Burkholderia ambifaria H8 as an effective biocontrol strain against maize stalk rot via producing volatile dimethyl disulfide

Abstract

BackgroundMaize stalk rot (MSR) caused by Fusarium graminearum is the primary factor contributing to the reduction in maize yield and quality. However, this soil‐borne disease is challenging to control in agriculture through field management and the use of chemical agents. The process of screening novel biocontrol agents can aid in the creation of innovative and successful MSR control strategies.ResultsA total of 407 strains of bacteria were isolated from the rhizosphere soil of a resistant maize inbred line. One strain exhibited significant antagonistic activity in plate and pot experiments and was identified as Burkholderia ambifaria H8. The strain could significantly inhibit the mycelial growth and spore germination of F. graminearum, induce resistance to stalk rot, and promote plant growth. The volatile compounds produced by strain H8 and its secondary metabolites in the sterile fermentation broth exhibited antagonistic activity. The primary volatile compound produced by strain H8 was identified as dimethyl disulfide (DMDS) using gas chromatography tandem mass spectrometry (GC–MS/MS). Through in vitro antagonistic activity assays and microscopic observation, it was confirmed that DMDS was capable of inhibiting mycelial growth and disrupting the mycelial structure of F. graminearum. This compound could be the major active compound for the strain H8. The transcriptome data of F. graminearum further indicates that strain H8 and its volatile compounds can alter the metabolism of pathogenic fungi, influence the related metabolic pathways of pathogenic fungi, and potentially induce cell apoptosis.ConclusionOur results showed that the strain B. ambifaria H8 was capable of producing the volatile substance dimethyl disulfide, which influenced the synthesis and permeability of cell membranes in pathogens. Thus, B. ambifaria H8 was found to be a promising biological control agent against MSR.This article is protected by copyright. All rights reserved.