Transcriptomics and root morphology analyses reveal the molecular mechanisms underlying the interaction between Mengnong Clover No.1 and rhizobium

Abstract Background The regulatory mechanisms underlying symbiotic nitrogen fixation between rhizobium and legumes remain unclear. Results In this study, integrated transcriptomics and root morphology analyses revealed that the inoculation of five rhizobial strains significantly increased root length, the number of tips, and nodule size in Mengnong clover No.1. Key genes involved in nitrogen metabolism, MAPK, and plant hormone signaling pathways were initially downregulated but later upregulated during the nodulation process, indicating their temporal regulatory roles in response to rhizobial infection. qRT-PCR confirmed the dynamic changes in gene expression. Conclusions This study provides a comprehensive understanding of the essential molecular mechanisms involved in rhizobium-Mengnong clover No.1 symbiotic nitrogen fixation, laying the theoretical foundation for improving crop yields.