Analysis of Rhizosphere Bacteriomes from Different Dominant Plants in the Water-Level Fluctuation Zone of the Three Gorges Reservoir

This study aims to reveal the rhizosphere bacteriome patterns, biomarkers, and metabolic functions of dominant plants in the water-level fluctuation zone (WLFZ) of the Three Gorges Reservoir through comparative analyses with the non-rhizosphere bacteriome. The present study showed that a total of 4546–5011 amplicon sequence variants (ASVs) were identified in both rhizosphere and non-rhizosphere soils of Artemisia annua L. and Persicaria lapathifolia (L.) Delarbre. Pseudomonadota and Acidobacteriota were the most abundant bacterial phyla in both rhizosphere and non-rhizosphere bacteriomes. The α-diversity indices of microbial communities in the non-rhizosphere soils were lower than those in the rhizosphere soils associated with the two dominant plant species. Distinctive key biomarkers were successfully identified for both rhizosphere and non-rhizosphere bacterial assemblages, and these biomarkers exhibited a strong plant-specific pattern. Functional annotation revealed that metabolic processes, genetic information processing, and two core functional traits (chemoheterotrophy and aerobic chemoheterotrophy) accounted for the highest relative abundance within the bacteriomes. However, notable discrepancies were observed in the subdominant functional traits between the rhizosphere and non-rhizosphere bacteriomes. Overall, the present study brings novel insight into the plant-microbe interactions in the WLFZ of large reservoirs under the extreme environmental conditions.