Comparative analysis on rhizosphere microorganisms of Cynodon dactylon (Poaceae) from the natural restoration area and eco-restoration engineering area in water-level-fluctuation zone of Jinsha River-type reservoirs, China

Rhizosphere microorganisms may play an important role in plant growth and environmental adaptation during eco-restoration engineering in the water-level-fluctuation zone (WLFZ) of large river-type reservoirs. The purpose of this study is to compare the rhizosphere microbial community features of <i>Cynodon dactylon</i> derived from the natural restoration area (NEE) and eco-restoration engineering area (YEE) in the WLFZ of Jinsha River-type reservoirs using high-throughput sequencing and bioinformatic analyses. The dominant taxa were Proteobacteria and Ascomycota in <i>C. dactylon</i> rhizosphere from both NEE and YEE. The eco-restoration engineering improved the α-diversity of bacterial community, but reduced the diversity of fungal community. Eco-restoration engineering did not change the dominant pattern of aerobic respiration I (cytochrome c) [PWY-3781] and aerobic respiration II (cytochrome c, yeast) [PWY-7279] metabolic pathways in the rhizosphere microbial community. Many microbes (such as Alphaproteobacteria and Sphingomonadaceae) in YEE were identified as significantly enriched biomarkers, while the key biomarkers in the rhizosphere in NEE are relatively limited where Burkholderiaceae and Burkholderiales may be the key characteristic microbe. Our study provides a theoretical basis and potential clue for understanding the role of eco-restoration engineering in the re-assembly of rhizosphere microorganisms and supporting vegetation restoration in the WLFZ of large river-type reservoirs.