Characterisation of oxygen regulation mechanisms in Rhizobium leguminosarum for repurposing as tools in the engineering of nitrogen fixation

氮是植物生长的关键养分，氮肥的使用显著提高了作物产量。然而，这些肥料也会造成严重的环境破坏，而且对许多发展中国家来说是负担不起的。许多植物通过与固氮菌形成共生关系来获取氮。它们进入植物的根部，在那里转化为高度专业化的准细胞器，为植物提供从大气中固定的氮，以换取营养和庇护。氧是调节这种转化的关键信号，因为它对执行固氮的固氮酶是有毒的。两种细菌蛋白，NifA和FnrN，已知对调控和激活固氮至关重要。我们的目标是研究这些在转录和蛋白质水平上是如何调节的，并确定其发生的机制。我们下一步的目标是利用我们对这些机制的理解来开发合成生物学工具，这些工具可以用来将这种共生关系引入其他植物和细菌中。实现这一目标可以减少对污染性氮肥的需求，并提供一种可持续的方法来提高作物产量。BBSRC的优先领域涉及：粮食、营养和健康、可持续提高农业生产、合成生物学、环境和土地利用、全球粮食安全

Nitrogen is a key nutrient for plant growth and the use of nitrogen fertilizers has resulted in significant boosts in crop productivity. However, these fertilizers also cause significantenvironmental damage and are unaffordable for much of the developing world. Many plant species instead acquire their nitrogen by forming a symbiotic relationship with nitrogen fixingRhizobium bacteria. These enter into the plant's roots where they transform into highly specialized quasi-organelles, providing the plant with nitrogen fixed from the atmosphere inexchange for nutrients and shelter. Oxygen is a key signal in the regulation of this transformation because it is toxic to the nitrogenase enzyme that performs nitrogen fixation.Two bacterial proteins, NifA and FnrN, are known to be critical for the regulation and activation of nitrogen fixation. We aim to study how these are regulated at the transcriptional and proteinlevel and to determine the mechanisms by which this occurs. We next aim to use our understanding of these mechanisms to develop synthetic biology tools which can be used inefforts to introduce this symbiosis into other plants and bacteria. Achieving this could reduce the need for polluting nitrogen fertilizers and provide a sustainable way to boost crop yields.BBSRC priority areas addressed:Food, Nutrition and HealthSustainably enhancing agricultural productionSynthetic biologyEnvironment and Land UseGlobal Food SecurityAFS, ENWW