Fusaricidins producing Paenibacillus: a potential biocontrol agent against plant pathogens

Phytopathogens are responsible for substantial yield losses in global agriculture. Significant use of chemical fungicides for controlling these pathogens often poses a threat to the environment. Thus, the application of fusaricidin-producing Paenibacillus offers a promising and eco-friendly alternative to conventional chemical control strategies. Fusaricidins possess a hexapeptide core linked to a consistent 15-guanidino-3-hydroxypentadecanoic acid tail, which is instrumental in membrane disruption and the eradication of a broad spectrum of pathogens. Recent genomic mining studies have identified the fusGFEDCBA gene cluster and elucidated the pivotal role of the KinB-Spo0A-AbrB signaling cascade in integrating environmental stimuli with the developmental regulation of fusaricidin biosynthesis. Beyond their direct antimicrobial effects, fusaricidins function as plant-defense elicitors, primarily activating systemic responses through salicylic acid (SA)-dependent pathways. In vitro, greenhouse, and field trials have demonstrated significant disease suppression and plant growth promotion across various crops. However, variability in field performance, challenges in formulation, and limited understanding of in-field stability and ecological interactions present significant barriers to commercialization. Through integrated molecular and applied research, these limitations and future directions are being addressed. Collectively, these insights position fusaricidins as promising candidates for sustainable plant disease management in agriculture. This review concentrates on the current understanding of fusaricidins, encompassing their chemical diversity, biosynthetic gene architecture, regulatory networks, mechanisms of antimicrobial action, and advancements toward field-level application.