Abstract：
Nitrogen (N) is a vital nutrient and an essential component of biological macromolecules, such as nucleic acids and proteins. Microorganisms represent major drivers of N-cycling processes in all ecosystems, including the soil and plant environment. The availability of N is a major growth limiting factor for plants and it is significantly affected by the plant microbiome. Plants and microorganisms form complex interaction networks resulting in molecular signaling, nutrient exchange and other distinct metabolic responses. In these networks, microbial partners influence growth and N use efficiency of plants either positively or negatively. Harnessing the beneficial effects of specific players within crop microbiomes is a promising strategy to counteract the emerging threats for human and planetary health due to the overuse of industrial N fertilizers. However, in addition to N-providing activities (e.g. the well-known symbiosis of legumes and Rhizobium bacteria), other plant-microorganism interactions must be considered to obtain a complete picture of how microbial driven N-transformations might affect plant nutrition. For this, we review recent insights into the tight interplay between plants and N-cycling microorganisms focusing on microbial N-transformation processes representing N sources and sinks that ultimately shape the plant N acquisition.
摘要：
氮(N)是生物大分子的重要营养素,如核酸和蛋白质。微生物是所有生态系统中氮素循环过程的主要驱动因素，包括土壤和植物环境。N的可利用性是植物的主要生长限制因子,并且其受植物微生物组的显著影响。植物和微生物形成复杂的相互作用网络，导致分子信号，营养交换和其他不同的代谢反应。在这些网络中,微生物伴侣对植物的生长和氮利用效率有积极或消极的影响。利用作物微生物组中特定参与者的有益影响是一种有前途的策略，可以应对由于过度使用工业氮肥而对人类和行星健康造成的新威胁。然而,除了提供氮的活性（例如众所周知的豆科植物和根瘤菌共生），必须考虑其他植物-微生物相互作用，以全面了解微生物驱动的N转化如何影响植物营养。为此，我们回顾了植物与氮素循环微生物之间紧密相互作用的最新见解，重点是代表氮源和汇的微生物氮素转化过程，这些过程最终塑造了植物氮素的获取。
