While classical breeding traits have focussed on above‐ground tissues, it is becoming clear that underground aspects of plant life are a hidden treasure of tools applicable for resilient crop production. Plants of the legume family develop specialized organs, called nodules, which serve as hosts for Rhizobium bacteroids. A highly specialized symbiotic relationship exists deep inside the nodules. In exchange for carbohydrates, host‐specific rhizobia bacteroids can assimilate nitrogen from the air and fix it into a form that can be used by plants in a process known as biological nitrogen fixation. While we understand certain aspects of how this inter‐species relationship is established, the exact biochemistry of this exchange remains dogmatic. In their recent work, Christen and colleagues (Flores‐Tinoco et al , 2020) challenge the current model of nitrogen exchange and argue that that an expanded model is needed to fit experimental findings related to nitrogen fixation. The authors perform an elegant set of experiments and highlight that rather than a single‐way flow of nitrogen, the N‐fixing process is in fact an elaborate metabolic exchange between the nodule‐dwelling bacteroids and the host plant. Importantly, this work provides an updated theoretical framework with the “catchy” name CATCH‐N which delivers up to 25% higher yields of nitrogen than classical models and is suitable for rational bioengineering and optimization of nitrogen fixation in microorganisms.

中文翻译：

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如何捕捉 N - 具有正确化学反应的物种间交换。


虽然经典育种性状主要集中在地上组织，但越来越明显的是，植物生命的地下方面是适用于弹性作物生产的工具的隐藏宝藏。豆科植物发育出称为根瘤的特殊器官，它是根瘤菌类菌的宿主。结节深处存在着高度专业化的共生关系。作为碳水化合物的交换，宿主特异性根瘤菌类菌可以吸收空气中的氮并将其固定成植物可以利用的形式，这一过程称为生物固氮。虽然我们了解这种物种间关系如何建立的某些方面，但这种交换的确切生物化学仍然是教条性的。在最近的工作中，Christen 及其同事（Flores-Tinoco等人，2020）对当前的氮交换模型提出了挑战，并认为需要一个扩展的模型来适应与固氮相关的实验结果。作者进行了一系列巧妙的实验，并强调，固氮过程实际上不是氮的单向流动，而是居住在根瘤中的类菌体和寄主植物之间复杂的代谢交换。重要的是，这项工作提供了一个更新的理论框架，其名称为“吸引人”的 CATCH-N，其氮产量比经典模型高出 25%，适用于合理的生物工程和微生物固氮的优化。