Interdomain ecological network analysis infers the endophytic bacteria protect against Fusarium root rot invasion

Abstract

Fungi and bacteria coexist assembling complex communities in plant rhizosphere and endosphere that are important for plant health and agricultural productivity, however, the influence of root rot pathogen on bacterial-fungal interactions in plant ecological settings remains unclear. Here, bacterial communities from soil to endophyte of tobacco during Fusarium root rot invasion were comprehensively investigated. The bacterial community diversity and composition of stem endophytes were significantly altered by Fusarium root rot invasion. Molecular ecological network analysis revealed that the interactions among bacterial microbes in infected plant soils exhibit more intricate network structures compared to those found in healthy plants. The pathogens invasion led to changes in the crucial species within both the rhizosphere soil and plant endophytic bacterial communities. Furthermore, the interactions among fungal and bacterial species indicated that diseased samples, encompassing both the rhizosphere and endosphere, exhibited more complicated interdomain networks compared to their healthy counterparts. Importantly, the endophytic bacterial species Bacillus, Paenibacillus, Lactococcus, and two unclassified bacteria (OTU11999 and OTU730) from infected roots, and Bacillus, Raoultella, Leminorella, Pseudomonas, and three unclassified bacteria (OTU12058, OTU3 and OTU11435) from infected stems were negatively correlated with the pathogen Fusarium oxysporum f sp. psidii. It suggested that these endophytic bacteria may be associated with anantagonist effect and resistant against Fusarium root rot.