氨基酸生物有效性环境调控、氨基酸碳-氮代谢及提高农田生态系统有机氮管理等待解决的科学问题.

英文摘要：

Plant can directly take up the intact amino acids,thus bypass the microbial mineralization of organic nitrogen. As an excellent carbon and nitrogen source,there exists competition for amino acid absorption between plant roots and soil microorganisms. And the total flux of amino acids in soil may be enormous due to the extensive sources and short half-life. Studies on amino acid nitrogen nutritional contribution for plant by the technique of nitrogen isotopic tracer,has become a research topic in recent years,which will help us better understand the principle of soil fertility.This paper summarized the recent researches on amino acid morphological characteristics in soil and its metabolic mechanism and nitrogen nutritional contribution for plant in different ecosystems,and discussed the present status and development trend of the amino acid circulation mechanism in the plant-soil-microorganism ecosystem and its bioavailability for plant. Finally,the topics of environmental regulating mechanism of amino acid bioavailability,amino acid carbon-nitrogen metabolism,and how to improve the field organic nitrogen management were all the core issues to be resolved.