Weapons hidden underneath: bio-control agents and their potentials to activate plant induced systemic resistance in controlling crop Fusarium diseases

Fusarium is a genus among the major pathogens affecting cereals production worldwide. At present, the control of Fusarium diseases in farm largely relies on the use of chemical fungicides, which are persistent in environments and harmful to human health. To reduce the risk of using chemical compounds, it becomes urgent to find an alternative strategy, such as bio-agents to control Fusarium diseases. Beneficial microorganisms underground have been well known for their activity to trigger induced systemic resistance (ISR) against pathogens, existing either in the soil or aboveground. Despite numerous studies suggesting various beneficial microorganisms, also recognized as bio-control agents (BCAs), including Bacillus spp., Trichodema spp., Pseudomomas spp. and others, as capable of suppressing diverse crop diseases, the function and mechanisms underlying ISR triggered by these beneficial microbes in controlling Fusarium diseases remain to be systemically understood. In this review, we summarize the roles of diverse beneficial microbes in limiting crop Fusarium diseases and also discuss the possible involvement of ISR with associated signaling pathways employed in Fusarium disease control. Finally, we consider the practical application of diverse BCAs with ISR activity for ecological and sustainable crop production.