Nitrogen is an essential element for the growth and development of plants and animals. It is also one of the main components of fertilizers used in modern agriculture. However, fertilizers contribute to the eutrophication of water bodies like rivers and lakes, as well as soil acidification, which severely disrupts ecosystems and hinders the sustainable development of agriculture. Biological nitrogen fixation is a natural process by which nitrogen-fixing organisms convert atmospheric molecular nitrogen into a bioavailable compound form. Unlike industrial nitrogen fixation, biological nitrogen fixation does not require high temperatures and pressures and relies on biological energy rather than fossil fuels. As a result, it is considered an economical, efficient, and ecologically sustainable method of nitrogen fixation. Therefore, elucidating the molecular mechanisms of biological nitrogen fixation and exploring ways to enhance its efficiency are of significant theoretical and practical value in addressing the national need for "green agriculture" that reduces fertilizer use while increasing efficiency.

    Among various biological nitrogen fixation systems, the symbiotic nitrogen fixation between leguminous plants and rhizobia is the most efficient, accounting for over 65% of global biological nitrogen fixation and providing 30% to 50% of the nitrogen required by agricultural land. Our research group has made significant breakthroughs in studying the key protein machinery involved in the recognition, signaling, and transcriptional regulation of symbiotic signals in leguminous plants.