Fusarium head blight biocontrol using cyclic lipopeptides produced by Bacillus velezensis RC218

Authors: OCHOA, GUSTAVO - National University Of Rio Cuarto; REYNOSO, AGUSTINA - National University Of Rio Cuarto; ZURITA, ALICIA - National University Of Rio Cuarto; YERKOVICH, NADIA - National University Of Rio Cuarto; Dunlap, Christopher; Bowman, Michael; CHULZE, SOFIA - National University Of Rio Cuarto; PALAZZINI, JUAN - National University Of Rio Cuarto

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2025
Publication Date: 7/31/2025
Citation: Ochoa, G., Reynoso, A., Zurita, A., Yerkovich, N., Dunlap, C.A., Bowman, M., Chulze, S.N., Palazzini, J.M. 2025. Fusarium head blight biocontrol using cyclic lipopeptides produced by Bacillus velezensis RC218. Biocontrol Science and Technology. https://doi.org/10.1080/09583157.2025.2541203.
DOI: https://doi.org/10.1080/09583157.2025.2541203

Interpretive Summary: Fusarium head blight is a major disease in wheat which causes yield losses and reduced quality due to the production of mycotoxins during the infection process. In previous research, we identified a bacteria that can produce antifungal compounds to kill the causal agent of Fusarium head blight when applied to wheat at flowering. The current study builds upon this discovery and tests the effects of using antifungal compounds produced by the bacteria, without applying the bacteria. The results show the antifungal compounds were sufficient to significantly reduce the severity (69-79%) and incidence of the disease (66-83%), in susceptible wheat lines. This research shows that antifungal compounds produced by the bacteria are a promising option to control this disease in wheat. This research helps us understand how these bacteria function to control plant diseases, which allows us to develop better biological control products.

Technical Abstract: Cyclic lipopeptides produced by Bacillus species have been reported to have several antimicrobial effects against plant pathogens through different mechanisms such as destabilization of plasma membrane and loss of electrolytes. In a previous study, the genome mining of B. velezensis RC218 identified nine secondary metabolite clusters linked to the production of cyclic lipopeptides (CLPs) from the surfactins, fengycins and iturins families. The present study focused on the production, extraction, identification by UPLC-MS-MS and evaluation under greenhouse against the wheat phytopathogen Fusarium graminearum. Mass detection and identification of the metabolites revealed the presence of the predicted lipopeptides, with several carbon-length variants in each family. In addition, some molecules from polyketide synthetase clusters with known antimicrobial activity such as: macrolactin, dificidin and bacilysin were also detected. In vitro experiments with the extracted metabolites showed a significant reduction in the radial growth (up to 84 %) of three F. graminearum strains isolated at different locations during an epidemic of Fusarium head blight (FHB). Greenhouse experiments were carried out on two wheat varieties: the FHB susceptible BioINTA 1005 and the tolerant Cronox. Application of the pure extract to flowering wheat heads, prior to pathogen inoculation, resulted in reduced disease incidence and severity in both cultivars. As expected, the biocontrol effect was more pronounced in the susceptible variety (78.5% reduction in incidence and 82.5% reduction in severity) compared to the tolerant Cronox (69.3% and 66.3% reductions, respectively). Given that metabolite production by bacteria at the in planta level can be altered by the plant-environment interaction, applying the purified lipopeptide extracts from B. velezensis RC218 could be a promising method for controlling FHB pathogens.