Integrated transcriptomics and metabolomics reveal the mechanism of Aspergillus neoalliaceus MR-86–mediated biocontrol of Fusarium root rot in Saposhnikovia divaricata

Fusarium equiseti is a globally significant fungal pathogen that causes severe diseases in numerous crops and medicinal plants. To address its widespread impact, environmentally friendly disease management strategies based on rhizospheric microorganisms have attracted increasing attention. In this study, we investigated the potential of rhizospheric-derived fungi as biological control agents against F. equiseti . Specifically, we evaluated their antifungal activity and biocontrol potential for suppressing root rot disease in Saposhnikovia divaricata . In this study, 104 fungal isolates were obtained from the rhizospheric soil of Saposhnikovia divaricata and screened for antagonistic activity against Fusarium equiseti . Among these isolates, strain MR-86 exhibited broad-spectrum antifungal activity and effectively suppressed the growth of F. equiseti . Its morphological characteristics were examined, and phylogenetic analyses based on the rDNA internal transcribed spacers (ITS), β-tubulin, and calmodulin gene sequences identified strain MR-86 as Aspergillus neoalliaceus , representing a new record of this species in China. The fermentation broth of MR-86 inhibited conidial germination and induced mycelial malformations, colony degeneration, and cytoplasmic leakage in F. equiseti . Furthermore, integrated transcriptomic and metabolomic analyses suggested that glycerophospholipid and glutathione metabolism-related responses in A. neoalliaceus MR-86 were induced during confrontation with F. equiseti . Pot experiments further confirmed that MR-86 effectively suppressed root rot development in S. divaricata , achieving a biocontrol efficacy of 67.31% ( p < 0.05). Aspergillus neoalliaceus , reported here for the first time in China, was isolated from the rhizosphere soil of S. divaricata . Its strong antagonistic activities against fungal phytopathogens highlight its potential as a promising biocontrol agent for agricultural applications.