Senlei Zhang began his research on symbiotic nitrogen fixation at the Institute of Genetics and Developmental Biology (IGDB), Chinese Academy of Sciences, where he focused on the role of microRNAs (miRNAs) in regulating soybean root nodule development. During this period, he developed a keen interest in the differentiation and functional mechanisms of bacteroids within nitrogen-fixing cells of root nodules. Motivated by this interest, he moved to the Biological Research Centre (BRC) at the Hungarian Academy of Sciences, where he discovered that the expression of Nodule-specific Cysteine-rich (NCR) peptides, which govern the terminal differentiation of bacteroids in Medicago truncatula, is regulated by a conserved transcriptional mechanism that is widely shared among plant species. Subsequently, Dr. Zhang secured a position at Northwest Agriculture and Forestry University, where he expanded his research to further investigate the regulation of bacteroid development and function, the evolution of symbiotic nitrogen fixation, and the identification of key regulatory factors that could be leveraged for soybean breeding to enhance nitrogen fixation efficiency and crop yield.