Root nodules of Lindera aggregate select specific microbiota for nitrogen fixation and nutrition metabolism

Abstract

Abstract Plants have the capability to assemble microbiota in the rhizosphere soil (RS) and subsequently select specific microbial communities in the root endosphere (ES). However, the difference in the microbial community composition among root microhabitats remain inadequately elucidated despite their critical roles in the plant-microbiota feedback. In this study, we initially assessed fungal and bacterial communities in ES and RS of Lindera aggregate, aiming to investigate the microbial community composition and ecological functions of diverse root microhabitats using amplicon sequencing and multivariate analysis. Our findings revealed a significant reduction in the fungal diversity in ES compared to RS, with the lowest diversity observed in root nodules (RN). Additionally, the bacterial community composition of lateral roots (LR) exhibited significant distinctions when compared to RN. Further analysis indicated that the entire microbial networks of RN displayed a higher total number of nodes, edges, and modularity, albeit with a lower density in comparison to those in LR. Moreover, the potential functional composition in RS was significantly different from that of ES. Bacteria and fungi in ES play an active part in carbon, nitrogen, sulfur, and iron respiration, especially in nitrogen fixation. Altogether, our study unveiled that root microhabitats of the L. aggregate could recruit specific microbial communities, thereby regulating nutrient absorption and metabolism. This insight enhances our understanding of the selective influence that plants exert on soil microorganisms.