Bacillus velezensis SYL-3 Shows Multifactorial Power in Controlling Fusarium Root Rot and Enhancing Soil Health

Bacillus velezensis SYL-3: A Multifactorial Ally Against Fusarium Root Rot

A recent study published in Pesticide Biochemistry and Physiology (Elsevier, 2025) unveils the powerful and multifaceted role of Bacillus velezensis SYL-3 in managing Fusarium oxysporum-induced root rot in tobacco plants. The research, led by He Liu and colleagues from Shenyang Agricultural University and Guizhou University, demonstrates that this beneficial bacterium operates through synergistic biological, microbiological, and molecular strategies that collectively strengthen plant health and suppress disease.

In controlled experiments, B. velezensis SYL-3 inhibited the pathogenic F. oxysporum by over 70%, disrupting spore formation and deforming hyphae. When applied to field-grown tobacco, SYL-3 reduced root rot incidence by nearly 75% within 30 days and continued to provide effective protection during the crop growth cycle.

Beyond direct antagonism, SYL-3 reshaped the rhizosphere microbiome — enriching beneficial microbes like Bradyrhizobium, Sphingomonas, and Rhodanobacter while sharply reducing pathogenic Fusarium. The treatment enhanced soil organic matter, nitrogen availability, and pH, fostering a healthier microbial environment that supported vigorous root development.

Transcriptomic analyses revealed that SYL-3 treatment upregulated several key plant genes linked to nitrogen and carbon metabolism, including ARR22, 6PGL, and NR2. These molecular shifts further improved nutrient cycling and plant growth, reflecting an intricate interplay between soil, microbes, and host plants.

The study highlights B. velezensis SYL-3 as a promising biocontrol agent offering dual benefits — effective pathogen suppression and improved soil ecosystem functioning. Its multifactorial strategies align with global goals for sustainable agriculture, reducing chemical inputs while maintaining productivity.

Reference

Liu, H., Huang, H., Wang, Y., An, M., Bai, J., Zhou, J., Lan, H., Qi, A., Song, B., & Wu, Y. (2025). Multifactorial synergistic strategies mediate the biocontrol of Fusarium oxysporum-induced root rot by Bacillus velezensis SYL-3. Pesticide Biochemistry and Physiology, 106745. https://doi.org/https://doi.org/10.1016/j.pestbp.2025.106745