Diversity, Composition, and Co-occurrence Network of Rhizosphere and Endophytic Bacterial Communities in Two Growth Stages of Leonurus japonicus.

Leonurus japonicus, a widely distributed plant species, is influenced in its growth by both rhizosphere and root endophytic bacteria; however, the specific interactions between L. japonicus and these two bacterial communities remain poorly understood. To address this, high-throughput Illumina MiSeq sequencing was used to study the dynamics of rhizosphere and endophytic bacterial communities at two key growth stages: seedling and flowering. The sequencing results showed that the ratio of endophytic bacterial community (ASV: 1432) to rhizosphere bacterial community (ASV: 11,329) was approximately 12.64%. Significant differences were observed in the diversity and evenness of the endophytic bacterial community between the two stages of L. japonicus (P < 0.001). Meanwhile, microbial composition shifted, as shown by differences in some specific genera between stages. Co-occurrence network analysis revealed that interactions between the two bacterial communities and L. japonicus were different at the two growth stages. Specifically, the endophytic bacterial network in the flowering stage was more complex and stable than that in the rhizosphere (avgCC: 0.763 vs 0.633; P/N: 1.451 vs 0.737), while in the seedling stage, the rhizosphere bacterial network exhibited greater complexity and stability (avgCC:0.646 vs 0.615; P/N:0.804 vs 0.633). These studies provide valuable insights into the interaction between L. japonicus and the rhizosphere and endophytic bacterial communities, revealing how it selectively recruits and interacts with microbial partners at two key growth stages. Our findings offer new insights for future studies aimed at elucidating the dynamic mechanisms of plant–microbe interactions and the potential impact of microorganisms on plant growth.