Proteomic Analysis of Soybean Nodules: Insights into Efficient Nitrogen Fixation

The protein research on soybean root nodules has provided effective assistance for humans to understand the molecular mechanism of efficient nitrogen fixation. This study mainly summarizes the progress made in the field of soybean rhizoma protein research in recent years, with a focus on several aspects: energy metabolism, signal transduction, antioxidant defense, and nutrient transport, etc. By comparing different proteomes, research has found that the levels of related proteins in highly efficient nitrogen-fixing root nodules significantly increase during processes such as energy supply, stress resistance and defense, and signal regulation. This is directly related to the enhanced activity of nitrogenase and the improved assimilation capacity of ammonia. Further research has found that when nutrients such as phosphorus and nitrogen are insufficient, the protein expression and nitrogen fixation efficiency in root nodules will also be affected. Some proteins (such as GmHSP17.1, GmSPX8 and GmPAP12) play an important regulatory role in nitrogen fixation under adverse conditions. There are still some undeniable limitations in current proteomics research: insufficient coverage, limited dynamic range, and inadequate spatial resolution, etc. However, with the development of new technologies, these limitations are expected to be broken through in the future. The combination of single-cell and spatial proteomics, multi-omics, and artificial intelligence modeling may all lead to deeper research and development in this field. The aim of this study is to promote the improvement of soybean nitrogen fixation capacity at the molecular level in the future by summarizing these advancements.