Assembly, diversity and coexistence of bacteria communities in various rhizocompartment niches in Sorghum Cultivars

Root-associated microbial communities play a vital role in plant health, but the assembly processes in sorghum and associated soil factors remain unclear. We conducted 16S rDNA sequencing on bulk soils and rhizocompartments (rhizosphere, rhizoplane, and endosphere) of three sorghum cultivars. Physicochemical properties were measured in bulk and rhizosphere soils. Alpha-diversity decreased from bulk soil to endosphere, and betadiversity showed compartmental separation. Relative abundances of 16 dominant genera varied among compartments and cultivars. Dispersal limitation increased from (17.0%) to endosphere (35.8%), with homogenous selection dominating rhizocompartment assembly (51.1%-83.0%). Certain soil factors mediated community assembly and shaped phylogenetic structures. Rhizosphere displayed the most complex network, followed by bulk soil, rhizoplane, and endosphere. Differentially abundant taxa were more important in maintaining network stability and connectivity in the endosphere (47.0%-68.4%) compared to the other rhizocompartments. This study provides insights into the factors influencing the assembly of root-associated bacterial communities in sorghum, highlighting the roles of compartment niches, sorghum cultivars, and soil properties. These findings contribute to our understanding of plant-microbe interactions and have implications for agricultural management and ecological restoration efforts. Furthermore, the identification of key soil factors that mediate community assembly processes and shape phylogenetic structures offers potential targets for manipulating microbial communities in agricultural systems, leading to improved plant health and productivity.